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THE
ELEMENTS
OF
PHYSIOLOGY.

[titlePage_recto] [titlePage_verso]

LONDON:
printed by A. & R. Spottiswoode,
New-Street-Square.

[titlePage_recto]
THE
ELEMENTS
OF
PHYSIOLOGY,

TRANSLATED FROM THE LATIN OF THE FOURTH AND
LAST EDITION,
AND SUPPLIED
WITH COPIOUS NOTES,
BY
JOHN ELLIOTSON, M. D. Cantab.
fellow of the royal college of physicians;
physician to, and lecturer on the practice of medicine in,
st. thomas’s hospital.

FOURTH EDITION.

Quaeramus optima, nec protinus se offerentibus gaudeamus:
adhibeatur judicium inventis, dispositio probatis.
(Quintilian.)

LONDON:
printed for
LONGMAN, REES, ORME, BROWN, AND GREEN,
paternoster-row.
1828
.
[titlePage_verso]

TO
PROFESSOR BLUMENBACH.

[Seite v]

My dear Sir,

Some few persons I do envy, and you are of the
number. In a green old age, still enjoying great
mental activity and a most cheerful disposition, living,
like so many of your scientific countrymen, in a little
village, with the utmost simplicity, a stranger to the
desire of wealth and the absurd ambition of worldly im-
portance, but holding highly responsible offices in an
illustrious though humble university, – you are cele-
brated in every country for an extensive and profound
knowledge of natural history, for the number of facts
which you have yourself contributed, for a perfect
acquaintance with all the writings of others, for the
production of numerous works, translated into various
languages, and distinguished by copiousness and
[Seite vi] accuracy of information, sound opinions, and a con-
ciseness, perspicuity, and elegance that are seldom
seen; and no less for the powerful impulse which
you gave to the study of natural history, and espe-
cially of the Natural History of Man, almost before
the present generation existed.

To you I take the liberty of dedicating this work,
and with the more delight, as I know from the hap-
piness of personal acquaintance your liberal and
amiable disposition, your attachment to England,
and admiration of whatever is English.

Believe me,
My dear Sir,
Your very faithful friend and servant,

JOHN ELLIOTSON.
LONDON, March 1st, 1828.

TRANSLATOR’S PREFACE.

[[vii]]

Since the last publication of this work, a new
edition of the original has appeared. The text con-
tains no additions, and very few alterations, but
the references are augmented. According to this,
the present edition is re-modelled, and the whole
translation has been carefully revised.

The notes are doubled in amount, and indeed may
be almost considered perfectly new. Many points
are for the first time examined, former notes are
modified and enlarged, and the numerous and im-
portant discoveries lately made in physiology are
introduced.

Every opinion defended is that which seems to
me the fairest conclusion from our facts relative
to the subject. I can never bow to authority in
matters of investigation, but feel myself compelled
sentire quae velim; and, when a necessity for ex-
pressing an opinion exists, I hope always to have
courage sufficient dicere quae sentiam.

[Seite viii]

I have taken great pains to make myself master of
all important physiological facts, and to reason cor-
rectly from them; to give every author the credit of
originality which he deserves; and to be accurate in
my references. But after all I may frequently have
failed. If my inaccuracies cannot be excused on
the ground of the number and diversity of the points
examined, or my almost constant occupation with
another branch of medicine, both as a lecturer and a
public and private practitioner, I can only assure my
readers that the detection of any failure in reasoning
or inaccuracy of statement will be gratefully received,
and that my highest object and happiness are the ac-
quisition and dissemination of truth.

JOHN ELLIOTSON.

Grafton Street, Bond Street,

March 1. 1828.

THE AUTHOR’S PREFACE
TO
THE LAST EDITION.

[[ix]]

Whenever my booksellers have informed me that
a new edition of any of my works was required, my
greatest pleasure has been at having an opportunity
of correcting inaccuracies arising either from care-
lessness or the imperfection of human nature, and of
adding in some places and altering in others; in
short, of sending forth the production of my abilities
in as improved a state as possible.

In preparing this new edition of my Institutions
of Physiology for the press, the same anxious wish
has been considerably heightened by the importance
of the subject, and by the approbation evidently
bestowed upon the last edition from its translation
[Seite x] into various languages,a not to mention other proofs
of its favourable reception. I have endeavoured,
therefore, to enrich it not so much with an addition
of pages, as of various matter, and to render the
whole as useful to students as possible.

The little figure which I have thought a very
appropriate ornament for the title-page of the work,
viz. a representation of the human body, made by
Prometheus, but animated by Pallas, I borrowed
from the relievo of a sarcophagus in the Capitoline
Museum.b

May 7. 1821.

THE AUTHOR’S PREFACE
TO
THE FIRST EDITION.

[[xi]]

The same considerations which led Boerhaave, and
after him Haller, to write their Compendiums of
Physiology, induced the Author to compose these
Institutions.

The former says, ‘“that a teacher succeeds better
in explaining his own thoughts than in commenting
upon a work written by another, – that his instruction
will be clearer, and his language generally animated,
”’
&c.a

The latter, ‘“That, although he formerly used
Boerhaave’s work as a text-book, he afterwards
lectured upon one written by himself because anatomy
[Seite xii] had been so improved since the time of
Boerhaave,
as to have become almost a new science.”’b

What Haller said at that period respecting ana-
tomy, will be allowed to apply much more forcibly
at present to Physiology, by any one who considers
the most important parts of the science, – the princi-
pal purpose of respiration, animal heat, digestion,
the true nature and use of the bile, the function of
generation, &c.

More, therefore, must be ascribed to the age than
to the Author, if in these Institutions, after so many
modern physiological discoveries, he has delivered
doctrines more sound and natural than it was in the
power of his most meritorious predecessors to
deliver.

Whatever he can claim as his own, whether really
new or only presented in a new view, will easily be
discovered by the learned and impartial reader:
especially from the notes, in which he has treated
some of these subjects rather more minutely than
was compatible in the text with the conciseness of
his plan.

[Seite xiii]

He has been at great pains in arranging the
subjects, so that the sections might succeed naturally
and easily, and arise, as it were, one out of another.

He has not quoted a dry farrago of books, but a
select number, in doing which, he has been desirous
both of pointing out to students some excellent au-
thors not commonly known, especially those who
have professedly treated on particular branches of
the subject, and of opening, besides medical sources
of information, others not yet applied, he conceives,
to Physiology, as they deserve.

He has referred to the best anatomical plates;
most frequently to those of Eustachius, because he
would wish every medical student to possess Albinus’s
edition of them, as the richest and most perfect work
of the kind, or rather, he should say, as a treasure
which can never be praised sufficiently.

He has indeed given some original engravings of
parts either not represented at all by Eustachius, or
not in the same point of view.c

[Seite xiv]

His grand object has been to deliver, in a faithful,
concise, and intelligible manner, the principles of a
science inferior in beauty, importance, and utility, to
no part of medicine, if the words prefixed by the
immortal Galen to his Methodus Medendi, are true,
as they most certainly are: – ‘“The magnitude of a
disease is in proportion to its deviation from the
healthy state; and the extent of this deviation can be
ascertained by him only who is perfectly acquainted
with the healthy state.
”’

CONTENTS.

[[xv]]

Sect.

page

The Translator’s Notes follow the section to which the subject
of each respectively belongs.

The note on the characteristics and varieties of mankind, being
an independent addition, is placed last, and begins at p. 539.

THE
ELEMENTS
OF
PHYSIOLOGY. SECT. I.
OF THE LIVING HUMAN BODY IN GENERAL.

[Seite 1]

1. In the living human body, regarded as a peculiar
organisation, there are three objects of consideration.a

The materials of its subsistence, afforded by the fluids;
The structure of the solids, containing the fluids;
Lastly, and principally, the vital powers, by which the solids
are enabled to receive the influence of the fluids, to propel
the fluids, and to perform various other motions; and which,
as they, in a certain sense, constitute the essence of the living
machine in general, so, likewise, are of very different orders,
some being common to animals and vegetables, some peculiar
to animals and intimately connected with the mental faculties.

[Seite 2]

2. But these three, although really distinct, and, therefore,
distinctly considered by us, are so closely connected in the
living system (the phenomena, conditions, and laws of whose
functions, in the healthy state, are the object of physiology),
that no one can be contemplated but in its relation to the
rest.

For the materials of the body, although originally fluid,
are naturally disposed to become solid; and, on the other
hand, the solids, besides having been formed from the fluids,
abound, however dry they may appear, in various kinds of
fluid constituents, both liquid and permanently elastic, – gasi-
form, as they are termed; lastly, it may probably be affirmed
that no fibril, during life, is destitute of vital power.

3. We shall now examine each of these separately; and,
first, the materials afforded by the fluids, which form both
the fundamental and most considerableb portion of our
bodies.


NOTE.

Attempts have been made to specify the elementary tissues of
which the various organs are composed.

Dr. Carmichael Smyth, in an admirable paper upon inflammation,
considered the disease according to the structures which it
affects, – the skin, cellular membrane, serous membranes, mucous
membranes, and muscular fibresc Dr. Pinel, some years afterwards,
[Seite 3] adopted this arrangement,d and Bichat at length suggested that
all diseases might be considered in this manner, and distributed
the structures, or elementary tissues, into twenty-one kinds: –

1. Cellular, 12. Fibro-cartilaginous,
2. Nervous, of animal life, 13. Muscular, of animal life
3. Nervous, of organic life, 14. Muscular, of organic life,
4. Arterial, 15. Mucous,
5. Venous, 16. Serous,
6. Exhalant, 17. Synovial,
7. Absorbent, with its glands, 18. Glandular,
8. Osseous, 19. Dermoid,
9. Medullary, 20. Epidermoid,
10. Cartilaginous, 21. Pilous.e
11. Fibrous (tendino-fibrous),

This arrangement, Dr. Rudolphi remarks, is physiological rather
than anatomical, and he distributes the elementary tissues into
eight classes only: –

Cellular, Tendinous,
Horny, Vascular,
Cartilaginous, Muscular, and
Osseous, Nervousf

The primary solids, of which these tissues are said to be com-
posed, are, the cellular fibre, the muscular fibre, and the nervous
fibre.g

[Seite 4]

The proximate principles, or distinct chemical compounds of
animal bodies, are: –

xxx

The elements, or ultimate principles of animal bodies, into which
the distinct compounds may be resolved, are: –

Hydrogen,

Carbon,

Oxygen,

Azote,

Chlorin, iodin, fluorin?

Sulphur,

Phosphorus,

Potassium,

Sodium,

[Seite 5]

Calcium,

Magnesium, silicium?

Manganese?

Iron.

The ultimate principles of vegetables may be considered the
same as those of animals.

Vegetable proximate principles are very numerous; the follow-
ing may be considered as the chief: –

Sugar,
Starch,
Lignin,
Gum, mucus, jelly,
Extractive, colouring matters, bitter
principles,
Gluten,
Oils, fixed and volatile,
Resins,



} All subject to endless
variety as occurring in
different plants.

The following are constant in their character, or are peculiar
to certain vegetables.

Various acids – Oxalic, citric, tartaric, malic, moroxylic, gallic,
laccic, kinic, boletic, prussic, meconic, benzoic.

Various alkaline bodies – Quinina, cinchonina, morphina, strych-
nina, brucina, delphina, picrotoxina, atropia, veratrina,
hyoscyamina.

Indigo,

Tan,

Suber,

Caoutchouc,

Wax,

Asparagin, ulmin, inulin, fungin, polychroite, haematin, nicotin,
pollenin, emetin, sarcocol, olivile, medullin, lupulin,
cathartin, piperin, &c.

SECT. II.
OF THE FLUIDS IN GENERAL, AND PARTICULARLY OF THE
BLOOD.

[Seite 6]

4. The fluids of the bodya may be conveniently reduced
to three classes.

A. The crude; viz. the chyle, contained in the primae viae
and destined to become blood; and matters absorbed on the
surface and conveyed to the chyle.

B. The blood itself.

C. Those secreted from the blood, whether inert and ex-
crementitious, like the urine; or intended for certain pur-
poses in the economy: the latter may be permanently liquid,
as the bile; or disposed to solidity, as the osseous and other
plastic juices.

5. Of the first and third of these classes we shall hereafter
speak, in treating of chylification, secretion, and the other
functions to which each fluid appertains. At present our
attention shall be devoted to the bloodb – the chief and pri-
mary fluid –the vehicle of those successions of oxygenous
and carbonaceous particles, that cease with life only – the
nourisher of the frame – the source of almost every fluid –
that into which the crude fluid is converted, and from which
all the secretions are derived – and which, with the excep-
tion of some exsangueous parts, as the epidermis, the arach-
noid, the amnion, &c., the vitreous substance of the teeth, the
body of the crystalline lens, &c., is universally diffused
through the system; in various proportions, indeed, according
[Seite 7] to the various natures of parts, v. c. abundantly in the muscles,
and still more so in certain viscera, as the spleen, placenta,
and uterus at an advanced period of pregnancy; very spar-
ingly, on the other hand, in the tendons and cartilages.c

6. The blood is a fluid sui generis, of a well known colour
and peculiar odour; its taste is rather saline and nauseous;
its temperature about 96° of Fahrenheit; it is glutinous to
the touch; its specific gravity, though different in different
individuals, may be generally estimated as 1050, water being
1000; when fresh drawn and received into a vessel, it ex-
hibits the following appearances:d

7. At first, especially while still warm, it emits a vapour
which has of late been denominated an animal gas, and shown
to consist of hydrogen and carbon, suspended by caloric.e
This, if collected in a bell glass, forms drops resembling dew,
of a watery nature, but affording a nidorous smell, which is
most remarkable in the blood of carnivorous animals, is
peculiar, and truly animal. Much of this watery liquor still
remains united with the other parts of the blood, hereafter to
be mentioned. (C)

8. In the mean time the blood, when its temperature has
fallen to about 78° Fahr., begins to separate into two portions.
A coagulum is first formed, from the surface of which exudes,
[Seite 8] as it were, a fluid of a yellowish slightly red colour, denomi-
nated serum: the more abundantly this exudes, the greater is
the contraction of the glutinous coagulum, which has received
the appellations of crassamentum; and, from some resemblance
to the liver in colour and texture, of hepar sanguineum; of
placenta; and, from the circumstance of its being surrounded
by the serum, of insula. (D)

9. The crassamentum may, by agitation or repeated ablu-
tion, be easily separated into two constituent parts – the
cruor, which gave to the blood its purple colour, – and the
lymph, which on washing is forsaken by the cruor, and called,
from its greater solidity, the basis of the crassamentum. The
stronger affinity of the cruor for the lymph than for the serum,
is proved by the necessity of violence to effect their disunion.
By the removal of the cruor the lymph becomes gradually
paler, till it is at length merely a white tenacious coagulum.
(E)

10. Besides the watery fluid first mentioned, these are the
three constituents of the blood, viz. the serum, the cruor, and
the lymph, of each of which we shall presently treat more
particularly. These, however, while perfectly recent, and in
possession of their native heat, are intimately mixed, and
form an equable, homogeneous fluid. Their relative propor-
tion is astonishingly diversified, according to age, tempera-
ment, diet, and similar circumstances which constitute the
peculiar health of each individual.

11. The serum is a peculiar fluid, the chief cause of the
viscidity of the blood, and easily separable by art into dif-
ferent constituent principles. If subjected to a temperature
of 150° Fahr. a portion is converted into a white scissile sub-
stance, resembling boiled albumen: the rest exhibits, besides
the watery fluid so often mentioned, a turbid fluid of a gela-
tinous,
or rather mucousf nature, which on cooling appears a
tremulous coagulum. The serum is remarkable for the
quantity of soda (mineral alkali) which it contains. (F)

[Seite 9]

12. The cruor has many peculiarities, in regard to both
the colour and the figure of its particles.

It consists of globules, which in recent blood are of a con-
stant form and size, and said to be 1/3300 of an inch in diame-
ter. Their form, indeed, has been a subject of dispute, but
I am disposed to consider it as much more simple than some
writers of great celebrity have imagined. I have always
found it globular, and could never discover the lenticular
shape which some have asserted that they remarked.

It has been likewise advanced, that the globules change
their form while passing through a vessel of very small capa-
city, – that, from being spherical, they become oval; and,
when they have emerged into a vessel of larger area, that
they resume their globular shape.g This, although I would
by no means deny it, I cannot conceive to occur during the
tranquil and healthy motion of the blood, but should refer it
to a spasm of the small vessels.

Their globular figure can be seen in a living animal only,
or in blood very recently drawn: for they are soon unobserv-
able, becoming a shapeless mass which resembles serum in
every circumstance excepting colour.h

13. Their colour is red, and from it is derived the colour
of the blood. In intensity it varies infinitely; paler in ani-
mals which have been poorly nourished or have suffered
from haemorrhage; more florid, when oxygenisedi (rendered
arterial, to use the common phrase) by exposure either to
[Seite 10] atmospheric air, or, more especially, to oxygen; darker when
carbonised (in common language, rendered venous) and
placed in carbonic acid gas or hydrogen.k The redness is
most probably to be ascribed to the oxide of iron,l the quan-
tity of which, however, is so minute, that it has been most
variously estimated. (G)

14. The last constituent principle of the blood to be
noticed, is the plastic lymph, formerly confounded with the
serum. This has been called the basis of the crassamentum,
the glutinous part, the fibre or fibrous matter of the blood,
and, like the caseous part of milk, and the gluten of veget-
ables, been discovered by late analysis to abound in carbon
and azote. (H)

15. It is properly denominated plastic, because it affords
the chief materials from which the similar parts, especially the
muscles, are immediately produced; nourishes the body
throughout life; repairs wounds and fractures in an extraor-
dinary manner; fills up the areae of large blood vessels when
divided;m and forms those concretions which accompany
inflammations,n and that remarkable deciduous membrane
found in the recently impregnated uterus for the attachment
of the ovum.

16. Thus much have we said respecting the constituent parts
and nature of the blood, the most important fluid of the
animal machine, – a fluid which excites the heart to contrac-
tion; which distributes oxygen to every part, and conveys
away the carbon to the excretory vessels, giving rise, by this
change, to animal heat; which supplies the materials of the
[Seite 11] solids originally, and ever afterwards their nourishment; and
from which all the other fluids, with the exception of the
crude (4), are, secreted and derived. Of the multifarious im-
portance of the blood, we shall speak particularly hereafter.


NOTES.

(A) Most cold-blooded animals, as fishes and the amphibia,
have a much smaller proportion of blood and fewer blood-vessels
than those with warm blood, though a much greater number of
colourless vessels arising from the arteries. In. an experiment
which Blumenbach made on this subject, he ‘“obtained from
twenty-four adult water-newts (lacerta palustris), which had been
just caught, and weighed each an ounce and a half, ℈ iiiss. of blood.
The proportion to the weight of the body was as 2 1/2 to 36, while
in healthy adult men it is as 1 to 5.”’o

(B) Dr. Magendie stated, in 1809, to the Institute, that this as-
sertion is incorrect. If air is injected rapidly, the animal screams
and dies in a moment: but if slowly, he informs us that no incon-
venience results, and that some animals bear the injection of
enormous quantities without perishing.p Dr. Blundel injected
five drams into the femoral vein of a very small dog, with only
temporary inconvenience, and subsequently three drams of ex-
pired air even without much temporary disturbance.q Nysten has
established, that many gases soluble in the blood, as oxygen and
carbonic acid, may be thrown into the circulating system in very
large quantity without serious inconvenience; while danger often
ensues upon the introduction of those which are sparingly or not
at all soluble in the blood.r

In the same way, if about 15 grains of bile are rapidly introduced
into the crural vein of an animal, instant death occurs; but, if
slowly, no inconvenience results. This quantity may be even
rapidly injected into the vena portae without injury, and so likewise
may atmospheric air, probably because the extreme subdivision
of the vessel acts like slowness of introduction, – causes the com-
plete diffusion and dilution of the bile, and solution of the air,
before it reaches the heart.

[Seite 12]

If warm water is introduced (an equal quantity of blood being
first removed to prevent over distension) mere debility ensues,
proportionate to the quantity; but if oils, or mucilages, or an inert
impalpable powder, are injected, life is at once destroyed by the
obstruction of the minute ramifications of the pulmonary artery.s
Poisons act powerfully if injected into the veins; and, as will
presently be mentioned, medicines thus introduced, exert their
specific powers on the different organs.

(C) When blood, venous or arterial, is placed in the vacuum of
an air pump,t or coagulates in the air,u it emits a quantity of
carbonic acid gas. Professor Brande obtained two cubic inches
from every ounce of blood; Dr. Scudamore less than half a cubic
inch from six ounces. The quantity is said to be much greater
after a meal, and much less if the blood is buffy.x

(D) Blood coagulates when it has escaped from the body,
whether warm or cold, in the air or in vacuo, diluted within cer-
tain limits, or undiluted, at rest or in motion. Within the
vessels, rest, which causes a cessation of intercourse between
the motionless portion and the general mass, always disposes
it to coagulate. Yet its coagulation, after escape from the
body, is said to be accelerated by motion, a high tempera-
ture, and a vessel calculated to preserve its temperature, by
a vacuum, and by the stream from the vessel being slow,
and vice versa: in short, by every circumstance which favours
the escape of carbonic acid gas, and to be proportioned to
the quantity of carbonic acid gas evolved; this being evolved
during the coagulation, and ceasing to escape when the coagu-
lation is complete.y Galvanism and oxygen gas raise its tem-
perature and hasten coagulation, while carbonic acid gas, azote,
and hydrogen, have the opposite effects.

The coagulation of the blood is ascribed by J. Hunter to its
life:z by Mr. Thackrah,a on the contrary, to its death, as the se-
paration of a portion from the mass, by escape from a vessel, is
[Seite 13] likely to kill it if alive; as every change likely to impair life pro-
motes coagulation, for example, debility, fainting; and as blood
frozen, and therefore likely to be killed if alive, and again thawed,
instantly coagulates. But the coagulation appears, in most in-
stances, if Dr. Scudamore’s experiments be accurate, though
others have not found the same resultsb, attributable merely to the
escape of carbonic acid: and as coagulated blood or fibrine (and
the coagulated part of effused blood is fibrine) becomes vascular,
one can hardly, if the fluid is alive, regard a coagulum as ne-
cessarily dead. See also Sect. VI. Note B.

Large quantities of blood are found fluid in every dead body,
showing that simple loss of vitality is not sufficient to cause coa-
gulation. Indeed, the blood of the heart and vessels is found,
most frequently, in opposite states, fluid in one part, coagulated
in another, yet it is all equally dead. From all these contradic-
tory circumstances, I regard the coagulation of the blood as quite
unconnected with its vitality or lifelessness, and as entirely a che-
mical result. That it, however, is influenced by the vital pro-
perties of the containing vessels is possible, but these may ope-
rate upon the blood, in this respect, as a mere chemical compound;
and even if it be alive, and they influence its life, still the in-
fluence, as far as respects coagulation, may in effect be chemical.

The blood generally coagulates in the living body on escaping
from its vessels, and even in its vessels if its motion be prevented
by ligatures; and when it does not, its subsequent escape from
the body almost always produces instant coagulation.c It almost
always coagulates also in the vessels running through healthy parts
to others in a state of mortification, and in large vessels adjoining
a pulmonary abscess; in which cases, the final cause – prevention
of haemorrhage, is evident. The efficient cause, however, in all
these examples is unknown. In all, the blood is still in contact
with living parts: in the two last, it is not at rest till it coagulates.
J. Hunter, after mentioning that after a mortification of the foot
and leg he found the crural and iliac arteries completely filled
with strongly coagulated blood, adds, that this could not have
arisen from rest, because the same thing ought then to hap-
pen in amputation, or in any case where the larger vessels are
tied up.d Besides, coagulation after extravasation, or when a
[Seite 14] quantity is included in a vessel between two ligatures, is not an
invariable occurrence.

These facts, in addition to those stated above, show that fluidity
or coagulation is not dependent on the simple presence or absence
of vitality. Whatever connection coagulation out of the body
may have with the escape of carbonic acid gas, there is no proof
of it in the case of internal coagulation. Some have thought that
heat is evolved during its coagulationc; others have denied this.f
The latest experimenter supports the opinion.g

(E) To suppose any affinity of the red particles for either the
lymph or the serum is erroneous. Leeuwenhoek and Hartsoeker
long since proved that serum merely suspends them, for if, when
separated, they are triturated in some serum, part of them is
taken up and the serum assumes a red colour; but, if the fluid is
allowed to settle in a cylindrical glass, they slowly precipitate
themselves to the bottom, and the serum above becomes clear
as before. When blood is drawn, the serum easily separates on
the coagulation of the lymph. But the lymph coagulates before
the colouring particles have time to fall to the bottom, and en-
tangling them acquires a red colour, forming the crassamentum:
if, however, the lymph coagulate slowly, and is thinnerh, as in the
phlogistic diathesis and pregnancy, the greater specific gravity of
the cruor detaches it very considerably from the lymph, which
remains colourless above, constituting what is called the inflam-
matory coat, crust, or buff. Berzelius even believes the lymph
to be in a state of solution in the serum, while the cruor is simply
suspended in this solution. In the phlogistic diathesis both the
fibrin and the serum are more abundant, and the blood lighter.i

Thinness of the blood and a disposition to slow coagulation gene-
rally co-exist. But the rapidity of the stream greatly affects the
rate of coagulation, so that one portion of the same blood coa-
gulates slowly that is drawn quickly, and another quickly that is
drawn slowly.

The appearance of the buffy coat does not arise from the slow
coagulation, though increased by it; because, of two portions of
the same blood, one has afforded no buffy coat, although it
[Seite 15] remained fluid at least ten minutes after the buffy coat began
to be formed on the other;k proving, too, if the buffy coat arise
from thinness of the fibrin, as appears from Mr. Hewson’s ex-
periments, the red particles continuing of their usual weight, that
slow coagulation is not altogether dependent on mere thinness
of the blood, though generally connected and proportional with
it. Yet rapid coagulation, by means of a slow stream when the
blood is thin, may prevent the buffy coat, by not allowing time for
the difference in the weight of the fibrin and red particles to
have effect. Stirring such blood has the same consequence, and
the slower the coagulation of thin blood, occasioned, for instance,
by rapid bleeding, the greater will be the buffy coat.

The different cups of blood drawn in an inflammatory disease
may vary as to the buffy coat, according to accidental variations
in the stream, but generally it is the first cup that abounds in
buff, and the last frequently has none. This occurs when there
is no difference in the stream.l Therefore, if the buff arise from
thinness of the fibrin, we must conclude with Hewsonm that its
qualities may be changed even during bleeding. Dr. Scudamore
finds much more fibrin in buffy blood; and, consequently, that
not merely the thinness, as Hewson found, but the quantity, of
fibrin, may vary during the flow of blood.n

The greater the strength of the patient and the intensity of the
inflammation, the firmer is the coagulum of fibrin and the more
cupped its appearance.

Dr. Scudamore did not find a buffy coat in blood drawn imme-
diately after violent exercise.

The blood of different brutes coagulates in different times.
Mr. Thackrah imagines the rapidity to be inversely as the
strength and size. Thus, while in health, human blood coagulates
in from 3 or 4 to 7 minutes, that of the

Horse, in from 2 to 15
Ox, 2 to 10
Dog, 1/2 to 3
Sheep, hog, rabbit, 1/2 to 1 1/2
Lamb, 1/2 to 1 1/2
Fowls, 1/2 to 1
Mice, in a moment,
Fish, according to Huntero, also in a moment.
[Seite 16]

(F) The coagulable part of serum is albumen; that which
remains fluid is called serosity, – a name given it by Cullen, and
contains no gelatin as the French chemists asserted, but an ani-
mal matter different from both gelatin and albumen, with a mi-
nute portion of albumen and fibrin, and affords a little free soda,
muriate, lactatep, and phosphate, of soda, and muriate of potash,
with 905/1000 of water.q

If mixed with six parts of cold water, serum does not coagulate
by heat.

Under the influence of the galvanic pile, the soda collects
at the negative wire, and the albumen coagulates at the
positive.

(G) When venous blood acquires a florid colour by exposure to
oxygen or atmospheric air (and it does so even when covered
by a bladder, provided this is moistenedr), carbonic acid gas
is formed, and an equal volume of oxygen gas disappears. If
exposed to nitrous oxide, it becomes of a brighter purple, and
much of the gas is absorbed: carbonic acid gas renders it darker
and is a little absorbed: nitrogen and hydrogen have the same
effect. The dark colour produced in arterial blood by carbonic
acid or azotic gas takes place if blood is placed in vacuo, though
less rapidly and deeply than if exposed to hydrogen gas. Arte-
rial blood left in contact with oxygen gradually acquires the same
dark colour, and no oxygen will afterwards render it scarlet.
Berzelius finds the colouring particles only concerned in these
changes: and, after all, no difference of composition can be de-
tected between scarlet and purple blood. But Prevost and Dumas
found more particles, i. e. fibrin and red particles, in arterial than
in venous blood.

It has been generally supposed that iron exists in the red par-
ticles of the blood as a subphosphate. Berzelius informs us that
serum, although able to dissolve a small portion of the oxides,
not indeed of the phosphates, of iron, does not acquire a red
colour by their addition, and that he has never discovered iron
[Seite 17] nor lime in the entire blood, although both are so abundant in its
ashes. He concludes that the blood contains the elements of
phosphate of iron and of lime, and of carbonate of lime, and also
of phosphate of magnesia, united in a manner different from their
combination in the salts. But Dr. Engelhart has lately shown
iron to exist in blood, by the usual liquid tests, after passing a
stream of chlorin through a solution of red particles.l

Mr. Hewson asserted that the particles consist of a nucleus
and an enveloping coloured portion.m The nucleus is said to be
colourless; perhaps about 1/5000 of an inch in diameter, and the
whole globule nearly one-fourth larger.n MM. Prevost and
Dumas believe,o that the internal portion is spherical, but the
outer or vesicular, as Hewson noticedp, flattened. The inner part,
according to these enquirers, rolls in the outer, and, in the frog’s
web and bat’s wing, at least, the whole particle is carried, steadily
balanced, in the current of blood, sometimes flat, sometimes
oblique, sometimes gently turning upon itself; and lengthening
if driven into a vessel of diameter hardly sufficient for its admis-
sion: the assertion of Reichel, (12. note,) being thus corroborated.
Mr. Bauer has discovered a third set of smaller colourless globules
in the blood, 1/2800 of an inch in diameter. They appear to
belong to the fibrin, and are accordingly denominated lymph
globules. It is thought probable that the central globule of the
red particles is the same, and thus really fibrin. Colourless
globules gradually form also in serum.q

[Seite 18]

It was mentioned in the note to Section I. that Dr. Hodgkin
and Mr. Lister had lately employed a microscope superior
to those of former investigators, and disproved the opinion
of the globular composition of living structures. They, at the
same time, examined the blood, and though, like Hewson, they
found its particles flat and circular, and indeed with edges somewhat
raised, so that the middle of each surface was depressed, they
could detect no central particle; and satisfied themselves that the
diameter was pretty exactly 1/5000 of an inch.

(H) Oxygen and hydrogen also exist in fibrin. The fibrin,
albumen, and colouring matter, afford, on decomposition, the
same saline and gaseous products. Berzelius views them all
three as modifications of the same substance. Albumen contains
a greater proportion of oxygen than fibrin, and has sulphur for a
constituent part, which, however, cannot be detected while the
albumen is entire, any more than the iron while the cruor is entire.
The chief differences between the colouring matter and fibrin
are, colour; the spontaneous coagulation of fibrin at all temper-
atures, while the colouring matter may be dried without losing its
solubility in water, and becomes insoluble only at a certain tem-
perature; and the peculiarity in the latter of not diminishing in
volume like fibrin during exsiccation. Albumen is intermediate
between the two, and its only character of distinction from fibrin
is, that it does not coagulate spontaneously, but requires a high
temperature or some chemical agent.

The crystalline lens is a sort of albumen; the epidermis, nails,
hair, horn, cartilage, are nearly composed of it; of bone and
muscle it is an essential part. Fibrin exists in muscles only, be-
sides the blood, and is indeed their chief constituent, giving them
form, and rendering them fibrous. Gelatine, or rather what becomes
so by the agency of boiling water, contains somewhat less carbon
and more hydrogen and oxygen than albumen, and although
not obtained from blood, is an important part of our frame: the
cutis, serous membranes, and tendons, are a species of it; it forms
the chief part of cellular membrane, and is an essential constituent
of bones, muscles, ligaments, hair, &c. The composition of the
substance of the viscera is not well known.r

[Seite 19]

The blood of brutes has the same general character as our
own, and Rouelle obtained the same ingredients, though in dif-
ferent proportions, from the blood of a great variety of them.
Berzelius finds a larger proportion of nitrogen in that of the ox, and
analogy would lead us to suppose there is a peculiarity in the blood
of every species. Muscles look pretty much alike in various ani-
mals, yet when cooked they disclose the greatest diversities.
Transfusion, or pouring the blood of one system into another,
satisfies us, that the blood, whether arterial or venous, of one in-
dividual,
agrees well enough with another of the same species;
but some late experiments of Dr. Leacock,s and subsequently of
Dr. Blundel,t render it unlikely, contrary to the opinion of
former experimentalists, that the blood of one species suits the
system of another. Dr. Young found the large outer globules of
the skate to be somewhat almond-shaped, and Hewson found
them of different shapes in different animals, and Rudolphi ob-
served them to be more or less oval in the common fowl and many
amphibia.u MM. Prevost and Dumas have noticed, in their mi-
croscopic experiments, a great difference in the blood of different
animals as to the globules, and in this way explain the impossi-
bility of transfusing the blood of some animals to others without
danger to life. They assert that the quantity of the particles
is proportionate to the temperature of the animal, and that, con-
[Seite 20] sequently, most exist in the blood of birds: that the size and
shape also vary, although the size of the central portion is the
same in animals in which they are spherical, and is about 1/7500 of
an inch in diameter; and that the shape of the external part is
circular in the mammalia, and elliptical in birds and cold-blooded
animals, thus confirming and generalising the observations of
othersx, (and this is again confirmed by Dr. Hodgkin) and
the shape of the central portion correspondent with that of the
external, – spherical when the latter is circular, oval when ellip-
tical. They found, that if the blood of two animals of different
species, the blood of one of which was transfused into the other,
differed in the size only of the globules, temporary restoration
of energy took place; but that if it differed in their shape,
convulsions and death were the result. They also find a
larger proportion of fibrin and red globules in warm than in cold-
blooded animals, and a larger in the former according to the
height of the temperature – (of 10,000 parts by weight; in pi-
geons, 1557; man, 1292; frogs, 690): – a smaller also, accordingly
as animals are bled; it thus appearing that bleeding promotes the
absorption of watery fluid.y The colour of the particles differs
in different animals: hence red and white-blooded animals.

Hewsonz saw the red particles of the blood of the foetal
chicken and viper larger than those of the adult animal: and
Prevost and Dumas have observed the red particles of the
foetal goat to be as large again as those of the adult; and
those of the chicken to be circular, till about the sixth day,
when some elliptic ones are first seen; and on the ninth, from
their progressive multiplication, none but elliptic ones can be
detected.a

The blood of invertebral animals is colourless, but has not been
analysed.

The sap of vegetables corresponds to the blood of animals, but
is totally different; is nearly as liquid as water; has always an acid,
sometimes free, more commonly united with lime and potash.
It has various vegetable principles; but sugar and mucilage are
[Seite 21] the most remarkable. Sometimes it contains albumen, tannin,
and gluten.

It soon effervesces if left alone, and grows sour, or even vinous,
if much sugar be present.

About forty years after the discovery of the circulation of the
blood, transfusion was practised upon brutes, and at length upon
the human subject, though some contend that the operation was
known to the ancients. Experiments were made upon the
effects of injecting medicated liquids into the blood, first by
Wahrendorf, in Germany. It was ascertained that they exert their
specific powers exactly as when swallowed, – cathartics, v. c.
purging, and emetics emptying the stomach. Among other liquids,
Dr. Christopher Wren proposed that blood should be injected,
and Dr. Lower first put this into practice. It was found that
if an animal was drained of its blood, and lay faint and almost
lifeless, and the blood of another was transfused into its cir-
culating system it soon revived, stood up, and presently ran
about as before, apparently none the worse for the operation.
If too much was poured in, the animal became drowsy, breathed
with difficulty, and died of plethora. An idea of curing diseases
in this way, by substituting the blood of the healthy for that
of the diseased, was immediately entertained when the possibility
of the operation was proved.

But the first case of human transfusion proved fatal, and the
unfortunate results of some careless trials caused the Pope and
the King of France to prohibit the practice.

The extravagant hopes of curing diseases and restoring youth,
at first entertained in France, were disappointed, and the operation
fell into complete neglect, notwithstanding that Denys, in France,
was declared to have made a fool clever by a supply of lamb’s blood;
a Mr. Cox, in England to have cured an old mongrel of the mange
with the blood of a young spaniel; and a M. Gayant to have
made a blind old dog frisk with juvenile bound which before could
hardly stir; till Dr. Leacock brought it again into notice a few
years ago, and Dr. Blundel prosecuted this gentleman’s re-
searches. Dr. Blundel conceived it might be rationally expected
to be of benefit in cases of dangerous haemorrhage, and he soon
proved it to be void of danger in the human subject, if properly
performed. Many women who would probably otherwise have
[Seite 22] perished from uterine haemorrhage, now owe their lives to his
disinterested zeal in establishing the practice.

I should think it applicable to many cases of exhaustion, be-
sides those arising from haemorrhage. The original history of
transfusion will be found in the early numbers of the Philosophi-
cal Transactions:
the successful cases of its employment as a
remedy, in the late English journals. The double pump em-
ployed for emptying the stomach, or a common syringe, capable
of holding four or six ounces, answers very well. But Dr. Blundel
at present, when he has able assistants, sometimes receives the
blood from the blood-vessel into a funnel, the tube of which is
very long, and inserted into the vein of the subject supplied, so
that the blood enters by its gravity only.

SECT. III.
OF THE SOLIDS IN GENERAL, AND OF THE MUCOUS WEB IN
PARTICULAR.

[Seite 23]

17. The solidsa are derived from the fluids. In the first
rudiments of the gelatinous embryo, they gradually commence
in their respective situations, and differ infinitely in their
degreesb of cohesion, from the soft and almost pulpy medul-
lary matter of the brain, to the vitreous substance of the
corona of the teeth.

18. Besides the gelatinous (11) and glutinous (14) parts
of the solids, earth enters more or less into their composi-
tion, and is principally lime united with phosphoric acid,
whence it is commonly termed phosphate of lime. The bones
possess this in the greatest abundance, particularly in ad-
vanced age: whereas in childhood the gelatinous matter
abounds.

19. With respect to texture, the majority of the similar
parts of the body, as the ancients called them,c consist of
fibres more or less parallel. This may be observed in the
bones, especially of foetuses,d in the muscles, tendons, liga-
[Seite 24] ments, aponeuroses, and in certain membranes, as the dura
mater, &c.

20. In other parts no fibres can be discovered, but the
texture is peculiar, has been called parenchyma from the time
of Erasistratus, and differs in different viscera, especially the
secreting, – of one kind in the liver, for example, and of
another in the kidneys.

21. But in all these structures, whether fibrous or paren-
chymatous, there is interwoven a general mucous web,e com-
monly styled cellular, but improperly, because it rather is
continuous, equal, tenacious, ductile, sub-pellucid, and glu-
tinous.f By handling, it is easily converted into a cellular
and vesicular membrane, and demands a place among the
most important and remarkable constituents of the body. (A)

22. For, in the first place, many solid parts, v. c. most
membranes and cartilages, may, by long-continued maceration,
be resolved into it alone. With some it is so intimately
united, as to afford a receptacle and support for other con-
stituents: v. c. the hardest bones consisted at first of cartilage,
which itself was a dense mucous web originally, though
subsequently distended by the effusion of bony matter into its
substance, and rendered more lax and cellular. In fact, it is
universally present in the solids, if we except the epidermis,
nails, hairs, and the vitreous exterior of the corona of the
teeth, in which I have never been able to discover it by em-
ploying the strongest acid.

23. To the muscles and membranes especially it serves for
separation from other parts; to the vessels and nerves espe-
cially for support; and to every part it acts as the common
medium of connection.

24. From these facts, two inferences may be drawn.

First: That this membrane is so fundamental a constituent
[Seite 25] of our structure, that, were every other part removed, and it
to retain its position, the body would still preserve its form.

Secondly: That it forms a connection and sort of passage
between all parts of the system, however different from each
other in nature, or remote in situation: – a circumstance
worthy of attention, as putting an end to the verbal disputes
respecting the continuation of membranes, and affording an
explanation of many morbid phenomena.

25. As most of the solids owe their existence to this mem-
brane, so again its origin is derived from the lymph of the
blood, for I have seen lymph transuded on the surface of
inflamed lungs, and changed into this mucous web, which,
by forming false membranes, unites these organs to the pleura.

26. We shall now consider some varieties of this membrane.

First: its strength is not the same in every part.

In general, it is more delicate, caeteris paribus, in man than
in brutes, – a distinguishing prerogative, by which our sense
is rendered more delicate, and our motions and other func-
tions more perfect.g

Among different individuals, it varies much in laxity and
firmness, according to age, sex, temperament, mode of life,
climate, &c.

Finally, it varies in different parts; – more lax in the pal-
pebrae and praeputium, and behind the fraenum of the tongue;
less so around the ears.

27. Besides the purposes before mentioned (22, 23,) it
is destined for the reception of several kinds of fluids.

Its chief use in this respect is to receive the serous halitus
which moistens and lubricates every part. This, when formed
by the blood vessels, it imbibes like a sponge, and delivers
over to the lymphatics, thus constituting the grand connec-
tion between these two systems of vessels.

28. In certain parts its office is to contain peculiar fluids;
v. c. in the eye, existing as the vitreous membrane, it contains
the vitreous humour:

[Seite 26]

In the bones, as the medullary membrane (improperly
denominated internal periosteum), the marrow:

In soft parts, it is in great abundance, and contains the
rest of the fat, of which we shall speak hereafter. (B)


NOTES.

(A) Since this structure neither secretes mucus, nor consists of
mucus, but chiefly of what becomes gelatin by the operation
of boiling water, the generally-received appellation of cellular
membrane
appears preferable to that of mucous tela adopted by
Blumenbach from Bordeu,h and especially in this work, as our
author (40) suggests the title of vis cellulosa for the contractile
power of the membrane.

(B) Dr. William Hunter contended that the fat is not contained
in the same cells of the cellular membrane as the fluid of
anasarca, but in distinct vesicles: because, – 1. The marrow, which
strongly resembles fat, is contained in vesicles or bags; 2. Parts
which are most loaded in anasarca, as the eyelids, never contain
fat; 3. In dropsical subjects, exhausted of the fat, the membrane
which contained fat appears still very different from the other, –
that immediately under the skin, for example, being thin and col-
lapsed, while that opposite the tendon of the latissimus dorsi is
thick and gelatinous; 4. Parts which become filled with fluid
from gravitation in dropsy, as the penis and scrotum, never con-
tain a drop of oil in the fattest persons; 5. Dropsical parts pit
on pressure; the fluid disperses, and returns when the pressure is
resumed. This is not the case with parts distended by fat,
although it is when oil is poured into the common cellular mem-
brane after death.i

CHAP. IV.
OF THE VITAL POWERS IN GENERAL, AND PARTICULARLY OF
CONTRACTILITY.

[Seite 27]

29. Hitherto we have spoken of the solids as the con-
stituents of the system; we now shall view them as endowed
with vitality, – capable of receiving the agency of stimuli,
and of performing motions.

30. Although vitalitya is one of those subjects which are
more easily known than defined, and usually, indeed, rendered
obscure rather than illustrated by an attempt at definition, its
effects are sufficiently manifest and ascribable to peculiar
powers only. The epithet vital is given to these powers,
because on them so much depend both the actions of the whole
body during life and those which remain in some parts for a
short time after death, that they are not referable to any
qualities merely physical, chemical, or mechanical.

31. The latter qualities, however, are of great importance
in our economy. For instance, by physical powers, depen-
dent on the density and figure of the humours of the eye,
the rays of light are refracted to the axis; by mechanical,
the epiglottis is elastic; by chemical affinity, the changes of
respiration are effected. But the perfect difference of these
dead powers from those which we are now about to examine,
is evident on the slightest comparison of an organised eco-
[Seite 28] nomy with any inorganic body, in which these inanimate
powers are equally strong.

32. Indeed, the energy and strength of the vital powers are most
conspicuously manifested by their resistance and superiority
to the others; v. c. during life, they so strongly oppose the
chemical affinities which induce putrefaction, that Stahl and
his followers referred their notion of life to this antiseptic
property;b they so far exceed the force of gravity, that,
according to the celebrated problem of Borelli, a dead muscle
would be broken asunder by the very same weight, which
it could easily raise if alive, &c.

33. As, on the one hand, the vital properties are com-
pletely different from the properties of dead matter, so, on
the other, they must be carefully distinguished from the
mental faculties, which will form the subject of the next chap-
ter: between them, however, there exists an intimate and
various relation, observable in many phenomena, but espe-
cially in the diversity of temperament.

34. The vital energy is the very basis of physiology, and has
therefore been always noticed, though under different appel-
lations.
The titles of impetum faciens, innate heat, archaeus,
vital spirit, brute life, head of the nervous system, active
thinking principle, vital tonic attraction, have been bestowed
upon it by different authors.

35. Nor has there been less variety in the notions and de-
finitions to which it has given rise; though in this one point
all have agreed, – that its nature and causes are most
obscure.

36. As to the question so long agitated by physiologists, –
whether the diversity of the phenomena exhibited in the
similar parts of the living solid is to be attributed to mo-
difications only, or to distinct species, of the vital energy, we
think it best to establish distinct orders of the vital powers,
[Seite 29] according to the variety of phenomena by which they are
manifested.

37. These phenomena are threefold. – Organic formation
and increase; motion in the parts when formed; sensation
from the motion of certain similar parts.

38. The first requisite involved in the name and notion of
an organised body, is a determinate form designed for certain
ends. That species, therefore, of the vital powers is most
general, which produces the genital and nutritive fluids and
prepares them for organic nature, and which we have deno-
minated the nisus formativus, since it is the source of all
generation, nutrition, and reproduction, in each organised
kingdom.

39. Those vital powers which are manifested by motion, (37)
properly so called, in parts already formed, may be divided
into common and proper. The common are those belonging
to similar parts which are widely distributed: v. c. contrac-
tility to the mucous web; irritability to the muscular fibre.
The proper are those possessed by some singular organs only,
for the purpose of peculiar and anomalous motions.

40. Contractility is as generally distributed as the mucous
web, which it may be said to animate; and therefore would
perhaps not improperly be called the vis cellulosa. It is
characterised by a simple and not very perceptible effort of
the mucous web to contract and react upon its contents, espe-
cially upon its source of moisture, – the serous vapour, and
to propel this into the lymphatic system.c

41. Irritability, we mean the irritability of Haller, is pecu-
liar to the muscles, and may, therefore, be called the vis mus-
cularis.
It is marked by an oscillatory or tremulous motion,
distinguished from the action of simple contractility, both by
occurring far more easily on the application of any pretty
[Seite 30] strong stimulus,d and by being attended with a much more
considerable constriction.

42. Such are the common (39) moving vital powers. But
some organs differ from the rest so much in their structure,
motions, and functions, as not to come under the laws of the
common orders of vital powers.

We must, consequently, either reform the characters of
these orders, institute new ones, and extend their limits; or,
till this be done, separate these peculiar motions from the
common orders, and designate them by the name of vitae
propriae.
e

As examples may be adduced, the motions of the iris; the
erection of the nipple; the motions of the fimbriae of the Fal-
lopian tubes; the action of the placenta; and of the womb
during labour; and probably the greater part of the function
of secretion.f

43. So much in regard to the vital powers displayed by
motion. (37. 39–42.)

We have now to speak of sensibility, which is peculiar to
the nervous medulla communicating with the sensorium. It
bears the title of vis nervea, and is the cause of perception in
the mind when irritation is excited in parts to which it is
distributed.g

44. The order which we have followed in enumerating the
vital powers (38–43) is that in which they successively arise
both during our formation and after birth.

[Seite 31]

The nisus formativus must take place before we can ascer-
tain the existence of the new conception.

Then contractility is exerted in the gelatinous substance of
the embryo.

When the muscular fibres are produced, they have
irritability.

Next, in those few organs whose motions cannot properly
be referred either to contractility or irritability, there exists a
vita propria.

Finally, after birth, sensibility is superadded.

45. Similar also is the order, according to which these vital
powers, both common and proper, are distributed to the
organised bodies of each kingdom.h

The formative power must be most universal; without it,
indeed, organisation cannot be conceived to exist.

Contractility likewise is common to each kingdom.

Irritability and sensibility, in the sense above explained,
are peculiar to animals.

Lastly, the vita propria is variously observable in some
organs, particularly the generative, both of certain animals
and vegetables.

46. It is scarcely necessary to remark that most of these
modes of vital energy, though necessarily distinguished into
orders, are intimately connected; v. c. the mucous web,
forming the basis of so many organs and the seat of their
contractility, is interwoven also with the irritable muscular
fibresi and the sensible nerves.

47. Whatever may have been the opinions of physiologists
respecting the difference or similarity of the vital powers, it is
universally agreed that they exist in the similar solid parts,
as the ancients called them, of which the organs or dissimilar
parts are composed.

[Seite 32]

But it has been disputed, and particularly of late, whether
vitality is peculiar to the solids, or common also to the fluids;
and, the latter being granted, whether or no the blood only is
so endowed.

48. As to the first question, the whole natural history of
each organic kingdom, as far as it has hitherto been cultivated,
abundantly shows that the living parts, however delicate, of
all known animals and vegetables, are solid; – a circumstance
necessarily implied in their determinate figure destined for
certain uses. For, not to speak of entire animals (which,
however simple, as worms, are, nevertheless, supplied with
enveloping membranes), the newly-laid egg, though at first
sight merely fluid, on a more careful examination is discovered
to consist of different membranes, of the halones, the cica-
tricula, &c.

Humidity is, indeed, necessary in the living solid for the
exertion of vitality. But that vitality exists in the solid, as
solid, is proved by the well-known instances of animalcules
and the seeds of plants, in which, although long dried, the
vital principle is so entire, that they again live and germinate.

49. With respect to the supposed exclusive vitality of the
blood, I candidly confess that no fact has been adduced in its
favour since the time of Harvey, which might not, I think, be
more easily, simply, and naturally explained on the contrary
supposition.

For example, the incorruptibility of the blood during life,
is far more explicable by the perpetual changes which it
undergoes, especially in respiration.

That the blood is the material from which the living solids
are produced, is no stronger an argument of its vitality than
the formation of nymphaeae, and of so many other remarkable
plants, would be for the vitality of river water.

It is difficult to comprehend how the coagulation of the
lymph of the blood when drawn from a vein can demonstrate
its vitality. The organisation of this lymph in generation,
nutrition, and reproduction, depends not upon the lymph
[Seite 33] itself, as lymph, but upon the action of the nisus formativus
(38) upon it.

50. Those who formerly contended that the blood acquires
in the lungs from the air a certain principle to be universally
distributed during circulation, for the purpose of imparting
motion, &c. to the organs, were right, if they regarded that
principle (analogous to the oxygen of the moderns) as the
stimulant of the living solid; wrong, if they regarded it as
vitality itself.k

51. For it is on all hands agreed, that no motion occurs but
upon the action of stimuli, to receive which action the vital
powers are naturally adapted and intended.

52. These stimuli,l however multifarious, are conveniently
reduced to three classes; – chemical, mechanical, and mental.
For the present, we shall say nothing of their various modes
of action, – in some instances direct, – in others indirect, by
sympathy and sensorial reaction. It is sufficient at present to
cite a few examples of functions, to which each class of stimuli
conspires; such is the increased secretion of tears, saliva, bile,
&c. and the venereal turgescence of the genitals.

53. If the nature of stimuli is infinitely various, no less so
are their effects, according to their nature, intensity, or con-
tinued and repeated application to the living solid. Hence
they are generally divided into exciting and depressing.

54. The power of certain stimuli in increasing the effects
of others, is very remarkable: v. c. the power of caloric, upon
which probably national temperament chiefly depends.m That
of joy, a most energetic mental stimulus, is similar.n Like-
[Seite 34] wise perhaps that of oxygen, (50) by whose chemical stimulus
the vital powers, particularly irritability, are greatly excited,
and more disposed to react upon the impulse of other stimuli.

55. Not less considerable than the variety of stimuli, is that
mare minute discrepancy of the different organs, and of the
same organs in different individuals, according to age, sex,
temperament, idiosyncrasy, habit, mode of life, &c., to which
are owing the diversified effects of the same stimuli upon dif-
ferent organs of the same body,o and even upon the same in
different individuals, and upon which depends what the
English have lately termed specific irritability.p

56. Lastly, the influence of stimuli by means of sympathy,
is very extraordinary: by its means, if one part is excited,
another, frequently very remote, consents in feeling, motion,
or some peculiar function.q

The primary and most extensive cause of sympathy must
be referred to the nerves,r and indeed chiefly to the sensorial
reaction;
s that if one nervous portion is excited, the sen-
sorium is affected, which, reacting by means of the nerves on
another part, draws it into consent with the first, although
there exist between them no immediate nervous connection.
Such is the sympathy of the iris, when the retina is stimulated
by light; and of the diaphragm during sneezing, when the
Schneiderian membrane is irritated.

There are other examples of sympathy, in which the nerves
[Seite 35] have, if any, but a more remote and accessory share:t among
these must be placed the sympathy along the blood vessels,
strikingly instanced, especially in advanced pregnancy, be-
tween the internal mammary and epigastric arteries, from
their anastomosis; that along the lymphatic vessels,u also most
remarkable during pregnancy and suckling; and again, that
dependent on analogy of structure and function, v. c. the sym-
pathy of the lungs with the common integuments and in-
testines. (A)

57. So much with respect to the vital powers in general.
They will be hereafter separately considered, under the distinct
heads of our subject:

The nisus formativus under the head of Generation;

Irritability under that of the Muscles;

Sensibility under that of the Nervous System;

The vita propria whenever occasion requires.

58. Besides our former brief remarks (40) upon contrac-
tility,
a few more minute will at present be very appropriate.

It prevails universally, (40) wherever the mucous tela is
discoverable.

It is consequently most abundant in parts, destitute of
proper parenchyma, but composed almost entirely of mucous
tela, v. c. in certain membranes. For no one will deny their
contractility, who reflects upon the spastic motions of the
dartos, the male urethra, or of the gall bladder, which after
death has often been found closely contracted upon any calculi
it may contain.

It appears also in those viscera which consist chiefly of this
tela, v. c. in the lungs, whose external surface we have found
[Seite 36] on frequent living dissection very contractile, but by no means,
as Varnier asserted, truly irritable. (B)

The presence of contractility, even in the bones, is demon-
strated by the shrinking of the alveoli after the loss of the
teeth, and by the process of necrosis, by which the new bone,
when the dead portion is extricated from its cavity, gradually
contracts to its natural size and figure.

The vitreous substance of the teeth, being destitute of this
tela (22), possesses no contractility, as I think appears from
the circumstance of its not shrinking, like the alveoli, if a
portion is separated by caries or fracture.

59. This contractility of the mucous tela (C) is the chief
cause of strength, health, and beauty; since on it depend the
vital elasticity and fulness,x and indeed the tone, of parts, so
elegantly described by Stahl; for by its means, the mucous
tela, to mention one only of its functions, absorbs, during
health, the serous fluid (27) like a sponge, and propels it into
the lymphatic vessels: in disease, on the contrary, having lost
its tone, it is filled with water, giving rise to oedema and
similar cachexies.

60. Finally, the great influence of this contractility upon
the other vital powers, is manifest from its universal existence,
and its effect in producing the peculiar constitution and tem-
perament of individuals; and from its infinite varieties and
degrees in different persons.


NOTES.

(A) John Hunter divides sympathy into general and partial;
such as pyrexia from a wound, and convulsion of the diaphragm
from irritation in the nose. Partial sympathy he subdivides into
remote, contiguous, and continuous, – Where there is no evident
connection between the sympathising parts, sufficient to account
[Seite 37] for the circumstance; as vomiting from the pregnant state: –
Where there is proximity of the sympathising parts; as tenesmus
when a stone exists in the urinary bladder: – and Where, as most
commonly, the sympathising parts are continuous; as itching
of the nose and verge of the anus from worms in the in-
testines.y

Bichat’s divisionz cannot be understood till after the perusal
of Note B, Sect. VI. He considers sympathy as affecting either
animal sensibility or contractility, as pain of the knee in diseases
of the hip, or tetanus from a wound of the extremities; or or-
ganic sensibility or contractility, as palpitation from disorder of
the stomach.

Sympathy does not arise from mere nervous connection, because
it frequently happens that no particular nervous communications of
sympathising parts are discoverable, as between the nose or eye and
diaphragm, although sneezing follows from a pinch of snuff in the
nose or the sun’s glare upon the eyes, while remarkable ones exist
between other parts not particularly disposed to sympathise, as the
neck and diaphragm.a Vegetables, which are not known to have
nerves, show sympathy: if a leaflet of the sensitive plant is stimu-
lated by a burning-glass, the whole leaf contracts and the foot-stalk
drops; when the branches of trees feel the warmth of summer, the
sap ascends in the roots; and even in a frost it will ascend from the
roots through the stem, if a single branch is introduced into a hot-
house.b

Sympathy of animal contractility occurs only when the nerves
connecting the affected muscles with the brain are entire; when
[Seite 38] they were divided by Bichat, the convulsions in the correspond-
ing muscles ceased.

Neither, where sympathetic muscular action arises from a sen-
sation, will it occur, if the nerves communicating impressions from
the affected part to the brain are compressed or divided, or if the
brain itself is unable to receive the impression: – although the
stomach may be thrown into contraction in an animal newly dead,
by mechanical irritation, no sympathetic action of the diaphragm
and abdominal muscles, no vomiting, occursc; sneezing or con-
traction of the iris cannot be induced in coma, by stimulating the
nostrils or letting the sun’s rays into the eye. Even when the im-
pression is not perceived, but the action is of voluntary muscles,
as in hiccup, the action ceases if the brain is disqualified for
the impression; v. c. a forcible distraction of the attention arrests
hiccup. The necessity for sighing after reading or listening
attentively arises from our forgetting to breathe fully, – not fully
perceiving the want of breath while our attention was so oc-
cupiedd; and the general coughing and sneezing in church at
a pause in the sermon, is owing to the sensations which give rise
to those actions having been for a time overpowered throughout
the congregation by other feelings.e

The sympathies of the organic functions are not all ascribable,
as many might imagine, to continuity of surface; for after dividing
the oesophagus of a dog, Bichat produced vomiting equally as
before, on irritating the fauces.

Sympathy depends on the peculiarity of the sensation as well
as upon the part. ‘“When the sides or soles of the feet are
[Seite 39] tickled,”’ says Whytt, ‘“the body is often thrown into convulsive
motions; but nothing of this kind happens when those parts are
either inflamed or wounded: neither an acrid injection of a so-
lution of corrosive sublimate, nor the introduction of a catheter
into the urethra, occasions any alternate convulsive motions of the
acceleratores urinae, although the semen, which stimulates the
nerves of the urethra much more gently, has this effect.”’

The same cause, too, will produce the same sympathetic effect,
though applied to different parts. Convulsions arise from tickling
any part; nausea from a disgusting smell, taste, or sight.

The same sympathetic effect, lastly, may arise from many dif-
ferent causes in different parts: vomiting may arise from injuries
of the head, a stone in the kidney, disgust, sailing, &c.f

Sympathy is of the utmost importance in health. When the
glans penis is irritated to a certain pitch, not only the ejacula-
tores seminis, but the levatores ani, are thrown into violent action:
when the uterus has arrived at the term of gestation, the breasts se-
crete milk. Sympathy often occurs, in disease, in parts which
showed none during health; as pain of the right shoulder in affec-
tions of the liver: and new sympathies occur in parts which were
sympathetically connected in health, as vomiting in constipation;
pain, and even secretion of milk, in the breasts, when the uterus or
ovaria are diseased.

(B) Our author here, as below (135), means the pulmonary
portion of the pleura, and very properly regards this and other
serous membranes, as condensed cellular substance; that is, as
a substance not originally cellular and now condensed, but of the
same nature with the cellular membrane, though much more
compact.g

I may mention that Rudolphi asserts that serous membranes
are incapable of inflammation, are not vascular, and do not secrete;
but that the secretions of close sacs take place from the subja-
cent parts, and transude the serous membranes, which are thus
regarded only as a kind of cuticle; and he further asserts, that
they in a similar way line all the mucous surfaces.h

(C) The shrinking of cavities on the removal of the distending
cause (58), is referable to mere elasticity; and also, the constant
effort (if real) of the cellular membrane to contract upon its con-
tents. (40)

SECT. V.
OF THE MENTAL FACULTIES.

[Seite 40]

61. Man, whom we have found possessed of a body, an-
swering completely, both in matter and texture, as well as in
vital powers, the purposes of its formation, is endowed like-
wise with a mind, a ‘“divinae particula aurae,”’ intimately con-
nected with the body, and developing by education and
exercise various kinds of faculties, which we shall concisely
enumerate, as far as they belong to our subject.a

62. The sensibility of the nerves, mentioned above among
the vital powers, (43) constitutes, as it were, the medium
which propagates the impressions of stimuli upon sensible
parts, and especially upon the organs of sense (the functions
of each of which we shall hereafter examine), to the sensorial
portion of the brain, in such a manner that they are perceived
by the mind.

63. The mental faculty to be first enumerated, and indeed
to be placed at the bottom of the scale, is the faculty of per-
ception,
by means of which the mind takes cognisance of im-
pressions made upon the body, and chiefly upon the organs
of sense, and becomes furnished with ideas.

64. This faculty is assisted by another of a higher order, –
attention, which so directs the mind, when excited, to any
idea, that it dwells upon that idea alone, and surveys it fully.

65. To preserve and recall the marks of ideas, is the office
[Seite 41] of memory – the part of the mind, that, in the language of
Cicero, is the guardian of the rest.

66. Imagination,b on the contrary, is the faculty of the
mind, that represents not merely the signs, but the very images
of objects, in the most lively manner, as if they were present
before the eyes.

67. Abstraction forms general notions more remote from
sense.

68. Judgment compares and examines the relations both of
the ideas of sense and of abstract notions.

69. Lastly Reason – the most noble and excellent of all the
faculties, draws inferences from the comparisons of the judg-
ment.c

70. The combination of these constitutes the intellectual
faculty.
But there is another order, relating to appetency, the
word being taken in its most extensive meaning.

71. For since we are impelled by various internal stimuli
to provide food and other necessaries, and also to satisfy the
sexual instinct, and are impelled the more violently, in pro-
portion as we are inflamed by imagination, desires, properly
so called, are thus produced; and if, on the other hand, the
mind becomes weary of unpleasant sensations, aversions occur.

72. Finally, that faculty which selects out of many desires
and aversions, and can at pleasure determine to perform
functions of the body for certain purposes, is denominated
volition.

73. Our order of enumeration corresponds with that of
[Seite 42] the developement of the faculties, and with the relation in
which those which were first mentioned, – common to man
and brutes, and those more or less peculiar to man, stand to
each other.


NOTE.

Dr. Gall gives a very different view of the mental faculties. In-
stead of dividing them into perception, attention, memory, judg-
ment, &c. as fundamental faculties; and viewing ‘“the Power of
Taste, a genius for Poetry, for Painting, for Music, for Mathe-
matics,”’ &c. as ‘“more complicated powers or capacities, which
are gradually formed by particular habits of study or of business;”’d
he regards these last powers as distinct faculties, and perception,
attention, memory, judgment, &c. merely as modes or varieties
common to the action of each faculty.e He contends that when
we see a boy, brought up exactly like his brothers and sisters,
displaying fine musical talents or an astonishing power of calcu-
lation, though in all other respects a child, his pre-eminence cannot
be explained by particular habits of study or of business, nor by
mere strength of judgment, memory, &c.: – That the boy has a
strong perception of melody, a strong memory of tunes, a strong
musical imagination, a strong musical judgment, or a strong per-
ception, memory, and judgment, of numbers; but is not clearer-
headed or more attentive on any other point, while men of the
strongest sense may have no perception, memory, or judgment,
of tunes, or may calculate with extreme difficulty. It is the same
with regard to instinct. Writers consider instinct a general faculty,
while it is only the inherent disposition to activity possessed
by every faculty, and there are, therefore, as many instincts as
fundamental faculties. By instinct ‘“the spider spreads a web and
ensnares flies; the working bee constructs cells, but does not kill
flies to support itself; it takes care of the young but does not
[Seite 43] copulate. Many male animals copulate, but take no care of their
young; the cuckoo, both male and female, abandons the charge
of bringing up its young to other birds, although it is compelled
to copulation by a very ardent instinct. The castor builds a hut,
but neither sings nor hunts; the dog hunts, but does not build;
the butcher-bird sings, builds, and preys; the quail does not
mate, but copulates, takes care of its young, and migrates; the
partridge mates, copulates, and takes care of its young, but does
not migrate; the wolf, fox, roebuck, and rabbit, marry, and take
care of their young conjointly with the female: the dog, stag, and
hare, copulate with the first female they meet, and never know their
offspring. The vigorous wolf, the artful and timid hare, do not
burrow like the courageous rabbit and the cunning fox. Rabbits
live in republics, and place sentinels, which is done by neither the
fox nor the hare. How can these various instincts exist in one
species of animals and not in another? How can they be com-
bined so differently? If instinct were a single and general faculty,
every instinct should show itself, not only at once, but also in the
same degree, and yet while in the young animal many instincts act
with great force, others are still quite inactive: some instincts act at
one season, others at another. There is one season for propagation,
another for emigration; one season for living solitarily, another
for assembling in companies, and for collecting provisions. And
how can we explain, on the supposition of a general instinct, why
the different instincts do not exist merely separate in different
species of animals, but that many of them are even con-
tradictory?”’f

For my own part, when I reflect upon the various talents and
dispositions of persons who are all placed in the same circum-
stances, – how unsuccessfully some apply, with the utmost per-
severance,
to a branch of study, in which another, under the same
instructors, or, perhaps, scarcely assisted at all, or even with every
impediment thrown in his way, reaches excellence with little
trouble, and, again, fails in one in which the first is, on the other
hand, successful, – how early various tempers are developed among
children of the same nursery, – how hereditary are peculiarities of
talent and of character, – how similar some persons are to each
other in one point of talent and character, and dissimilar in
another, – how positively contradictory many points of the same
[Seite 44] character are found; – how exactly the same is true of all species
of brutes, and of all individuals among them, – each species having
its peculiar nature, and each individual its peculiar character: –
I confess myself unable to deny that there is one innate faculty
for numbers, another for colours, a third for music, &c. &c., with
a variety of distinct innate sentiments and propensities; and
that memory, judgment, &c. are but modes of action common to
the different faculties.g

The faculties of whose existence Gall has satisfied himself are:
1. The instinct of generation; 2. The love of offspring; 3. The
disposition to friendship; 4. Courage; 5. The instinct to destroy
life; 6. Cunning; 7. The sentiment of property; 8. Pride; 9. Vanity;
10. Circumspection; 11. Sense of things; 12. Sense of locality, or
of the relations of space; 13. Sense of persons; 14. Sense of
words; 15. Sense of language; 16. Sense of the relations of colours;
17. Sense of the relations of tones; 18. Sense of the relations of
numbers; 19. Sense of construction; 20. Comparative sagacity;
21. Metaphysical sagacity; 22. Wit; 23. Poetic talent; 24. Good-
ness; 25. Faculty of imitation; 26. Religious feeling; 27. Firm-
ness. He has been long inclined to admit also a sense of order
and a sense of time, and waits only for proofs of their organs.

Gall gives various other names to each faculty, more anxious
to express his view of the nature of each than to quibble for
appellations.

For information respecting the precise nature of each faculty,
many of which may be ill understood from their designations, I
refer to the latter part of the third, and to the fourth and fifth
volumes of Gall’s Fonctions du Cerveau, – portions of the work
which the most indolent will find entertaining.

That the faculties enumerated are not modifications of each other,
or of any other, but distinct and primitive, Gall considers proved
by the circumstance of each having one or more of the following
conditions.

‘“An instinct, inclination, sentiment, talent, deserves,”’ says he,
‘“the denomination of fundamental, primitive, radical:’

‘“1. When a quality or faculty, (or its organ) is not manifested
nor developed, nor diminishes, at the same time with others.
[Seite 45] Thus, the instinct of generation (with its organ) is generally deve-
loped and manifested later than other inclinations. Thus, the
memory of names usually grows weak sooner than the other
faculties.’

‘“2. When, in the same individual, a quality or faculty is more or
less active (and its corresponding cerebral part more or less de-
veloped) than the others. Thus, the greatest sculptors, painters,
designers, have sometimes not the least disposition to music; the
greatest poets little talent for mathematics.’

‘“3. When a single quality or faculty is active, whilst the others
are paralysed (and only the corresponding organ developed).
Thus, persons imbecile in every other respect, are often violently
impelled by physical love, or have a great talent for imitation, &c.’

‘“4. When, all the other qualities and faculties being active
(and all the other organs sufficiently developed), one single quality
or faculty is inactive (and one single organ not developed). Thus,
certain individuals cannot comprehend that two and two make
four; others detest music, or women.’

‘“5. When, in mental diseases, one quality or faculty only suffers,
or one only is entire. Thus, one insane person is mad only in
regard to religion, to pride, &c.; another, although mad in every
respect, still gives lessons in music with great intelligence.’

‘“6. When the same quality or faculty is quite differently mani-
fested in the two sexes of the same species of animal (and the
organ is differently developed in the two). Thus, the love of off-
spring (with its organ) is more developed in the females of most
animals: thus, among singing birds, the male only sings (and has
the organ well developed).’

‘“7. Lastly, when the same quality or faculty (and the same
organ) always exists in one species and is deficient in another.
Thus, many species of birds, the dog, the horse, &c. have no in-
clination (nor organ) for construction, though so strikingly mani-
fested in other kinds of birds, in the squirrel, in the castor. Thus,
certain kinds of animals are predaceous, migrate, sing, take care
of their young, while other kinds are frugivorous, lead stationary
lives, do not sing, abandon their offspring.”’h

Perception, memory, judgment, &c. are modes of action of
these distinct faculties. ‘“As often as there exists a fundamental
faculty, a particular and determinate intellectual power, there
[Seite 46] necessarily exists likewise a perceptive faculty for objects related
to this faculty. As often as this faculty is active upon the objects
of its option, there is attention. As often as the ideas or traces
which the impressions of objects have left in the brain are re-
newed, either by their presence, or in the absence of these
same objects, there is remembrance, reminiscence, passive memory.
If this same renewal of received impressions takes place by an
act of reflection, by a voluntary act of the organs, there is active
memory.
As often as an organ or a fundamental faculty compares
and judges the relations of analogous and dissimilar ideas, there
is comparison, there is judgment. A series of comparisons and
judgments constitutes reasoning. As often as an organ or a fun-
damental power creates, by its own inherent energy, without the
concurrence of the external world, objects relative to its func-
tions; as often as the organ discovers, by its own activity, the
laws of the objects related to it in the external world, there is
imagination, invention, genius.’

‘“Whether, now, we consider perception, attention, memory, re-
miniscence, recollection, comparison, judgment, reasoning, imagin-
ation, invention, genius, either as gradations of different degrees
of the same faculty, or as peculiar modes of being of this faculty,
it still remains certain, that all the fundamental faculties which
have been demonstrated, are endowed, or may be endowed, with
perception, attention, memory, recollection, judgment, imagin-
ation; and that, consequently, it is they which ought to be con-
sidered intellectual and fundamental faculties, and that the
pretended mental faculties of my predecessors are only common
attributes. Here, then, is a perfectly new philosophy of the
intellectual faculties, founded upon the details of the natural
history of the different modifications of human intellect. The
same may be said of the appetitive faculties or rather qualities.”’i

‘“When a person has the talent for music, poetry, construction,
judging of distance, &c. in only a weak degree, he will not have a
very decided inclination for those objects. If, on the other hand,
the organs of these fundamental forces are more energetic, the
person feels a pleasure in the exercise of their functions; he
has an inclination for these objects. When the action of these
organs is still more energetic, he feels a want to occupy himself
[Seite 47] with them. Lastly, when the action of these organs prepon-
derates, the person is impelled towards these objects; he finds
his happiness in them, and feels disappointed, unhappy, when he
cannot follow his inclination; he has a passion for these objects.
Thus it is that certain individuals have a passion for music,
poetry, architecture, travelling,”’ &c.k

‘“‘‘You shall not persuade me however,’’”’ Gall fancies it will be
said to him, ‘“‘‘that the faculties acknowledged by philosophers as
faculties of the soul, are chimaeras. Who will dispute that under-
standing, will, sensation, attention, comparison, judgment, me-
mory, imagination, desire, liberty, are not real operations of the
soul, or, if you please, of the brain?’’”’ ‘“Yes,”’ replies Gall,
‘“without doubt these faculties are real, but they are mere ab-
stractions, generalities, and inapplicable to a minute study of a
species, or of individuals. Every man, who is not imbecile, has
all these faculties. All men, however, have not the same intel-
lectual or moral character. We must discover faculties, the
various distribution of which determines the various species of
animals; and the various proportions of which explain the
varieties among individuals. All bodies have weight, all have
extension, all have impenetrability; but all bodies are not gold
or copper, all are not any plant, or any animal. Of what use to
the naturalist would be the abstract and general notions of weight,
extension, and impenetrability? If we confined ourselves to
these abstractions, we should still be in the most profound
ignorance of every branch of physics and natural history.’

‘“This is exactly what has happened to philosophers with their
generalities. From the most ancient period down to the present
day, one has not made a single step farther than another in the
precise knowledge of the true nature of man, his inclinations and
his talents, or of the source of his motives and determinations.
Hence we have as many philosophies as soi-disant philosophers:
hence the vacillation and uncertainty of our institutions, especially
of those which relate to education and criminal legislation.”’l

Gall does not pretend to have discovered the ultimate nature
of all the fundamental faculties which he has pointed out. The
poet’s faculty, for example, he regards as distinct and fundamen-
tal, because it has the conditions of a fundamental faculty above
[Seite 48] enumerated, but what are the ordinary functions of that part of
the brain, which, when greatly developed, produces the poet, he
dares not determine.m

Neither does Gall pretend to have enumerated all the funda-
mental faculties of the mind. ‘“Probably,”’ says he, ‘“those who
follow me in the career which I have opened, will discover some
fundamental forces and some organs which have escaped my
researches.”’n

He doubts, however, whether so many will be discovered as
some apprehend. A modification of a faculty must not be mis-
taken for a faculty, nor the result of the combined action of
several faculties for a particular faculty. ‘“If”’ he says, ‘“we
reflect on the number of possible combinations which may result
from the twenty-seven or thirty fundamental faculties or qualities,
from the reciprocal action of as many organs, we shall not be
surprised at the infinite number of shades of character among
mankind. How many different combinations result from the ten
ciphers, from the twenty-four letters.”’o

This view of the mental faculties may be considered quite in-
dependently of the peculiar doctrines of Gall respecting the
cerebral organs of each faculty, and even quite independently of
the fact of the brain being the organ of the mind. It may be
examined precisely like the metaphysics of Locke, Reid, Stewart,
Brown, &c.p

[Seite 49]

It, however, derives its great proofs from the fact of the indivi-
dual faculties being, caeteris paribus, strong in proportion to the
development of particular parts of the brain, as we shall see in
Sect. XII.; and these facts suppose the other general fact of
the brain being the organ of the mind.

On the subject of paragraph (73), I shall speak in the Note
(F), Sect. XLIV.

Every sentiment and propensity was given us for a good pur-
pose, and it is only when one or more are excessive, or defective,
or too much or too little excited by external circumstances, or by
disease, that error occurs; and on this subject the profound
metaphysical sermons, preached at the Rolls Chapel by the exem-
plary Bishop Butler,q and an essay on the constitution of man by
Mr. George Combe,r highly deserve perusal. The natural tend-
ency of all our united faculties and feelings, the Bishop proves, is
to virtue; and Mr. Combe ably and beautifully shows, by nu-
merous illustrations, that obedience to the laws of nature, in
strict accordance with phrenology, is the only source of virtue and
of the happiness of individuals and nations.

SECT. VI.
OF HEALTH AND HUMAN NATURE.

[Seite 50]

74. Since health,a which is the true subject of physiology,
depends upon such an harmony and equilibrium of the matter
and powers of the system, as is requisite for the due perform-
ance of its physical functions, it is very evident how the four
principles, examined above, contribute to its support.

75. Fluids properly prepared are the first requisite; in the
next place, solids duly formed from the fluids; then the invi-
gorating influence of the vital powers upon the solids; lastly,
a sound mind in this sound body.

76. These four principles act and react perpetually upon
each other. The fluids are stimuli to the solids; these again
are calculated by their vital powers to experience the influence
of these stimuli, and to react upon them. In reference to the
intimate union of the mind with the body, suffice it at present
to remark, that it is far more extensive than might at first
be imagined. For instance, the influence of the will is not con-
fined within the narrow limits of those actions designated
voluntary in the schools of physiology; and the mind, on
the other hand, is influenced by the affections of the body, in
many other ways than by the perceptions of sense, properly
so called.b

77. From the endless variety and modification of the con-
ditions belonging to these four principles, it may be easily
[Seite 51] understood what great latitudec must be given to the notion
of health.

For since, as Celsus long ago observed, almost every one
has some part weaker than the rest, Galen may in this sense
assert with truth, that no one enjoys perfect health.

And even among those who, in common language, we say
are in good health, this is variously modified in each indi-
vidual.d

78. Upon this endless modification is founded the differ-
ence of temperaments;e or, in other words, of the mode and
aptitude of the living solidf in each individual, to be affected
by stimuli, especially the mental; and again, of the mental
stimuli, to be excited with greater or less facility.

79. So various are the differences of degree and combin-
ation in the temperaments, that their divisions and orders may
be multiplied almost without end. We shall content our-
selves with the four orders commonly received:g – The san-
guineous,
– excited most readily, but slightly; The choleric,
excited readily and violently; The melancholic, – excited
slowly, but more permanently; And the phlegmatic, – excited
the most slowly of all, and indeed with difficulty. (A)

This division, although built by Galen upon an absurd
foundation derived from an imaginary depravation of the
[Seite 52] elements of the blood, appears, if made to stand alone, both
natural and intelligible.

80. The predisposing and occasional causes of the diver-
sity of temperaments are very numerous, v. c. hereditary ten-
dency, habit of body, climate, diet, religion, mode of life, and
luxury.h

81. Besides the variety of temperaments, circumstances
to which every individual is exposed, increase, by influencing
the number, as well as the energy and vigour, of the functions,
the latitude (77) in which the term health must be received.
In regard to age, the health of a new-born infant is different
from that of an adult; in regard to sex it differs in a mar-
riageable virgin and an old woman past child-bearing, and
during menstruation and suckling; in regard to mode of life,
it is different in the barbarous tribes of North America and in
effeminate Sybarites. Moreover, in every person, custom
(whose great power has obtained for it the title of second
nature) has an extraordinary influencei over every function,
v. c. sleep, diet, &c.

82. The more functions flourish simultaneously in the
body, the more considerable is its life; and vice versâ. Hence
life is the greatest when the functions have attained their
highest exaltation in adult age; and least when the functions,
although very perfect according to the course of nature, are
fewer and more sluggish, v. c. in the newly conceived embryo;
life is for the same reason less vigorous during sleep than
during the opposite state, &c.

83. The functions have been long divided by physiologists
into four classes.k This division, although not unexception-
[Seite 53] able, nor exactly conformable to nature,l may assist the me-
mory.m

1. The first class comprehends the vital functions, so
termed, because their uninterrupted and complete perform-
ance is necessary to life; such are the circulation of the blood
and respiration.

2. The second comprehends the animal functions, by which
animals are chiefly distinguished from vegetables; such is the
communication of the mind with the body, especially sense,
and muscular motion.

3. The third is the natural, by means of which the body is
nourished.

4. The fourth, the genital, intended for the propagation of
the species.

We shall now examine each of these separately; beginning
with the vital. (B)


NOTES.

(A) The sanguineous temperament is denoted by a full habit,
and rather soft fibre, a delicate skin, with large veins, a fresh
complexion; often red or yellow, and, occasionally, darkish hair;
great sensibility, a quick pulse, free secretions, and a cheerful
disposition.

The melancholic, on the contrary, often by a spare habit, by a
firm fibre, a thick, dark, hairy skin, black hair and eyes, and a
dark complexion: a slow pulse, little sensibility, sparing secre-
tions, and a gloomy cast of character; great perseverance in all
pursuits, and constancy of passion.

The choleric lies between the two, and is marked by a softer
fibre, a more irritable habit, a less dark and hairy skin, a more
[Seite 54] florid countenance, a quicker and stronger pulse, and a more irrit-
able mind than the melancholic.

The phlegmatic is characterised by a lax and weak habit, a
pale smooth skin generally destitute of hair, very light hair upon
the head, a slow weak pulse, small blood-vessels, languid secre-
tions, and dulness of mind and feeling.n

The cheerfulness of the sanguineous temperament, and the
gloom and constancy of the melancholic, are subject to great
exceptions, as they depend entirely upon the developement of
certain parts of the brain.o

A new view of temperaments has lately been published by Dr.
Thomas, of Paris.p He arranges them according to the predo-
minance of the head, chest, or abdomen, – the mental, circula-
tory, or digestive organs: so that we have, – 1. The cranial or
encephalic temperament: 2. The thoracic: 3. The abdominal: with
their combinations, 4. The encephalo-thoracic: 5. The encephalo-
abdominal: 6. The thoracico-abdominal; and, lastly, 7. The mixed,
in which all three are equally blended. Men of genius or enter-
prise are of the first, Hercules may represent the second, Bacchus
the third, and the Apollo Belvidere the last.

According to the relative bulk of the three regions, will
be the relative energy of the mental, muscular, or abdominal
functions.

The idea is exceedingly ingenious, and capable of extensive
applicationq; but evidently does not interfere with the established
view of temperaments. For every individual is, throughout his
frame, of the sanguineous, or melancholic, &c., and at the same
time has a particular proportion of each of the three regions to
each other.

(B) The consideration of a division, as ancient as Aristotle,
and by some considered preferable to that which Blumenbach
adopts, will perhaps form an useful note to the eighty-third
paragraph and the greater part of the fourth section.

In this, the functions are arranged in two classes: – the animal
constituting one peculiar to animals; and the vital and natural
[Seite 55] united into another, common to vegetables and animals, under
the title of organic or vital. The generative, relating in their
object to the species rather than to the individual, and of but
temporary duration, are thrown into a separate and inferior divi-
sion, but in fact, except the animal passion, are part of the organic.

We owe the revival of this classification, and our knowledge
of the characteristics of each class of functions, to Dr. Wilson
Philip,r and Xavier Bichat,s although the latter, from having
published a work expressly on the subject, has received the whole
honour, both in Great Britain and on the Continent.

The animal functions prove us feeling, thinking, and willing
beings: they are the actions of the senses which receive impres-
sions; of the brain which perceives them, reflects upon them, and
wills; of the voluntary muscles which execute the will in regard
to motion; and of the nerves which are the agents of transmission:
The brain is their central organ. The vital or organic functions
are independent of mind, and give us simply the notion of life:
they are digestion, circulation, respiration, exhalation, absorption,
secretion, nutrition, calorification: The heart is their central
organ.

The organs of the animal functions are double and correspon-
dent, there being on each side of the median line of the body,
either two distinct organs, as the eyes, ears, extremities; or two
correspondent halves, as is the case with the brain, spinal marrow,
nose, tongue, &c.

The organs of the vital or organic functions, are, in very few
instances, double, or situated with their centres in the median
line, and possessed of symmetrical halves; v. c. the heart,
stomach, liver. There are, indeed, two kidneys, but they con-
tinually differ in size, figure, and situation: the two lungs are
very dissimilar.

Hence Bichat infers, that in the animal functions a harmony of
action in each organ, or in each half of the organ, is indispensable
to perfection, when both organs or sides act together; and that
if such harmony do not occur, it is better for one organ or one
[Seite 56] half to act alone. This certainly appears true of the eye,
and ear, and even of the brain. It certainly does not hold good
in the actions of the voluntary muscles, nor in the operations of
the brain or spinal marrow in willing those actions. From the
duplicity of the organs it also happens that one side may cease
to act without detriment to the function of the other; while, in
the vital or organic class, no harmony of action is possible, and
the derangement of any one part of an organ generally affects the
whole of it, – an obstruction in the colon disturbs the functions
of all the alimentary canal.

The animal functions experience periodical intermissions –
sleep. The organic or vital continue incessantly, suffering merely
remissions: – the blood constantly circulates, the perspiratory
fluid is constantly secreted, the stomach has no sooner digested
one meal than we commit another to it; yet we shall hereafter
see that the actions of the heart, lungs, &c., have intervals of
remission.

The animal functions are much influenced by habit; the vital
or organic are considered by Bichat as removed from its influence.
The power of habit over our sensations and voluntary motions
is manifest: yet I think it equally great over the organic func-
tions. The operation of food and of all descriptions of ingesta
is most remarkably modified by habit; through it poisons become
comparatively innoxious, and divers bear a long suspension of
respiration.

Bichat regards the passions as directly influencing the organic
functions only, and springing from the state of the organs of
that class. Here he is to me perfectly unintelligible. Vexation
indeed disturbs the stomach, and fear augments the quantity of
urine; but does not vexation equally and as directly disturb the
mind, – confuse the understanding, and occasion heat and pain
of the forehead? Are not, in fact, the passions a part of the
mind? – a part of the animal functions? They powerfully affect,
it is true, the organic or vital functions, but this shows the close
connection merely between the two classes of functions.t

[Seite 57]

This connection is conspicuous in respiration, the mechanical
part of which belongs to the animal functions, the other to the
organic; and in the alimentary functions, in which the food is
swallowed and the faeces rejected by volition, and digestion, &c.
performed, independently of our influence, by the powers of
simple life. So close indeed is this connection, that every organ
of the animal class is the seat of organic functions; – in the vo-
luntary muscles, the organs of sense, and even in the brain,
circulation, secretion, and absorption are constantly carried on.
This connection is likewise apparent in the property of sensibility.
In the language of Bichat there are animal sensibility and contrac-
tility,
and organic sensibility and contractility, besides the common
extensibility of matter, which he terms extensibilité de tissu, and
common contractility upon the removal of distension, – con-
tractilité par défaut d’extension,
confounded by Blumenbach
(58. clause 5 and 6) with purely vital contractility, and, indeed,
greater during life than afterwards.u Animal sensibility is accom-
[Seite 58] panied by a perception in the mind, as in seeing, hearing, tasting,
smelling, feeling: animal contractility is excited by the volition
of the mind conveyed to the voluntary muscles by means of the
[Seite 59] nerves. Organic sensibility is attended by no perception, and is
followed by contraction totally independent of the will: – the
[Seite 60] heart is said to feel – (physiology has no proper term for the
idea, but excitability would answer the purpose) – the stimulus of
the blood, and, without our influence, forthwith contracts; the
lacteals to feel the stimulus of the chyle without our knowledge,
and they then propel it without our assistance.x But although we
never acquire the least direct voluntary power over the actions of
organic contractility, – over the peristaltic motion of the in-
testines or the contractions of the heart, yet every organ of
the organic functions may have its organic sensibility height-
ened into animal sensibility, as inflammation, for instance, of the
pleura and the joints, daily demonstrates; indeed, in some organs
of that class of functions, we invariably have sensation; – the
stomach is the seat of hunger, in the lungs we experience an un-
easy sensation nearly as soon as their air is expelled.

The nerves of the animal functions run to the brain or spinal
marrow; those of the organic chiefly to ganglia; but, as might
be expected, the two nervous systems have abundant commu-
nications.

The animal functions have not only a shorter existence than
the organic, from their necessity of alternate repose,y but they
flourish for a shorter duration, – they do not commence till birth,
they decline, and in the natural course of events, terminate,
earlier, v. c. the organs of sense and the mental faculties fail before
the action of the heart and capillaries. But the decay of the
animal functions must, in truth, be only the consequence of the
decay of the organic, because there are fundamentally in every
part organic functions, – circulation, nutrition, &c.; and the perfect
performance of these in the organs of the animal functions is in-
dispensable to the perfect performance of the animal functions.
[Seite 61] Hence the impairment of these organic functions, even to a small
extent, must derange or diminish the animal functions, and the
decline of the latter is really owing to the decline of the former,
although these still remain vigorous enough to appear unimpaired.

We thus find in every living system a class of functions, not
in themselves dependent upon mind, as perfect in the vegetable
as in the animal, and pervading every part of the system. In
animals there further exist certain parts which, when endowed
with the common life of other parts, – with the organic pro-
perties, – are able to perform peculiar functions which give us the
notion of mind: the organ of these functions is termed brain, and,
by means of nerves and medullary prolongations, it maintains a
correspondence with the whole machine, influenced by and
influencing the most distant parts. The phenomena of the mind
have been metaphysically considered in the fifth section; they
will be examined as functions of the nervous system in the
twelfth.

The organic functions depend on life, in the proper accept-
ation of the word. The word life should be regarded, like the word
attraction or repulsion, as merely an expression of a fact. In this
point of view it may be as easily defined as any other expression.
By life we generally mean the power of organised matter to pre-
serve its particles in such chemical relations as to prevent other
chemical relations from inducing disorganisation, or even to
increase or decrease by internal appropriation and separation;
to produce peculiar matters for its own purposes; to preserve, in
some measure, a temperature distinct from that of the surrounding
medium; to move certain parts of itself sensibly (as muscles) or
insensibly (as the capillaries) independently of mere impulse,
attraction, or repulsion: or if not organised (as the fluid which
becomes the embryo, the blood,) the power of matter produced by
an organised body endowed with the properties above mentioned,
to resist the ordinary chemical influences, and even directly form
(as the embryotic fluid) an organised system so endowed, or
directly become (as the fibrin, when it is secreted from the blood or
blood is effused, becoming vascular, and its new vessels inosculat-
ing with those of adjoining parts), the organised substance of an
already formed system so endowed.

That fluids as well as solids are susceptible of life, I cannot
doubt. There is no reason why they should not be so, although
[Seite 62] a person who has not thought upon the subject may be as unable
to conceive the circumstance as a West Indian to conceive that
water may by cold become solid. It is impossible to deny that
the male or female, or both, or united, genital fluids are alive, be-
cause from their union, or one influenced by the other, a living
being is produced which partakes of the vital qualities of each
parent. Accordingly Blumenbach, in his Commentatio de vi vitali
sanguini deneganda,
grants both male and female genital fluids to
be alivez, notwithstanding that he fancies his victory over the
defenders of the blood’s life so complete, that like that of the un-
fortunate Carthaginian Dido, as he says, ‘“in ventos vita recessit.”’
It is as easy to conceive the blood to be alive as the genital fluids.a

Many facts adduced as arguments of its life are certainly explic-
able without such a supposition. Its freedom from putrefaction while
circulating may be owing to the constant renovation of its particles,
for the thinness of hybernating animals at the end of their torpid
[Seite 63] season, shows it has received accessions even in them and from
the absorption of fat. Its inability to coagulate after death from
arsenic, opium, and some other narcotics, and from lightning
and electricity (though Dr. Scudamore found it to coagulate as
usual in the latter case), from hard running, anger, or a blow on
the stomach, all three of which deprive the muscles of their usual
stiffness, may depend upon chemical changes. The admixture of
opium with the blood has been said to prevent its coagulation,
and this by destroying its life. But Dr. Scudamore found that the
admixture of prussic acid and belladonna, both strong poisons,
has no such effect, and that many mere salts, as common salts,
weaken or prevent its coagulation, and these are not likely to kill
it, but to act chemically. Its accelerated coagulation by means of
heat, when frozen by cold, and some other circumstances, and the
reverse, were believed to depend upon an affection of its vitality,
but are, perhaps, referable to the escape or detention of its car-
bonic acid gas. Its earlier putridity when drawn from young than
from old persons may arise from its inferior qualities. Parts die
if deprived of a supply of blood, yet, though necessary as a
material and agent to maintain the life of parts, it is not, therefore,
necessarily itself alive. But the circumstance of it freezing more
readily, like eggs, frogs, snails, &c., when once previously frozen,
(which change may be supposed to have exhausted its powers,b)
is, if really the case, an argument in favour of its life, as
these are certainly endowed with life. The organisation of
extravasated blood,c and the inosculation of new vessels with
those of surrounding parts, showsd that the solidified lymph
is now endowed with life; and one may more easily believe it to
have been alive in the mass of blood, than that it should have
acquired vitality after its effusion. Indeed Sir Everard Home
declares that a coagulum of blood becomes vascular out of the
body and may be injected;e but if the vessels are formed by the
[Seite 64] mere extrication of carbonic acid gas, as he contends, their mere
formation is no proof of life.

John Hunter believes that the chyle is alive, and some that
vivification commences even in the stomach, and Albinus grants
life even to the excrement. But the excretions must be regarded
as dead matter, useless and foreign to the system, and they all
run with the greatest rapidity into decomposition. In operating
for retention of urine, the surgeon finds this fluid abominably
foetid; the faeces become so when not discharged in due time;
and the neglect of washing the surface is the source of filth and
disease.

The essential nature of life is an impenetrable mystery, and no
more a subject for philosophical inquiry than the essential nature
of attraction or of heat. To attempt explaining the phenomena
of life by a vital fluid is only increasing the intricacy of the
subject by an unfounded hypothesis, and always reminds me of
Mr. Dugald Stewart’s remark, – ‘“That there is even some reason
for doubting, from the crude speculations on medical and chemical
subjects which are daily offered to the public, whether it (the
proper mode of studying nature) be yet understood so completely
as is commonly imagined, and whether a fuller illustration of the
rules of philosophising, than Bacon or his followers have given,
might not be useful even to physical inquirers.”’f We see matter
in a certain state possessed of a certain power which we term life,
and the object of physiology is merely to observe its effects, just
as it is the object of chemistry to observe the circumstances of
the affinity of different bodies and of physics to observe other
phenomena of matter, without vainly speculating on the essence
of affinity or the essence of matter, to comprehend which our
faculties are, in their nature, incompetent. By attributing life,
the power of attraction, &c. to subtle and mobile fluids, we not
only do not advance a single step, for we have still to explain
what these fluids are, and how they obtain their powers, just as we
had before in regard to common matter; but we make the addi-
tional mysteries of their being united with ordinary matter, and
so united that life appears a power possessed by it. The editors
of a medical review have in vain searched John Hunter’s works
[Seite 65] for such an hypothesis,f and Mr. Lawrence has had no better
success,g so that I apprehend his meaning has been misunderstood
by those who constitute him its patron.h Granting for a moment
that life depends upon a peculiar, fine fluid, we have still to
account for mind, because life is not mind, – a cabbage is as much
gifted with life as the wisest man. Yet those whose faith makes
life a subtle fluid strangely imagine that the doctrine of a soul is
thereby advanced. The life of a brute requires a subtle fluid as
much as the life of a man, and of a cabbage as much as the life of
a brute.

We have reason to believe that life never originates, but began
at the creation, and is communicated to assimilated matter and
propagated from parent to offspring (XLII. D). It is the property
of organised systems, producing various effects by various kinds
of organisation, but is not quite peculiar to organised matter,
because capable of being possessed by matter in a fluid state.i

The animal functions demonstrate mind. This is seated in
the brain, to which the spinal marrow, nerves, and voluntary
muscles are subservient. Mind is the functional power of the
[Seite 66] living brain. As I cannot conceive life any more than the power
of attraction unless possessed by matter, so I cannot conceive
mind unless possessed by a brain, or by some nervous organ,
whatever name we may choose to give it, endowed with life.
(XLIV. F). I speak of terrestrial or animal mind; with angelic and
divine nature we have nothing to do, and of them we know, in the
same respects, nothing. To call the human mind positively a
ray of the divinity, (Divinae particula aurae,k Ex ipso Deo decerp-
tus, Ex universa mente delibatus
l) appears to me absolute non-
sense. Brutes are as really endowed with mind, – with a con-
sciousness of personality, with feelings, desire, and will, as man.m
Every child is conscious that it thinks with its head, and common
language designates this part as the seat of mind.n Observation
shows that superiority of mind in the animal creation is exactly
commensurate with superiority of brain (XLIV. F);o that activity
[Seite 67] of mind and of brain are coequal; and that as long as the brain
is endowed with life and remains uninjured, it, like all other
[Seite 68] organs, can perform its functions, and mind continues; but, as
in all other organs, when its life ceases, its power to perform its
function ceases, and the mind ceases; when disease or mechanical
injury affects it, the mind is affected, – inflammation of the stomach
causes vomiting, of the brain delirium, a blow upon the loins
causes nephritis or haematuria, a blow upon the head stuns; if ori-
ginally constituted defective, the mind is defective;p if fully
developed and properly acted on, the mind is vigorous; accordingly
as it varies with age, in quality and bulk, is the mind also varied, –
the mind of the child is weak and very excitable, of the adult
vigorous and firm, and of the old man weak and dull, exactly like
[Seite 69] the body;q and the character of the mind of an individual agrees
with the character of his body, being equally excitable, languid,
or torpid, evidently because the brain is of the same character as
[Seite 70] the rest of the body to which it belongs, – the female mind ex-
ceeds the male in excitability as much as her body;r the qualities
of the mind are also hereditary,s which they could not be, unless
they were, like our other qualities, corporeal conditions; and the
mind is often disordered upon the disappearance of a bodily com-
plaint, just as other organs, besides the brain, are affected under
similar circumstances, – the retrocession of an eruption may affect
the lungs, causing asthma, the bowels, causing enteritis, or the
brain, causing insanity, – phthisis and insanity sometimes alter-
nate with each other, just like affections of other organs; the
laws of the mind are precisely those of the functions of all other
organs, – a certain degree of excitement strengthens it, too
much exhausts it, physical agents affect it, and some specifi-
cally, as is the case with other functions, for example, narcotics.
The argument of Bishop Butler, that the soul is immortal and
independent of matter, because in fatal diseases the mind often
[Seite 71] remains vigorous to the last,t is perfectly groundless, for any
function will remain vigorous to the last if the organ which
performs it is not the seat of the disease, nor much connected
by sympathy or in other modes with the organ which is the seat
of the disease, – the stomach often calls regularly for food and
digests it vigorously, while the lungs are almost completely con-
sumed by ulceration. All the cases that are adduced to prove
the little dependence of the mind upon the brain, are adduced in
opposition to the myriads of others that daily occur in the usual
course of nature, and are evidently regarded as extraordinary
by those who bring them forward. An exact parallel to each
may be found in the affections of every other organ, and each
admits of so easy an explanation that it may be always truly
said, ‘“Exceptio probat regulam.”’u

[Seite 72]

I have placed the preceding arguments alone, but to them may
be subjoined another equally demonstrative as any, – that the
strength of the various intellectual powers and inclinations ac-
cords with the size of the various parts of the brain; that ex-
actly as the various parts of the brain are successively developed
is the character developed, and as they shrink with age does the
character again change.

In contending that the mind is a power of the living brain, and
the exercise of it the functions of that organ, I contend for merely
a physical fact, and no Christian who has just conceptions of the
Author of Nature will hesitate to look boldly at Nature as she is,
lest he should discover facts opposite to the pronunciations of
his revelation; for the word and the works of the Almighty cannot
contradict each other. Lord Bacon accordingly, in a very memor-
able part of his writings, directs the physical enquirer to be unin-
fluenced by religious opinions,x as the more independently truth
is pursued the sooner will it be gained, and the sooner will the
real meaning of the divine statement of natural things, and the
conformity of this to physical fact, be established.

The assertion, however, that the mind is a power of the living
brain, is not an assertion that it is material, for a power or property
of matter cannot be matter.

[Seite 73]

Neither is it an assertion that this power cannot be a something
immortal, subtle, immaterial, diffused through and connected with
the brain. A physical enquirer has to do with only what he
observes. He finds this power, but attempts not to explain it.
He simply says the living brain has this power, medullary matter
though it be. Seeing that the brain thinks, and feels, and wills, as
clearly as that the liver has the power of producing bile, and does
produce it, and a salt the power of assuming a certain form,
and does crystallise, he leaves others at liberty to fancy an
hypothesis of its power being a subtle, immaterial, immortal
substance, exactly as they fancy life to be a subtle fluid, or,
perhaps, though very extraordinarily, the same subtle fluid (if
subtlety is immateriality and immortality),y elucidating the subject
no more than in the case of life, and equally increasing the num-
ber of its difficultiesz (p. 64.); as though we were not created
[Seite 74] beings or not altogether ignorant what matter is, or of what it is
capable and incapable; as though matter exhibited nothing but
extension, impenetrability, attraction, and inertness; and as
though an Almighty could not, if it seemed good to him, have
endowed it, as he most evidently has, with the superaddition of
life, and even of feeling and will.a

Nor does this assertion imply that the resurrection from the
dead is impossible or even improbable. The physical enquirer,
finding the mind a power of the brain, and abstaining from
hypothesis, must conclude that, in the present order of things,
when the brain ceases to live the power necessarily ceases, – that,
[Seite 75] in the language of scripture, Dust we are and unto dust we all
return, – that our being is utterly extinguished and we go back
to the insensibility of the earth whence we were taken.b Our
consciousness of personality can afford no reason for imagining
ourselves immortal and distinct from earth, more than brutes,
for this the fly possesses equally with the philosopher about
whose head it buzzes.c The moral government of the world,
the sublime reach of our acuteness, the great improvableness of
our characters, –

‘“–––– this pleasing hope, this fond desire,’
‘This longing after immortality,’
‘–––– this secret dread and inward horror’
‘Of falling into nought,”’d

have been thought to completely harmonise with a life hereafter,
but certainly fall so short of proof as to have left the wisest of
antiquity, – Solomon, Socrates, Cicero, &c. – in uncertainty,e
when they saw how death reduces us to our pristine elements.
The hope of immortality inspired by such reflections, assisted by
the desire of explaining every thing in some way or other, first,
I apprehend, made men attempt to find, in the imagined ethereal
essence of the soul, a reason for our not totally perishing as our
senses would lead us to suppose. But, because we refuse to
listen to a mere hypothesis respecting spirit, we are not necessa-
rily
to deny the resurrection. For if a divine revelation pronounce
that there shall be another order of things in which the mind shall
exist again, we ought firmly to believe it, because neither our
experience nor our reason can inform us what will be hereafter,
and we must be senseless to start objections on a point beyond
the penetration of our faculties.f The scripture so pronounces,
[Seite 76] – not that we are naturally immortal, but that ‘“in Adam (by
nature) all die,”’g – have our being utterly extinguished,h and in
another order of things, – when the fashion of this world shall
have passed away and time shall be no more, that in Christ (by
the free, additional, gift of God, granted through the obedience
of Christ, but, consequently, by a miracle, not by our nature,i) –
we shall all again be made alive. St. Paul declares the resurrec-
tion to be ‘“a mystery:”’ it must, in truth, be a miracle, and there-
fore the enquiry ‘“how can these things be”’, altogether fruitless.
The miracle of Christ’s resurrection, to which the scriptures refer
us as the foundation of the hope of a future state, would not have
been necessary to convince us of a necessary truth, discoverable
by sense and reason. That the promises of the New Testament
are the proper and only foundation of our hopes of immortality,
was the opinion of the late Regius Professor of Divinity in the
University of Cambridge, whose powerful intellect and sincere
love of truth render his opinions weightier than the decrees of
councils. ‘“I have no hope of a future existence,”’ says he,
‘“except that which is grounded on the truth of Christianity.”’k
[Seite 77] While those are wrong who think there can be any thing like an
argument against a future life in another order of things, if de-
clared by a revelation, it is strange that others should think it
necessary to attempt rendering the pronunciations of scripture
more probable, and that by an hypothesis which is at best but the
remains of unenlightened times,l and should require any as-
[Seite 78] surance besides that of the gospel, which, they read, ‘“has
[Seite 79] brought life and immortality to light.”’m They should reflect
that the belief of an immaterial substance removes no imagined
difficulty, as it is the peculiar doctrine of scripture, in distinction
to that of all the heathen philosophers and people,n that the
resurrection will be positively of body, – that in our flesh we shall
see God,o and that therefore our minds must appear as much a
property of body hereafter as at present.p

[Seite 80]

This only, the christian, doctrine of a future state is reason-
able. The heathen doctrine was grounded on the supposed in-
herent immortality of a supposed substance distinct from the body.
The christian doctrine teaches the resurrection of what we obvi-
ously are – bodies, and that through a miracle of the Almighty.q

SECT. VII.
ON THE MOTION OF THE BLOOD.

[Seite 81]

84. The blood, to whose great and multifarious import-
ance in the system we have slightly alluded (16), is conveyed,
with a few exceptions (5), into the most internal and extreme
recesses. This is proved by the minute injection of the ves-
sels, and by the well known fact of blood issuing from almost
every part on the smallest scratch.

85. This red fluid does not, like an Euripus, ebb and flow
in the same vessels, as the ancients imagined, but pursues a
circular course; so that being propelled from the heart into
the arteries, it is distributed throughout the body, and returns
again to the heart through the veins.a

86. We shall, therefore, say something at present of the
vessels which contain the blood; and afterwards, of the powers
by which they propel and receive it.

87. The vessels which receive the blood from the heart
and distribute it throughout the body, are termed arteries.

These are, upon the whole, less capacious than the veins:
but in adult, and advanced age especially, of a texture far
more solid and compact, very elastic and strong.

88. The arteries consist of three coats:b

[Seite 82]

I. The exterior, called, by Haller, the tunica cellulosa
propria
; by others, the nervous, cartilaginous, tendinous, &c.
It is composed of condensed cellular membrane, externally
more lax, internally more and more compact: blood vessels
are seen creeping upon it:c it gives very great tone and
elasticity to the arteries.

II. The middle coat consists of transverse fibres,d lunated
or falciform, and almost of a fleshy nature: hence this has the
name of muscular coat, and appears to be the chief seat of
the vital powers of the arteries.

III. The inner coat lining the cavity of the arteries is
highly polished and smooth.

This is much more distinct in the trunks and larger
branches than in the smaller vessels.

89. Every artery originates, either

From the pulmonary artery (the vena arteriosa of the
ancients), which proceeds from the anterior ventricle of the
heart and goes to the lungs;

Or from the aorta, which proceeds from the posterior ven-
tricle and is distributed throughout the rest of the system.

These trunks divide into branches, and these again into
twigs, &c.

90. According to the commonly received opinion, the
united capacity of the branches in any part of the sanguiferous
system, is greater than that of the trunk from which they
arise. But I fear that this is too general an assertion, and
even that the measure of the diameter has been sometimes
improperly confounded with that of the area. I myself have
never been able to verify it, although my experiments have
been frequently repeated, and made, not on vessels injected
with wax, after the bad example of some illustrious physiolo-
gists, but on the undisturbed vessels of recent subjects, v. c.
on the innominata and its two branches – the right carotid
[Seite 83] and subclavian, on the brachial and its two branches – the
radial and ulnar.e

The inconstancy of the proportion between the capacity of
the branches and that of the trunks is clearly shown by the
various sizes of the vessels under different circumstances, v. c.
by the relative capacity of the inferior thyreoid artery in the
infant and the adult; of the epigastric artery in the virgin
and the mother near her delivery; and also of the uterine
vessels in the virgin and the pregnant woman; of the omental
vessels during the repletion and vacuity of the stomach.f

91. The arteries, after innumerable divisions and important
anastomosesg connecting different neighbouring branches,
terminate at length in the beginning of the veins. By this
means, the blood is conveyed back again to the heart. The
distinction between artery and vein, at the point of union,
is lost.

In the present state of our knowledge, the umbilical vessels
are to be regarded as the only exception to the termination of
arteries in veins. We shall show that they are connected
with the uterine vessels by the intervention of a spongy sub-
stance, called parenchyma.

92. Another description of vessels arise universally from
the arteries, and are called colourless, from not containing pure
blood, either on account of their minuteness, or of their
specific irritability which causes them to reject that fluid.
Such are the nutrient and other secretory vessels: of which
hereafter.

[Seite 84]

The blood conveyed from the heart throughout the
body by the arteries is carried back by the veins.h

These are very different in function and structure from the
arteries, excepting, however, the minutest of both systems,
which are indistinguishable.

94. The veins, except the pulmonary, are universally
more capacious than the arteries; more ramified; much
more irregular in their course and division; in adult age,
softer and far less elastic, but still very firm and remarkably
expansile.

95. Their coats are so much thinner that the blood appears
through them. They are likewise less in number, being
solely a cellular external, somewhat resembling the nervous
of the arteries; and a very polished internal, also nearly
agreeing with that of the arteries.

A muscular coat exists only in the trunks nearest the
heart.

96. The interior coat forms, in nearly all veins of more
than a line in diameter, very beautiful valves, of easy play,
resembling bags, generally single, frequently double, and
sometimes triple, placed with their fundus towards the origin
of the vein and their edge towards the heart.

These valves are not found in some parts; not in the
brain, heart, lungs, secundines, nor in the system of the vena
portae.

97. The twigs, or, more properly, the radicles, of the
veins, unite into branches, and these again into six principal
trunks: viz.

Into the two cavae, superior and inferior:

And the four trunks of the pulmonary vein (the arteria
venosa of the ancients).

The vena portae is peculiar in this, that, having entered
the liver, it ramifies like an artery, and its extreme twigs pass
[Seite 85] into the radicles of the inferior cava, thus coalescing into a
trunk.

98. That the blood may be properly distributed and circu-
lated through the arteries and veins, nature has provided the
heart,i in which the main trunks of all the blood vessels
unite, and which is the grand agent and mover of the whole
human machine, – supporting this – the chief of the vital
functions, with a constant and truly wonderful power, from
the second or third week after conception to the last moment
of existence.

99. The heart alternately receives and propels the blood.
Receiving it from the whole body by means of the superior
and inferior vena cava, and from its own substance through
the common orifice of the coronary veins, that is supplied
with a peculiar valve,k it conveys that fluid into the anterior
sinus and auricle, and thence into the corresponding ventricle,
which, as well as the auricle, communicates with both orders
of the heart’s own vessels by the openings of Thebesius.l

100. From this anterior, or, in reference to the heart of
some animals, right, ventricle, the blood is impelled through
the pulmonary artery into the lungs: returning from which,
it enters the four pulmonary veins and proceeds into their
common sinus and the left, or, as it is now more properly
termed, posterior, auricle.m

101. The blood flows next into the corresponding ventricle;
and then, passing into the aorta, is distributed through the
arterial system of the body in general and the coronary vessels
of the heart itself.n

[Seite 86]

102. Having proceeded from the extreme twigs of the
general arterial system into the radicles of the veins, and
from the coronary arteries into the coronary veins, it finally
is poured into the two venae cavae, and then again pursues
the same circular course.

103. The regularity of this circular and successive motion
through the cavities of the heart is secured, and any retrograde
motion prevented, by valves, which are placed at the prin-
cipal openings, viz. at the openings of the auricles into the
ventricles, and of the ventricles into the pulmonary artery and
aorta.

104. Thus the ring, or venous tendon, which forms the
limit of the anterior auricle and ventricle, descending into the
latter cavity, becomes these tendinous valves.o These were
formerly said to have three apices, and were, therefore, called
triglochine or tricuspid: they adhere to the fleshy pillars,
or, in common language, the papillary muscles.

105. In a similar manner, the limits of the posterior auricle
and ventricle are defined by a ring of the same kind, forming
two valves, which, from their form, have obtained the appel-
lation of mitral.p

106. At the opening of the pulmonary arteryq and aortar
are found the triple semilunar or sigmoid valves,s fleshy and
elegant, but of less circumference than the mitral.

107. It is obvious how these differently formed valves must
prevent the retrocession of the blood into the cavities which
it has left. They readily permit the blood to pass on, but
are expanded, like a sail, against it, by any attempt at retro-
grade movement, and thus close the openings.

[Seite 87]

108. The texture of the heart is peculiar: fleshy, indeed,
but very dense and compact, far different from common
muscularity.t

It is composed of fasciculi of fibres, more or less oblique,
here and there singularly branching out, variously and
curiously contorted and vorticose in their direction, lying
upon each other in strata, closely interwoven between the
cavities, and bound by four cartilaginous bands at the basis
of the ventricles, which thus are, as it were, supported and
are distinguished from the fibres of the auricles.u

109. These fleshy fibres are supplied with very soft nerves,x
and an immense number of blood vessels, which arise from
the coronary arteries, and are so infinitely ramified,y that
Ruysch described the whole structure of the heart as com-
posed of them.z

110. This universal vital viscus is loosely contained in the
pericardium,a which is a membraneous sac, arising from the
mediastinum, very firm, accommodated to the figure of the
heart, and moistened internally by an exhalation from the
arteries of that organ. Its importance is evinced by its
existence being, in red blooded animals, as general as that of
the heart; and by our having but two instances on record of
its absence in the human subject.b

111. By this structure the heart is adapted for its perpetual
[Seite 88] and equable motions, which are an alternate systole and
diastole, or contraction and relaxation of the auricles and
ventricles in succession. (A)

112. Thus, as often as the auricles contract to impel the
blood of the venae cavae and pulmonary veins into the
ventricles, the latter are at the same moment relaxed, to
receive the blood: immediately afterwards, when the distended
ventricles are contracting to impel the blood into the two
great arteries, the auricles relax and receive the fresh venous
supply.

113. The systole of the ventricles, upon which is said to
be spent 1/3 of the time of the whole action of the heart, is
performed in such a way that their external portions are
drawn towards their septum, and the apex of the heart
towards the base.a This at first sight seems disproved by the
circumstance of the apex striking against the left nipple, and,
consequently, appearing elongated, – a circumstance, how-
ever, to be attributed to the double impetus of the blood
flowing into the auricles and expelled from the ventricles,
by which double impetus the heart must be driven against
that part of the ribs. (B)

114. The impulse imparted by the heart to the blood, is
communicated to the arteries, so that every systole of the
heart is very clearly manifested in those arteries which can
be explored by the fingers and exceed 1/6 of an inch in the
diameter of their canal, and in those also whose pulsation can
be otherwise discovered, as in the eye and ear. The effect
upon the arteries is called their diastole, and is perfectly
correspondent and synchronous with the systole of the heart.

115. The quickness of the heart’s pulsations during health
varies indefinitely; chiefly from age, but also from other
conditions which at all ages form the peculiar constitution of
an individual: so that we can lay down no rule on this point.
I may, however, be permitted to mention the varieties which
[Seite 89] I have generally found in our climateb at different ages,
beginning with the new-born infant, in which, while placidly
sleeping, it is about 140 in a minute.

Towards the end of the first year, about 124
. . . . . . . . . . . . . . . . . . second year 110
. . . . . . . . . . . . . . . . . . third and fourth year 96
When the first teeth begin to drop out 86
At puberty about 80
At manhood about 75
About sixty 60

In those more advanced, I have scarcely twice found it
alike.

116. The pulse is, caeteris paribus, more frequent in
women than in men, and in short than in tall persons. A
more constant fact, however, is its greater slowness in the
inhabitants of cold climates.c

Its greater frequency after meals and the discharge of
semen, during continued watchfulness, exercise, or mental
excitement, is universally known. (C)

117. The heart rather than the arteries is to be regarded
as the source of these varieties, which we have, therefore,
detailed here.

Its action continues in this manner till death, and then all
its parts do not, at once, cease to act; but the right portion,
for a short period, survives the left.d

For, since the collapsed state of the lungs after the last
expiration impedes the course of the blood from the right
[Seite 90] side, and the veins must be turgid with the blood just driven
into them from the arteries, it cannot but happen that this
blood, driving against the right auricle, must excite it to
resistance for some time after the death of the left portion of
the heart.

118. This congestion on the right side of the heart affords
an explanation of the small quantity of blood found in the
large branches of the aorta.

Weiss,e and after him Sabatier,f ascribe to this cause
likewise the comparatively larger sizeg of the right auricle
and ventricle after death, especially in the adult subject.

119. The motion of the blood is performed by these two
orders of vessels in conjunction with the heart. Its celerity
in health cannot be determined. For this varies not only in
different persons, but in different parts of the same person.

Generally, the blood moves more slowly in the veins than
in the arteries, and in the small vessels than in the large
trunks, although these differences have been overrated by
physiologists.

The mean velocity of the blood flowing into the aorta is
usually estimated at 8 inches for each pulsation, or about 50
feet in a minute.

120. Some have affirmed that the globules of the cruor
move more in the axis of the vessels, and with greater rapidity,
than the other constituents of the blood. I know not whether
this rests upon any satisfactory experiment, or upon an im-
proper application of the laws of hydraulics; improper,
because it is absurd to refer the motion of the blood through
living canals, to the mere mechanical laws of water moving in
an hydraulic machine. I have never been able to observe
this peculiarity of the globules.

My persuasion is still more certain that the globules pass
[Seite 91] on with the other constituents of the blood, and are not
rotated around their own axis; – that besides the progressive,
there is no intestine motion in the blood, although indeed
there can be no doubt that the elements of this fluid are
occasionally divided, – where they are variously impelled
according to the different direction, division, and anastomoses
of the vessels.

121. The moving powers of the sanguiferous system are
now to be examined: first, those of the heart, by far the
greatest of all; afterwards, those which are only subsidiary,
though indeed highly useful.

122. That the powers of the heart cannot be accurately
calculated is clear, upon reflecting that neither the volume of
the blood projected at each pulsation, nor the celerity nor
distance of its projection, much less the obstacles to the powers
of the heart, can be accurately determined, &c.

123. A rough calculation may be made by taking every
probable conjecture together: v. c. if the mean mass of the
blood is considered as 10 pounds, or 120 ounces; the puls-
ations 75 in a minute, or 4500 in an hour; and the quantity
of blood expelled from the left ventricle at each contraction,
as 2 ounces; it follows that all the blood must pass through
the heart 75 times every hour.

The impetus of the blood passing from the heart, may be
conceived by the violence and altitude of the stream projected
from a large wounded artery situated near it. I have seen the
blood driven at first to the distance of above 5 feet from
the carotid of an adult and robust man.h

[Seite 92]

124. This wonderful, and, while life remains, constant,
strength of the heart, is universally allowed to depend upon
its irritability, (41) in which it very far surpasses, especially
as to duration,i (98) every other muscular part.k

That the parietes of the cavities are excited to contraction
by the stimulus of the blood, is proved by the experiment of
Haller, who lengthened at pleasure the motion of either side
of the heart, by affording it the stimulus of the blood for a
longer period than the other.l (D)

125. Since a supply of nerves and blood is requisite to the
action of the voluntary muscles, it has been enquired whether
these, both or either, are requisite to the heart also.m

The great influence of the nerves over the heart, is demon-
strated by the size of the cardiac nerves, and by the great
sympathy between the heart and most functions, however dif-
ferent. A convincing proof of this, is the momentary sym-
pathy of the heart during the most perfect healthn with all
the passions, and with the primae viae in various disorders.

The great importance of the blood to the irritability of the
heart, is evident from the great abundance of vessels in its
muscular substance.

[Seite 93]

Nevertheless it is very probable, that the importance of the
nerves in this respect is greater in the voluntary muscles, and
of the blood in the heart.

126. Besides these powers of the heart, there is another,
which is mechanical, dependent on structure, and contributing
greatly, in all probability, to sustain the circulation. For,
when the blood is expelled from the contracted cavities, a
vacuum takes place, into which, according to the common
laws of derivation, the blood from the venous trunks must
rush, being prevented, by means of the valves, from regur-
gitating.o (E)

127. We must now enquire what powers are exerted by
other organs in assisting the circulation. The existence of
some secondary powers and their ability to assist, or even in
some cases to compensate for, the action of the heart, are
proved by several arguments: v. c. the blood moves in some
parts to which the influence of the heart cannot reach, – in
the vena portae and placenta; not to mention instances of the
absence of the heart.p

128. The principal of these powers is the function of the
arteries, not easy indeed to be clearly understood and demon-
strated. 1. It is well known that they have a peculiar coat,
which is all but muscular. (88) (F) 2. That they are irri-
table, has been proved by repeated experiments.q 3. The
size of the soft nerves arising from the sympathetic, and sur-
[Seite 94] rounding the larger arterial branches with remarkable net-
works, particularly in the lower part of the abdomen,r argues
the importance of these vessels in assisting the motion of the
blood.s

129. All know that the arteries pulsate, and indeed vio-
lently, so that if, v. c. we place one leg over the other knee, we
find not only that it, but even a much greater weight, may be
raised by the pulsation of the popliteal. Hence an alternate
systole and diastole, corresponding with those of the heart,
have long been assigned to them.

But this, although commonly believed on the evidence of
sense, is open to much question:t it may be asked, especially,
whether this pulsation is referable to the power of the artery,
or only to the impulse given by the heart to the blood pro-
pelled into the aorta.

130. And indeed, after all, it appears that the diastole of
an artery is owing to a lateral distension given by the impetus
of the blood, so that the coats are expanded, and, by their
elasticity, the next moment reacquire their natural thickness.
To the same impulse may be ascribed the lateral motion
of the axis, observable in the larger arteries, if serpentine
and lying in loose cellular substance. (G)

The genuine systole, produced by a contraction of their
substance, scarcely occurs, probably, while the heart acts
with vigour, but may, when they are unusually influenced
by local stimulants; whence the pulse during illness is very
different in different arteries of the same person at the same
time; or when the action of the heart itself fails, &c.

[Seite 95]

131. Since Whytt,u especially, and other illustrious physi-
ologists have been convinced that the influence of the heart
could not reach the extreme arteries and the origins of the
veins, they have ascribed the progression of the blood in
those vessels to a kind of oscillation, and have happily em-
ployed this to demonstrate the nature of inflammation.

Many kinds of phenomena, both physiological, as those re-
garding animal heat, and pathological, as those observed in
spasms and particularly in fevers, favour the supposition of
this oscillatory faculty, but it is not demonstrable during life
to the eye, even aided by glasses. (H)

132. It remains for us now to examine the aid given to the
returning blood by the veins, their radicles not being taken into
the account. We should conclude at first sight that they have
far less active powerx than the rest of the sanguiferous system,
and that the return of their purple blood to the heart is
chiefly ascribable to the impetus a tergo of the arterial blood,
and to their valvular structure which prevents any reflux.
The efficacy of the valves in this point of view, is shown by
the distensions and infarctions of the veins in the lower part
of the abdomen, which are found destitute of valves.y

The existence of vital powers in the venous trunks is pro-
bable,z from the example of the liver and placenta (127), and
from experiments instituted on living animals. We formerly
mentioned the muscular layer in the extreme veins near the
heart (95). (I)

[Seite 96]

133. These are the chief powers which move the blood and
depend upon the structure and vitality of the sanguiferous
system. We say nothing of the effect of gravity, attraction,
and other properties, common to all matter. The more
remote assistance derived after birth from particular functions,
v. c. respiration and muscular motion, will appear in our
account of those functions. (K)


NOTES.

(A) On applying the ear or a stethoscope to the region of the
heart, the distinct sounds of the action of the ventricles and
auricles may be at once perceived. At the moment of the
arterial pulse is heard a dull sound, and immediately afterwards,
without any interval, a clearer sound, similar to the noise of a
valve or to the licking of a dog. The former arises from the
action of the ventricles, the latter from that of the auricles.

The former occupies about 2/4 of the whole time; the latter 1/4
or 1/3, and then a pause occurs of another 1/4. This is termed the
rhythm of the heart’s action.a

The sounds of the heart are ordinarily heard in health between
the cartilages of the fourth and seventh ribs, and under the
inferior part of the sternum; those of the left side of the heart in
the former situation, and those of the right in the latter.

The shock, or stroke, occurs, as mentioned in the text, at the
contraction of the ventricles. The force and extent of the sound
and of the shock, and the rhythm of the heart’s action, are
variously altered in disease, and other sounds superadded.

(B) Dr. W. Hunter accounted for this in 1746.

‘“The systole and diastole of the heart, simply, could not pro-
[Seite 97] duce such an effect; nor could it have been produced, if it had
thrown the blood into a straight tube, in the direction of the axis
of the left ventricle, as is the case with fish, and some other
classes of animals: but by throwing the blood into a curved tube,
viz. the aorta, that artery, at its curve, endeavours to throw itself
into a straight line, to increase its capacity; but the aorta being
the fixed point against the back, and the heart in some degree
loose and pendulous, the influence of its own action is thrown
upon itself, and it is tilted forwards against the inside of the
chest.”’b

Though this is generally allowed, Haller remarks that in the
frog also, which has a straight aorta, the point of the heart moves
forwards during the contraction;c and some say that while the
heart of a dog continues to palpitate, after being extracted from
the chest, the apex is lifted up at each contraction of the empty
ventricles.d

The occurrence is ascribable likewise, in some measure, to the
distension of the auricles, for Haller found the apex give the
usual stroke at the nipple, on his distending the left auricle with
air,e and Senacf has shown a similar influence from the right
auricle also.

Dr. Barclay has the following passage on this point:

‘“When the blood is forced into the arteries, their curvatures,
near where they issue from the ventricles, are from their disten-
sion lengthened and extended towards straight lines; and, causing
the heart to palpitate in their motions, compel it to describe the
segment of a circle, when the apex moving atlantad and sinistrad,
is made to strike against the left side. The same kind of motion
having also been observed by the celebrated Haller, in distending
the left or systemic auricle, it must follow, that the stroke which
is given to the side, may be the effect of two distinct causes,
either acting separately, or in combination: but acting on a heart
obliquely situated, as ours is, in the cavity of the thorax, where
the aspect of the base is atlantad and dextrad, and that of the
[Seite 98] apex sinistrad and sacrad. In combination, as the first of the two,
by removing the pressure, will facilitate the influx of the venous
blood into the left or systemic auricle, which is situated dorsad;
so the second, by the influx of blood into the auricle, will contri-
bute in its turn to facilitate the circular motion of the heart,
proceeding from the arteries.”’g

(C) It is commonly believed, that the pulse of every person is
quicker in the evening than in the morning, and some have sup-
posed an increase of quickness also at noon. Upon these suppo-
sitions Dr. Cullen builds his explanation of the noon and evening
paroxysms of hectic fever,h as others had theirs of the evening
exacerbation of all fevers,i regarding them as merely aggrava-
tions of natural exacerbations. The existence of the noon pa-
roxysms is doubtful, and the evening one cannot be so explained
if Dr. R. Knox is correct,k though he is opposed to Haller, &c.
His observations make the pulse to be slower in the evening, and
quicker in the morning.

Dr. Heberden saw a woman fifty years of age who had always
an intermitting pulse, yet an able anatomist could discover nothing
unusual after death; and two persons whose pulse was always
irregular in strength and frequency when they were well, and be-
came quite regular when they were ill.l

(D) The heart, however, of frogs, for instance, contracts and
relaxes alternately, for a length of time, when out of the body
and destitute of blood.

Mr. Brodie divided the great vessels in rabbits and found the
action of the heart ‘“apparently unaltered, for at least two minutes
after that viscus and the great blood-vessels were empty of
blood.”’m But the quantity of blood greatly influences the action
of the heart.

(E) The influence of a vacuum, pointed out by Rudiger,n en-
larged upon by Dr. Andrew Wilson, and mentioned as probable
[Seite 99] by Haller,o John Hunter,p &c., has been very ably displayed by
Dr. Carson of Liverpool.q

The quantity of the blood, the length of its course, and the vari-
ous obstacles opposed to its progress, render, in his opinion,
the mere propulsive power of the heart insufficient to main-
tain the circulation perpetually. But assistance must be given
by the vacuum which takes place in all the cavities of the
organ, when the contraction of the muscular fibres is over. The
blood is thus drawn into each relaxed cavity, and the heart per-
forms the double office of a forcing and a suction pump. The
situation of the valves of the heart is thus explained. There are
valves between the auricles and ventricles, and at the mouths of
the two great arteries, because behind each of these four openings
is a cavity of the heart, alternately dilating and affording a
vacuum, into which, were there no valves, the blood would be
drawn retrograde. At the venous openings of the auricles no
valves exist, because they do not open from a cavity of the
heart, – from a part ever experiencing a vacuum, and, therefore,
the blood cannot, when the auricles contract, move retrograde,
but will necessarily pass forwards into the ventricles, which at
that moment are offering a vacuum. The inferior elasticity and
irritability of the veins are also explained. If veins were capable
of contracting equally with arteries, on the diminution of their
contents, the suction influence of the heart would constantly
reduce their cavities to a smaller capacity than is compatible with
their functions. The collapse of the veins by pressure, during
the suction of the heart, is prevented by the fresh supply of blood
afforded by the vis a tergo, which does exist, although it is not
[Seite 100] considered by him as of itself adequate to convey the blood back
to the right auricle.

All allow that when the heart is relaxed its cavities enlarge,
though some ascribe this to its elasticity, and others regard it as
a necessary consequence of the arrangement of its fibres.r Ex-
periment proves the same Dr. Carson extracted the hearts of
some frogs, and immediately put them into water, blood-warm.
They were thrown into violent action, and, upon some occasions,
projected a small stream of a bloody colour through the trans-
parent fluid. The water could not have been projected unless
previously imbibed. It was thought that a stream of the same
kind continued to be projected at every succeeding contraction;
but that, after the first or second, it ceased to be observable, in
consequence of the liquid, supposed to be imbibed and projected,
losing its bloody tinge and becoming transparent, or of the same
colour with the fluid in which the heart was immersed. The
organ was felt to expand during relaxation, – a fact stated long
ago by Pechlin.s

Dr. Carson accounts, however, for the full dilatation of the
heart upon another principle, upon the consideration of which it
will be impossible to enter before the next section, where the sub-
ject will therefore be prosecuted.

(F) Most physiologists grant to the capillaries irritability, to-
nicity, or organic contractility; but some deny that arteries pos-
sess muscular properties. Bichat’s objections are, the absence of
contraction on the application of stimuli to them, the much greater
resistance of the middle coat to a distending force than of mus-
cular parts, and, lastly, the difference of the changes which it and
muscles undergo both spontaneously and by the action of other sub-
stances.t Berzelius has multiplied the latter description of proofs.u
However this may be, I must remark, first, that the capillaries
have certainly vital powers of contraction as fully as any parts of
[Seite 101] the body. This appears in their various degrees of local dilatation
and contraction, under inflammation, passions of the mind, &c.
When different stimuli are applied to them, they are seen
under the microscope locally to experience various degrees of
contraction and dilatation, and this even after connection with the
heart has been cut off by absolute excision of this organ.x Under
similar circumstances, when no stimulus was applied, the blood
was seen by Dr. Hastings often to cease, indeed, to flow, but still
to oscillate. If the capillaries are allowed to possess organic con-
tractility, it is impossible to say in which point of the arterial tract
it begins.

The evidence of muscular fibres is not necessary to irritability.
The iris and uterus are strongly endowed with irritability, but
their muscularity is disputed by many. No muscularity is dis-
cernible in the plant called dionoena muscipula, nor in the sensitive
plant, nor in those zoophytes which appear gelatinous masses,
yet contractility dependent on life is very manifest in them.

Verschuir actually found the larger arteries contract on irritating
them with a scalpel, in fifteen out of twenty experiments.y Dr. L.
Bikker, and J. J. Vandembos assert the same of the aorta, and
Van Geuns of the carotid when influenced by electricity.z Zim-
merman, Bichat, and Magendie, saw the arteries contract upon the
application of acids, but the two last considered it a chemical
change. Dr. Hastings, however, saw the same from the appli-
cation of ammonia. J. Hunter found the posterior tibial artery of
a dog contract so as nearly to prevent any blood from passing
through it on merely being laid bare, and facts similar to this are
mentioned by Drs. Hastings, Fowler,a Jones,b and the Drs. Parry.
The fact of continued contraction, and of alternate contraction
and relaxation in arteries, being occasioned by stimuli is therefore
certain, and although some have not succeeded in stimulating
them, we must remember that others have failed in the application
of electricity to parts indisputably muscular; – Verschuirc in the
[Seite 102] case of the heart and urinary bladder, and Zimmerman in other
parts of known muscularity.d Dr. Hastings caused contraction
in veins also by the application of stimuli.e

Dr. Parry instituted a number of experiments upon this ques-
tion. After exactly ascertaining the circumference of arteries in
animals, he killed them, and again measured the circumference;
and after a lapse of many hours, when life must have been per-
fectly extinguished, he measured the circumference a third time.
Immediately after death, the circumference was found greatly
diminished, and on the third examination it had increased again.
The first contraction arose from the absence of the blood which
distended the vessel and antagonised its efforts to contract, and it
was evidently muscular, or to speak more correctly, organic,
contraction, because, when vitality had ceased, and this kind of
contraction could no longer exist, the vessel was, on the third
examination, always found enlarged.f

The forced state of distention in arteries was proved by the
contraction immediately occurring on making a puncture in a
portion of vessel included between two ligatures. An experiment
of Magendie’s is of equal weight, in which a ligature was fixed on
the whole of a dog’s leg except the crural artery and vein, and
the vein and artery were compressed, when, upon wounding the
vein, the artery completely emptied itself.g The capacities of
arteries are thus always accommodated to the quantity of blood,
and this circumstance gives the arterial canal such properties of
a rigid tube as enable an impulse at the mouth of the aorta to be
instantly communicated throughout the canal. This appears the
great office of the contractile powers of arteries, for,

(G) They do not incessantly dilate and contract to any amount,
as many imagine. Dr. Parry, on the most careful examination,
could never discover the least dilatation in them, during the
systole of the ventricle, – when the pulse is felt. Dr. Hastings
declares he has seen it, as does Magendie in the case of the
aorta and carotid of the horse; but from the number and accuracy
of Dr. Parry’s experiments, I incline to believe it does not occur
in the ordinary undisturbed state of the circulation to any extent.
Dr. Barry plunged his arm into the thorax of a horse and found
the aorta constantly full, nearly to bursting, not perceptibly vary-
[Seite 103] ing in distention for an instant, though he held it during five
minutes and examined it afterwards again; while at every expira-
tion the cava was so empty as to feel only like a flaccid thin mem-
brane.h The fact of a continued stream occurring from a wounded
artery, only augmented at each pulsation of the heart, is thought
by Magendiei to prove that the arteries assist in propelling the
blood: but an opening takes off the resistance to its course so
considerably that the vessel cannot but contract between the im-
pulses of the heart.

Although the blood is constantly streaming onwards, the pulse
is felt only when arteries are more or less compressed; under
which circumstance, the motion of the blood onwards, by the
impulse of a fresh portion from the left ventricle, is impeded: and
this effort of the fluid against the obstructing cause gives the
sensation called the pulse,k which follows the stroke of the heart
successively later throughout the arterial system, though the
interval is in general too minute to be appreciated. Dr. Barry
found no pulsation in the aorta of the horse, unless he compressed
it violently.

The elastic coat both assists and antagonises the muscular:
assists it in preventing distention when the distending force is
very strong, and antagonises it – tends to prevent the canal from
becoming too narrow, when it attempts to contract the vessel
excessively.l

Still, independently of the whole quantity of blood, and of the
heart’s action, particular arteries may be in various degrees of
distention, according to the various states of their individual
contraction. For example, when a finger has a whitlow, the
[Seite 104] digital branches are found larger than usual at the very roots
of the fingers; in many affections the pulse of the two wrists differ
for a time. In fact, their condition may vary like that of the
capillaries, and probably does vary every time that altered cir-
culation occurs in a part, although Dr. Parry’s opinion holds true
during the tranquil and ordinary condition of circulation. I am
thus inclined to agree with and differ from both Dr. Parry and
Dr. Hastings; believing the former to be right as to the ordinary
state, the latter in irregularity.

The elastic power is said to be greater in the arteries, and the
muscular in the capillaries; and as the muscular power is proved
by Dr. Parry’s experiments to be able to overcome the elastic in
the arteries, it must be very considerable in the capillaries.

Dr. Curry, the late senior physician and distinguished lecturer
on the practice of medicine at Guy’s Hospital, concluded, without
doubt hypothetically, from some microscopic experiments which
he had made on inflammation in the presence once of Mr. Charles
Bell and once of Mr. Travers, that the circulation is indispensably
facilitated by a sort of electric repulsion between the vessels and
their contents, and that in inflammatory accumulation, the tone
of the vessels being impaired, this repulsion is diminished and the
blood passes onwards with difficulty in consequence.m

(H) These oscillations are quite imaginary, and now disallowed.
Although variations of dilatation must affect the course of the blood
through vessels, it is difficult to conceive how any regular action
of them can assist it, while the blood is propelled and drawn by the
heart; and the influence of the heart was seen by Dr. Hastings in
some microscopical experiments, in which partial obstruction was
produced, to extend to arteries, capillaries, and veins, as the blood
in them all received a sensible impulse at each contraction of the
ventricles. Indeed we have ocular proof that the capillaries do
not contract on the blood in the ordinary state of things, for the
blood in them, as well as in the arteries and veins, may be seen for
an hour together in the frog’s foot, under the microscope, to move
in a stream unvarying, – neither becoming finer alternately nor
experiencing impulses.n

[Seite 105]

In foetuses without hearts,o it is not proved that the vascular
system carries on the circulation by its own power, because a
twin without a heart has never been seen unless accompanied by
a perfect foetus, whose heart might circulate the blood of both; for
the placentae often communicate, so that one child has died of
haemorrhage from the chord of the other: and in the only case
where the matter was ascertained,p the akerious foetus was ac-
tually injected by the navel-string of the perfect foetus.q When,
however, the blood is not moved by the heart, the capillaries do
impel it. Dr. Wilson Philip once saw it moving freely in some
mesenteric capillaries of a rabbit for an hour and a quarter after
the excision of the heart;r and Haller and Bichat made similar
observations.

Mr. Burns,s anxious to prove that the arteries are of more
importance than the heart, that they themselves circulate the
blood which they receive,t and that the auricles are of more
importance than the ventricles, mentions, among other ex-
amples of diseased heart, one in which both ventricles were
as completely ossified as the cranium, except about a cubic
inch at the apex, and in which there had been no palpi-
tation or pain in the heart. As bony ventricles could not con-
tract, nor easily be moved, palpitation could not readily have
occurred, and pain rarely attends the ossification of any part.
That the circulation was deranged is proved by the woman having
experienced great dyspnoea, and expectoration, and dropsy. The
auricles were healthy and thicker than usual, and had evidently
performed the duty of the ventricles, through which, as an un-
changing reservoir between the auricles and the pulmonary artery
and aorta, the auricles drove the blood. The invariable languor
of circulation in cases where the action of the heart is languid,
proves the power of the heart in the circulation.

On the other hand, the large arteries of the extremities are
continually found ossified without any apparent deficiency of cir-
culation. I have seen long tracts of vessels in the lower ex-
[Seite 106] tremities ossified, where no such circumstance had been suspected.
Mr. Burns himself mentions an instance ‘“of the arteries of the
head, pelvis, legs, and arms, being almost entirely ossified,u”’ the
heart and aorta being healthy; and yet the man clearly died of
diseased liver induced by hard drinking, hot climate, &c.

The ventricles are certainly of more importance than the
auricles, because these are absent in many animals, and are only
reservoirs to supply the ventricles.x

(I) In a young lady whom I attended for chronic bronchitis ac-
companied by violent cough, and who ultimately recovered, all
the veins of the back of the hands and fore-arms distinctly puls-
ated synchronously with the arteries. An universal pulsation of
the veins synchronous with that of the arteries, occurred for some
days twice in a young man who died of cerebral disease, with
constriction of the mouth of the aorta;y once in a middle-aged
man with affections of the head and abdomen, who recovered;z
once in a middle-aged man who died with dropsy and palpitation,a
and lately in a girl who died with symptoms of hydrocephalus.b
In a case of epidemic fever, the same was observed by Weitbrecht
for twenty-four hours;c and he had previously seen a similar case,
but doubted his senses. Haller’s remark upon it is, ‘“Ego quidem
non intelligo.”’d

In venesection at the bend of the arm I have frequently seen
the jet regularly stronger at each pulsation of the heart, and
Hunter mentions the same thing, and states it to be more ob-
servable at the head or foot, saying, ‘“The fact is, however, that
there is a pulsation in the veins.”’e

Yet ordinarily there is, speaking of the veins in general, no venous
pulsation, and the stream in the veins, though caused mainly by
the left ventricle, – as may be seen by tying all the vessels of an
extremity but the artery, and wounding the vein, when the jet from
the vein may be regulated by pressing the artery, – is perfectly
uniform. By the infinite subdivisions and great increase of ca-
[Seite 107] pacity of the arterial system, the blood which is moved in jerks
in the larger arteries, giving a pulse, and, if the vessel is wounded,
flowing more forcibly at the heart’s pulsation, gives no pulse in the
small vessels, and, if they are wounded, flows regularly; and in
the capillaries, through the augmentation of space, experiences no
increased momentum at the heart’s pulsation. When the capilla-
ries unite into veins, and the capacity of the whole vascular chan-
nel diminishes, the blood moves more quickly again through the
diminished space;f but though the smaller space augments its
flow again, the impulses of the heart lost in the capillaries cannot
be felt in the veins, and the current in them is smooth. Neither,
generally speaking, is it by any means so rapid as in the arteries,
because much of the heart’s force is expended, and the veins are
generally so much more numerous than the arteries, and the
space therefore, however less than in the capillaries, still much
greater than in the arteries. Neither ought the momentum to be
strong when the veins have all united into the cavae, because it has
only to reach the heart where there is no resistance, but, on the
contrary, more than one source of vacuum prepared; whereas in
the aorta it ought to possess a force sufficient to carry it a great
distance, and surmount great obstacles.

When the veins have pulsated, the action of the heart must
have been very violent, or some obstruction occurred, which, in
Dr. Hastings’s experiments, was seen to cause the heart’s action to
be sensible in the capillaries and veins.g

There is always a pulsation in the large veins near the heart, as
we shall see when considering respiration, but that arises from a
different circumstance.

The heart of mammalia and birds has no peculiarity necessary
to be mentioned here. In most amphibious animals, the arteries
of the system as well as of the lungs spring from the right ventricle,
with which the left, that sends off no vessel, communicates: hence
their circulation continues under water. In amphibious mammalia
and diving birds, some vessels, especially one vena cava, are dilated
to form a receptacle during the suspension of respiration. The
heart of fish is extremely small, and has but one auricle and ven-
[Seite 108] tricle, the latter propelling the blood to the gills, from which it
streams to the system through a large artery. Neither blood-
vessels nor absorbents have been discovered in insects, yet a
large tube, close throughout, pulsates in their back; and Professor
Carus has lately discovered a circulation in them through a gra-
nular substance. With respect to the mollusca: the cuttle fish
has three detached hearts, consisting of a ventricle only, two for
the gills and one for the aorta; the rest have a simple heart, the
blood of the cava passing through the gills before it reaches the
heart. The same is the case with the crustacea, and their heart
has no auricle. Worms have circulating vessels distinctly con-
tracting and dilating, but no heart, and their veins communicate
with the general cavity of the body, and probably absorb. Zoo-
phytes
have no heart, nor circulating system, properly so called.
In the echinus, indeed, there are two vessels that run along the
intestines, and are thought to be an aorta and vena cava.

Vegetables have no central organ of circulation. The sap rises
in tubes, called common vessels, up the wood, is distributed in thin
minute ramifications over the surface of the leaves, experiencing
changes by its exposure to air and light, and descends through
other tubes, called proper vessels, in the inner layer of bark,
affording the various peculiar secretions of the plant. The power
of the common vessels is such, that if a piece of the stem is cut
out, they entirely empty themselves; and the sap has been found
to flow from the extremity of a branch with a force sufficient to
overcome a column of water 43 feet 3 1/3 inches in height.h

(K) It would not be right to terminate this section without a note
upon the discovery of the circulation of the blood; – a truth of
which the ancients are thought to have remained ignorant, from
finding the arteries empty after death; but it was known that these
contained blood during life.i The discovery was made by our
countryman, Dr. Harvey, Physician to St. Bartholomews Hos-
pital, and promulgated by him, at the age of forty-one, in an
anatomical and surgical course of lectures at the College of
Physicians, in 1619. He is entitled to the glory of having made
it, says Hume,k ‘“by reasoning alone, without any mixture of
[Seite 109] accident.”’ He informed Boyle, that he was led to it by reflect-
ing on the arrangement of the valves of the heart and veins, as
exhibited by his master Fabricius. Nothing, he knew, was
planned in vain, and they clearly allowed a fluid to pass but
one way. By this argument, and the fact of a ligature upon an
artery causing the blood to accumulate in it on the side nearest
the heart, and, upon a vein, beyond the ligature; and that animals
bleed to death by wounds in arteries or veins, he chiefly established
his doctrine. After his time it was demonstrated with the
microscope in cold-blooded animals. His immediate reward was
general ridicule and abuse, and a great diminution of his practice;l
and no physician in Europe who at the time had reached forty
years of age, ever, to the end of life, adopted his doctrine of the
circulation of the blood.m When the truth could be denied no
longer, he was pronounced a plagiarist; the circulation was de-
clared to have been known to Plato, nay, more, to king Solomon.n
The circulation through the lungs had certainly been imagined
by Servetus, a Spanish physician, who was slowly burnt to death
by Calvin for not being of the same opinion as himself upon a
point in divinity.

SECT. VIII.
OF RESPIRATION AND ITS PRINCIPAL USE.

[Seite 110]

134. The lungs,a closely connected with the heart both by
proximity and by relation of function, are two viscera, large
after birth, so light as to swim in water, and composed of a
spongy, and, as it were, spumous, but pretty tenacious and
elastic,b parenchyma.c

135. They fill each cavity of the chest, and are contiguous
to the sacs of the pleurae, to which, as well as to the other
contents of the thorax, they model and apply themselves. (A)

136. They, in a manner, hang from the wind-pipe, usually
called the aspera arteria, which, besides its interior coat always
smeared with mucus, and the subjacent very sensible nervous
coat, consists of another which is muscular, surrounding the
latter, and divided, except posteriorly, by an indefinite number
of cartilaginous falciform arches.

137. The aspera arteria, having entered the thorax, is
bifurcated into the trunks of the bronchiae, and these, the
more deeply they penetrate into the lobes and lobules of the
lungs, are the more and more ramified, losing both their car-
tilaginous rings and muscular coat, until their extreme di-
visions terminate in those cells which form the chief part of
the substance of the lungs, and alternately receive and emit the
air we breathe.

[Seite 111]

138. The shape and magnituded of the air-cells are various.
The former is generally polyedrical. The latter, in regard
to surface, is scarcely to be defined:e though, indeed, the
capacity of the lungs of an adult, during a strong inspiration,
is about 120 cubic inches. The immense size to which the
lungs may be inflated, when the chest has been opened, has
no relation to our present subject.

139. The cells are invested and connected by the common
but delicate mucous web – the general vinculum of the
body, and must be carefully distinguished from it. In healthy
and very recent lungs, I have found the cells so unconnected
that they were distended in one insulated spot by air cauti-
ously inflated into a fine branch of the bronchiae, while neither
the neighbouring cells nor the cellular membrane, which lies
between the cells, admitted the smallest portion. If air is
forcibly thrown in, the air-cells are ruptured and confounded
with the cellular membrane, and both parts distended.

140. The mucous web surrounding the air-cells of the
lungs is supplied with innumerable blood-vessels – di-
visions of the pulmonary artery and four pulmonary veins,
the branches of which accompany the ramifications of the
bronchiae,f and, after repeated division, form at length an
immense collection of most delicate and reticulated anasto-
moses. This extraordinary network, penetrating the mucous
web on every side, closely surrounds the air-cells, so that the
prodigious quantity of blood existing in the pulmonary vessels
is separated from the contact of the air by very fine mem-
branes only, which Hales estimated as scarcely 1/1000 of an
inch in thickness.

141. As each ramification of the bronchiae possesses its
own bunch or lobule of air-cells (139), so again each of these
possesses a peculiar system of blood-vessels, the twigs of
[Seite 112] which anastomose in the wonderful net-work with one an-
other, but scarcely at all with the blood-vessels of the other
lobules, as is proved by microscopic observations on living
frogs and serpents, by minute injections, and by the pheno-
mena of vomicae and other local diseases of the lungs. (B)

142. The common membrane investing the lungs is the
chief seat of a remarkable net-work of lymphatic vesselsg
which run to numerous lymphatic or conglobate glands,h
carefully to be distinguished from a neighbouring order of
glands, called bronchial, that are supplied with an excretory
duct and are of the conglomerate kind.i

143. The thorax, which contains the lungs, has an osseous
and cartilaginous base, somewhat resembling a bee-hive,
throughout very firm and stable, but in every part more or
less movable for the purpose of respiration.k

This holds good chiefly with the six pairs of true ribs
below the first, each of which is more movable than the one
above in proportion to the greater length both of its own
body and of its cartilaginous appendix. The cartilages are
united by a kind of amphiarthrosis to the margin of the ster-
num on each side. (C)

144. Between the edges of the ribs lie two strata of inter-
costal muscles, differing in the direction of their fibres, but
conspiring to produce the same motion.

At the base of the thorax, the diaphragml is subtended in
in the form of an arch. It is a considerable muscle, and, in
the words of Haller, next in importance to the heart. Its
utility in the mechanical part of respiration was long since
[Seite 113] shown, by the excellent experiments of Galenm upon living
animals, to depend chiefly on the phrenic nerve.n

Its antagonists are the abdominal muscles, especially the
two sets of oblique and the transverse.

145. The thorax, thus constituted, is, after birth, dilated
by inspiration, and subsequently reduced to a smaller capacity
by expiration.

During the former act, the thorax is enlarged laterally and
inferiorly, so that the bodies of the six ribs mentioned above
(143) are elevated and their inferior margin drawn somewhat
outwards; the arch of the diaphragm is at the same time
rather depressed and flattened.

I have never observed the inferior extremity of the sternum,
in the tranquil respiration of health, to be thrust forwards, as
some have asserted. (D)

146. This alternate motion of the chest continues, during
health and freedom from restraint, from the moment of birth
till death. Its object is, that the lungs may be expanded to
admit the air and contracted to expel it, in perpetual altern-
ation. This alternation occurs, in an adult at rest, about 14
times in a minute, – once to about five pulsations of the
heart.

147. For man, in common with all warm-blooded animals,
cannot long retain the inspired air, but is compelled to dis-
charge it and take in a fresh supply of this pabulum of life, as
it always has been denominated.o Common observation
teaches, that, however pure may be the air entering the lungs,
it instantly undergoes remarkable changes, by which it is con-
[Seite 114] taminated and rendered unfit for another inspiration, unless it
is renewed.p

148. It may be asked, what are the changes which the air
experiences during inspiration, and which consist not in the
loss of elasticity, as was formerly imagined, but in the decom-
position of its elements.q For the atmospheric air, which we
breathe, is a peculiar mixture of constituents, differing very
much in their nature from each other; and, not to mention
heterogeneous matters, such as odorous effluvia, various other
besides aqueous exhalations, and innumerable other matters
which are generally present, is always impregnated with
aqueous vapour, electric and magnetic matter, and generally
with carbonic acid gas; and is itself composed of unequal
parts of two aëriform fluids, viz. 79 of azotic gas, and 21 of
oxygen gas in 100.

149. In the first place we know for certain, that, at every
inspiration (the fulness of which varies infinitely in different
persons of the same age, breathing placidlyr), besides the
quantity of azotic gas being somewhat diminisheds, the oxy-
gen gas is in a great measure converted into carbonic acid
gas or fixed air; so that the air of expiration, if collected, in-
stantly extinguishes flame and live coals, precipitates lime
from lime water, and is specifically heavier than atmospheric
air, and rendered unfit for inspirationt; it also contains much
[Seite 115] aqueous vapour, which is condensed in a visible form by a
temperature not exceeding 60° of Fahr.u

150. There is, consequently, no doubt that the carbonic
acid of the expired air is derived from the venous blood
carried to the lungs from the right side of the heart.x But
it has been of late disputed, whether the inspired oxygen
goes wholly to form carbonic acid in the bronchial cells,y
or whether it is in part united with the arterial blood and
distributed through the arterial system.z Many weighty
arguments seem to favour the latter opinion, as well as the
phenomena of both kinds of blood in the living body,a
compared with the changes which this fluid experiences when
exposed to these two kinds of air. (F)

151. This perpetual change of elements occurring in re-
spiration after birth, we shall show to be very differently
[Seite 116] accomplished in the foetus, viz. by means of the connection of
the gravid uterus with the placenta.

But, when the child is born and capable of volition, the
congestion of blood that takes place in the aorta, from the
obstruction in the umbilical arteries; the danger of suffoca-
tion from the cessation of those changes of the blood, in
regard to oxygen and carbon, (13) hitherto produced in the
uterine placenta; the novel impression of that element into
which the child, hitherto an aquatic being, is conveyed; the
cooler temperature to which it is now exposed; and the many
new stimuli which are now applied, seem to induce new
motions in the body, especially the dilatation of the chest and
the first inspiration.

The lungs, being for the first time dilated by inspiration,
open a new channel to the blood, so that, being obstructed in
the umbilical arteries, it is derived to the chest.

Since the inspired air becomes hurtful and unpleasant to
the lungs by the decomposition which it experiences, I should
ascribe to the most simple corrective powers of nature, the
subsequent motion by which the poisonous mephitis, as it
may be called, is expelled and exchanged for a fresh supply.

The consideration of all these circumstances, especially if
the importance of respiration to circulation, demonstrated by
the well-known experiment of Hookeb, be remembered, will,
in my opinion, explain the celebrated problem of Harvey,c
betterd than most other attempts of physiologists. (G)e

[Seite 117]

NOTES.

(A) A correct notion can scarcely be formed from this descrip-
tion. The pleurae are two closed sacs, one of which lies over each
lung, one portion of the sac adhering closely to it, and one lying
over this again; the internal surfaces of both portions are always
in contact, because, if the parietes of the thorax expand and
draw with them the external portion, the lung at the same time
expands with air and forces forwards the internal in the same de-
gree. It is commonly said that a quantity of fluid (not vapour)
exists in serous membranes for the purpose of lubrication. Dr.
Marshal, from many experiments, believed that this is not the
case, but that whenever fluid is discovered, we must regard it as
the effect of either disease or the struggle of dying. His experi-
ments were made on the ventricles of the brain, the theca ver-
tebralis, the pleura, and the pericardium;f yet, when Dr. Magendie
has opened the membranes of the brain or spinal marrow, I have
myself seen a colourless clear fluid instantly escape.

The serous membranes during life and health are translucent.
M. Richerand tells us, that, on removing a portion of the thorax
when cutting away a cancer, he saw the heart through the peri-
cardium.g

(B) The best treatise with which I am acquainted upon the
lungs, is the prize commentary of Reisseisen, published by the
Royal Academy of Sciences at Berlin in 1808, and printed in
1822, with six beautiful coloured engravings, and a Latin version,
under the care of Professor Rudolphi.h

xxx

He asserts, 1st. That the subdivisions of the
bronchiae occur more and more thickly, the
twigs proportionally decreasing in diameter
and length, and that each ultimate twig ends
in a close bulbous extremity, or cell, com-
municating with other bulbous extremities
only in an indirect manner, – by means of
the twigs which end in them. Malpighi had
described them as round, and mere dilatations
[Seite 118] in the course as well as at the ends of the bronchial twigs.i
2d. That, as Malpighi proved, and contrary to the subsequent
opinion of Helvetius and others, these ramifications and cells
have no connection with the surrounding common cellular mem-
brane. 3d. That they consist of, – 1. mucous membrane, behind
which lies, – 2. a coat of elastic white fibres, their existence being
visible as far as the canals can be traced, and the regular discharge
of any fluid injected into the bronchiae after death proving the
existence of elasticity in the bronchial ramifications; – 3, a coat of
muscular fibres, transverse relatively to the course of the canals, and
visible by the aid of a magnifier as far as the size of the canals will
allow them to be traced. He conceives the muscularity of the twigs
and cells to be shown also from the necessity for its existence in
them no less than in the large trunks and trachea, where it is
visible; from their evident contraction in the experiments of
Varnier, who irritated them by the injection of stimulating liquids
and gases and by mechanically stimulating the surface of the
lungs;k and from the circumstance of the lungs shrinking much
more if an opening is made in the thorax of a living than of a dead
animal, in the latter of which it can shrink from elasticity only.
4th. That the ramifications of the bronchial and pulmonary arteries
freely anastomose both in the air-passages and on the surface of
the lungs, and that the bronchial arteries run chiefly direct to the
pulmonary veins. 5th. That the air-passages and blood-vessels of
the lungs are most abundantly supplied with nerves from the par
vagum, whose conjunctions with the sympathetic take place ex-
ternally to the lungs.

Some other conclusions are drawn, but unimportant or un-
satisfactory.

(C) Although each lower rib must execute a greater extent of
motion from being longer than the one above, yet the first is
asserted by Magendie to be absolutely more moveable than the
second, the second than the third, &c.: and this because the
first has but one articular surface, is articulated with but one
vertebra, and possesses neither internal nor costo-transverse liga-
ment and has the posterior ligament horizontal, and because
slight shades of difference exist in the disposition of the ligaments
of the six other ribs.l

[Seite 119]

(D) Dr. Carson gives the following account of the mechanical
part of respiration.

The substance of the lungs is highly elastic, and constantly
kept in a forced state of distention after birth by the pressure
of the atmosphere.m This is evident also from the lungs collaps-
ing upon our puncturing the walls of the thorax, – a circum-
stance arising from the atmospheric pressure on the one hand
becoming counterbalanced on the other, so that their elasticity,
experiencing no opposition, becomes effective.n During inspiration,
the intercostal muscles raise and draw out the ribs, and the dia-
phragm descends: the enlargement of the thoracic cavity is
instantly followed of necessity by the greater distention of the
substance of the lungs from the diminished resistance to the
atmosphere gravitating in the bronchiae. The diaphragm and
intercostal muscles ceasing to act, the substance of the lungs
exerts its elasticity with effect, recovers its former dimensions,
and drives out the additional volume of air just admitted, and
the passive diaphragm follows the shrinking substance of the
lungs, offering, from its relaxation, no resistance to the atmo-
sphere pressing on the surface of the abdomen. Thus expiration
is produced. The muscular power of the diaphragm and inter-
costal muscles is far greater than the elastic power of the lungs,
and therefore, when exerted, overcomes it, producing inspiration:
but, ceasing to be exerted, the elastic power gains efficiency, and
produces expiration.

To the elastic, Reisseisen adds the muscular, contraction of the
bronchial ramifications and cells. ‘“Thorace ampliato, aër va-
cuum in pulmone spatium occupat, victisque fibris, fistulam spirit-
alem quaquaversum extendit, ultra modum, quo quiescit, explicari
coactam, unde fibrae elasticae resilire, circulares sese contrahere
nituntur, quo fit ut desidente thorace omnes simul ad expellendum
spiritum vires intenduntur. Sunt autem, thoracis undique desi-
dentis pressio, turn fibrarum fistulam spiritalem in brevius contra-
hentium vis elastica, denique muscularium illam constringentium
irritabilitas.”’

[Seite 120]

‘“The contractile power of the diaphragm (and intercostal
muscles
) in conformity with the laws of muscular motion,”’ says
Dr. Carsono, ‘“is irregular, remitting, and sometimes altogether
quiescent. The elasticity of the lungs, on the other hand, is
equal and constant. The superior energy of the former is
balanced by the permanency of the latter. By the advantage
which the inferior power, from the uniformity of its operations, is
enabled to take of the remissions of its more powerful antagonist,
the ground which had been lost is recovered, and the contest pro-
longed; that contest in which victory declaring on one side or
the other is the instant death of the fabric.”’

In the common account of respiration, the elasticity and mus-
cularity of the lungs are unnoticed, and expiration is ascribed to
the elasticity of the cartilages of the ribs, and to the contractions
of the abdominal muscles emptying the lungs by pressure. Now,
according to Dr. Carson, in the first place, the elasticity (and
muscularity
) of the lungs is of itself sufficient for the purpose; in
the second, there is no proof of the agency of the abdominal
muscles in expiration, – it proceeds equally well in cases of ina-
nition, when their contraction would rather enlarge than diminish
the abdominal cavity, and in experiments when they are entirely
removed from animals, – a child was born without them, and had
lived eighteen months at the time of the publication of its case,
and was very well;p – and, I may add, thirdly, that, although the
elasticity of the cartilages of the ribs must conspire with that of
the lungs, numerous cases are recorded of immobility of the ribs,
by ossification of their connections, where respiration was not
materially impeded.q These cases are adduced to show that the
diaphragm is the chief instrument of respiration; but as its
elasticity cannot produce expiration, they show that this was
accomplished entirely, or in a great measure, by the lungs them-
selves. Even where there is no ossification, the motion of the ribs
has very little share in respiration, and Dr. Bostock considers the
chief use of the intercostals to be that of giving a fixed point for
the action of the diaphragm, and the operation of the abdominal
muscles in expiration to be nearly passive.r It is commonly
[Seite 121] known, however, that if the pleura is wounded, air rushes into
the chest during inspiration only, and is in some measure ex-
pelled again during expiration. Galen showed this, notwithstand-
ing his object was different, by wounding the chest, and fixing
a bladder upon the wound. The bladder shrunk at inspiration,
and became distended at expiration.s Were the ascent of the
diaphragm and descent of the ribs in expiration the effect of
solely the contraction of the lungs, – of a tendency to vacuum
occasioned by their shrinking, – air and fluids should stream to the
chest as much during expiration as inspiration, – should rush to
fill up the vacuum as much as the diaphragm should ascend and
the ribs descend for that purpose: nor should air be expelled
from the wounded pleura; for we may regard the thoracic cavity
as bounded above by the surface of the lungs, and always in the
sound state possessing the same dimensions, – the expansion of
the lungs being commensurate with the descent of the diaphragm
and ascent of the ribs, and the descent of the diaphragm and
ascent of the ribs commensurate with the shrinking of the lungs.
The fact that air does not stream into the wounded pleura in
expiration, but even streams from it, while the ribs are moveable
and the abdominal muscles active, proves, I think, that the descent
of the ribs and ascent of the diaphragm, one or both, in ordinary
expiration, do partly occasion, by compression,t the diminution of
the lungs, or, at least, are not its passive effect, but coincide with
it by independent powers, – which are, the elasticity of the elevated
ribs (and displaced abdominal organs?) if not the contraction
of the extended abdominal muscles. We shall presently see another
reason for believing that the organs of the chest are really
compressed during expiration. Haller refers expiration to the
pressure of the lungs by the elastic ribs, and the abdominal and
other muscles, and to the elastic and muscular contraction of the
lungs themselves, which he considers more forcible than the
compression. It appears to me that he is right; but that, never-
theless, either the lungs alone, or the walls of the chest alone,
[Seite 122] are able, when unassisted by the other, to produce expiration.
The change in the situation of the ribs is, moreover, trifling
compared to that of the diaphragm, and respiration often proceeds
very well by the diaphragm alone. Animals which are remarkable
for swiftness and perseverance in the race scarcely employ the
intercostal muscles, using the diaphragm almost solely.t

The beautiful contrivance in the shape of the thorax deserves
attention. By its being conical, every degree of motion in the
diaphragm produces a greater effect on the capacity of the chest
than could occur were it of any other shape.

The passage of the air into the cells may be distinctly heard
on applying the ear to the corresponding part of the chest, and
is called by Laennec the respiratory murmur. It is much louder
in children, and in them the cells are far more numerous and
small. Whence an equal portion of lung from an infant a few
days old weighs fourteen times more than from a man of seventy.u

The elasticity and muscularity of the lungs are not sufficiently
great to expel the whole of their air in expiration. Thus they
remain constantly in a certain degree of distention.x

I now recur to the subject of the circulation of the blood, as
promised in note (E) of the last section.

The vacuum constantly threatening in the chest, according to
Dr. Carson, either from the shrinking of the lungs or the con-
traction of the inspiratory muscles, and I may add from the ex-
pulsion of blood from the ventricles of the heart, will evidently be
prevented, not only by the falling of the ribs and the ascent
of the diaphragm in the former case, and ingress of additional air
into the bronchiae in the latter, but also by the flow of venous
blood into the auricles: for the venous blood, being subject to
the full atmospheric pressure without the chest, will necessarily
be driven into the chest to prevent a vacuum; the blood of the
pulmonary artery and aorta is under the same circumstances, but
the propelling force of the ventricles at one moment, and the
action of their valves during their relaxation, prevent its retro-
gression. The atmospheric pressure on the blood-vessels creates
a necessity for greater strength in the ventricles, as it impedes
[Seite 123] the progress of blood from the heart; but it also facilitates the
return. Thus the smaller pressure on the heart acts, by the in-
tervention of the blood, as an antagonist to its contracting fibres,
assisting to dilate them when they become relaxed.

That the blood is drawn towards the heart during inspiration
has been long acknowledged. ‘“In my experiments,”’ says Haller,
‘“if you open the chest, abdomen, neck, or fore-extremities of an
animal, and lay bare the great veins, the superior and inferior
cava, the jugular, subclavian, brachial, or mammary, you will see
the blood return to the heart whenever the animal inspires, and
these veins recede some lines from it, become empty and pale,
flat and bloodless:”’ – depleri, pallescere, explanari, exsangues
fieri.”y In the words of Dr. Magendie, sixty years afterwards,z
‘“when the chest dilates, it inspires the blood of the cavae, and
successively that of the veins ending in them; much in the
same way as it does the air into the trachea.”’ Were Dr.
Carson’s account of respiration correct, as a vacuum would be
threatening in the chest equally during expiration and inspira-
tion, the shrinking of the lungs should occasion the blood to
stream towards the heart as much during the one as the other,
to fill up the vacuum. But this is not the fact, any more than,
as we saw, that air rushes into the wounded pleura during
expiration. The coincidence of the effect of inspiration on the
venous blood, and, when the pleura is wounded, on the air,
[Seite 124] prevents us from supposing that inspiration affects the circulation
merely by giving a free passage of blood through the lungs.
‘“The great venous trunks of the head, neck, chest, abdomen,
fore-extremities,”’ says Haller, ‘“swell during expiration, from
the blood either being obstructed or retrograding, and at
inspiration are emptied of it from its flowing freely to the heart.”’a
Or, in the words of Magendie, ‘“when the chest contracts, the
blood is driven back into the cavae by the pressure experienced
by all the organs of the chest.”’ That the blood does really
retrograde during expiration, appears by an experiment of Ma-
gendie’s, in which a hollow bougie was passed into the great
veins as far as the cava, or auricle itself, and the blood flowed
from its extremity during expiration.b This fact seems to show
compression of the thoracic organs during expiration, and there-
fore is an additional argument that ordinary expiration is not the
effect solely of the elastic and muscular shrinking of the lungs.
Such, indeed, is the pressure of expiration, that the heart during it
propels the blood more violently into the arteries, and even into
the veins; and, on the other hand, less forcibly during inspiration.c
[Seite 125] A continuance in refraining to inspire after a violent expiration, of
course almost suspends the circulation by depriving the heart of
blood,d which is no longer drawn to the heart by inspiration, and
has been squeezed out by expiration: a continuance in refraining
to expire after a deep inspiration has the same effect, but more
slowly. In both cases the blood is no longer drawn to the heart
by inspiration, and does not experience those chemical changes
in the lungs which are indispensable to its free passage through
them; though, they being, in the former, filled with air, and empty
in the latter, it can continue to pass through them much longer in
the former.

And this leads me to observe, that the mere suspension of
respiration impedes the circulation through the heart by causing
obstruction in the lungs, and that, consequently, inspiration, by
giving free passage to the blood through those organs will
accelerate its course through the veins, independently of a
vacuum; although the influence of the vacuum is shown by the
effect of inspiration upon the contents of tubes inserted, not into
the veins, but merely into the cavity of the pleura or pericardium.
Whether respiration is suspended after an expiration or an in-
spiration, the effect is the same: – the blood accumulates in the
lungs and right side of the heart, if the windpipe is tied, whether
the lungs be empty or full at the time of the ligature; and there-
fore it is not merely the mechanical condition of the lungs that
produces the obstruction in this case, as was once supposed,
but the want of chemical changes.e

But for this consideration, the effects of the thoracic vacuum
on the circulation might be overrated; and, indeed, that too high
an estimate has been formed of it is very certain: for,

1. In the foetus, and in animals which do not respire at all, or
not by a thoracic vacuum, the vacua arising from the dilatation of
the heart’s cavities, and from its diminished bulk under contraction,
only can occur.f

2. If we suspend respiration and prevent the influence of both
sources of vacuum, the circulation continues till the want of chemi-
[Seite 126] cal changes arrests it; and if the vena cava, or any great vein, is
obstructed so as to cut off connection with the heart, it becomes
distended with bloodg coming up towards the heart; and if wounded
between the ligature and the extremities, the blood flows, whatever
the position of the animal, till death ensues.h In these cases no
vacuum assists. If the pericardium is laid bare, so that no vacuum
can occur, except that from the dilatation of the heart’s cavities,
and the trachea tied, the right ventricle swells enormously with the
arriving blood,i – a fact not to be explained, even by the heart’s
own vacuum. The influence of the left ventricle upon the
course of the blood in the veins, was also shown by Magendie,
who firmly tied every part of a dog’s leg, except the great artery
and vein, and then tied the latter and wounded it below the
ligature, when the blood was projected to some distance, and
continued to be so, except when the artery was compressed;
and as long as the circulation continued, the stream from the
vein was regulated at pleasure by compressing or liberating the
artery.k – If a turgid vein in the hand is compressed, it will not
become empty above, as it should if suction from one or all of
the three sources mentioned, were considerable; and the jet of
blood from an artery was found by Hales to be greater during a
deep inspiration,l (probably from the more abundant supply to
the left side through the lungs,) showing the action of the ven-
tricle to be proportionably greater than the power of the thoracic
vacuum at the moment of inspiration to oppose the discharge of
blood from it. Still the effects of the vacuum are such as we
have seen, and it must lessen the labour of the heart.

The empty condition of the arteries after death, has been
ascribed by Dr. Carson to the thoracic vacuum. He states, that
if an animal is destroyed by admitting air into each pleura, the
arteries are found as turgid as the veins;m but the same results
have not been obtained by others;n and I presume that the obstruc-
tion in the lungs from the want of chemical changes, gradually
[Seite 127] lessening the supply to the arteries and producing accumulation
in the veins, together with the superior contractile powers the of
arteries, are, jointly, quite sufficient to explain the circumstance.
The effect of the obstruction in the lungs while the left ventricle
continued to propel blood, was strikingly shown by Bichat, who
produced enormous congestion of the lungs, liver, spleen, &c.,
by strangling animals slowly, and found much less if respiration
was completely arrested at once, so that the left ventricle ceased
to propel blood very soon after the obstruction in the lungs took
place.o The greater the space into which the former blood can
flow from the arteries, the less blood will they contain. Hence, if
a ligature is passed round the cavae, some quantity of blood is
found in the arteries; if around the pulmonary artery, less; and
when the lungs have been kept distended after death by artificial
inflation, after opening the chest, so that all their vessels might
be unfolded, the arteries have been found quite empty, though
there was no thoracic vacuum,p and though the effect of the left
ventricle of the heart was destroyed by a ligature on the aorta.

Hence, if Dr. Carson’s experiments on this point are accurate,
I should ascribe the turgidity of the arteries when the pleurae were
filled with air, and the lungs compressed, to the diminution; and
when this was not done, the emptiness of the arteries, to the
largeness, of the pulmonary space into which the blood could pass.

The influence of suction has been thought by Dr. Carson to
assist in explaining venous absorption.q

Dr. Carson ascribes the effects experienced in elevated situa-
tions to the rarity of the atmosphere, by which it cannot compress
the blood sufficiently to aid the return of this fluid towards the
heart. Saussurer says, that when he was on the summit of the
Alps he experienced extreme fatigue and loss of muscular power,
and irresistible, rapid, and violent palpitation, and difficulty of
breathing, all which soon ceased on his assuming the horizontal
posture, in which, of course, the blood circulates more easily.
His guide, a slim old man, was unaffected, and climbed with
ease like a goat; and many unaccustomed to such elevations
have been equally unaffected, for habit and a strong heart will
render the influence of pressure but little necessary.

[Seite 128]

Gravity has been thought by Dr. Carson, as well as by older
writers, materially to aid the circulation: – ‘“by the stroke of the
heart, a quantity of fluid is withdrawn from one end of the
column, and by the synchronous vibration of the arteries an
equal quantity is added to the other.”’ ‘“A perpetually repeated
generation of motion must be produced through the different
parts of the venous system by gravity, and this motion must be
from the ends of the veins to the trunks.”’s ‘“The simplest
weight of a column of blood in any descending artery is suffi-
cient to raise the blood through open capillaries to an equal
height in the corresponding vein, according to the hydrostatical
law, that fluids attain the same level in all communicating ves-
sels.”’t Yet, in the horizontal posture, there can be no assistance
from gravity, but the circulation proceeds perfectly well; and,
indeed, gravity, on the whole, seems to impede the circulation,
for if the arms hang down for a length of time, or the legs are
not rested horizontally, they ultimately swell. Nothing assists
the heart more than a horizontal posture, as seen in syncope, in
which the restoring effects are perfectly explicable by its mecha-
nical aid to the heart, without reference to the brain.u The
effects of posture are necessarily greater in tall persons. In the
horizontal posture, the heart having less to do, beats more slowly,
and in very tall persons the pulse has been found 12 or 20 beats
quicker in the upright posture.

The operation of exercise is very material. If an extremity is
not exercised, its circulation always becomes languid, it resists ex-
ternal temperature with difficulty, and wastes, and, if gravity also
co-operates by a vertical position, it swells; and exercise will pre-
vent the congestive agency of a continued vertical position. Violent
exercise causes proportionate violence of circulation. The action
of muscles evidently operates by compression, and chiefly of the
veins, as the coats of the arteries are so much stronger. The
blood can go but one way. The stream behind, and the valves
in the veins of the extremities, determine the effects of the
pressure to be in the course of the circulation. The compressed
vessels are at once nearly emptied, and the instant that the pres-
sure is alternately removed are again filled; and the momentary
[Seite 129] impediment during the compression is immaterial, on account of
the innumerable venous anastomoses. The progress of the blood
cannot but be accelerated. The dyspnoea that is felt arises from
the force with which the blood drives through the lungs, and
which renders frequent respiration necessary.

In the foetus the case is analogous, although Dr. Carson has
imagined it different, and thought it necessary to frame a little
hypothesis to reconcile circumstances. The foetal lungs, ex-
periencing no atmospheric pressure, are contracted to the utmost,
and the diaphragm, suffering no stimulus from the will on account
of uneasy sensation arising from want of breath, is completely
relaxed, and forced upwards to remove the vacuum; and the
venous blood without the thorax must be drawn forcibly into the
right auricle, preventing the vacuum which the discharges of blood
from the left ventricle tend to produce. In the foetus, moreover,
the blood is propelled into the aorta by both ventricles, as Mr.
John Bell remarks, and, therefore, the circulation less requires
other assistance. The vacuum from the dilatation of the cavities
of the heart occurs in the foetus and all animals which have a heart:
but in those which have no such respiration as the human, there
can be no assistance to the circulation by thoracic vacuum.

The ordinary cause of the first inspiration appears to be the novel
impression of cool air upon the surface; for if at any time we are
suddenly exposed to a cold wind, or plunge into cold water, the
diaphragm and intercostal muscles instantly contract, and a sudden
inspiration takes place. The blood rushes into the expanded
lungs, and, being afterwards obstructed when the inspiratory
muscles cease to act and the elastic lungs shrink, gives rise to
an uneasy sensation, which is instinctively removed by another
inspiration, and thus respiration afterwards continues through life.
The fact of respiration commencing before the chord is tied,
shows that neither congestion in the aorta, nor deficiency of
chemical changes, is the cause of the first inspiration. If an
animal is born under warm water, its respiration begins at the
moment you choose to bring it up into the air. Buffon proved this
by causing a bitch’s accouchment to take place in a tub of
warm water, and allowing the pups to remain there for half an hour.

The power of excitement of the surface to cause inspiration
has been recently shown by Beclard and others, who, on me-
chanically irritating foetal kittens still enclosed in the membranes,
found inspiratory efforts take place at each irritation.

[Seite 130]

(B) After much uncertainty, it was thought ascertained by the
experiments of Messrs. Allen and Pepys that no oxygen is
absorbed in ordinary respiration, but that what disappears goes
entirely to unite with the carbon of the blood and produce carbonic
acid, the latter being exactly equal in bulk to the oxygen which
disappears, – about 27 1/2 cubic inches per minute, or 39,534 in
twenty-four hours, according to the experiments of these gentle-
men, – a quantity containing about 11 oz. troy of solid carbon,
and, perhaps, about double the average result of most other
experiments.

But Dr. Edwards has since shown that, however correct were
these results, it was erroneous to generalise from them; that more
oxygen is continually consumed by brutes than goes to the form-
ation of carbonic acid; and that this excess varies from above 1/3 of
the volume of the latter to almost nothing.u The variation depends
not only upon the species, but upon the developement relative
to the age, and upon individual differences in adults.

He therefore finds that the bulk of the air is not unaffected by
respiration, but that generally a diminution takes place. Dr. Le
Galloisx and Dr. Delarochey also found that oxygen disappeared
in greater quantity than carbonic acid was formed.

Allen and Pepys observed, that if the same air was breathed
repeatedly, some oxygen was absorbed and some azote discharged,
and that if nearly pure oxygen was employed in the case of
guinea-pigs, carbonic acid was produced and a portion of the oxy-
gen replaced by azote, this portion decreasing, however, as the
experiment proceeded.

Dr. Edwards ascertained that respiration causes sometimes an
increase of azote, sometimes a diminution, and sometimes no im-
portant difference in its quantity. He thinks that it is always being
absorbed and discharged, and that the proportion of these processes
differs under different circumstances. Its discharge exceeds at all
times in very young animals, as guinea-pigs; and in spring and sum-
mer; while its absorption exceeds in autumn and winter, as far as his
experiments upon adult sparrows and yellow-hammers go; though
occasional exceptions occurred from unappreciated circumstances,
powerful enough to overbalance the effect of season.z The differ-
[Seite 131] ence in the proportion of the inspired and expired azote never
equalled the greatest differences observed between the oxygen
which disappeared and the carbonic acid formed. Cold-blooded
quadrupeds were shown by Spallanzania to absorb azote, and fish
by Humboldt and Provençal.b Sir Humphrey Davy had already
ascertained the absorption of azote in his own person.

Dr. Edwards’s reasons for believing azote to be constantly both
absorbed and discharged are: –

1. That if an animal is made to breathe oxygen mixed with 1/20 of
azote, azote is discharged in abundance, as was found by Allen and
Pepys, so that when there is little or no azote to be absorbed,
its exhalation at once shows itself: and we may conclude that in
common respiration its exhalation may be as great, but not ob-
servable because nearly an equal quantity is absorbed:

2. When a mixture of oxygen and hydrogen was employed by
those chemists, and pure hydrogen by Dr. Edwards, not only was a
large quantity (much exceeding the bulk of the animal) given
out, but a considerable quantity of hydrogen was absorbed, – in
Dr. Edwards’s experiment equal to the azote given out,c proving
that exhalation and absorption can proceed together: and he
asks why, if hydrogen is absorbed, not much more so azote,
which is more fit for respiration and the support of life; and
concludes that its absorption may be as great in common re-
spiration, but not observable because a nearly equal quantity is
discharged.d

Carbonic acid itself is shown by Spallanzani and Dr. Edwardse
to be exhaled from the lungs independently of the operation of
oxygen; – when snails, frogs, fish, or very young kittens are im-
mersed in hydrogen.

Mr. Ellisf contends that the carbon is excreted by the pul-
monary vessels, and unites with the oxygen externally, and
Dr. Prout thinks this opinion corroborated by the fact,g – that,
[Seite 132] when phosphorus dissolved in oil is injected into the blood-
vessels, vapours of phosphorous acid stream from the mouth and
nostrils, – what would hardly have occurred if the acid had been
formed in the vessels, as it would probably have remained in
solution in the blood, not being volatile. The phosphorus was
probably excreted from the vessels in minute subdivision, and
united with the oxygen of the atmosphere upon coming in contact
with it, producing phosphorous acid; and the same may be
imagined respecting the carbonic.h

There can be no reason to adopt this hypothesis on account
of the supposed difficulty of the air and blood acting upon
each other through the vessels, because we saw in Sect. II. note
(G), that they do so, through moistened bladder, out of the body.
The well-known secretion and absorption of air by membranes,
shown by the existence of air in the air-bladder of fish, the
sudden formation of air in the alimentary canal in disease, the
separation of carbonic acid gas and of azote in the lungs,
the absorption of azote and oxygen in the experiments of
Dr. Edwards, the absorption of air in emphysema, and the
occurrence of emphysema without injury of the lungs,i together
with the evolution of carbonic acid gas from the blood under the
air-pump or when hydrogen only is breathed,k – all show the
possibility of oxygen being absorbed by the blood, and carbonic
acid given out from it in the lungs, ordinarily, in respiration, as a
secretion. Dr. Edwards contends that, since so much carbonic
acid is given out from the blood in the respiration of pure hydro-
gen; and that, since the quantity given out in hydrogen is as great
as is observed in common air, there can be no reason to doubt that,
in common air, the carbonic acid proceeds from the same source
as in hydrogen, viz. – is exhaled; more especially as carbonic acid
exists largely in the blood: and that the oxygen, therefore, must be
absorbed by the blood. But whether mere carbon leaves the blood
and forms carbonic acid with the oxygen externally to the
vessels, or the oxygen unites with, and the carbonic acid separates
from, the blood, much of the affair would appear chemical, – nei-
ther all the carbon nor all the carbonic acid gas to be secreted;
because when venous blood is exposed to oxygen out of the body
[Seite 133] it becomes florid, and oxygen disappears and is replaced by car-
bonic acid.

With respect to the change of arterial to venous blood, although
exposure to hydrogen or carbonic acid – positive substances, will
effect it, and the fact of the separation of carbon occurring when
the florid colour is acquired looks as though the presence of
carbon were the cause of the dark hue; yet arterial blood,
inclosed in vials or in vacuo, grows purple,l – a proof that the
mere action of the constituents of the blood upon each other is a
sufficient cause. And the circumstance of venous blood remaining
dark, though by the air-pump carbonic acid is evolved from it, looks
rather as if the florid colour were dependent on the operation of
oxygen.

The generality of respiration or something analogous among
living beings,m and all the circumstances attending its perform-
ance, induce Dr. Prout to believe that it does something more
than effect chemical changes.n He considers galvanism as an
instrument extensively used by the vital principle, and since gal-
vanic operations probably occur in the action of the constituents
of the blood on each other, especially when oxygen is pre-
sent; and the combination of carbon with oxygen resembles the
union of the more oxidisable metal and oxygen in the galvanic
[Seite 134] battery, – a great additional purpose of respiration is, in his
opinion, to supply or excite galvanism.

Dr. Crawford observed that less carbonic acid was formed in pro-
portion to the height of the temperature;o Dr. Jurine, that more
was produced when the circulation was quickened, – during the
hot stage of fever, digestion, or exercise, and less in the cold stage;p
and his results were confirmed by Lavoisier and Seguin.q Dr. Ed-
wards has found less formed in summer than in winter.r

Dr. Prout and Dr. Fyfes have found the quantity of carbonic
acid gas diminished by mercury, nitric acid, vegetable diet, tea,
substances containing alcohol, depressing passions, long fasting, and
fatigue, and probably by sleep. Dr. Prout found that it under-
goes in himself an increase from day-break till noon, and a de-
crease from noon till sun-set, remaining at the minimum till day-
break. In the experiments of Allen and Pepys, the formation of
carbonic acid gas slackened when their guinea-pigs fell asleep.
Dr. Prout also observed that an increase or decrease from the
maximum or minimum was followed by a proportional decrease or
increase during a diurnal period. It would appear, also, that less
is formed in infancy, and more as the adult age is approached, in
brutes.t

The average number of respirations in a minute, in adults is
probably twenty, but the absolute number, and the number re-
lative to the pulse, vary both in different individuals, and in the
same under different circumstances.

The common quantity of air taken in at each inspiration is
about 16.5 cubic inches, and the quantity remaining after death
in the lungs of a stout adult man, about 100 cubic inches, accord-
[Seite 135] ing to Allen and Pepys. Dr. Bostock, agreeing with Dr. Menzies
and many others, believes 40 cubic inches to be the average inspir-
ation, and thinks that 160 or 170 remain in the lungs after ordinary
expiration,u for these organs are never emptied by expiration.

The ordinary quantity of aqueous vapour emitted by the lungs,
trachea, throat, and mouth, may be about 20 oz. in 24 hours.x

Camphor, phosphorus, ether, diluted alcohol, gases, and various
odorous substances, when introduced into the system, escape in a
great measure by the lungs: whence they are perceived in the
breath. Dr. G. Breschet and Dr. Milne Edwards, conceiving that in
the dilatation of the lungs by inspiration, the enlarged space would
cause not only the air to rush in, but the exhalation from the sur-
face of the air-cells and pleura to increase and exceed that from
other parts, have made several experiments which prove this to
be the case. On injecting a small quantity of oil of turpentine
into the crural vein, the breath instantly smelt strongly of it,
and the pleura on being cut open did the same; while no odour
of it arose on exposing the peritonaeum. If a larger quantity was
employed, it impregnated every part. If, instead of natural re-
spiration, artificial was instituted, in which the air does not enter
the lungs by the formation of a vacuum on the expansion of the
chest, but is forced into them and itself expands the chest, no
more exhalation of odorous substances took place from the lungs
than from other parts; and, indeed, if a cupping-glass was applied
over another denuded part, the odorous substance was given out
there, while the lungs afforded no sign of it.y

(F) When the air is not changed, death in general occurs long
before all the oxygen is consumed, through the carbonic acid
which is formed; but bees, some worms and mollusca, completely
deoxidize it.z

Lavoisier removed the carbonic acid by potash as quickly as it
was produced, and found that a guinea-pig could live in air con-
taining but 6.66 per cent. of oxygen, and with still less became only
drowsy.a

[Seite 136]

Dr. Edwards advances, contrary to Morozzo,b that every warm-
blooded animal perishes instantlyc when placed in the air in which
another has died through want of renovation, and that all of the
same class among them deoxidize it equally, though in different times.
This time will occasionally differ 1/3, notwithstanding the size of the
body and the movements of the chest be equal in them, and the car-
bonic acid be removed as quickly as formed. The young deoxidize
it more slowly than adults; and the young, if quite deprived of air,
die later than adults.d Indeed, Buffon found, and Dr. Le Gallois
and Dr. Edwards have confirmed his discovery, that new-born
animals of many species, as dogs and rabbits, will live a long time
without air, even after they have been allowed to respire. This
period lessens as the animal’s temperature rises with age; and in
those whose temperature is at birth high, as guinea-pigs, it is
very short.e They live longer than adults also in a limited quan-
tity of air.f Amphibious animals likewise live long without air.g

Persons have been said to be able, by habit, to live without air
a considerable time. Death generally occurs at the latest in one or
two minutes, when respiration is suspended; but by habit some few
divers of the swimming school at Paris can remain under water
three minutes.h If the system is in an extraordinary nervous
[Seite 137] state of insensibility, the absence of air, like the absence of food
or the administration of strong agents, may be borne for a very
long time. Even fainting renders submersion less dangerous.

Whether venous blood differs from arterial in containing more
carbon or less oxygen, it is not calculated for life. When injected
into the carotids, the brain becomes affected, as if poisoned, and
death gradually ensues; and when it circulates through the
coronary arteries of the heart, – the action of which organ will con-
tinue though its left cavities are supplied with venous blood, – the
heart’s motion ceases, and the functions of each organ are impeded
and at length cease if venous blood circulates through its arteries.i
When death occurs by impediment to the functions of the lungs,
the heart loses its irritability by its substance becoming penetrated
with venous blood and ceases to propel the blood of its cavities;
and the brain, becoming powerless from the same cause, ceases
both to perceive uneasiness in the lungs from the want of fresh
air and to be able to will inspiration. If the death of the body
arise from the brain, it is by the brain being unable to continue
respiration.

Some suppose that respiration is very instrumental in prevent-
ing the putrefaction of the living body; and this by carrying off
its carbon, – the substance which, in the spontaneous decomposi-
tion of animals, is the first rejected, and unites with the oxygen
[Seite 138] of the atmosphere; and indeed Spallanzani found, that the
dead bodies of animals deoxydated the air after death, and often
as much as during life, before decomposition was perceptible.k
He says also, that torpid animals, whose respiration had entirely
ceased, also carbonated it. As the latter fact cannot be ascribed
to the separation of carbon to the lungs, nor to the mere chemical
changes of decomposition, it probably arises from the functions
of the skin.

From the chyle entering the venous blood about to arrive at the
lungs, respiration has been thought to assist in assimilation.
More carbonic acid, however, is not found after every meal, nor
less during fasting, till it proceeds to the length of debility.
Many animals sleep after feeding; yet in sleep less is produced.

(G) The experiment consisted in laying the lungs completely
bare, and reviving the animal by artificial respiration. Hooke
varied it by pricking the surface of the lungs and forcing a con-
tinued stream of air through them.

The following are the words of Harvey: ‘“It would appear that
the use of expiration is to purify and ventilate the blood, by sepa-
rating from it these noxious and fuliginous vapours.”’

SECT. IX.
OF THE VOICE AND SPEECH.

[Seite 139]

152. We have described the chief use of respiration. We
shall hereafter mention how far it contributes to the con-
version of the chyle into blood, and to the support of almost
the whole class of natural functions. Its other uses are at
present to be considered.

And first, respecting the voice.a This begins after birth,
and proceeds from the lungs, as was observed long ago by
Aristotle, who called those animals only vocal, which breathed
by means of lungs. The voice is, properly speaking, a sound,
formed, by means of expiration, in the larynx, which is a
most beautifully constructed organ, fixed upon the top of the
windpipe, like a capital upon a pillar.b

153. The larynx is composed of various cartilages, which,
being united together in the form, as it were, of a little box,c
and supplied with a considerable and wonderful apparatus of
muscles,d may be moved altogether, or separately, according
to the variations of the voice.

154. The part of the larynx most concerned in producing
the voice, is the glottis, or narrow opening of the windpipe,
having the epiglottis suspended, and, in a manner, fixed upon
it. It is clearly ascertained, that the air, expired from the
lungs, and striking properly upon the margins of the glottis,
becomes sonorous.

[Seite 140]

155. But it has been disputed what changes the glottis
undergoes in modulating the voice: whether it is alternately
widened and contracted, as Galen and Dodart supposed, or
whether, according to Ferrein, the variations of voice are
effected rather by the tension and relaxation of its ligaments.

The latter, consistently with his opinion, compared the
larynx to a violin; the former, more consistently with nature,
to a flute.e

Every thing considered, we must conclude that the glottis,
when sounding, experiences both kinds of changes; since the
grave and acute modulation of the voice must depend very
much upon the alterations produced in the glottis by the
ligaments, especially the inferior thyreo-arytenoids – the vocal
chords
of Ferrein, and by the corresponding modification of
the sinuses or ventricles of the larynx.f (A)

156. That every degree of motion in the glottis is directed
by the numerous muscles of the larynx, is proved by the
beautiful experiment of tying or dividing the recurrent nerves,
or par vagum,g and thus weakening or destroying the voice
of animals. (B)

157. Man and singing-birds have the power of whistling.
In the latter, it is accomplished by a larynx placed at each
extremity of the wind-pipe and divided into two portions.
[Seite 141] The former, though possessing a single and undivided larynx,
has learned, I imagine, to imitate birds by the coarctation of
his lips.h (C)

158. Singing, which is compounded of speech and a musical
modulation of the voice, I conceive to be peculiar to man and
the chief prerogative of his vocal organs. The power of
whistling is innate in birds; many of them may easily be
taught to pronounce words, and instances have been known
of this even in dogs. But it is recorded, that genuine singing
has once or twice only, and then indeed but indifferently and
with the utmost difficulty, been taught to parrots; while, on
the other hand, scarcely a barbarous nation exists, in which
singing is not common.i

159. Speech is a peculiar modification of the voice, ad-
justed to the formation of the sounds of letters by the expir-
ation of air through the mouth or nostrils, and in a great
measure by the assistance of the tongue, applied and struck
against the neighbouring parts, the palate and front teeth in
particular, and by the diversified action of the lips.k (D)

The difference between voice and speech is therefore evi-
dent. The former is produced in the larynx; the latter
by the peculiar mechanism of the other organs above
described.

Voice is common to both brutes and man, even imme-
diately after birth, nor is absent in those unfortunate infants
who are born deaf. But speech follows only the culture
and employment of reason, and is consequently, like it,
[Seite 142] the privilege of man in distinction to the rest of animal
nature. For brutes, natural instinct is sufficient: but man,
destitute of this and other means of supporting his existence
independently, enjoys the prerogative of reason and language;
and following, by their means, his social destination, is en-
abled to form, as it were, and manifest his ideas, and to com-
municate his wants to others, by the organs of speech.

160. The mechanisml of speech and articulation is so
intricate and so little understood, that even the division of
letters and their distribution into classesm are attended with
much difficulty.

The division, however, of Ammann,n into 1. vowels, 2.
semi-vowels, and 3. consonants, is very natural:

I. He divides the vowelso into simplea, e, i, y, o, u,

And mixed – ä, ö, ü.

These are formed by the voice only.

The semi-vowels and consonants are articulated by the
mechanism of speech.

II. The semi-vowels are nasalm, n, ng (n before g,
which is nearly related to it), that is, the labio-nasal m, the
dente-nasal n, and the gutture-nasal ng;

Or oral (lingual) – r, l, that is, r with a vibration of the
tongue, or l with the tongue less moved.

III. The consonants he distinguishes into sibilant (pro-
[Seite 143] nounced in succession) – h, g, ch, s, sh, f, v, ph, that is h,
formed in the throat, as it were a mere aspiration; g and ch,
– true consonants; s, sh, – produced between the teeth;
f, v, ph, – formed by the application of the lower lip to the
upper front teeth:

And explosive (which are, as it were, suddenly exploded,
by an expiration, for a time suppressed or interrupted), viz. k,
q,
– formed in the throat; d, t, – about the teeth; p, b,
near the lips;

And double (compound) – x, z. (E)

161. We must just mention certain other modifications of
the human voice, of which some, as hiccup and cough, belong
more properly to pathology than to physiology, but are very
common in the most healthy persons; and others, as crying
and laughing, appear peculiar to the human race.

162. Many of these are so closely allied, as frequently
to be converted into each other; most also are variously
modified.

In laughter there is a succession of short, and, as it were,
abrupt expirations.p

Coughing is a quick, violent, and sonorous expiration, fol-
lowing a deep inspiration.q

Snoring is a deep, sonorous, and, as it were, tremulous
inspiration, from the vibration of the velum palati during deep
sleep with the mouth open.

Sneezing, generally the consequence of an irritation of the
mucous membrane of the nostrils, is a violent and almost
convulsive expiration, preceded by a short and violent in-
spiration.r

Hiccup, on the contrary, is a sonorous, very short, and
almost convulsive, inspiration, excited by an unusual irritation
of the cardia.s

[Seite 144]

In crying there are deep inspirations, quickly alternating
with long and occasionally interrupted expirations.t

Sighing is a long and deep inspiration, and the subsequent
expiration is sometimes accompanied by groaning.u

Nearest in relation to sighing is gaping,x which is produced
by a full, slow, and long, inspiration, followed by a similar
expiration, the jaws at the same time being drawn asunder,
so that the air rushes into the open fauces and the Eustachian
tubes. It occurs from the blood passing through the lungs
too slowly: v. c. when the pressure of the air on the body is
diminished, as upon very high mountains. A peculiar feature
of gaping is the propensity it excites in others to gape like-
wise; arising, no doubt, from the recollection of the pleasure
it produced. (F)


NOTES.

(A) Numerous explanations have been attempted of the me-
chanism of the human voice, but these, having been formed at a
time when the laws of sonorous bodies were but very imperfectly
understood, are all more or less unsatisfactory. The recent in-
vestigations of Dr. Savart, have enabled him to explain the con-
struction of the vocal organs from principles which had hitherto
escaped the observations of experimentalists. The facts adduced
by him prove that the production of the voice is analogous to that
of the sound of wind instruments, and that the short column of
air contained within the larynx is susceptible, from the nature of
the elastic sides which confine it
and from the manner by which
it is excited, of rendering sounds, both of a peculiar nature and
much graver than its dimensions would seem to indicate. After
establishing the preliminary facts by numerous experiments, he
thus accounts for the formation of the voice.

The vocal organ, composed of the larynx and the cavity of the
[Seite 145] mouth may be considered a conical tube, in which the air is
put in motion in a similar manner as in flute organ-pipes; this tube
is so constructed that, notwithstanding its small dimensions, it is
capable of rendering a great variety of sounds, some of which are
very grave; its inferior part being composed of elastic sides capa-
ble of different degrees of tension, whilst the mouth opening more
or less, and thus changing the dimensions of the column of air,
exercises a considerable influence on the number of its vibrations.
By constructing a pyramidal tube of nearly the same length and
capacity as the vocal tube, and membranous at its lower part, all
the sounds of an ordinary voice can be produced from it, either
by varying the tension of the membranes, or by altering the size
of its orifice. The trachea is terminated at its upper part by a
narrow opening which may be diminished or increased by the
approximation or recession of the arytenoids, and by the contrac-
tion of the thyreo-arytenoid muscles. This opening performs the
same office as the lumière (sound-hole) of organ-pipes. But, for
the sound thus produced to unite all the known qualities, the
tension of the extensible parts of the sides of the vocal tube
must be proportionate with that of the sides of the ventricle, as
well as that of the superior and inferior ligaments; and the orifices
through which the air escapes must be susceptible of varying and
of adapting themselves so as to give the best possible result. For
these purposes nature has formed these parts of elastic or mus-
cular tissues. The thyreo-arytenoid constitutes itself the inferior
and external sides of the ventricles; the uses of this muscle (of
which Dr. Savart gives a very accurate description), are the follow-
ing: when it contracts it gives the proper degree of tension for
the sound required, to the lower part and external side of the ven-
tricle, as well as to the edge of the orifice through which the air
passes from the trachea; by means of the extremities of its
oblique fibres it acts also on the fold of mucous membrane which
forms the upper part of the extensible portion of the vocal tube.
Its action upon this part is aided by that of a small muscle which
should be called the superior thyreo-arytenoid, for it extends
obliquely from the external and lower part of the arytenoid, up-
wards and forwards, to the rounded angle of the thyreoid carti-
lage, to which it is attached by very short tendinous fibres. The
office of this muscle is to increase the tension of the external side
of the ventricle, conjointly with the oblique fibres of the thyreo-
[Seite 146] arytenoid, several fibres of which are interwoven with it, and to
which it serves as a support. After death, these two muscles
being more or less relaxed, the external and internal sides of the
ventricles collapse together, and the folds of the mucous mem-
brane are found relaxed. The superior ligaments have no
peculiar muscle, and they are sufficiently rigid and thick to dis-
pense with this aid. The two folds of mucous membrane placed
at the upper termination of the larynx, and which float in the air
which vibrates around them, are susceptible of a variable tension
which also influences the sound.x

(B) Dr. Le Gallois ascertained that the division of the recurrent
nerves frequently proves even fatal to animals. This effect, how-
ever, varies with the species and age. The danger diminishes as
the animal is older; and, after a certain age, little inconvenience
follows, because the (anterior part of the?) opening of the glottis
is larger proportionally to the capacity of the lungs, not merely in
some species than in others, but in old than in young animals.y

(C) In whistling, the coarctation of the lips only serves as an
embouchure to the column of air contained within the mouth and
larynx. The varieties of intonation entirely depend on the altera-
tions of the tongue and on the corresponding motions of the larynx.
For the higher sounds the tongue is brought forwards and the
larynx raised, and for the lower sounds the tongue recedes and
the larynx is depressed.

(D) I am indebted to the powerful Dr. Conyers Middleton for
the knowledge of two cases of distinct articulation with at least
but little tongue.z In his exposure of the pious deceptions of
weak and wicked Christians during the first centuries of the
Christian era, he notices a pretty tale of an Arian prince cutting
out the tongues of some of the orthodox party and these being as
able to talk as before; nay one (O hominum impudentia !), who
had been dumb from his birth, gained the faculty of speech by
losing his tongue. Granting the fact, and even that the tongues
were completely extirpated, he refers, for the purpose of proving
[Seite 147] there was no miracle in the case, to two relations of similar in-
stances by medical men.a Professor Thomson found the speech
little impaired after the bullets had carried away more or less of
the tongue.b Louis, Richter, Huxham, Bartholin, and Tulpius
mention similar cases. An instance of good articulation after the
loss of the apex and body of the tongue quite down to the os
hyoides occurred in this country, and was seen by the Royal
Society.c

(E) For this note, as well as (C) I am indebted to my excellent
friend, Mr. Charles Wheatstone, who has already contributed so
much to science as to justify the highest expectations.

The elements of which all the spoken languages of mankind
are composed, consist of the modifications given sometimes
to the breath, and at other times to the voice, during their pas-
sage through the cavity of the mouth; these modifications are
principally effected by the altered positions of the lips and tongue
with respect to the fixed parts of the containing cavity.

The classification of these articulations into vowels and conso-
nants has been generally recognised.

The vowels are formed by the voice, modified, but not inter-
rupted, by the varied positions of the tongue and lips. Their
differences depend on the various proportions between the aper-
ture of the lips and the internal cavity of the mouth, alterable by
the different elevations of the tongue. The vowel aw (as pro-
nounced long in all, and short in got) is formed by augmenting
the internal cavity by the greatest possible depression of the
dorsum of the tongue, and, at the same time, enlarging the sepa-
ration of the lips. Departing from this sound there are two
series: 1st. In which the external aperture remains open, and
the internal cavity gradually diminishes by the successive alter-
ations of the tongue. 2d. In which the positions of the tongue
are successively the same as in the first series, but the aperture
of the lips is diminished. The approximation of the lips produces
[Seite 148] a more sensible effect as the inner cavity is more enlarged;
hence two modifications of the first sounds of the second series are
easily recognised, whilst only one variety of the others is readily
appreciable, as will be shown in the following table.d Each of
these vowels may be long or short, according to the duration
of its sound in a syllable.

TABLE OF VOWELS.

Each series formed by the gradual elevation of the tongue.

xxx

e

The above table exhibits all the most usually pronounced vowel
sounds, but practised ears might distinguish others intermediate
in each series. When these vowels are sounded, the soft palate is
raised so as to prevent the voice from issuing through the nasal
channels; when, on the contrary, the soft palate is depressed
the partial escape of the breath through the nostrils modifies all
the preceding sounds in a very evident manner. To distinguish
these two modes of articulating the vowel sounds, we may adopt
Dr. Darwin’s terms, orisonant and narisonant vowels.

Consonants may be divided into continuous (sometimes called
liquids or semi-vowels,) and explosive. For the latter, the breath
or voice is stopped in its passage through the mouth; for the
former, it is allowed a free passage, though the apertures are
more narrowed than for the vowels.

[Seite 149]

But the most comprehensive and important division of these
articulations is into aspirates and sonants; meaning by the former
term, the modifications of the breath, and by the latter, those of
the voice. In ordinary speaking these are mingled together to
form the elementary syllables of language. The aspirates, or
sounds indicated by the characters p, f, sh, s, th (in thing), t,
k, ll,
(Welsh), differ from the sonants, or those represented by
b, v, z (in azure), z (in puzzle), th, (in the), d, g (in gay), l, only
by the latter being accompanied with the vocal sound.

Every sonant has its corresponding aspirate, though many of
the latter are unknown to the English language, such are the
aspirates corresponding to the sonants r, m, n, ng (in song), &c.

When forming the component parts of syllables, the aspirates,
as well as the sonants, are always articulated with sonant vowels.
An aspirate vowel, followed by its vocal enunciation, is always
represented by the character h, but it is never pronounced
separately, except in whispering.

The consonants, like the vowels, are divided into orisonant and
narisonant. The only narisonant consonants in our language, are
those corresponding to the orisonant explosives b, d, and g
(in gay), – viz. m, n, and ng (in song). By this mode of pronun-
ciation the sounds are rendered continuous.

TABLE OF CONSONANTS.

xxx
[Seite 150]

This table shows that for all the consonants employed in the
English language, only ten positions of the mouth are required,
the modifications being effected by other means. Among the
modifications not already described, may be particularised the
reduplication of the 10th, 11th, and 12th sounds; the first occa-
sioned by the vibratory motion of the lips, the others by that of
the tongue.

Observations: – 1. The lower lip presses on the upper teeth,
but allows the air to escape between them; a similar sound is
produced by allowing the breath to pass through the lips when
nearly closed: – 2, 3, 4, 5. These sounds may be considered as
the continuation of the first series of vowel sounds; for placing
the mouth in the position for e (5.), and continuing to elevate the
back part of the tongue, and, at the same time, to curl its tip,
these sounds will be successively produced: – 6, 7, 8. These
sounds differ from the preceding four, inasmuch that the back part
of the tongue does not approximate to the palate; the mouth being-
placed for the second vowel, the front of the tongue is elevated
so as to touch the palate just above the teeth; for the r, the
point is drawn back, so as to allow the air to escape; and for the
l, the point is firmly pressed against the palate, and the breath
escapes by the two sides: – for the l, (in fille), the air escapes with
more difficulty: – 9. These are used in the Gaelic and German,
but not in English: – 10, 11, 12. These sounds are produced by
the forcible escape of the breath, or voice, after a complete
obstruction by the lips or tongue. The obstruction by the lips
gives p, or b; that by the front of the tongue above the upper
teeth, t, or d; and that by the back of the tongue against the
palate, k, or g; these different articulations may therefore be
distinguished as Labial, Dental, and Palatal. When the sound
escapes through the nostrils it becomes continuous; the m, n, and
ng are therefore not explosives.

The alphabetic characters invented as visual and permanent
representations of the articulations of speech, are very inadequate
to effect the purpose intended. In the English language there
are but five characters to indicate all the varieties of the vowels,
viz. a, e, i, o, u; of these, one only is pronounced when un-
combined, as a pure vowel; this is e, – the 5th sound in the table
of vowels; the other four are diphthongs or combinations of
two vowels; a is the 4th and 5th; i is the 3d and 5th; o is
[Seite 151] the 6th and 11th; and u is the 5th and 11th. When constituting
parts of syllables, the same character represents many different
vowel sounds.

The consonantal characters are not quite so arbitrary, though
among these there are some simple sounds expressed by two let-
ters, and others which have no character to denote them; and on
the other hand there are several redundant letters representing
two simple sounds, f, v, r, l, p, t, k, b, d, m, and n, are generally
constant in their signification. The simple sounds represented by
two characters are sh, th (in think), th (in the), and ng (in song). The
single characters representing more than one sound are s (in sea,
his, sure, and vision); z (in zany and azure), g (in gay and George).
The redundant letters are, c (having the sound either of s or k),
q
(k followed by the eleventh vowel); j (compounded of d and
the second pronunciation of the z, and the same as the g in George),
and x (standing for ks, or z). y, as generally pronounced, and
w, are not consonants; the first represents the 5th, and the second
the 11th vowel of the table, when immediately succeeded by
another vowel.

The consonants will be best compared by articulating them all,
uniformly preceded or followed by the same vowel; as fe, she, se,
the, pe, te, ke,
&c. or ef, esh, es, eth, ep, et, ek, &c.

It is by no means improbable that the progress of modern art
may present us at some future time with mechanical substitutes for
orators and preachers. For, putting aside the magic heads of
Albert the Great and Roger Bacon, Kratzenstein actually con-
structed an instrument to produce the vowels,f and De Kempelin
has published a full account of his celebrated speaking machine
which perfectly imitated the human voice.g The celebrated
French mechanician, the Abbé Mical, also made two heads of
brass which pronounced very distinctly entire phrases; these
heads were colossal, and their voices were powerful and sonorous.
The French government refusing, it is said, in 1782, to purchase
these automata, the unfortunate and too sensitive inventor, in a
paroxysm of despair, destroyed these master-pieces of scientific
ingenuity.

Having fully explained the various articulations used in oral
[Seite 152] language, it now only remains to investigate the difference between
the inflexions of the voice in singing and in speaking.

The various muscular adaptations of the larynx renders it capable
of producing every inflexion of musical tone within a certain com-
pass, seldom exceeding that of two octaves. In singing, sounds,
each constant in its degree of tune, follow each other according to
the rules of melody: whilst in speaking, the voice slides up and down,
and ‘“does not dwell distinctly, for any perceptible space of time,
on any certain level or uniform tone, except the last tone on which
the speaker ends or makes a pause.”’ Provincial dialects, and even
individual modes of speaking, differ much in the extent and nature
of these slides. Steele has endeavoured to establish a system
of notation for these inflexions, and other modifications of the
voice necessary to be observed by the orator, and has by this
means proposed to perpetuate the most splendid specimens of his-
trionic, forensic, and senatorial eloquence.h To proceed farther
with this subject would be an infringement on the province of
philology.

(F) I know no reason to believe that the tendency to gaping on
seeing others do so, arises from the recollection of the pleasure it
affords; or that hiccup is produced by an irritation of the cardia
more than of any other part of the stomach. Gaping occurs
chiefly during fatigue or hunger; when we are but half awake,
either before or after sleep; and in ague and hysteria. In
hiccup, I think, that, after the inspiration has proceeded a
certain length, the glottis closes, and the diaphragm endeavours
in vain to contract farther.

In laughter, there is more or less noise at each little expiration,
from a mere sort of rustling sound to loud peals; the mouth
is more or less lengthened, and its angles drawn up, and in extreme
laughter it is opened still more by the descent of the lower jaw;
if hearty, the tears run over, the head shakes, and even the body,
and respiration is interrupted, and actual pain of the sides and
diaphragm is felt. Some of our comedians have absolutely ago-
nized me. It arises from drollery, the anticipation of gratification,
or actual gratification, or tickling; it is also common in hysteria.

In coughing, the mouth opens that the air may rush in that
[Seite 153] direction, since the current is not required in the nostrils as in
sneezing, and these would not afford sufficient vent. The
glottis lessens just before the expiration.

In sneezing, the opening of the fauces is lessened, and the head
bent back, that the current may be directly through the nostrils,
in which the irritation generally exists.

Haller is well worth reading on these subjects.i

Although brutes have no articulate sounds, they have a lan-
guage perfectly intelligible to one another. They make one noise
to express joy, another terror, another to summon their young,
&c., and comprehend the meaning of sounds made by us, not only
of an inarticulate kind, but also articulated. The sagacity of
some dogs in this respect is astonishing. ‘“They learn to under-
stand not merely separate words or articulate sounds, but whole
sentences expressing many ideas. I have often spoken,”’ continues
Gall, ‘“intentionally of objects which might interest my dog,
taking care not to mention his name, or make any intonation or
gesture which might awaken his attention. He, however, showed
no less pleasure or sorrow, as it might be; and, indeed, manifested
by his behaviour that he had perfectly understood the conversation
which concerned him. I had taken a bitch from Vienna to Paris;
in a very short time she comprehended French as well as German,
of which I satisfied myself by repeating before her whole sen-
tences in both languages.”’k

SECT. X.
OF ANIMAL HEAT.

[Seite 154]

163. Man, other mammalia, and birds, are distinguished
from the rest of animals by the natural temperaturea of their
bodies greatly exceeding that of the medium in which they are
accustomed to exist. Man is again distinguished from these
classes of animals by possessing a much lower temperature
than they; so that in this climate it is about 96° of Fahr.,
while in them, and especially in birds, it is considerably
higher.b (A)

164. This natural temperature in man, is so constant,
equable,c and perpetual, that, excepting slight differences
from variety of constitution, it varies but a few degrees in the
coldest climate and under the torrid zone. For the opinion
of Boerhaave, – that man cannot live in a temperature ex-
ceeding his own, has been refuted, since the admirable observ-
ationsd of H. Ellis, the celebrated traveller, and formerly the
governor of Georgia, by the remarkable experimentse of
[Seite 155] many excellent physiologists.f (B) The striking prerogative
of man in this respect is evinced by his being restricted to no
climate, but inhabiting every part of the earth from Hudson’s
bay, where Mercury freezes, and from Nova Zembla, to the
scorching shores of Senegal. (C)

165. The explanation of this equable and perpetual tem-
perature is particularly simple and natural, and founded on
the doctrine which makes the lungs the grand focus, and the
decomposition of the oxygenised portion of the air (148)
which we breathe, the fomes, of our heat.

166. For, as the oxygenous part of the inspired air is de-
composed in the air-cells of the lungs, in such a way that its
base, viz. oxygen, which by its union with latent caloric was
before aëriform, now separates from this caloric; it would ap-
pear that, by this decomposition, one portion of the caloric is
rendered sensible in the bronchiae, while the other enters in a
latent form into the blood while circulating in the innumerable
and delicate net-works of the pulmonary vessels.g

167. When the oxygenised blood thus charged with latent
heat circulates through the aortic system, it acquires carbon
in the small vessels and sets free much of the latent heat which
it had received: in this way is our animal temperature prin-
cipally produced and modified.h (D)

168. Its production and regulation, however, appear much
influenced by the secretion of the various fluids from the blood,
[Seite 156] and by digestion as well as other functions of the animal
economy.

169. Since the changes are effected by the energy of the
vital powers only, the great influence of these in supporting
our temperature must be easily perceived.i

170. Many arguments render it probable, that the action
of the minute vessels is dependent upon the varied excite-
ment or depression of the vital principle, and the conver-
sion of oxygenised into carbonised blood, again, upon this.

For the remarkable phenomena of the stability of our tem-
perature,k (proved by the thermometer, and not by the sense
of touch, which may be fallacious) – that it is scarcely in-
creased by the heat of summer, or diminished by the cold of
winter, but found sometimes even to increase on immersion in
cold water,l demonstrate that the action of the minute vessels
varies according to the temperature of the medium in which
we are placed: so that, when exposed to a low temperature
(by which their tone is probably augmented) more oxygen is
exchanged for carbon and more heat evolved, while in a high
and debilitating temperature this exchange is diminished and
less heat evolved.m

[Seite 157]

171. The corium, which covers the body, and the internal
surface of the alimentary canal, eminently contribute, if we are
not much mistaken, to regulate our temperature.n For both
these organs are supplied with an immense number of blood-
vessels, being analogous in this respect to the lungs, and are
so intimately connected with the lungs by means of sym-
pathy,o as to be able to perform a part, and, for a time, the
whole, of some of their functions in their room. This is ex-
emplified in adults labouring under nearly total consumption
or other violent affections of the lungs, and nevertheless,
existing for a length of time almost without respiration.p

172. This opinion respecting the action of the cutaneous
vessel in exciting, moderating, or almost extinguishing, our
heat, receives much support from the physiological and pa-
thological facts of some parts being frequently of a higher or
lower temperature than the rest of the system.

Thus we must attribute the coldness of the dog’s nose to
the specific action of its own vessels being modified differ-
ently from that of the rest; so on the other hand, the burning
at one time of the cheeks and of another of the palms of the
hands in hectic fever, to a similar locally increased action of
vessels; besides other phenomena of the same description,
v. c. the heat of the genitals during the venereal oestrum, and
the obstinate coldness of the feet in so many invalids.

173. The alimentary canal is the only internal part, besides
the lungs, exposed to the contact of the atmosphere. There
is scarcely occasion to prove that it is so exposed, and that
we swallow a considerable quantity of air.

The air, when swallowed, is decomposed in the stomach
and intestines, so that, during health, it soon loses its elastic
form: not, however, when the capillaries of the canal are de-
bilitated, nor when it exists in too great quantity.

[Seite 158]

The immense congeries of blood-vessels in the intestines
on their internal surface which is usually thought equal to
the external surface of the body, agrees very well with this
idea.


NOTES.

(A) All animals, as far as can be ascertained, and even vege-
tables, have a tendency to preserve a temperature more or less
distinct from that of the surrounding medium; yet the difference
among them in this respect is so great that they have been di-
vided into warm and cold-blooded. To the former belong the
more complicated, those whose pulmonary apparatus is most ela-
borate, – man and mammiferous quadrupeds and birds. To the
second, oviparous quadrupeds, fish, and most of the invertebrate.
Birds have the highest temperature, – 107° to 110°; mammiferous
quadrupeds, 100° to 101°; man 96° to 98 1/2°. There is some va-
riety, not only in individuals, but according to age, season, and
climate. It is less in the young, according to Dr. Edwards and
Despretz:q the former states the human temperature in infancy
to be 94 1/4°; the latter asserts, that while in birds it is 105° in
winter, it is nearly 111° in summer, gradually increasing in spring
and decreasing in autumn. In the high temperature to which we
shall see Dr. Fordyce and his friends were exposed, the temper-
ature of the body rose two or three degrees, and Dr. Delaroche in
a vapor-bath at near 120°, found the heat under his tongue in-
creased but about five degrees at the end of seventeen minutes.r
In sparrows and yellow-hammers Dr. Edwards found it five or six
degrees higher in summer than in winter; and Dr. Davy one or
two degrees higher in Ceylon than in England.s In disease it will
fall, and on the other hand rise; in fever it has been noted at 107°,
in tetanus at 110°,t and probably, on some occasions, it rises still
higher, at least, locally. In old age it is not so high as in the
[Seite 159] age of full vigour; nor in remote parts as in those nearer the
heart.u John Hunter made observations on the heat of cold-
blooded animals.v The thermometer in the stomach and under
the skin of the abdomen of the frog and toad stood at 40°, when
the atmosphere was 36°; in the lungs of snails at 35°, 36°, 37°,
38°, when the atmosphere was 28°, 30°, 30°, and 34°; the heat
of earth-worms was 58 1/2°, when the atmosphere was 56°. Fish
are not above two degrees warmer than the water.w Cold-blooded
animals placed in an elevated temperature are much more in-
fluenced by surrounding media than the warm-blooded. Yet
frogs are but at 80° or 82° in a medium of 110° or 115°.x The
heat of insects when congregated is considerable: J. Hunter
found the thermometer rise to 93° or 98° in a hive of bees in
spring; to 104° in summer; to be at 82° when the air was at 40°;
and at 73° in winter.

The same tendency in vegetables is shown by the greater
difficulty with which the juices in their stems and branches are
frozen than lifeless fluids; by ice thawing when roots shoot into
it;y and by snow upon the leaves or stems of plants thawing
sooner than that which lies on surrounding inanimate bodies.
J. Hunter observed a branch of growing fir and a bean leaf thaw
the part of the surface of a freezing mixture on which it was
placed, and the fir subsequently another to which it was removed.z
When the sheath of the arum maculatum and cordifolium is burst-
ing and the cylindrical body just peeping forth, it is said, by
Sennebier, to be so hot for some hours as to seem burning;a and
twelve of them placed round the bulb of a thermometer to have
raised the mercury from 79° to 143°.

Even eggs are cooled and frozen with more difficulty than equal
masses of inanimate matter; although, when once frozen and their
life destroyed, they freeze readily.b

[Seite 160]

(B) Dr. Fordyce, one of the most eminent of my predecessor
at St.Thomas’s Hospital, went successively into three rooms heated
to 90°, 110°, and 120°. In the first he staid five minutes, and
sweated gently. – In the second, he sweated more profusely, and
remained ten minutes. – In the third, after remaining twenty
minutes, the thermometer under the tongue and exposed to the
urine was at 100°; the pulse 145°; the veins of the surface were
enlarged, and the skin red. He afterwards entered a room heated
to 130°, and staid 15 minutes: the thermometer under the tongue,
in the hand, and exposed to the urine, was at 100°.

Sir Joseph Banks, Sir Charles Blagden, and Dr. Solander, went
subsequently into rooms heated to between 96° and 211°, – the
temperature of boiling water, and remained several minutes. If
they breathed on the thermometer it sunk several degrees, and
every expiration felt cold to the scorched nostrils: the thermo-
meter under the tongue was 98°, and the body felt cold to the
touch, though at 98°. Sir C. Blagden remained eight minutes in
an apartment heated to 260°. The air felt hot, and for seven
minutes the breathing was natural, but anxiety and oppression
then came on; the sensible heat of the body varied but little.
Dr. Dobson went into a room heated to 224, and felt no op-
pressive heat, though every metal about him speedily became
hot. A bitch of moderate size was subjected to a heat of 220°.
In ten minutes the only sign of distress was that of holding out the
tongue, and when taken out at the end of half an hour, the tem-
perature being at 236°, the bottom of the basket was found wetted
with saliva. The thermometer applied to her flank was only 110°,
i. e. 9° above the natural standard.

In these rooms, eggs on a tin plate were roasted hard in twenty
minutes; beef steaks cooked in thirty-three minutes; and if the
air was impelled upon them in a stream, they were cooked dry in
about thirteen minutes.

Tillet and Duhamel relate that the young female servant of a
baker at Rochefoucault went habitually into ovens heated to 276°,
and remained without great inconvenience for twelve minutes,
taking care not to touch the oven. These gentlemen themselves
bore a heat of 290° for nearly five minutes. Dr. Delaroche and
Dr. Berger found various warm and cold-blooded animals support
from 108° to 113° for an hour and a half in heated dry air; but
an elevation of about 30° beyond this kill them all except a
[Seite 161] frog, in from half an hour to two hours. They themselves expe-
rienced a sense of scalding in a vapour-bath of 122°, and could not
bear it more than about ten minutes; while M. Lemonnier could not
bear a water-bath of 113° above eight minutes.c Hence, at the
very same high temperature of the surrounding medium, there is
more secretion by the skin in a vapour-bath than in dry air, and
more in a water-bath than in a vapour-bath.

(C) At Sierra Leone the mean temperature is 84°, and Watt
and Winterbottom frequently saw it 100° and even 103° in the
shade. At Senegal it has been 108 1/2° and even 117 1/2°. During
the sirocco it is 112°, in Sicily; Humboldt saw it 110° and 115°
near the Orinoco, in South America. On the other hand, at Nova
Zembla the cold is so intense that when the sun sinks below the
horizon the polar-bear is no longer seen, the white fox only endur-
ing the cold. Yet the Dutch, who wintered there under Hemskerk
(76° N. L.) withstood the cold if moving about and previously in good
health. When some of our countrymen were on Churchill river,
in Hudson’s Bay, lakes ten or twelve feet deep were frozen to the
bottom, and brandy froze in their rooms, though provided with fires.
They suspended in their rooms red hot twenty-four pounders, and
kept an immense fire; but if these went down, the walls and beds
were covered with ice three inches thick.d Yet in Hudson’s Bay the
Canadians and Esquimaux live and hunt in the coldest weather.
Gmelin, sen. witnessed at Jenisiesk, in 1735, a cold of 120° below
zero, that froze mercury and killed all the sparrows and jays.e
Captain Parry once observed a temperature of 52° below zero.
When the air was at – 49° the party used to walk on the shore.
It was usually at – 32°. The temperature of eleven out of six-
teen foxes was from 100° to 106 3/4, of four about 100°, and of one
only 98°, although the air was from – 3° to – 32°. No relation was
observable between the temperature of the body and of the atmo-
sphere;f it thus appearing that the temperature is more steady
under cold than heat. Some cold-blooded animals bear heat very
badly. Dr. Edwards says that frogs die in a few seconds in water at
107°.g Yet a species of taenia has been found alive in a boiled carp;
[Seite 162] but then the carp which it inhabits will live in water as hot as
human blood.h Some of the lowest animals appear intended for
high temperatures. Dr. Reeve found living larvae in a spring at
208°; Lord Bute, confervae and beetles in the boiling springs of
Albano, that died when plunged into cold water.

The germs of many insects, &c. are unaffected by a great range of
temperature. I know a gentleman who boiled some honey-comb
two years old, and, after extracting all the sweet matter, threw the
remains into a stable, which was soon filled with bees. Body lice
have appeared on clothes which had been immersed in boiling water.
Spallanzani found long ebullition in the open air favourable to the
appearance of the animalcules of vegetable infusions, and the
application of great heat in close vessels, although it prevented the
appearance of a larger kind of animalculae, did not that of a smaller.
The eggs of silk-worms and butterflies hatch after exposure to a
cold of 24° below zero. On the other hand, insects may be
frozen repeatedly, and recover as soon as thawed, as we shall
see when speaking of torpidity.

(D) No phenomenon in living bodies is more remarkable than
their peculiar temperature, and no one was of more difficult
explanation before the modern progress of chemistry. Dr. Mayow
had indeed advanced, that it depended on respiration, and that this
was a process similar to combustion, and so far from cooling the
blood, as others believed, supplied it with heat.

If two different bodies are placed in a temperature higher or
lower than their own for a certain length of time, they will, at
the end of the period, be found not of the same, but of different
temperatures. That which has the higher temperature is said
to have a smaller capacity for caloric; that which has the lower,
a greater capacity. To raise the former to a given temperature,
therefore, requires less caloric than to raise the latter to the same
degree.

The temperature of solids is more easily affected by a given
quantity of caloric, than that of fluids, and the temperature of
fluids than that of aëriform bodies: or, in other words, solids
have a smaller capacity for caloric than fluids, and fluids than
aëriform bodies. If, therefore, a solid becomes fluid, or a fluid aëri-
form, it absorbs a great quantity of caloric, notwithstanding its tem-
perature remain precisely the same. And the converse holds
[Seite 163] equally good, – if an aëriform substance becomes liquid, or a
liquid solid, the caloric which it before contained is now (from its
diminished capacity) much more than sufficient for the tempera-
ture which before existed, and the temperature of the body
accordingly rises.

In respiration, the dark blood of the pulmonary artery parts
with a portion of its carbon and acquires a florid hue. Oxygen
disappears and carbonic acid is expired with the other constituent
of the atmosphere, – nitrogen or azote, which appears generally
to have experienced little or no change from inspiration.

The celebrated Dr. Crawford of St. Thomas’s Hospital appeared
to prove, by his experiments, that the arterial blood has a larger
capacity for caloric than the venous, and common air than car-
bonic acid gas. When, therefore, the carbonic acid appears in
the lungs, the smaller capacity of this than of common air for
caloric, must cause an increase of temperature; but the blood,
having changed from venous to arterial, has acquired a greater
capacity than before, and absorbs the heat given out by the car-
bonic acid. The blood, of course, does not become warmer, be-
cause the caloric is not more than sufficient to render its tem-
perature equal to what it was previously; and indeed, according
to some, it is not quite sufficient for this, since the temperature
of the arterial blood of the pulmonary veins has appeared two
degrees lower than that of the pulmonary artery to some experi-
menters, although the greater number have found it a degree or
two higher than the venous.

The body in this way acquires a fund of caloric, and yet the
lungs, in which it is acquired, do not experience any elevation of
temperature, or if they do, this is very inconsiderable.

The arterial blood, charged with much caloric, which, as it
circulates through the small vessels, is not sensible, becomes
venous, – acquires a dark hue, and its capacity for caloric is
diminished; consequently its temperature rises, – the caloric
which was previously latent, is, from the decrease of capacity,
sufficient to raise its temperature, and is evolved. In this mode,
the loss of caloric which occurs from the inferior temperature of
the medium in which we live, is compensated. The fresh supply
is taken in at the lungs, and brought into use in the minute
vessels.

Of late this theory has fallen into some discredit.

[Seite 164]

All experiments upon the capacities of bodies for heat are very
delicate and liable to error; and the conclusions of Crawford on
this point have been denied by Drs. Delaroche and Berard, with
respect to gases, and by Dr. Davy, with respect to arterial and
venous blood.i

The experiments of these chemists have led them to believe
the difference of capacity less than Crawford supposed, and in-
sufficient to account for animal temperature. With respect to
the gases, Dr. Bostockk justly remarks, that the objection does
not apply more to the doctrine of animal heat, than to the theory
of combustion in general. Whenever carbon unites with oxy-
gen, and carbonic acid is produced, caloric is liberated, whe-
ther in fermentation, or combustion, &c. With respect to the
blood, he declares, and Dr. Bostock’s reputation for accuracy and
soundness in chemical matters is not little, that ‘“after attentively
perusing the experiments of Crawford, and comparing them with
those that have been performed with a contrary result, he con-
fesses that the balance of evidence appear to him to be greatly in
favour of the former, though he acknowledges that they are of so
delicate a nature as not to be entitled to implicit confidence,
and that it would be extremely desirable to have them carefully
repeated.”’

If, however, it were true that Dr. Crawford’s statement of the re-
lative capacities is incorrect, still the fact of heat being necessarily
evolved on the disappearance of oxygen in the lungs, and the ap-
pearance of carbonic acid, would stand unaffected, and we should
only be obliged to adopt the doctrine of Mayow, that the lungs are
the focus of the heat of the body. This was relinquished on the
objection that the lungs should then be hotter than other parts.
But when we consider that the blood is incessantly streaming to
the lungs from all parts, and again leaving them, we may, I think,
presume that the blood will always convey away their heat, and
prevent their temperature from rising above that of other parts.
The heat of all parts is, caeteris paribus, commensurate with the
quantity of blood circulating through them. This is equally ex-
plicable on either supposition. If their heat is derived from the
heat of the blood conveyed to them, the more blood streams
through them, the hotter will they be; if from chemical changes
[Seite 165] in the blood while in them, the more blood streams through them,
the greater will be the amount of chemical change, and the
greater the extrication of caloric. The quantity of blood is ineffi-
cient unless constantly renewed, on either supposition. On the
first, fresh blood must come incessantly from the lungs with its
high temperature; on the second, if not renewed, the chemical
changes will cease, having already occurred.

A host of circumstances show that our temperature depends
upon respiration, and therefore upon chemical changes.

In high temperatures we have less necessity for the evolution
of heat; in low temperatures, more. Accordingly, in the former,
the arterial blood remains arterial, – is nearly as florid in the veins
as in the arteries, and the inspired air is less vitiated; in low
temperatures, the venous blood is extremely dark, and the in-
spired air more vitiated.l Some have imagined that the body
remains at its standard high temperature by the refrigeration of
the evaporating sweat. But though this must contribute, it is not
the sole cause:m for frogs lose as much proportionally to their size
by evaporation as any other animal, yet they follow pretty closely
the surrounding temperature. Whenever, on the other hand, the
body itself heightens its temperature, as in fever, more oxygen is
consumed by the lungs;n (in the cold stage of fevers we saw that
less was consumed). The temperature of the various classes of
animals, and their vitiation of the air, are always proportional; and
inverse to the length of time they can live without air.

The temperature of young animals is lower than of adults, or
rather they maintain a peculiar temperature much less, and they
vitiate the air less, and require respiration less, proportionally,
than adults.o As they proceed to vitiate it more, and require
respiration more, their calorific power increases. While their ca-
lorific powers are weak they breathe, if they are exposed to cold,
quicker, so as to keep up their temperature as much as possible.p
The same is also found in adult warm-blooded animals, not of the
hybernating family, when exposed to cold.q

[Seite 166]

Dr. Edwards found that habit has great influence on the calo-
rific powers of animals; – that a given low artificial temperature
in winter will reduce the animal heat much less than in summer:r
and that with the habit of evolving more heat in winter, is
acquired the habit of consuming and requiring more oxygen, so
that animals supplied with a given quantity of air, and placed in
a given warm temperature in winter, die much sooner than in
summer.s Yet the momentary application of heat or cold has a
different effect: the former heating less if the body has been
subjected to a low, and the latter cooling less if the body has
been subjected to a high, temperature. We all feel the cold less
quickly on leaving the house in winter if well warmed first, than
if we leave it already chilly.

When animals hybernate, their temperature falls, and respira-
tion is nearly or entirely suspended.t Their consumption of air
lessens as the temperature falls, whence they consume less in
November than in August.u If hybernating animals, while torpid
and still placed in the same temperature, are stimulated mecha-
nically to breathe, their temperature rises with the progress of
respiration.x

If the cold to which they are exposed is so intense that it
threatens death, it actually no longer depresses respiration, but
for a time, excites it, and their temperature rises proportionally.y
Man, and other non-hybernating animals, breathe more quickly
when exposed to cold, no doubt for the purpose of supplying
heat, till the powers become exhausted.z

The higher the temperature of the animal, the more extensive
is the aggregate surface of the air-cells, the more blood passes
through its lungs, and the more necessary to its existence is re-
spiration. – The lungs of cold-blooded animals are not subdivided
into minute cells, but formed into vesicles; and birds, which have
the highest temperature among animals, are drowned the soonest.a

[Seite 167]

The changes of the air by the blood, are seen to be effected
entirely by the red particles. Prevost and Dumas found that the
number of red particles is proportionate to the temperature.

If the blood circulates without being first properly changed in
the lungs, the temperature is below the natural standard. Those
who have the blue disease (coeruleansb), as Blumenbach notices
(p. 155), are cold: and coldness is a symptom of hydrothorax, and
of the repletion of the air-cells with mucus in chronic bronchitis;
in the former of which affections the lungs cannot fully expand,
and in the latter the air is prevented from coming fully in contact
with the air-cells.

In cold climates, and in temperate ones in cold weather, animal
food is desired and taken in abundance; in hot climates, and
during the summer in temperate regions, light vegetable food is
preferred, and the appetite is less. We may conceive the former
diet more calculated to support a process similar to combustion,
and under the former circumstances we have seen that the changes
of the air in the lungs are actually more considerable.

The temperature of parts falls if not maintained by a constant
stream of blood from the lungs through the aorta and its rami-
fications, and is, caeteris paribus, in exact proportion to this
supply.

Whether Crawford’s theory be correct or not, the production
of animal heat must be as evidently a chemical process, as changes
of temperature among inanimate bodies; yet some ascribe it to
nervous energy. I cannot imagine nervous energy to cause heat
any more than to cause chemical affinity. As it may bring sub-
stances together which have an affinity for each other, and thus
produce their union, so it may effect those changes which are,
according to physical laws, accompanied by changes of tempera-
ture; but caloric in the body must, I apprehend, like affinity, follow
the same laws, and no others, as out of the body. This, however,
does not prevent animal temperature from deserving the epithet
vital, because it is regulated by the vital powers of the system, al-
though through the instrumentality of chemical changes. If the high
temperature of an inflamed part is owing to the increased momen-
tum, – the increased sum of the quantity and velocity of its blood,
– yet this increased momentum is produced by the vital powers.

[Seite 168]

Mr. Brodie removed the brain of animals, and continued re-
spiration artificially. The usual chemical changes of the blood
continued in the lungs; yet the temperature of the animals
diminished, and even more rapidly than if the respiration had not
been continued, owing, it is said, to the succession of cool air
sent into the lungs. He therefore concludes, that animal heat
depends much more upon the nervous energy than upon the
chemical changes of the blood.c But this experiment proves no-
thing, because Dr. Le Gallois asserts, that under artificial respir-
ation the temperature may fall, and the animal actually be killed
by cold, even though every part remain uninjured.d In artificial
respiration the air does not rush into the pulmonary cells, because
these are in a vacuum, but is propelled into, and forcibly and
therefore injuriously dilates, them; the consequence is, the form-
ation of a large quantity of frothy mucus. Whether the fall of
temperature be owing to the evaporation of this copious secretion
and its prevention of contact between the air and air-cells,
or to the injurious nature of artificial respiration, still the fact
ascertained by Le Gallois destroys the conclusion which appeared
deducible from Mr. Brodie’s experiment. Indeed, Le Gallois
found, that less oxygen was consumed than in natural breathing,
and that the temperature fell exactly in proportion to the small-
ness of the quantity of oxygen consumed. Dr. Crawford himself
stated, that the chemical process of respiration may, in certain
cases, be the means of cooling the body. If the pulmonary ex-
halation, he said, is in very great abundance, it will carry off so
much of the heat given out during the change of the oxygen into
carbonic acid, that there may not be sufficient to saturate the
increased capacity of the arterial blood: this, therefore, will ab-
sorb caloric from the system, as it passes along, till its temper-
ature equals that of all parts.e I may here remark, that the tem-
[Seite 169] perature is kept down in a heated atmosphere by the diminution of
chemical changes in the lungs, and by free secretion and evapora-
tion from the bronchiae and skin. How much each contributes is
not ascertained; but the importance of evaporation was shown in
some experiments of Dr. De la Roche, who raised the tempera-
ture of animals considerably by placing them in a heated atmo-
sphere loaded with moisture, thus preventing evaporation. In a
cold atmosphere, the chemical changes in the lungs are great,
and the skin is dry; the aqueous matter which leaves the body
then, does so by the kidneys, in a fluid form, and even in much less
quantity, because our thirst, and the amount of our drink, are
much less.

Dr. Philip has made experiments equally conclusive with those
of Dr. Le Gallois against the inferences drawn by Mr. Brodie. As
very little air is taken into the lungs in natural inspiration, and a
regard to the bulk and frequency of each inspiration not always
attended to in experiments, it is very probable that that gentle-
man had thrown too much air into the lungs, so that the unnatural
quantity of cold air, and the augmented secretion of bronchial
fluid, made the temperature fall. By impelling little, and that
not frequently, Dr. Philip found that artificial respiration, after
the destruction of the brain, actually retarded the cooling of the
animal, while stronger respiration did actually cool the body.

Of two rabbits killed in this way, their temperature being 104°,
one was subjected to 6 artificial inspirations, and the other to from
26 to 30, in a minute: the temperature of the former was 100° at
the end of an hour, and the latter 98°. Of two, with the temperature
of 102.5°, one was undisturbed, and one subjected to about 30
inspirations in a minute: the temperature of the former at the
end of half an hour was 98.75°; of the latter, only 98.5°. But
the lungs of the latter being now inflated but about twelve times
in a minute, the temperature of the former at the end of another
half hour was 95.25°, and of the latter, 96°. In one experiment,
in which the lungs were inflated but a few times in a minute, the
temperature actually rose nearly a degree by artificial respiration.f
Dr. Hastings, at the same time, made similar comparative experi-
ments, and with similar results. In one, the rabbit in which
artificial breathing was performed, cooled only 4°; while that
which was left undisturbed cooled 7.5°.

[Seite 170]

Dr. Philip afterwards took pairs of rabbits, killed them in the
same way, and then in one experiment destroyed the brain and
spinal marrow of one with a wire, while he left the other un-
touched: in another, precisely similar, he inflated the lungs of
both. Yet, in each experiment, they both cooled equally. In a
third, the brain and spinal marrow of one only was destroyed,
and the lungs of both inflated. These, too, cooled equally.

The temperature of foetuses born without brain is maintained
during the few days they may live.

Professor Rudolphi remarks, that the temperature of animals
bears no proportion to their nervous system: that if it did, man
should be warmer than any brute; the mammalia much more so
than birds; fish much more so than insects; and birds and am-
phibia nearly upon a par; – all which would be the reverse of fact.g

Vegetables have a tendency to preserve a peculiar temperature,
yet they have no nervous system.

But that the nervous system affects the temperature is certain:
a passion of the mind will make the stomach or the feet cold, or
the whole body hot. Paralysed parts are often colder than
others, or, more properly, are more influenced than others by all
external changes of temperature.h But every function is affected
by the mind, though not dependent upon the brain for its regular
performance. And in varieties of temperature, both by the state
of the mind, and by paralysis, there is, as far as we can judge, a
commensurate affection of the local circulation. Parts heated by
any passion are also red, and vice versâ; and paralytic parts must
have imperfect vascular functions, in some measure at least, from
the want of the compression of the vessels by muscular action,
and of the general excitement by volition; they waste, and some-
times inflame and ulcerate, or slough, on the slightest injury.
And parts perfectly paralysed still maintain a temperature above
that of the surrounding medium, as well as circulation, secretion,
&c.i and sometimes the same as in health.

[Seite 171]

Dr. Philip considers galvanism an important agent in the
nervous system, and found that it raised the heat of fresh arterial
blood 3° or 4°, and, at the same time, made the blood venous;
a circumstance proving that the action is purely chemical, – an
alteration of the blood to that state in which its capacity for
caloric is less.k

There is certainly no more reason to believe animal heat de-
pendent on the nervous system, than secretion and every organic
function. That, like these, it is influenced by the state of the
nervous system, is certain; but never, I imagine, except through
the instrumentality of chemical changes.

Besides the power of generating heat, animals are luminous, and
display electric phenomena.

The glow-worm is known to all, and many insects of the beetle
tribe, as well as others, emit light. Many can extinguish or con-
ceal their light, or render it more vivid, at pleasure. In some it
has been found to proceed from masses not dissimilar, except in
their yellow colour, from the interstitial substance of the rest of
the body, lying under the transparent integuments, and absorbed
when the season of luminousness is passed.l The ocean is fre-
quently luminous at night from the presence of certain animal-
cules, to some sort of which, perhaps, is owing the phosphor-
escence of dead herrings. Some fish, as the gymnotus electricus
and torpedo, give electric shocks, and possess a regular galvanic
battery.

I have adopted the common language in speaking of animal
heat, as though the phenomena depended upon a specific sub-
stance. But there is every reason to believe that neither caloric
nor light are fluids, but peculiar states only; and electricity will
probably prove so likewise, and, indeed, all these to be but modi-
fications of the same state.

SECT. XI.
OF PERSPIRATION.

[Seite 172]

174. The functions of the skin, which affords a covering
to the body, are so extremely various, that they cannot all be
easily described with advantage in one chapter, but each will
be considered far more conveniently under that class of ac-
tions to which it belongs.

For, in the first place, the skin is the organ of touch, and
will be examined in this view, under the head of animal
functions.

It is an organ of inhalation, and in this point of view be-
longs to the absorbent system, to be spoken of among the
natural functions.

It is likewise the organ of perspiration, and on this account
is related in many ways to the function of respiration, and may,
we think, very properly follow it in this place.

175. The skin consists of three membranes – The corium,
internal; the cuticle, external; and the reticulum, interme-
diate.

176. The cuticle, or epidermis,a forms the external cover-
ing of the body, is separable into several lamellae,b and ex-
posed to the atmosphere, the contact of which can be borne
by scarcely any other part, if you except the enamel of the
teeth. For this reason, the internal cavities, and the canals
which communicate with the surface for the purpose of admit-
ting air, especially the respiratory passages and the whole of
the alimentary canal, the tongue, the inside of the cheeks, the
[Seite 173] fauces, and the organ of smell, are covered by a fine epithe-
lium, originating from the epidermis.c

177. The texture of the epidermis is extremely simple,
destitute of vessels, nerves, and of true mucous web, and
consequently but little organised; very peculiar, however;d
remarkably strong, considering its pellucidity and delicacy, so
that it resists suppuration, maceration, and other modes of
destruction, for a great length of time; and reproduced more
easily than any other of the similar parts.

178. It is completely sui generis, somewhat like a horny
lamella, and adheres to the subjacent corium by the interven-
tion of a mucus, and by numerous very delicate fibrils which
penetrate the latter.e

The pores, which Leuwenhoek imagined in it, do not
exist; but it allows a very ready passage to caloric, carbon,
[Seite 174] hydrogen, and to matters immediately composed of these,
v. c. oil.

179. The importance of the cuticle to organised systems,
is demonstrated by its universality in the animal and vege-
table kingdoms, and by its being distinctly observable in the
embryo from the third month at latest after conception.

180. The inner part of the cuticle is lined by a fine mucous
membrane, denominated, from the opinion of its discoverer,
reticulum Malpighianum, and by means of which chiefly the
cuticle is united more firmly to the corium.f

Its nature is mucous, it is very soluble, and, being thicker
in Ethiopians, may be completely separated in them from
both the corium and cuticle, and made to appear as a true
distinct membrane.g (B)

181. Our colour resides in it. In all persons the corium
is white, and, in almost all, the cuticle white and semipellucid,
though in Ethiopians it inclines to grey. But the mucous re-
ticulum varies after birth, with age, mode of life, and especially
with difference of climate.

Thus among the five varieties into which I would divide
the human race, in the first, which may be termed Caucasian,
and embraces Europeans (except the Laplanders and the rest
of the Finnish race), the western Asiatics, and the northern
Africans, it is more or less white.

In the second or Mongolian, including the rest of the
Asiatics (except the Malays of the peninsula beyond the
Ganges), the Finnish races of the north of Europe, as the
[Seite 175] Laplanders, &c. and the tribes of Esquimaux widely diffused
over the most northern parts of America, it is yellow or re-
sembling box-wood.

In the third or Ethiopian, to which the remainder of the
Africansh belong, it is of a tawny or jet black.

In the fourth or American, comprehending all the Ame-
ricans excepting the Esquimaux, it is almost copper coloured,
and in some of a cinnamon, and, as it were, ferruginous hue.

In the fifth or Malaic, in which I include the inhabitants of
all the islands in the Pacific Ocean, and of the Philippine and
Sunda, and those of the peninsula of Malaya, it is more or
less brown, – between the hue of fresh mahogany and that of
cloves or chesnuts.

All these shades of colour, as well as the other character-
istics of nations and individuals, run so insensibly into one
another, that all division and classification of them must be
more or less arbitrary.

182. The essential cause of the colour of the Malpighian
mucus, is, if we mistake not, the proportion of carbon which
is excreted together with hydrogen from the corium, and which,
in dark nations, being very copious, is precipitated upon the
mucus, and combined with it.i

183. The corium, which is covered by the reticulum and
epidermis, is a membrane investing the whole body, and de-
fining its surface; tough; very extensible; of different degrees
of thickness; every where closely united, and, as it were, in-
[Seite 176] terwoven, with the mucous tela, especially externally, but
more loosely on its internal surface, in which, excepting in a
few regions of the body, we generally discover fat.

184. Besides nerves and absorbents, of which we shall speak
hereafter, innumerable blood-vessels penetrate to its external
surface, upon which they are shown, by minute injection, to
form very close and delicate net-works.

185. A vast number of sebaceous follicles also are dispersed
throughout it, and diffuse over the skin an oil, which isk very
thin, limpid, does not easily dry,l and is altogether distinct from
the common sweat, and from that which possesses an odour
resembling the smell of goats and is peculiar to certain parts
only.

186. Lastly, almost every part of the corium is beset with
various kinds of hairs,m chiefly short and delicate, more or
less downy, and found nearly every where but on the palpebrae,
penis, the palms of the hand, and the soles of the feet. In
some parts, they are long and destined for peculiar purposes;
such are the capillamentum, the eye-brows, the eye-lashes, the
vibrissae, mustachios, beard, and the hair of the arm-pits and
pudenda.

187. Man is, generally speaking, less hairy than most
other mammalia. But in this respect nations differ. For,
not to mention those nations who to this day carefully pluck
out their beard or the hair of other parts, others appear na-
turally destitute of hair, v. c. the Tunguses and Burats. (C)
On the contrary, creditable travellers assert that some inha-
bitants of the islands in the Pacific and Indian Ocean are
remarkably hairy.n (D)

188. Nor is there less variety in its length, flexibility,
colour, and disposition to curl, both in each race of men
[Seite 177] enumerated above (181) and in individuals: v. c. the hair of the
head in the Caucasian variety is rather dingy or of a nut brown,
inclined on the one hand to yellow, and on the other to black;
in the Mongolian and American, it is black, stiffer, straight,
and more sparing; in the Malay, black, soft, curling, thick,
and abundant; in the Ethiopian, black and woolly: In indi-
viduals, especially of the Caucasian variety, there are great
differences, and chiefly in connection with temperament, which
is found intimately and invariably connected with the colour,
abundance, disposition to curl, &c. of the hair;p and there
also exists a remarkable correspondence between the colour
of the hair and of the irides.

189. The direction of the hairs is peculiar in certain parts,
v. c. – spiral on the summit of the head; – diverging up-
wards on the pubes; – on the exterior of the arm, as is
commonly seen in some anthropomorphous apes, (v. c. in the
satyrus and troglodytes) running in two opposite directions
towards the elbow, i. e. downwards from the shoulder, up-
wards from the wrist; to say nothing of the eye-lashes and
eye-brows.

190. The hairs originate from the inner surface of the
corium, which abounds in fat. They adhere to it pretty
firmly,q by a curious bulb, consisting of a double involucrum;r
– the exterior vascular and oval, the interior cylindrical,
apparently continuous with the epidermis,s and sheathing the
elastic filaments of which the hair is composed, and which
are generally from five to ten in each.

[Seite 178]

191. The hairs are almost incorruptible, and always
anointed by an oily halitus. Of all parts they appear most
truly electrical. They are very easily nourished and even
reproduced, unless where the skin is diseased. (E)

192. Besides the functions ascribed to the integuments in
the former section, must be enumerated their very great
excretory power, by which foreign and injurious matters are
eliminated from the mass of fluids.t

This is exemplified in the miasmata of exanthematic dis-
eases, in the smell of the skin after eating garlic, musk, &c.
and in sweating and similar phenomena.u

193. What is most worthy of our attention, is the transpira-
tion of an aëriform fluid, denominated, after the very acute
philosopher who first applied himself professedly to investigate
its importance, the perspirabile Sanctorianum,x and similar to
what is expired from the lungs.y It likewise is composed of
various proportions of carbon,z azote, and hydrogen,a precipi-
tates lime from solution, and is unfit to support either flame
or respiration.

194. The sweat, which seldom occurs spontaneously during
health and rest unless in a high temperature, appears to be
nothing more than the perspirable matter of Sanctorius
too much increased in quantity by the excited action of the
cutaneous vessels, its hydrogen uniting with the oxygen of the
atmosphere, and assuming the liquid form.

[Seite 179]

195. Upon the same hydrogen, variously modified by the
accession of other elements and constituents, would seem to
depend the natural and peculiar odour perceived in the per-
spiration and sweat of certain nations and individuals.b (F)

196. The quantity of matter perspired from the integu-
ments, which, in a well-grown adult, are equal to about fifteen
square feet, cannot be accurately estimated, but is probably
about two pounds in twenty-four hours.c (G)


NOTES.

(A) One of this family exhibited himself a few years ago in
Bond Street. He was thirty years of age, and stated himself to
belong to the fourth generation of the descendants of a savage
who was found in the woods of America, and had the same con-
dition of skin. He informed me that it is transmitted to every
male without exception in the male line, but has never appeared in
the females or their male offspring: and that the horny warts first
show themselves at two months from birth, are constantly grow-
ing, though most in summer, and are constantly being shed, but
particularly in winter, till the thirty-sixth year, after which they
are never shed, but continue to grow, so that in this man’s father,
who was eighty years of age, and lived in Suffolk when I saw the
man, they were of very great length. They are set so close to-
gether, that their tops form a tolerably smooth surface, unless
they are separated by extending the skin. Nearest those parts in
which there are none, they gradually become smaller. Besides the
parts mentioned by Blumenbach, the glans penis, I understood, was
free from them.

[Seite 180]

(B) Although Dr. Gordond and Mr. Lawrencee assert that
they have never been able to detach any thing from the cutis of
Europeans in the form of a distinct membrane, the rete Malpig-
hianum does exist in Negroes, and the latter gentleman allows
that the various complexions of Europeans and the peculiar cream
white of the Albino, who has unquestionably no colouring matter
in his eyes or skin, show that it exists even in us.

(C) Dr. Wells describes the singular case of a man whose hair
fell off throughout his body in about six weeks, without any evi-
dent cause or derangement of health, and did not return, except that
about two years afterwards, while labouring under a suppurating
tumour of the neck that discharged through several small holes, a
fine down appeared upon his cheeks and chin, which occasioned
him to shave once a week for about three months, when it disap-
peared. He always looked afterwards as if just shaved, and by
wearing a wig would not have been noticed for any peculiar ap-
pearance.f Dr. Frank saw a similar case.g We have an example
of bristly hair shed and renewed every autumn, in five sons of the
same family.h

(D) The reference is to the Kurille and neighbouring islands.
But Krusenstern, a late circumnavigator, declares that he ob-
served no particular hairiness of the people in this part of the
world, and that former accounts are at least exaggerations.i In
the island of Anicoa, he indeed met with one child, eight years
of age, covered with hair: but such an instance has occurred in
Europe. Zacchias, in 1613, saw a tall man at Rome covered
with fine, long, straight hair, of a light yellow colour. There was
a sister similarly hairy, and the father had been a hairy person, but
the mother had not differed from other women. The man married,
and, of four children, one girl and one boy were born covered with
black hair, looking, says Zacchias, like black kids, and reminding the
attendants of the account of Esau’s birth: – ‘“The first came out
[Seite 181] red, all over like a hairy garment.”’k In fifteen days the whole
of this hair fell off, and, as puberty approached, soft fine hair
sprung up all over the body, even over the temples and forehead.l
Shenckius has collected several similar cases.m

(E) The hairs have been represented destitute of life. But they
have turned grey in a single night from excessive copulation, and
from distress of mind. In illness they often grow soft, and hang
about the head. I know a lady whose hair will not keep in curl if
she is in the slightest degree indisposed, and a young gentleman
whose profuse curly hair becomes straight under the same cir-
cumstances: on the other hand, a case is recorded in which it
always curled in a fit of the gout.n Lastly, the hair has been
so sensible in phrenitis after an injury, that the slightest touch
gave severe pain, and when the surgeon clipped a hair unseen
by the patient, this was instantly felt, and occasioned a paroxysm
of rage:o sensibility cannot be acquired by a part not already
alive.

Hair often grows abundantly in portions of the skin usually not
much supplied with it, and these are generally of a brown colour:
it will sometimes grow in parts naturally destitute of it, as the
tongue and even the heart.p Sometimes it grows in encysted
tumours accompanied by fat, and occasionally by teeth and portions
of jaw and amorphous bone; and feathers covered by fat are some-
times found in the thorax and abdomen of tame geese and ducks.q
Hair has also been discharged from the urethra.

(F) The odour of the secretions of the mucous follicles differs
in different parts. In the tonsils, when the secretion is solid, it
is horridly offensive, really faecal, and is a frequent cause of
foetid breath: in the glands behind the ears, when the secretion
is squeezed out in a solid form, its smell is said to be caseous: in
the parts of generation, peculiar. In many brutes, the odour of the
female genitals attracts the male, and is strongest when the animal
is in heat. The mere sweat has a different smell in different parts:
in the arm-pits hircine; in the feet, sometimes like that of tan,
[Seite 182] and sometimes of cabbage-water. Persons differ not only in the
amount of their general perspiration, but in its amount in different
parts; and under exercise and heat, different persons sweat most in
different parts. A person from merely happening to sweat most in
a part whose secretion is generally offensive, may probably acquire
the characteristic odour, without having a particular disposition
to filthiness of secretion. The general perspiration of every one
probably smells peculiarly; for savages can distinguish the nation
of persons by the smell. (Haller and Humboldt.) The boy born
deaf and blind, whose history is related by Mr. Dugald Stewart,
distinguished people by their odour; and I saw in the report
of a trial lately in the newspapers, that dealers in hair boasted
of being able to tell the nation from which the hair came merely
by the smell. The power possessed by brutes in distinguishing
and tracing other animals is well known.

The odour of some persons is said to have been quite a per-
fume. In the memoirs of the Queen of Navarre, we read that
Catharine de Medicis was a nosegay; and Cujacius the civilian,
and Lord Herbert of Cherbury, were equally delightful.

(G) The skin produces chemical changes similar to those which
occur in the lungs (171);r forms a watery secretion (193. sqq.),
and is an organ of absorption.

[Seite 183]

To ascertain the quantity of watery secretion, Lavoisier and
Seguins inclosed the body in a silk bag varnished with elastic gum
and having a small opening carefully cemented around the mouth,
so that, by weighing the body previously and subsequently to the
experiment, they were able to ascertain exactly what had been
lost, and, by substracting from this loss the weight of the perspired
contents of the bag, they also ascertained how much of this had
passed off by the lungs. From repeated trials they found the
mean pulmonary discharge in twenty-four hours amounted to
15 oz. and the cutaneous to 30 oz. The quantity of carbon se-
parated by the lungs ought however to be taken into the account.
If it amount to 11 oz. in twenty-four hours, – the quantity stated by
Allen and Pepys, – there will be but 4 oz. of pulmonary exhala-
tion. But if oxygen and azote are absorbed in respiration, there
must have been correspondently more pulmonary exhalation; and
we have seen that Hales estimated it at about 20 oz. in the
twenty-four hours. They found the cutaneous transpiration at its
minimum during and immediately after meals, and at its maximum
during digestion.

The minimum after digestion was found by them to be 11 grs.
per minute; the maximum 32 grs.: at and immediately after dinner
10 2/10, and the maximum 19 1/10, under the most favourable and un-
favourable circumstances. It was increased by liquid, but not by
solid, food. The pulmonary they regard as greater than the cu-
[Seite 184] taneous proportionally to the surface on which it occurs.t What-
ever was taken, the weight was found to become ultimately as
before. Indigestion lessened transpiration, and the body continued
heavier generally till the fifth day, when the original weight was
restored. Transpiration was less in moist air and at a low tem-
perature, and the pulmonary and cutaneous transpirations obeyed
the same laws.

Dr. Edwards has made a great number of experiments upon
this subject.u He distinguishes the loss of fluid by evaporation of
what is exuded, from that by secretion.x The former occurs even in
the dead body, and is increased, in both the dead and living, and
among all animals, by the dryness, motion, and diminished pressure
of the atmosphere. It may be suspended by saturating the air with
moisture, and by employing animals (vertebrated, cold-blooded)
whose temperature is not above that of the atmosphere; for if those
are employed whose temperature exceeds that of the atmosphere,
the air as soon as it touches them is rarefied, can take up more
moisture, and is no longer air saturated with moisture. These
circumstances, of course, affect only the removal or evapor-
ation of fluid which may have either transuded or been se-
creted, but do not affect the secretion. In frogs, which perspire
copiously, the loss by evaporation at 68° is thus found six times
greater than by mere secretion, and the proportion in man, the
temperature being the same and the air dry, must be greater, as
his skin secretes much less.

The secreted fluid may be carried off by evaporation as quickly
as it is formed, so as to be insensible perspiration, or may be too
abundant for this, and appear as sweat. The transuded fluid may
also be condensed and precipitated on the skin in the form of
sweat.

The cutaneous secretion is not so much augmented by moderate
elevations of temperature as might be imagined; but as the
elevation proceeds, the augmentation of secretion becomes more
than proportionate. It appeared increased after meals and
during sleep, and, though subject to great fluctuations if observed
at short intervals, from accidental changes in the atmosphere,
underwent successive diminutions when observed every six hours,
from six o’clock a. m., – the hour of rising, – till the return of the
[Seite 185] same period. In frogs this regular diminution might be detected
every three hours.y

In frogs the cutaneous secretion continues, though at its mini-
mum, in the moistest air and in water; and it would appear to do
so also in man.z

The matter of the cutaneous secretion contains an acid, pro-
bably the acetic, a muriate of potash and soda, acetate of soda,
and perhaps albumen.a What evaporates is mere water.

Dr. Edwards makes some curious remarks upon the different
effects of dry and moist air when hot, and when cold. When hot,
dry air will of course communicate less heat to the body than if
moist, and will, by its dryness, cause more evaporation; so that the
two operations of air, dry or moist, will correspond in temperatures
above that of the body. When cold, dry air will remove less
heat from the body than moist, but, by its dryness, will cause
more evaporation, and therefore tend to cool more, so that the two
operations oppose each other in temperatures inferior to that of
the body.b The same remarks apply to cold water.

He did not find moist cold air to cool animals more than dry
cold air.

In low temperatures, we have seen that the loss by evaporation
greatly exceeds that by secretion. In high, it is the reverse, and,
when the body is covered with sweat, there can be no loss by the
evaporation which occurs, independent of secreted fluid, whether
the air be dry or moist. Vapour will cause more loss by secretion
than dry air; but no loss can take place by the lungs in hot
vapour.c

Perspiration can never be entirely suppressed, because the
cold which suppresses secretion, causes the air, however moist,
and therefore opposed to evaporation, to rise in temperature, by
coming in contact with the body; and the superior temperature,
which it instantly acquires, enables it to hold more moisture, and
evaporation from the skin is thus instantly promoted.d

Absorption by the skin, unless friction is employed or the cu-
ticle abraded, has been denied. We are told that Dr. Currie’s
patient, labouring under dysphagia seated in the oesophagus,
[Seite 186] always found his thirst relieved by bathing, but never acquired
the least additional weight:e that Dr. Gerard’s diabetic patient
weighed no more after cold or warm bathing than previously:f
that Seguin found no mercurial effects from bathing a person in a
mercurial solution, provided the cuticle remained entire; while
they occurred when the cuticle was abraded.g

But the two former cases are no proofs that water was not
absorbed, because the persons immersed did not lose in weight,
which they would have done if not immersed, owing to the pul-
monary and cutaneous excretions; these therefore must have been
counterbalanced by absorption somewhere, and no shadow of proof
can be urged against its occurrence by the skin, as Dr. Kellie
remarks in his excellent paper on the functions of this part.h
Seguin besides found two grains of the mercurial salt disappear in
an hour from the solution when of the temperature of 72 1/2°.

There is every reason to believe the occurrence of cutaneous
absorption independently of friction or abrasion of the cuticle.
First, the existence of absorbents all over the surface cannot be
intended for use merely when friction is employed or the cuticle
abraded. Secondly, we have many facts which prove absorption
without these circumstances, either by the skin or lungs, or both,
while no reason can be given why they should be attributed
solely to the lungs. A boy at Newmarket, who had been greatly
reduced before a race, was found to have gained 30 oz. in weight
during an hour, in which time he had only half a glass of wine.i
Dr. Home, after being fatigued and going to bed supperless,
gained 2 oz. in weight before seven in the morning.i In three
diabetic patients of Dr. Bardsley’s, the amount of the urine ex-
ceeded that of the ingesta, and the body even increased in weight,
and in one of the instances as much as 17 lbs.k Dr. Currie
allows that in his patient, ‘“The egesta exceeded the ingesta in a
proportion much greater than the waste of his body will explain,
and, indeed, such facts occur every day.”’ The same patient’s urine,
too, after the daily use of the bath, flowed more abundantly and be-
came less pungent. Keill says that he one night gained 18 oz. in
his sleep: and Lining, that after drinking some punch one cool day,
‘“the quantity of humid particles attracted by his skin exceeded
[Seite 187] the quantity perspired in these two hours and a half by 8 1/3 oz.”’
and gives two more such instances in the same table.l Dr.
Edwards observed similar facts in guinea-pigs.m Thirdly, we
have positive evidence of cutaneous absorption without friction
or abrasion, in the case of frogs, toads, nay, in scaly lizards,
which will increase in weight by cutaneous absorption, even if
only a part of them is immersed in water; and remarkably so if
previously made to lose much of their moisture by exposure to the
air,n although they never surpass the point from which the loss of
weight began.o The increase is much greater in water than in
the moistest air.p

In all the cases which have been mentioned there is no reason
to suppose that exhalation did not continue, both on the skin and
in the lungs, so that the absorption must have been greater than
it at first sight appears. When no increase of weight has taken
place on immersion in the warm bath, absorption must have
occurred to maintain the weight notwithstanding the cutaneous and
pulmonary losses; and when some decrease of weight has been
observed, we are not justified in concluding that absorption had
not taken place, and not lessened the amount of the loss which
would have happened. Indeed, there is no doubt that perspira-
tion is considerably increased in the warm bath. – I may remark,
that while absorption is more active accordingly as more fluid has
been lost, it gradually becomes less as it approaches the habitual
standard of plenitude in the individual, and that while transpira-
tion is increased by elevation, the proportion of absorption is
increased by depression, of temperature.q

Dr. Massy, of America, about 1812, found that, if the body
were immersed in a decoction of madder, this substance became
discoverable in the urine by the alkalies, and Dr. Rousseau, in con-
junction with Dr. S. B. Smith, made, in consequence, a number of
experiments from which they conclude that rhubarb and madder
are so absorbed, and that these only of all absorbed substances
can be discovered in the urine, and are seen in that fluid only,
and are absorbed by no other parts than the spaces between the
middle of the thigh and hip, and between the middle of the arm
and shoulder.r

SECT. XII.
OF THE FUNCTIONS OF THE NERVOUS SYSTEM IN GENERAL.

[Seite 188]

197. We now come to the other class of functions termed
animal (83, II.), by which the body and mind are connected.
They have obtained their name from existing in animal sys-
tems only, and from enjoying a greater range than those
properly denominated vital.a

198. The principal organs of these functions are the brain
and medulla spinalis, together with the nerves, the greater
part of which originate from the two former. They may be
properly referred to two principal classes, sensorial and nerv-
ous:
the former comprehending all excepting the nerves and
their immediate origin, – all that serves more directly as the
connection between the office of the nerves and the faculties
of the mind.

199. Upon this division rests the beautiful observation of
Sömmerringb respecting the correspondence between the re-
lative size of each class with the faculties of the mind, – That
the smaller the nerves are, compared with the sensorial class,
the greater is the development of the mental faculties, and
that, in this sense, man has the largest brain of all animated
beings, – if its bulk be compared with that of the nerves
arising from it; but by no means, if its weight be compared
with that of the whole body.

[Seite 189]

200. Besides the bony cranium, a threefold covering is af-
forded to the brain,c viz. the dura and pia mater, and, be-
tween these two, the tunica arachnoidea.

201. The dura mater,d which lines the inside of the
cranium, like a periosteum, forms various processes. By the
falx it divides the hemispheres of the cerebrum and cere-
bellum; (A) by the tentoriume it supports the posterior lobes
of the cerebrum, and prevents their pressure upon the sub-
jacent cerebellum.

In its various duplicatures it contains and supports the
venous sinusesf and prevents their pressure. These receive
the blood returning from the brain to the heart, the pro-
portion of which to the blood of the rest of the body, Zinn,
who was formerly one of our number, long ago very truly
remarked, has been overrated by physiologists.

202. Next to the dura mater lies the arachnoid, so named
from its thinness. Its use is not exactly known; it is desti-
tute of blood-vessels (5), and extended, like the dura mater,
[Seite 190] merely over the substance of the brain, without following the
course of its furrows and prominences.

203. On the contrary, the membrane, called pia mater by
the ancients, closely follows the cortical substance of the
brain,g and possesses innumerable blood-vessels which pene-
trate into the latter. Hence, if a portion of this membrane is
detached, we find the external surface very smooth, while the
internal is villous and resembles the roots of moss.h (B)

204. The brain is composed of various parts which differ
in texture and figure,i but the use of which is unknown.
The most remarkable are the four ventricles,k in the two an-
terior and fourth of which are found the choroid plexuses, of
whose function also we are ignorant.l

205. The substance of the brain is twofold: the one called
cineritious or cortical, though not always situated exteriorly;
the other white or medullary. Between the two, the cele-
brated Sömmerringm has detected a third substance of a
whitish colour, most conspicuous in the arbor vitae of the ce-
rebellum and in the posterior lobes of the cerebrum.

206. The proportion of the cineritiousn to the medullary
substance decreases as age advances, being greater in children,
[Seite 191] less in adults. It is almost wholly composed of an immense
number of very fine vessels, both sanguiferouso and colour-
less (92), some few of which penetrate into the medullary
substance,p composed, in addition to these vessels and a very
fine cellular substance, of a pultaceous parenchyma, which, if
examined with glasses, exhibits no regular structure,q and,
upon chemical analysis, affords a peculiar matter, in some
measure resembling albumen (C), and containing a large
quantity of carbon.r

207. The brain, after birth, undergoes a constant and
gentle motion,s correspondent with respiration; so that,
when the lungs shrink in expiration, it rises a little, but, when
the chest expands, again subsides.t

[Seite 192]

208. The spinal marrow is continuous with the brain,u and
may be said either to spring from the brain, as from a root,
or, on the contrary, to terminate in it and grow into its sub-
stance.x Contained in the flexible canal of the vertebrae, it
is enveloped by the same membranes as the brain: its sub-
stance is also twofold, but the medullary is exterior to the
cineritious.

209. From these two sources – the brain and spinal
marrow, arises the greater part of those cords, which are more
or less white and soft, chiefly composed of fine cellular canals
containing nervous medulla,y and distributed throughout
nearly all the soft parts; some nerves,z however, may be more
properly considered as uniting with the brain and spinal mar-
row than springing from them. (D)

210. After the numerous experimentsa of Haller and
other very careful observers, we are certain, from minute
anatomical examination, that many of the similar parts do
[Seite 193] not exhibit any true vestige of nerves; and, from surgical ob-
servationsb and from dissections of living animals,c that they
do not evince the least sign of feeling.

Such are the cellular substance, the epidermis and reticulum
mucosum, the hairs and nails.

The cartilages, bones, periosteum, and medullary mem-
brane.

The tendons, aponeuroses, and ligaments.

Most extended internal membranes, as the dura mater and
arachnoid; the pleura, mediastinum, and pericardium; the
peritonaeum; also the cornea, &c.

The greater part of the absorbsent system, especially the
thoracic duct.

Lastly, the secundines and umbilical chord. (E)

211. The ultimate origin of most nerves from the brain
cannot be detected. A question is agitated even at the pre-
sent day, – whether the nerves of each side arise from the
[Seite 194] corresponding or the opposite portion of the brain.d The
latter opinion is countenanced by certain pathological pheno-
mena,e and by the decussation of fibres in the medulla ob-
longataf and conjunction of the optic nerves.g (F)

212. A continuation of the pia mater follows the medulla
of the nerves in their course,h thus affording it a very delicate
vascular cortex.i But, as soon as they have quitted the brain
or medulla spinalis, their structure becomes peculiar, different
from that of all the mother similar parts. They form small trans-
verse folds more or less obliquely angular, long since described
by P. P. Mollinelli,k who not inaptly compared them to the
rugae of earth-worms or the rings of the aspera arteria.

213. The nerves of particular classes, especially the in-
tercostals or great sympathetics,l are every where furnished
with ganglia, or nodules of a compact structure and reddish
ash colour, but with whose functions we are scarcely ac-
quainted.m I am inclined to believe with Zinn,n that they
[Seite 195] more intimately unite the nervous filaments which meet in
them from various directions, so that each fibre passing out
is composed of a portion of every fibre which has entered
in.o (G)

Nearly the same may, perhaps, be said of the plexuses,
which are produced by similar unions and reticulated anasto-
moses of different nerves, and by a similar contexture of fila-
ments into which the nerves are split.

214. The ganglia and plexuses are most abundantly
bestowed upon the spinal nerves and the intercostal or sym-
pathetic nerve. The latter, united by a few delicate filaments
only with the rest of the nervous system, constitutes a peculiar
system, chiefly belonging to the involuntary functions. For
this reason, Bichat, viewing it as presiding over organic life,
distinguished it from the other nerves belonging to animal
life, properly so called, to use his own language.p

215. The terminations of the nerves are no less concealed
from us than their origins. Excepting a few which spread
out in the form of medullary membranes, as the optic nerve
which becomes the retina, and the portio mollis of the seventh
pair which forms a zone in the spiral laminae of the cochlea,
the ultimate filaments of the rest, penetrating into the viscera,
muscles, corium, &c., are so intimately blended with the sub-
stance of these parts as, at length, to elude observation.

216. The parts just described, viz. the sensorium, and the
nerves originating from it, and distributed throughout the
body, constitute that system which, during life, is the bond of
union between the body and the mind.

217. That the mind is closely connected with the brain, as
the material condition of mental phenomena, is demonstrated,
to omit such arguments as the immediate connection between
[Seite 196] the brain and the organs of sense, by our consciousness and
by the mental disturbances which ensue upon affections of the
brain. (H)

218. The peculiar situation and form, before alluded to, of
certain parts of the brain, and likewise some pathological
phenomena, have induced various physiologists to suppose
certain parts, in particular, the seat of the soul. Some have
fixed upon the pineal gland,q others the corpus callosum,r
the pons Varolii, the medulla oblongata, the corpora striata,
and the water of the ventricles that washes against the origin
of some nerves. Others, not contented with one spot, have
assigned particular parts of the brain for individual faculties
and propensities. (I)

219. The energy of the whole nervous system does not
depend solely upon the brain. The spinal marrow, and even
the nerves, are possessed of their own powers, which are
sufficient to produce contractions in the muscles. These
powers are probably supported by the vascular cortex of those
parts (212). In man, the powers proper to the nerves are
less, and those dependent upon the brain greater, than in
brutes, especially the cold-blooded.

220. The importance of the nervous system to nearly all
the functions of the animal economy, – the motion of the heart,s
respiration,t animal heat, (169) digestion, nutrition,u and
[Seite 197] most others, is evidently great. It is, however, chiefly
two-fold, – To excite motion in other parts, especially in the
voluntary muscles, of which function we shall hereafter speak
at large; – and to convey impressions made upon the organs
of sense to the brain, and there to excite perception, or by
means of sympathies (56) to give occasion to reaction.

221. Experiment and observation put these functions of
the nervous system beyond the reach of controversy. To
unfold their nature is difficult indeed. (K)

222. Most opinions on this subject may be divided into
two classes. The one regards the action of the nervous
system as consisting in an oscillatory motion; the other
ascribes it to the motion of a certain fluid, whose nature is a
matter of dispute, by some called animal spirits,w and supposed
to run in vessels, by others conceived to be a matter analo-
gous to fire, to light, to a peculiar ether, to oxygen, to
electricity, or to magnetism, &c.

223. Although I would by no means assent to either of
these opinions, I may be allowed to observe that most argu-
ments brought by one party against the hypothesis of the
other, must necessarily be rude in proportion to the subtlety,
either of the oscillations (if any such exist) of the nerves, or
to that of the nervous fluid.

224. These two hypotheses may, perhaps, be united by
supposing a nervous fluid thrown into oscillatory vibrations
by the action of stimulants.

225. The analogy between the structure of the brain and
some secreting organs favours the belief of the existence of a
nervous fluid.x But tubes and canals are evidently no more
requisite for its conveyance, than they are requisite in bibulous
paper or any other matter employed for filtering.

This opinion receives much weight from the great resem-
blance of the action of the nerves to the phenomena which
[Seite 198] are produced by the series of a galvanic apparatus and by
the common electric machine,y in a living animal or in
parts not quite deprived of vitality, and, in fact, long
ago induced some physiologists to compare the nervous to
the electric fluid. The singular and undeniable effects attri-
buted to animal magnetism,z as well as other phenomena
which have given rise to the belief of a kind of sentient
atmosphere surrounding the nerves,a agree very well with the
hypothesis of a peculiar nervous fluid.b

226. If we regard the oscillation of the nerves, not as
similar to that of gross tense chords, but of such a description
as may be conceived to occur in the very soft pulp of the
brain, we shall find many physiological phenomena exactly
corresponding with the supposition.

It is demonstrated that hearing is excited by an oscillation,
and why should not this be propagated to the brain?

In vision, also, it very probably occurs, although not to the
extent imagined by Leon. Euler.

The penetration of Hartleyc in following up the conjec-
tures of the great Newton,d has rendered it so probable that
the action of the other senses is not very dissimilar from this
oscillatory motion, that, on the same supposition, he very
ingeniously explains, principally by means of the vapour of
the ventricles (called by him the denser ether),e first, the
[Seite 199] association of ideas, and, again, by the assistance of this, most
of the functions of the animal faculties. (L)


NOTES.

(A) Sir Anthony Carlisle, on opening a woman who had died
after amputation of a foot, found no falx. The cerebrum was not
divided into hemispheres. The edge of the longitudinal sinus
was received into a depression, about half an inch deep, that
existed along the middle of the superior part of the cerebrum.
The head had been unaffected, and the mental faculties perfect,
as far as observation was made during the woman’s stay in the
Westminster Hospital.f

I presented to the London Phrenological Society, the cast of
the head of a male idiot, aged eighteen years, that was given me
by Dr. Formby, of Liverpool, and is only 16 inches in circumfer-
ence, and 7 3/4 inches from ear to ear over the vertex. The cerebrum
weighed but 1 lb. 7 1/2 oz., and the cerebellum but 4 oz. The he-
mispheres were united as far back as the vertex, and no falx existed
except for about two inches from the anterior part of the tento-
rium.

(B) The pia mater and tunica arachnoides were considered
as the same, till the Anatomical Society of Amsterdam confirmed,
in 1665, the doubts which were arising on the subject, and Van
Horne demonstrated both membranes distinctly to his pupils.
The dura mater corresponds with the fibrous membranes, the
pia mater with the cellular, and the tunica arachnoides with the
serous. The latter is, in nature, office, and diseases, exactly like
the serous; – a close sac, affording, as the peritonaeum does to
the abdominal viscera, a double covering to the brain and spinal
marrow and the nerves before their departure through the fora-
mina of the dura mater, and, according to Bichat, lining the
ventricles; insulating the organs on which it lies, and affording
them great facility of movement; and liable to all the morbid
affections of serous membranes.g

[Seite 200]

Between the pia mater and arachnoid of both the brain and
spinal marrow, Dr. Magendie has discovered the existence, during
life, of a large quantity of clear and colourless fluid, passing from
the surface of one organ to that of the other.h Cotugnoi had
long ago asserted its existence in the cranial and spinal cavities,
after death, and its free communication, and accurately described its
qualities; but notwithstanding he gave excellent reasons for be-
lieving its existence during life, he imagined the space around the
spinal marrow, observed by him to be larger in the emaciated and
old, and the space which in these two descriptions of subjects he
found also around the brain, to be filled with an aqueous vapour;
he also believed its occasional mixture with the fluid of the ven-
tricles. Dr. Magendie has proved the communication, not only of
the fluid of the spinal and cerebral cavities but also of the ventri-
cles, by an opening at the point of the calamus scriptorius of the
fourth.k He conceives it to move from one part to another, as
they are severally compressed by sanguineous turgescence during
muscular efforts. Bichat had asserted that the arachnoid entered
the ventricles by the third, near the venae Galeni. Dr. Magendie
never observed the fluid to escape at this part. If he is correct,
I do not understand whether the ventricles are lined by the pia
mater or the arachnoid or both. He found the removal of the fluid
to occasion immediate dulness and immobility; but that these dis-
appeared as soon as the fluid was replaced, and that its secretion
took place very rapidly. He believes that two ounces may exist
in the ventricles without disturbance, but that a larger quantity,
whether secreted or injected, for example, into the spinal cavity,
causes more or less apoplexy and palsy. Much must, however,
depend upon the quickness of the accumulation, as the powers
of accommodation are very great in living systems.

(C) The medullary substance is evidently fibrous. Mr. Bauer
thought he had discovered globules, but then he thinks fibres are
series of globules.l Dr. Hodgkin has found no globules in either
brain or nerves, nor medullary matter in the latter.m

[Seite 201]

(D) Dr. Gall has shown that the nerves and spinal marrow do
not arise from the brain, but only communicate with it; nor the
spinal nerves from the spinal marrow: for, when the brain is
absent, the foetus equally possesses cerebral nerves and spinal
marrow,n and the brain and spinal marrow, and the brain and
cerebral nerves, are in no proportion to each other in the various
species of the animal kingdom, nor the spinal nerves to the spinal
marrow, nor does the latter diminish as the nerves go off.

The idea of the nerves proceeding from the brain, is as unfounded
as that of the arteries proceeding from the heart, or one portion
of an extremity from another. Foetuses are seen with an arterial
system, and no hearts; others born with no arms, but fingers at
the shoulders. Independently of contrary arguments, we may
demand proofs of the opinion: none are given, and it has, no
doubt, been derived from the shooting of vegetables.

(E) Although no nerves have yet been discovered in these
parts, and although ordinarily they have no feeling, yet that they
have, in a lower degree, what, in a higher, is called feeling, is
shown by the extreme sensibility which they acquire when in-
flamed, as they nearly all frequently are, and occasionally without
inflammation. Some have sensibility in health to only one kind
of irritation. The ligaments may be cut without pain, but if
stretched instantly ache. The brain itself will bear great mecha-
nical injury without evincing much pain.

(F) Dr. Gall has also shown, that, besides the numerous com-
munications of the whole nervous system, not only the two sides
of the cerebrum, cerebellum, and spinal marrow, are united by
commissures, but that the fibres of the anterior pyramidal emi-
nences decussate each other, forming an exception to the rule,
observed in every other part of the cranial nervous organs besides
the optic nerves and the fibres which run from the genitals to the
cerebellum, of the nervous fibres, destined to each side of the
body, running on the same side of the brain; and he hence explains
why injuries of one side of the brain generally influence the oppo-
site side of the body. The spinal marrow has no decussation.

‘“We now know, and especially from the modern researches of
Drs. Gall and Spurzheim,”’ says Cuvier, ‘“that the spinal marrow
is a mass of medullary matter, white without, grey within, divided
[Seite 202] longitudinally by an anterior and posterior furrow; that its two
bands communicate by transverse medullary fibres; that it is
enlarged at regular distances, and at each enlargement gives off a
pair of nerves; that the medulla oblongata is the superior part of
the spinal marrow contained in the cranium, and also gives off
several pairs of nerves; that the communicating fibres of its two
bands decussate, so that the left go to the right side, and the re-
verse; that these bands, after having enlarged once by an admix-
ture of grey matter, and having formed the prominence called
pons varolii, separate, and are termed crura cerebri, still continuing
to give off nerves; that they enlarge once more by a fresh addition
of grey matter to form the masses commonly called thalami optici,
and a third time to form what have the name of corpora striata;
that from all the external portion of these latter enlargements
arises a layer of greater or less thickness, more or less furrowed
externally in different species, completely covered by grey mat-
ter which comes above to cover them, forming what are termed
the hemispheres, and which, after bending down in the middle,
unite by one or more commissures, or bands of transverse fibres,
the most considerable of which, found only in mammalia, has the
title of corpus callosum. We also know, that upon the crura
cerebri, behind the thalami optici, are one or two pairs of smaller
enlargements, known, when there are two pairs of them, as in the
mammalia, by the name of tubercula quadrigemina, and from the
first of which the optic nerves seem to arise; that the olfactory
nerve is the only one which does not clearly arise in the medulla
or its columns; lastly, that the cerebellum, white within, and cine-
ritious without, like the hemispheres, but often much more divided
by external furrows, lies transversely behind the tubercula qua-
drigemina, and upon the medulla oblongata, with which it is
united by transverse bands that are styled crura cerebelli and
inserted into the sides of the pons varolii.”’o

In a word, the fibrous columns of the spinal marrow communi-
cate by intermediate fibres; the fibrous bands of the brain run
onwards from the medulla oblongata, diverging and forming the
convolutions which may be distended into a great bag, and be-
tween both halves of these are converging fibres for connection,
[Seite 203] called corpus callosum, the anterior commissure, as well as other
bands for the same purpose; the pons varolii is the great com-
missure of the cerebellum, under which the corpora pyramidalia
pass to form the anterior and exterior part of the crura cerebri,
and afterwards the anterior, inferior, and exterior portion of the
anterior and middle lobes (the organs of the intellectual faculties);
and the corpora olivaria to form the remaining part of the crura
cerebri, and after becoming the thalami optici, and plunging into
the corpora striata, to form the posterior lobes, and the superior
and more central convolutions (organs of the feelings or affective
faculties). Whenever, in the medulla spinalis, or brain, an en-
largement occurs in the fibrous bands, there is an accumulation
of pulpy matter; improperly termed cortical, because it is some-
times within; and improperly grey, because its colour varies in
different animals; but always coexisting with the white or fibrous:
from all which circumstances, and its formation before the fibrous,
and its great vascularity, Gall supposes it destined for the nou-
rishment of the latter.p

I refer to the writings of this physician for a minute accountq
of his great discoveries in the structure of the nervous system,
and shall merely bear testimony to the truth of most of his ana-
tomical assertions. Those few which I have not repeatedly
seen proved, are I doubt not perfectly accurate. Some of the
most candid anatomical lecturers of London have confessed that
they knew nothing of the anatomy of the brain till they saw it
dissected by his pupil Dr. Spurzheim, and it is a matter of
wonder, that, while students are not instructed to dissect limbs
and trunks by slices, as we cut brawn, they should be taught no
other mode of examining the brain, and thus be left in ignorance
of its true structure.

We see Cuvier’s admission of many of Gall’s discoveries, and,
I must add, of discoveries which were doubted or absolutely
[Seite 204] denied in a report presented by Cuvier and others to the French
Institute, in 1808, – ‘“a report,”’ says Gall, ‘“which will always
be one of the most valuable proofs of the backward state of the
anatomical and physiological knowledge of the nervous system at
that time, and how much science owes me in this respect.”’r ‘“Reil,”’
says Professor Bischoff, ‘“who, as a profound anatomist and judicious
physiologist, requires not my praise, rising superior to all the lit-
tlenesses of vanity, has declared that he found more in Gall’s dis-
sections of the brain than he thought any man could have dis-
covered in his whole life.”’s Loder, after specifying Gall’s disco-
veries, adds, ‘“These discoveries alone would be sufficient to
immortalise Gall’s name: they are the most important which have
been made in anatomy since the discovery of the absorbents.”’
‘“I am ashamed and indignant with myself for having, with others,
been slicing hundreds of brains, like cheese: I never perceived the
forest for the multitude of the trees.
”’t

(G) This opinion is controverted by the argument that the
nerves said to enter and leave ganglia are not proportionate; nor
the size of ganglia proportionate to the nerves belonging to them.

(H) See Sect. VI. Note (B), and Sect. XLIV. Note (F), near the
beginning.

(I) Gall has the immortal honour of having discovered parti-
cular parts of the brain to be the seat of different faculties, sen-
timents, and propensities.

If it is clear that the brain is the organ of mind, it is extremely
probable that particular portions of it have different offices.

Numerous old writers had assigned situations for the facul-
ties, but in the most fanciful manner; and, from regarding as
distinct faculties what are merely modes of action of faculties
to which they were altogether strangers, their assertions on
the subject were necessarily groundless and ridiculous. Bur-
ton, for example, in his compilation, says, – ‘“Inner senses are
three in number, so called, because they be within the brain-
pan, as common sense, phantasie, and memory:”’ of common
sense, ‘“the fore-part of the brain is his organ or seat;”’ of
‘“phantasie or imagination, which some call aestimative or cogi-
[Seite 205] tative,
”’ ‘“his organ is the middle cell of the brain;”’ and of me-
mory, ‘“his seat and organ, the back part of the brain.”’u This was
the account of the faculties given by Aristotle, and repeated, with
little variation, by the writers of the middle ages. In the 13th
century, a head divided into regions according to these opinions
was designed by Albert the Great, Bishop of Ratisbon;x and another
was published by Petrus Montagnana, in 1491.y One published
at Venice, in 1562, by Ludovico Dolce, a Venetian, in a work upon
strengthening and preserving memory, is copied into the Phre-
nological Journal,
vol. ii. No. 7. In the British Museum is a chart
of the universe and the elements of all sciences, and in which a
large head so delineated is conspicuous. It was published at
Rome so late as 1632, and, what is singular, engraved at Antwerp
by one Theodore Galleus, and the head is really a good family
likeness of Dr. Gall, who, however, was born at Tiefenbrun in
Suabia, between Stuttgard and the Rhine, March 9. 1757.z

It is, however, more than probable that the different parts of
the brain have different offices. Its faculties are so various, that
it is impossible to imagine them possessed by the same portion.
The faculty of melody is perfectly different from the love of
offspring. If to suppose all parts of the brain are organs for all
faculties is impossible, the difficulty appears greater on reflecting
[Seite 206] that in that case the whole brain must be concerned in every act
and feeling, or, if the whole brain is not thus constantly at work at
all things, that different parts must perform the very same offices at
different times, each part working in every kind of mental act and
feeling in its turn. Neither does the brain perform merely one
thing, as the liver secretes merely one fluid, bile; nor is its struc-
ture the same throughout, like that of the liver.

The best authors hold that its various parts have various offices,a
and Gall proves that they have.

If the old course, recommended by Mr. Dugald Stewart, of
investigating the mind by attending to the subjects of our own
consciousness, had been persevered in, the science of mind would
have remained stationary for ever.b Who can judge fairly of
[Seite 207] his own character and talents? Not only is ‘“the heart of man de-
ceitful above measure,”’ but we give ourselves credit for talents
which others know to be insignificant. Our powers, too, and dis-
positions, are distributed in such various degrees, that, from this
single circumstance, every man, judging from himself only, would
draw up a different account of the human mind. It is only by
extensive observation of others, of different sexes, ages, educa-
tion, occupations, and habits, that this knowledge is to be acquired.
Nor would much progress have been made without the discovery,
that strength of individual talent and disposition was associated
with proportionate development of particular portions of the brain.
By this remark the existence of particular faculties, sentiments,
and propensities, was firmly established, and indeed Dr. Gall
discovered them by observing persons conspicuous in some mental
points to have certain portions of the head extremely large. I
did but allude to craniology while detailing Dr. Gall’s account of
the mind (Sect. V.), because the arrangement may be perfectly
accurate, although craniology be false; nor when speaking of the
brain as the organ of the mind (Sect. VI.), because that fact also
is independent of Dr. Gall’s system. But if now the account of
the mind, the use of the brain, and craniology, be viewed together,
they will all be seen mutually and beautifully to confirm each
other.

Much invective, but little argument, has been written against
the doctrine. We are presented with a simple statement – that
strength of certain parts of the mind, is accompanied by strong
development of certain parts of the brain, and, consequently,
of the skull, except in disease and old age; and vice versa. The
truth must be ascertained, not by fancying, quibbling, and abusing,
but by observing whether this is the case; and every one has it in
his power to make the necessary observations. But those who
[Seite 208] have facts to offer in objection must first be so well acquainted
with craniology as to be able to judge accurately of the de-
velopment which they adduce, and have carefully ascertained the
character and exact talents of the individual whom they fancy
an exception. I had heard of a religious bump, a thievish bump,
and a murderous bump, and was as lavish of my ridicule and con-
tempt of Dr. Gall’s doctrines as any other ignorant person, till I
heard his pupil, Dr. Spurzheim, detail them in the Medico Chi-
rurgical Society. They struck me powerfully. The anatomical
facts were demonstrated; the metaphysics were simple and na-
tural; and the truth of craniology was evidently to be ascer-
tained by personal observations only. I commenced observations,
and so satisfied was I of its correctness, that, whilst the storm was
raging violently, I wrote a defence of Gall’s doctrine in the only
review that was its friend.c Above eleven years have now elapsed,
during which I have lived making daily observations, but they all
confirm Dr. Gall’s statements. I have never seen an exception to
the accuracy of his general departments of the organs, nor of the
situation of most particular organs. Upon some I have not yet
made sufficient observations, and I have no doubt that our views
of the functions of many will be much modified and improved.
It would be absurd to think the system perfect at present. The
wonder is that so much was done by only one individual. The
science of cerebral organology is entirely Gall’s; nearly so hence-
forward will metaphysics be regarded; and anatomy must acknow-
ledge him among its greatest benefactors. Those who wish to
become acquainted with phrenology I must refer to Gall’s octavo
work, Sur les Fonctions du Cerveau, or his Anatomie et Physiologie du
Système nerveux.
The former work deserves to be read, not only
by every medical man, but by every moralist, naturalist, legislator,
and metaphysician. It is exceedingly eloquent and full of new
and splendid truths and illustrations, and infinitely the best for
those who would learn phrenology. However great the merits of
the books written by Dr. Spurzheim and my excellent friend
Mr. G. Combe,d its perspicuity and richness at once declare it
the work of the great master himself.

[Seite 209]

The exact situation of the organs can be learnt from drawings or
marked heads only. I shall therefore confine myself to remarking:
1st. That the organs of the faculties or qualities common to man
and brutes, are placed in parts of the brain common to man and
brutes, – at the inferior-posterior, the posterior-inferior, and in-
ferior-anterior parts of the brain, v. c. of the instinct of propaga-
tion, the love of offspring, the instinct of self-defence, of appro-
priating, of stratagem, &c. 2dly. Those which belong to man
exclusively, and form the barrier between man and brutes, are
placed in parts of the brain not possessed by brutes, viz. the
anterior-superior and superior of the front; v. c. of comparative
sagacity, causality, wit, poetic talent, and the disposition to reli-
gious feelings. 3dly. The more indispensable a quality, or faculty,
the nearer are its organs placed to the base of the brain, or median
line. The first and most indispensable, – the instinct of propagation,
lies nearest the base; that of the love of offspring follows. The organ
of the sense of localities is more indispensable than that of the
sense of tones or numbers; accordingly the former is situated
nearer the median line than the two latter. 4thly. The organs of
fundamental qualities and faculties which mutually assist each
other, are placed near to each other, v. c. the love of propagation
and of offspring, of self-defence and the instinct to destroy life, of
tones and numbers. 5thly. The organs of analogous fundamental
qualities and faculties are equally placed near each other: v. c.
the organs of the relations of places, colours, tones, and numbers
are placed in the same line, as well as the organs of the superior
faculties, and the organs of the inferior propensities.d

Although the arrangement of the organs is so beautiful, we
must not imagine that Gall mapped out the head at pleasure, ac-
cording to preconceived notions. He discovered one organ after
another, just as it might happen, and often one became known to
him situated very remotely from the organ last discovered. The
set of organs discovered by him turned out as it is, and a strong
argument is thus afforded to the truth of his system.

‘“I defy,”’ says he, ‘“those who attribute my determination of
the fundamental faculties and of the seat of their organs to
caprice or arbitrary choice, to possess a tenth part of the talent
necessary for the most obscure presentiment of this beautiful
arrangement; once discovered, it displays the hand of God,
[Seite 210] whom we cannot cease to adore with wonder increasing as his
works become more disclosed to our eyes.”’e

If Gall’s is the only satisfactory account of the mental faculties,
and to me it certainly appears so, this alone is a proof of the truth
of his organology. For such an account could not have resulted
from imagination; and observation, unaided by reference to de-
velopment, never produced much that is satisfactory in me-
taphysics; and it was in fact derived from studying the organi-
sation.

Gall discovered each organ and its faculty either by meeting
with individuals very remarkable for the latter, so that he was led
to examine their heads; or by noticing a peculiarity of formation
in the head which induced him to ascertain their talents and cha-
racter. He would never have made his discoveries had he not
met with persons remarkable in these respects. Sometimes the
relation between the remarkable faculty or quality and the local
development was tolerably obvious, but generally he had to make
numerous observations before he found himself right. After find-
ing two individuals remarkable in the same point of character, and
casting their heads, he has examined the casts daily for months
before he could discover the precise spot in which they agreed.
The discovery being now made, a good organologist will give
judgments upon character which must astonish and incontestably
prove the truth of phrenology; but the difficulty of making the
discovery when all was utter darkness must have been extreme.
The indefatigable industry of Gall for so many years, travelling as
he did to most of the prisons, mad-houses and hospitals of the Con-
tinent; examining the habits and heads of brutes innumerable for
comparison; and engaging persons at salaries to examine points
for him, in the way of reading, dissecting, casting, and observing
living persons, is astonishing;f and the success and importance of
his researches will, I am satisfied, ensure him a place among the
greatest names of the human race, although, like every other
discoverer and benefactor, he has been loaded with ridicule and
abuse. Whoever knows him must, so far from finding him a
quack, admire the profundity and candour of his conversation and
the extent of his attainments, and be delighted with his disin-
terested kindness, and the gentleness and elegance of his manners.
[Seite 211] The composure with which he hears the ill-treatment of the world
is most enviable, and demonstrates a mind conscious of truth and
good intention.g

[Seite 212]

Whoever acquires sufficient knowledge of the subject to make
observations for himself, will soon find the shape of the skull to
be as various as character and countenance, and will have hourly
amusement both in remarking the relation between intellectual
and moral character, sexual, national, and individual, and cranial
form and size, and in tracing the resemblance of children in the
latter respect to their parents, as well as in talent and disposition.

Should any one doubt his acquaintance with the real talents
and character of those friends whose heads he can select for ob-
servation, he has only to study the heads of some celebrated men
now living, or the authentic casts of the departed, of whose
talents and disposition no one can have the slightest doubt, and he
will find the coincidence astonishing and invariable.

If these are facts, all objections on the score of fatalism and
materialism, however correct, are unworthy of attention. But in
truth, phrenology gives no additional support to such views. A
stone is destined not to feel; a fish is destined to swim, and a vul-
ture to be a bird of prey; man is destined to be

[Seite 213]
––––– ‘“Not prone’
‘And brute as other creatures, but endued’
‘With sanctity of reason, and to erect’
‘His stature, and upright, with front serene,’
‘Govern the rest, self-knowing.”’

The very expression ‘“human nature”’ implies certain innate
faculties and dispositions, generally; the circumstance of peculiar
degrees of disposition and talents being hereditary, and of each
age having its distinctive character, are quite as favourable as
phrenology to the belief of fatalism. Each has his own talents
and disposition; in some way or other they must be obtained, and
if the way is discovered, the case does but remain the same as
before.h Yet whatever may be our innate propensities and
powers, we know how much various circumstances influence the
development of faculties and the strength of dispositions, and we
feel as if we were free agents: we seem to move our right hand or
our left, and to sit still or walk, exactly as we choose, and we pos-
sess reason and conscience to guide our conduct. But the more
we yield to any inclination, the less are we able to withstand it.

‘“Reason in man obscured or not obeyed,’
‘Immediately inordinate desires’
‘And upstart passions catch the government’
‘From reason: and to servitude reduce’
‘Man, till then free.”’

Yet, notwithstanding this feeling of freedom, ‘“all theory is,”’
certainly, as Dr. Johnson said, ‘“against the freedom of the will.”’i
The objections on the ground of materialism are not more ap-
plicable to phrenology than to the doctrine now universally ad-
mitted, – that the brain is the organ of the mind; and were an-
swered at p. 66. sqq.

Those who have so little soul as always to ask what is the good
of any discovery in nature, may be told that phrenology is cal-
culated to assist parents in the choice of occupations for their
[Seite 214] children. And it may be of much service in confirming some
moral views which good sense indeed ought previously to have
suggested. Humility and benevolence are two leading duties.
If we detect the signs of intellectual deficiency and vice in our
own heads, we may learn to think humbly of ourselves; and being
put in possession of true self-knowledge, endeavour to strengthen
what is too weak and repress what is too strong. If we detect the
signs of great talents and virtues in the heads of others, we may
love them the more as superior and highly-favoured beings:
whereas if we detect the signs of great virtues and talents in our
own heads, we may learn to take no praise to ourselves, but be
thankful for the gift; and if we detect the signs of intellectual de-
ficiency and vice in others, we may learn to pity rather than to
censure. We may learn not to judge others, nor even our own-
selves, but to leave judgment to Him who only knows exactly what
natural strength of evil inclination, what weakness of good, and
what unhappy external circumstances, each has had to contend
with. Not revenge, but example, is the professed object of our
legal punishments: – example to the culprit himself and others,
or, if the punishment is capital, to others only; and therefore
frauds, which, from being very easily committed, may become very
detrimental to society, are punished more severely than those
which, caeteris paribus, from being difficult of perpetration, can
scarcely from their frequency become dangerous. Were moral
demerit regarded, the fraud easily committed, would, caeteris
paribus, be punished the most lightly. A vicious man must be
restrained, as a wild beast,k for the good of others, though, for
aught we know, his faults may, like the acts of the beast of prey,
be chargeable rather on his nature; and while we feel justified in
confining, and the culprit is perhaps conscious how richly he de-
serves his fate, we may pity in our hearts and acknowledge that
we ourselves have often been less excusable.

‘“Teach me to love and to forgive,’
‘Exact my own defects to scan,’
‘What others are to feel, and own myself a man.”’

Phrenology, too, may be of the highest use when in criminals
there may be suspicion of idiotism or insanity. Idiotism often
[Seite 215] depends on deficiency of cerebral development, and many idiots
have been executed for crimes when it was not exactly proved that
they were idiotic enough to be unfit for punishment, but whose
cranial development might have settled the point at once. Many
persons also have been executed who should have been con-
sidered madmen, but were not because the fact of illusion was not
made out; yet the extreme preponderance of the development of
the organs of the propensities over that of the moral sentiments
and intellect, would have proved that they were deserving of
coercion rather than punishment. Such does the skull of
Bellingham, the murderer of Mr. Percival, prove him to have been.

By phrenology the true mental faculties have principally been
discovered.

If phrenology teaches the true nature of man, its importance
in medicine, education, jurisprudence, and every thing relating
to society and conduct, must be at once apparent.l

(K) While the brain is evidently the organ of mind, the nerves
united with it, and the spinal marrow, together with its nerves,
are as evidently the instruments by which it affects, and is affected
by, the other parts of the body, to which these nerves are distri-
buted. By their instrumentality, the brain contracts the volun-
tary muscles, influences the functions of every other part when
under the operation of the different passions, and receives im-
pressions made upon every other part.m The consequences of
divisions of the nerves or spinal marrow, fully substantiate these
points.

If a nerve supplying an organ of sense, as the olfactory, optic, or the
portio mollis, is compressed, the organ becomes insensible to odours,
light, or sounds. If one supplying muscles only, as the motor oculi,
patheticus, abducens, portio dura, or lingualis, the will loses power
over such muscles. If the spinal marrow, or nerves conveying both
volition from the brain and impressions to the brain, the supplied
parts lose both sense and motion.n In either this or the preceding
[Seite 216] case, if the divided surface now unconnected with the brain, is
irritated (or if, indeed, the parts are not divided, but irritated by
pinching), contractions occur in the muscles supplied by them;
and if a sedative is applied the muscles become inert. In these
cases, too, if the divided surface connected with the brain is
irritated, acute pain is felt, as if in the part on which the nerve
originally terminated;o and after the removal of a limb, it is common
for sensations to be experienced by the patient as if he still pos-
sessed his hand or his foot. The nerves which only convey
volition, and those of the other four senses than touch, give little
or no pain when mechanical stimulus is applied: and these have
not, like those which are sensible, a ganglion at a short distance
from their origin.p When nerves supply both muscles and an
organ of sense, they are compound, one portion performing but one
function, as Mr. Charles Bell first and Dr. Magendie farther proved
by separately dividing the nervous bands proceeding from the
anterior and posterior parts of the spinal marrow, before their
conjunction, when the division of the former deprived the parts
supplied of the influence of volition; and the division of the latter,
of sensation.q The anterior portion of the spinal marrow is nearly
insensible, while the posterior is acutely sensible: the division
of the former has the same effect as the division of the anterior
nerves; of the latter, as the division of the posterior nerves. The
destruction of the centre of the spinal marrow by a wire, impairs
[Seite 217] neither sensation nor motion,r nor is pain felt by the experiment.
The effects of the division of the spinal marrow are of course
more extensive in proportion as the division is made higher up,
and if made above the origin of the phrenic nerves, which are
the chief agents in causing the contraction of the inspiratory
muscles, and consequently above the origin of all the nerves of
inspiration, death immediately ensues.s Yet, in brutes, after re-
moving the head or dividing the spinal marrow, if any limb is
irritated, its muscles are thrown into action: thus Sir Gilbert
Blane, whose practical labours have equalled and, in a national
point of view, surpassed in utility those of every other physician of
St. Thomas’s, found, after such operations in kittens a few days old,
the hind legs to shrink from the touch of a hot wire applied to the
hind paws; and the tail move when irritated, after the division of
the marrow below the last lumbar vertebra.t More divisions than
one do not prevent this effect, and if the whole brain is removed
except a portion to which the third pair is attached, and the
optic nerve is divided, the iris instantly contracts when the extre-
mity of the optic nerve is pinched.u Magendie also remarks, that
when the posterior roots of the spinal marrow are irritated, besides
signs of extreme pain, the muscles below the part irritated are
thrown into action, but only on the same side of the body; facts
[Seite 218] all showing a peculiar relation between the nerves of sensation
and motion, that originate at the same portions of the nervous
system.x

If the medulla oblongata exists, consciousness and volition be-
come evident. Mr. Lawrence saw a child with no more ence-
phalon than a bulb, which was a continuation for about an inch
above the foramen occipitale from the medulla spinalis, and to
which all the nerves from the fifth to the ninth pair were con-
nected.y The child’s breathing and temperature were natural;
it discharged urine and faeces and took food, and at first moved
very briskly, and lived four days. If the cerebrum and cerebellum
are removed in a living brute, and the same portion of the medulla
oblongata left, the poor thing cries if attempts are made to give
it pain, and moves its extremities, even sometimes for two hours.z
Cold-blooded animals live much longer, and the lower we descend
in the scale of brutes the more diffused appear the powers of the
nervous system: indeed, in the lowest there is, strictly speaking,
no brain nor spinal marrow, but ganglions and nerves, which, no
doubt, perform the same functions as far as required in those ani-
mals, and are, in fact, brains to them, but of a different form and ac-
commodated to their structure.a The higher we ascend, the more
parts exist above the medulla oblongata, till, rising from fish and
reptiles, through the numerous warm-blooded brutes, all distin-
guished by the relative magnitude of each cerebral part, accord-
ing to their several mental characters, and seeing the successive
additions of cerebral structure and cerebral mass, and of intelli-
gence, we arrive at man, in whom the successive imposition of
cerebral matter has reached its maximum, so that the summit of
the nervous system, which corresponds with the forehead and
vertex, is much larger in him than in any brute,b and his intellect
and moral feelings are proportionally greater. According to the
[Seite 219] smallness of the anterior-superior and of the superior portions of the
brain, will individual mental superiority to the brute creation be
small. Idiotism may arise from faultiness of texture, but many con-
genital cases depend upon deficiency of anterior development; and
such idiots, as well as the whole brute creation, may be regarded
as examples of various cerebral mutilations, made by nature, illus-
trating the use of the cerebral parts. Attempts to mutilate arti-
ficially are not calculated to afford much information. Animals
can generally give no opportunity of observing what mental
change has been produced by the removal. For instance, when a
writer says that the removal of the cerebellum causes no other
effect than sluggishness in the animal, – how does he know that
sexual desire is not extinguished? When various portions of brain
are removed, how can any inference be drawn, during the short
existence of the poor animal, as to the state of its various faculties
and inclinations? And when another asserts, that after the re-
moval of the hemispheres and cerebellum we may make observ-
ations whether the animal will copulate or not, – how can he ascribe
any indisposition that may occur, to the removal, when any circum-
stances of suffering, wound, confinement, or want of food, will
make it very difficult to induce an animal to indulge itself with
sexual intercourse?c It is, besides, difficult, if not generally im-
possible, to remove one cerebral organ entirely and alone; other
parts of the encephalon, &c. are almost certain to be injured;d
and if others should not be injured, they may be influenced
[Seite 220] by the irritation of the injury,e and the effects arising from the
sympathetic affection of such parts; just, for example, as we often
see epilepsy from exciting causes in every part of the encephalon,
and from exciting causes even in distant organs. Amaurosis is
frequently induced by wounds of the supra-orbital nerve; some-
times by wounds of the infra-orbital nerve and of the portio dura.f
Some parts which have distinct names are only portions of organs,
so that injury of several parts may have the same effect; we
may have blindness from wounding the optic nerves, the tractus
optici, or the corpora quadrigemina. Some parts which have distinct
names are compound, so that one immediate and obvious effect of
injuring them is not the only consequence which would be ob-
served if the others had an opportunity of becoming apparent, –
the medulla oblongata is an instance of this,g and the recent dis-
covery that many nerves are two-fold.h

[Seite 221]

Hence the contradictory and strange observations and inferences
of most experimenters on the brain of living brutes.i The same
effects moreover do not occur in the same experiments upon
different species of animals. The observation of nature’s own mu-
tilations in brutes which have little or no development of parts
that are large in others, or in man, is therefore preferable; and
next to this comes the observation of morbid changes of different
parts, a subject, however, incapable of affording information till
the faculties had been ascertained by Gall. (See supra, p. 71.) Still
some results of mutilating the living brain appear generally al-
lowed, and are not at all in contradiction to phrenology. The
experiments of Fleurens are allowed by Gall to be very ingenious
and sometimes satisfactory;k and with respect to injuring the
cerebellum, Gall remarks, ‘“if it is true that the lesion of the tu-
[Seite 222] bercles in birds always causes convulsions, it is not less true that
the tubercles are destined to vision; and in the same way the
cerebellum (connected as it is with the medulla oblongata, &c.)
may participate in the vital function of the medulla oblongata
and spinalis, may give rise to disturbed motion when injured, and
yet have its own particular animal functions.”’l That animals
should skip and jump, and eat, after losing their hemispheres, is
not surprising, if these parts perform the phrenological functions
assigned to them, and are not necessary to motion. The medulla
oblongata and other lower parts of the encephalon have, no
doubt, much to do with motion as well as the spinal marrow, and
accordingly, when the oblongata was pressed in the child men-
tioned by Mr. Lawrence convulsions occurred; and the same
effect ensued on irritating it, in Dr. Gall’s experiments and those of
Lorry.m Pressure, however, of it, is also said by vivisectors to
occasion stupor.

Dr. Magendie informs us, that,

1. Deep cuts of the hemispheres do not affect motion in mam-
malia, reptiles, fish, and many birds, any more than their removal;
but the latter is said to occasion a blindness in mammalia and
birds, though not in fish or frogs, probably from the arrangement
of the cerebral parts being different, so that a similar wound affects
different organs.

2. If the white matter of both corpora striata is cut, the animal
darts forward, and retains the attitude of progression, if prevented.
He often found animals perform very regular movements after the
removal of the cerebellum; yet he observed, that wounds of it and
of the medulla oblongata, gave mammalia and birds a tendency to
move backwards, though the same effect does not occur in fish.

3. In a vertical section of the crura of the cerebellum, or of
the pons varolii from before backwards, the animal immediately
rolls forcibly on the same side, making sometimes sixty revo-
lutions in a minute; and a vertical section of the cerebellum
from before backwards through the whole substance of the me-
dullary arch over the fourth ventricle has the same effect, and the
motion is the more rapid as the section is nearer to the pons
varolii. An animal will continue rolling for eight days. If a
section is made on each side, the animal rolls from one side to the
other.

[Seite 223]

4. Notwithstanding the decussation of the anterior pyramids, a
division of one or both had no sensible effect, except, perhaps, that
of retarding motion a little; and a complete division of one-half of
the medulla oblongata neither affects sensibility nor prevents ir-
regular motions, though the power of volition appears lost on the
same side.

Similar phenomena occur in disease. Persons labouring under
hysteria or chorea sometimes roll violently, or spin round.n Per-
sons have been known to feel an impulse to move forwards or
backwards.o An infinite variety, however, of extraordinary and
regular movements also occur.

From these experiments I draw no inference. The consider-
ations already mentioned prevent me from concluding that the
parts which are cut are the sole organs concerned in giving origin
to the peculiar motions, that their sole purpose is for such motions,
or even that peculiar motions depend originally upon them. We
can only say, as in the case of amaurosis following an injury of
the supra-orbital, or infra-orbital nerve, such effects ensue.

In foetuses without brain or spinal marrow,p the circulation, nu-
trition, secretion, &c. proceed equally as in others, which, besides
spinal marrow, nerves, and ganglia, possess a brain.q Vege-
tables absorb, assimilate, circulate, secrete, and in many instances
contract on the application of stimuli, and yet are not known to
possess nerves. Muscles, after the division of the nerves which
connect them with the brain, contract equally as before, when
irritated. In animals liable to torpor, the season of torpidity
produces its effects equally upon those muscles whose nerves have
been divided, or if the brain, &c. is destroyed. After the removal
or destruction of the brain and spinal marrow in animals, the heart
still continues to act and the blood to circulate, provided respir-
[Seite 224] ation is artificially supported.r But the involuntary functions
are closely connected with the brain and spinal marrow, for the
sudden destruction of these parts or a certain portion of them,
puts a stop to the circulation;s the application of stimuli to them
excites the action of the heart and, even after its removal, of the
capillaries;t the passions of the mind do the same; nay, more, the
involuntary functions seem, in some experiments, as dependent
upon the brain and spinal marrow as they probably are upon the
ganglia and gangliac nerves, for the removal of a piece of the par
vagum, or the destruction of that part of the brain with which it
is connected, or of a considerable portion of the spinal marrow,
heavily impairs the functions of the lungs and of the stomach,u
putting a stop, not to the muscular action of the stomach, or to its
circulation, but to the secretion of gastric juice and to digestion,
and causing the blood to experience no longer the chemical changes
in the lungs, but the air-cells to become filled with frothy mucus,
the substance gorged with blood, and the surface marked with dark
patches, and causing these changes in the two organs even after
death, if the experiment is made as soon as the animal is killed,x
for after the mental functions have ceased, secretion and capillary
circulation continue for a time; and although the division of the
spinal marrow, or of its nerves, or compression or disorganisation
of these or parts of the brain, prevents voluntary power over the
corresponding muscles, without suspending the circulation, &c.
in them, and does not impede the functions of the lungs or stomach,
[Seite 225] yet circulation, and what are dependent upon it, – nutrition and
frequently animal heat, are evidently impaired, though perhaps, in
some measure, from the want of muscular action and the stimulus
of volition. Sir Everard Home found that by dividing the nerves
running to the horn of a buck, the temperature of the horn fell
about 6° below that of the other, and as the divided ends pro-
ceeded in the course of union, the temperature rose again towards a
level.y In hemiplegia, the least irritation will often produce in-
flammation, ulceration, and a rapid slough. Division of the fifth
pair of nerves close to the brain causes inflammation of the upper
part of the eye, and cloudiness of the upper part of the cornea; and
its division at the ganglion Gasseri produces opacity of the cornea
and ulceration and destruction of the eye.z The indisputable con-
nection which exists between the brain and various parts of the
body, and the effect which any injury of them must, therefore, be
supposed to have over other parts, together with the fact of children
living and eating and preserving their temperature for many days,
though born without brains, and the fact of amaurosis and even
cataract following wounds of the nerves of the face, render it
doubtful how far the above-mentioned circumstances show a de-
pendence
of the organic or vegetable functions upon the brain and
spinal marrow, – more than a connection. But a powerful argu-
ment in favour of the dependence of these functions upon the gan-
glions and ganglionic nerves is, the fact, that the ganglionic system
of nerves is formed before the brain and spinal marrow; indeed,
the nervous system of the chest and abdomen are fully formed,
while the brain appears still a pulpy mass.a

These ganglia and nerves would hardly be formed before the
brain and spinal marrow but for the sake of the organs which they
supply, and the functions of which (with the exception of the ge-
nitals) are as perfect at birth as at adult age; while the mind and
brain are slowly perfected.

A striking difference is observed in the structure and effect of
injuries upon them. Bichat asks, ‘“What anatomist has not been
struck with the difference between the cerebral and gangliac
nerves? Those of the brain are larger, more numerous, whiter,
denser, subject to fewer variations. On the other hand, extreme
[Seite 226] tenuity, considerable number, especially at the plexuses, a grey
colour, remarkable softness, and very frequent varieties, are the
characters of the gangliac nerves, if you except those which com-
municate with the cerebral, and some of those which unite these
little nervous centres.”’b

If they are cut, or the ganglia torn, no pain is produced,
while similar operations on the cerebral or spinal nerves produce
horrid torture. If all the ganglia of the neck are removed, and
even the first thoracic, no sensible or immediate derangement of
the functions is observable, even in parts to which the filaments
united with them may be traced.c Bichat long since remarked
no disturbance of the heart’s motion on attempting to irritate, or
on dividing, the cardiac filaments of the sympathetic; nor of the
stomach, bladder, &c. by applying violence or stimuli to their
nerves. Neither did he succeed with galvanism,d but Humboldt
and Dr. Fowler say they succeeded with galvanism in the case of
the heart.e

(L) These oscillations are purely hypothetical. Were their
existence proved, we should know nothing more of the real nature
of the cerebral functions, for we should have to learn what were
the peculiar properties of the nervous system, that enabled it
alone of all substances to produce, when oscillating, the pheno-
mena which it exhibits. We might as well attempt to explain
the phenomena of motion or of chemical affinity and galvanism by
vitality and mind, as the phenomena of vitality and mind by me-
chanics or chemical affinity and galvanism. They are altogether
distinct principles, although there can be no question that the
laws of mechanics and of chemical affinity and galvanism are
important and indispensable in every living system, in subser-
vience to life and mind. The mind, for aught we know, may
stimulate the voluntary muscles by means of galvanism commu-
nicated along the nerves, but then the galvanism is not mind, it
is merely an instrument employed by the mind.f

SECT. XIII.
OF THE EXTERNAL SENSES IN GENERAL, AND OF TOUCH IN
PARTICULAR.

[Seite 227]

227. The other office of the nerves we found to consist in
communicating to the sensorium the impressions made by
external objects. This is accomplished by the external senses
which are, as it were, the watchmen of the body and informers
of the mind.

These alone belong to our present subject. For to regard,
with Gorter, the stimulus which inclines us to relieve the in-
testines, the sensation of hunger, and other internal calls of
nature, as so many distinct senses, is unnecessary minuteness,
as Haller long since observed.a

228. Touch merits our first attention, because it is the first
to manifest itself after birth, its organ is most extensively
spread over the whole surface, and it is affected by many
properties of external objects.

229. For we perceive not only some qualities, as heat,
hardness, weight, &c. by the touch only, but our knowledge
obtained by other senses respecting some qualities is rendered
more accurate by the touch; such qualities are figure, dis-
tance, &c. (A)

230. It is less fallacious than the rest of the senses, and
by culture capable of such perfection as in some measure to
supply the deficiency of others, particularly of vision.b

231. The skin, whose structure we formerly examined, is
[Seite 228] the general organ of touch.c The immediate seat of the sense
is the papillae of the corium, of various forms in different
parts, commonly resembling warts,d in some places fungous,e
in others filamentous.f The extremities of all the cutaneous
nerves terminate in these under the form of pulpy penicilli.

232. The hands are the principal organs of touch, properly
so called, and regarded as the sense which examines solidity,
and their skin has many peculiarities. In the palms and on
each side of the joints of the fingers, it is furrowed and free
from hairs, to facilitate the closing of the hand: and the
extremities of both fingers and toes are ridged internally by
very beautiful lines more or less spiral;g and are shielded
externally by nails.

233. These scutiform nailsh are bestowed upon man and a
few other genera of mammalia only (we allude to the qua-
drumana which excel in the sense of touch),i for the purpose
of resisting pressure, and thus assisting the action of the fingers,
while examining objects.

They are of a horny nature, but on the whole very similar
to the epidermis. For under them lies the reticulum, which
[Seite 229] in negroes is black;k and under this again is found the
corium, adhering firmly to the periosteum of the last phalanx.
These constituent parts of the nails are striated lengthwise.
The posterior edge, which, in the hands, is remarkable for a
little lunated appearance, is fixed in a furrow of the skin; and
the nails growing constantly from this, are protruded forwards,
so as to be perfectly renewed about every six months.


NOTE.

(A) The little analogy there is between our sensations of heat
and cold and the other sensations commonly ascribed to the sense
of touch, has led many writers to consider that such dissimilar
feelings must arise from the sensations of different organs. Dr.
Spurzheiml says, ‘“It may still be asked whether feeling produces
ideas of consistency, of hardness, of softness, of solidity and
fluidity, of weight and resistance? I think it does not. For the
mind to examine these qualities employs the muscular system,
rather than the sense of feeling properly so called.”’ This opi-
nion accords with that of Dr. Brown,m who states, ‘“The
feeling of resistance,”’ (of which he considers the qualities enu-
merated above as modifications), ‘“is, I conceive, to be ascribed,
not to our organ of touch, but to our muscular frame, to which I
have already directed your attention, as forming a distinct organ
of sense; the affections of which, particularly as existing in com-
bination with other feelings, and modifying our judgments con-
cerning these (as in the case of distant vision, for example), are
not less important than those of our other sensitive organs. The
sensations of this class are, indeed, in common circumstances, so
obscure as to be scarcely heeded or remembered by us; but there
is probably no contraction, even of a single muscle, which is not
[Seite 230] attended with some faint degree of sensation that distinguishes it
from the contractions of other muscles, or from other degrees of
contraction of the same muscle.”’

Some recent discoveries of Mr. Charles Bell corroborate the
views above stated in every essential particular. In a memoir
‘“On the nervous circle which connects the voluntary muscles
with the brain,”’ inserted in the Philosophical Transactions for
1826, he proves that every muscle has two nerves of different
properties supplied to it, so that between the brain and the
muscles there is a circle of nerves, one nerve conveying the
influence from the brain to the muscles, the other giving the
sense of the condition of the muscles to the brain; also, that if
the circle be broken by the division of the motor nerve, motion
ceases, and if it be broken by the division of the other nerve,
there is no longer a sense of the condition of the muscle, and,
therefore, no regulation of its activity. He shows that the
spinal nerves are compounded of filaments possessing these different
powers, and that each nerve having several properties or endow-
ments collected within itself, proceeds to its destination without
intricacy; but where nerves of different functions take their origin
apart (viz. when they are derived from the encephalon), and run
a different course, two nerves must unite in the muscles, in order
to perfect the relations betwixt the brain and these muscles.

The following passages are quoted in Mr. Bell’s own words:

‘“Why are nerves, whose office is to convey sensation, profusely
given to muscles, in addition to those motor nerves which are
given to excite their motions? To solve this question, we must
determine whether muscles have any other purpose to serve
than merely to contract under the influence of motor nerves.
For if they have reflective influence, and if their condition is to
be felt or conceived, it will presently appear that the motor
nerves are not suitable internuncii betwixt them and the senso-
rium. I shall first inquire if it be necessary to the governance of
the muscular frame, that there be a consciousness of the state or
degree of action of the muscles? That we have a sense of the
condition of the muscles appears from this: that we feel the
effects of over-exertion or weariness, and are excruciated by
spasms, and feel the irksomeness of continued position. We
possess a power of weighing in the hand; what is this but esti-
mating the muscular force? We are sensible of the most minute
[Seite 231] changes of muscular exertion, by which we know the position of
the body and limbs, when there is no other means of knowledge
open to us. If a rope-dancer measures his steps by the eye, yet,
on the other hand, a blind man can balance his body. In stand-
ing, walking, and running, every effort of voluntary power which
gives motion to the body is directed by a sense of the condition
of the muscles, and without this sense we could not regulate
their actions, and a very principal inlet to knowledge would be
cut off.”’

In the preceding quotation Mr. Bell attributes to the muscular
feeling the power of preservation of the equilibrium of the body.
This opinion was originally advanced by Dr. Wells,n the profoundest
philosopher who was ever physician to St. Thomas’s, in the follow-
ing words: – ‘“What is there within us to indicate these positions
of the body? To me it appears evident, that, since they are
occasioned and preserved by combinations of the actions of
various voluntary muscles, some feeling must attend every such
combination, which suggests, from experience, perhaps, the
particular position produced by it. But in almost all the positions
of the body, the chief part of our muscular efforts is directed
toward sustaining it against the influence of its own gravity.
Each position, therefore, in which this takes place, must be
attended with a feeling which serves to indicate its relation to the
horizontal plane of the earth.”’

SECT. XIV.
OF TASTE.

[Seite 232]

234. We perceive tastes by the tongue, and in some degree
by the other neighbouring internal cutaneous parts of the
mouth, especially by the soft palate, the fauces, the interior
of the cheeks, and lips; by them, however, we taste only
what is acrid and very bitter.a

235. The chief organ of taste is the tongue,b agile, obse-
quious, changeable in form; in its remarkably fleshy nature,
not unlike the heart; and endowed with far more irritability
than any other voluntary muscle.c

236. Its integuments resemble the skin. They are, an
epithelium, performing the office of cuticle; the reticulum
Malpighianum;d and a papillary membrane, but little different
from the corium.

237. The integuments of the tongue differ from the skin
chiefly in these respects – in the epithelium being moistened,
not by the oily fluid of the skin, but by a mucus which proceeds
from the foramen caecum of Meibomiuse and the rest of the
glandular expansion of Morgagni,f – and, secondly, in the
[Seite 233] conformation of the papillae, which are commonly divided into
petiolated, obtuse, and conical.g The first are in very small
number and situated in a lunated series at the root of the
tongue; the others, of various magnitudes, lie promiscuously
upon the back of the tongue, and chiefly upon its edges and
apex, where taste is most acute.h

238. These papillae are furnished with extreme filaments
of the lingual branch of the fifth pair;i and through them,
probably, we acquire the power of tasting.

The ninth pair,k and the branch of the eighth which also
supplies the tongue,l appear intended rather for the various
movements of the organ, in manducation, deglutition, speak-
ing, &c.

239. For the tongue to taste properly, it must be moist,
and the substance to be tasted must be liquid, holding salts
in solution.m (A) For if either is in a dry state, we may
perceive the presence of the substances by the common sense
of touch, which the tongue possesses in great acuteness, but
cannot discover their sapid qualities.

When the tongue tastes very acutely, the papillae around
its apex and margins seem to be in some degree erected.


NOTE.

(A) Certainly an infinite number of bodies are sapid, which con-
tain no kind of salt.

[Seite 234]

Two dissimilar metals in contact, when applied to the moistened
tongue, have a decidedly acid taste. It is by no means proved
that the moisture indispensable for taste is requisite to dissolve
the substance tasted and not to fit the papillae for their office.

Dr. Nehemiah Grew, an eminent naturalist of the seventeenth
century, endeavoured to show that there are at least sixteen
different simple tastes, which he enumerates. All these, he
states, have various degrees of intenseness and weakness, and
may be combined together in an innumerable variety of pro-
portions. Many of these have other modifications; in some the
taste is more quickly perceived upon the application of the sapid
body, in others more slowly; in some the sensation is more per-
manent, in others more transient; in some it seems to undulate
or return after certain intervals, in others it is constant: the
various parts of the organ, as the lips, the tip of the tongue, the
root of the tongue, the fauces, the uvula, and the throat, are some
of them chiefly affected by one sapid body, and others by another.
All these, and other varieties of tastes, Dr. Grew illustrates by a
number of examples.n

SECT. XV.
OF SMELL.

[Seite 235]

240. While taste and smell are closely related by the
proximity of their organs, they are not less so by the analogy
of their stimuli and by some other circumstances. For this
reason, they have been generally classed together under the
name of chemical or subjective senses.

By smell we perceive odorous effluvia received by inspir-
ation and applied principally to that part of the Schneideriana
membrane which invests both sides of the septum narium and
the convexities of the turbinated bones.

241. Although the same moist membrane lines the nostrilsb
and their sinuses,c its nature appears different in different
parts.

Near the external openings it is more similar to the skin,
and beset with sebaceous follicles, from which arise hairs
known by the name of vibrissae.

On the septum and the turbinated bones it is fungous and
abounds in mucous cryptae.

In the frontal, sphenoidal, ethmoidal, and maxillary sinuses,
[Seite 236] it is extremely delicate, and supplied with an Infinite number
of blood-vessels which exhale an aqueous dew.

242. It appears the principal, not to say the sole, use of
the sinuses,d to supply this watery fluid, which is perhaps
first conveyed to the three meatus of the nostrils and after-
wards to the neighbouring parts of the organ of smell, pre-
serving them in that constant state of moisture which is indis-
pensable to the perfection of smell.

The sinuses are so placed, that, in every position of the
head, moisture can pass from one or other of them into the
organ of smell.

243. The principal seat of smell, – the fungous portion
of the nasal membrane, besides numerous blood-vessels, re-
markable for being more liable to spontaneous hemorrhage
than any others in the body, is supplied by nerves, chiefly the
first pair,e which are distributed on both sides of the septum
narium, and also by two branches of the fifth pair. The
former appear to be the seat of smell:f the latter to serve for
the common feeling of the part, that excites sneezing, &c.

244. The extreme filaments of the first pair do not ter-
minate in papillae, like the nerves of touch and taste, but
deliquesce, as it were, into the spongy and regular parenchyma
of the nasal membrane.

245. The organ of smell is very imperfect and small at
birth. The sinuses scarcely exist. Smell consequently takes
[Seite 237] place but late, – as the internal nostrils are gradually evolved;
and it is more acute in proportion to their size and per-
fection.g

246. No external sense is so intimately connected with the
sensorium and internal senses, nor possesses such influence
over them, as the sense of smell.h

No other is so liable to idiosyncrasies, nor so powerful in
exciting and removing syncope.

Nor is any other capable of receiving more delicate and
delightful impressions; for which reason, Rousseau very
aptly called smell, the sense of imagination.i

No sensations can be remembered in so lively a manner as
those which are recalled by peculiar odours.k

[Seite 238]

NOTE.

The causes of the sensation of smelling are, as yet, unknown,
and in the absence of positive knowledge on this subject philo-
sophers have either avowed their ignorance or contented them-
selves with hypotheses destitute of proof. Among the opinions
respecting these recondite phenomena which have at various
times been advanced, three may merit our consideration. The
advocates of the first, designate by spiritus rector, or aroma, a
principle independent of the substances which contain it, very
volatile and expansible, imponderable, and imperceptible to every
sense excepting that of smell; and to the various modifications of
this immaterial substance they attribute the varieties of odour.
The second, and most generally received theory, is, that odours
are particles which evaporate from the odorous substance itself,
and that the cause of the sensation of smell is therefore inherent
in, and inseparable from, the odorous body. The third opinion,
which is maintained by Professor Walther, is, that olfaction is
independent of the emanations of material particles, and is a sim-
ple dynamic action of the odorous body upon the organs of smell-
ing, similar to the action of sound on the hearing.

However this may be, odours, to become objects of sensation,
must pass the pituitary expansion of the olfactory nerve during
the respiratory process. When the breath is held, the most
odorous substances may be spread in the interior of the nostrils
without their perfume being perceived; this observation was first
made by Galen. It has been frequently remarked that odours are
smelt only during inspiration, the same air when returned through
the nostrils always proving inodorous. But this is true only when
the odour has been admitted from without by the nostrils; for when
it is admitted by the mouth, as in combination with articles of nutri-
tion, it is only during expiration that the odour can be perceived;
a proof of this may be readily obtained, by placing the open neck
of a small phial, containing an essential oil, in the mouth during
the acts of inspiration, and subsequent expiration.

It was first observed by Willis,l that on placing a sapid sub-
stance in the mouth, and at the same time closing the nostrils,
the sensation of taste is suspended. This observation has since
[Seite 239] been frequently repeated, and has given rise to the generally
prevailing opinion that a very intimate relation exists between the
sensations of smelling and tasting, and that the same qualities of
bodies simultaneously affect both these senses. The fact is, that
the causes of taste and smell are totally distinct in their nature;
tastes, properly so called, affect only the gustatory expansion, and
are, consequently, unaltered by closing the nostrils; but as most
sapid substances have also an odour, and expiration takes place
frequently during mastication and generally directly after deglu-
tition, the odorous emanations are made to pass over the pituitary
membrane. Odour, which thus accompanies taste, is termed
flavour.

Sugar, salt, and vinegar, have each a real taste, which can be
affected neither by catarrh nor by stopping the nostrils; but the
flavour and odour of roast meats, of spices, of liqueurs, &c., are
identical, and they are affected equally by the same conditions.

Dr. Prout, I believe, was the first who pointed out the distinc-
tion between taste and flavour.l He conceived, however, that
flavour was intermediate between taste and smell.

SECT. XVI.
OF HEARING.

[Seite 240]

247. Sound, (A) which is excited by the vibration of elastic
bodies and propagated by the air, is perceived by the sense of
hearing,a and is first received by the conchiform cartilaginous
external ear,b which few of our countrymen have the power
of moving.c By this it is collected; then conveyed into the
meatus auditorius, which is anointed by a bitter ceru-
men;d (B) and strikese against the membrana tympani, (C)
which is placed obliquely in a circular furrow of the temporal
bone and separates the meatus from the internal ear.

248. Behind this membrane lies the middle portion of the
ear, – the cavity of the tympanum, whose fundus is directed
upwards and inwards.

It contains threef ossicula auditus; of which the exterior,
or malleus, adheres by its manubrium to the membrana tym-
pani, and is generally united in the adult to the circular fur-
row above-mentioned by its spinous process which is directed
forwards, and it lodges its round head in the body of the
incus.

The incus is united to the head of the stapes by the ex-
[Seite 241] tremity of its long process which extends into the cavity of
the tympanum.

The stapes, resting its base upon the fenestra ovalis, runs
towards the vestibule of the labyrinth, into which, sounds,
struck against the membrana tympani, are propagated by the
intervention of these three little bones.

249. The Eustachian tubeg runs from the interior of the
fauces into the cavity of the tympanum: and the inferior
scala of the cochlea has the same direction; the opening of
the latter, termed fenestra rotunda,h is closed by a peculiar
membrane. The true and principal use of each is not suf-
ficiently known.i

250. In the deepest part of the petrous bone is placed the
labyrinth, or internal ear, consisting of three parts.

First, of the vestibule, placed between the other two, and
into it open not only the fenestra ovalis, but the five orifices
of the semicircular canals which lie posteriorly, and the su-
perior scala of the cochlea which is placed anteriorly.

The vestibule and semicircular canals loosely contain very
delicate membranous bags, discovered by the celebrated
Scarpa: viz, two sacs which lie in the vestibule, and three
semicircular ducts in the canals of the same name.k

251. These sacs as well as the cavity of the cochlea, contain
a very limpid fluid, bearing the name of Cotugno, who shewed
it to be absorbed by two canals, which are by him deno-
minated aqueducts,l and by Meckel diverticula;m the one arises
[Seite 242] from the vestibule, the other from the inferior scala of the
cochlea.

252. The portio mollis of the seventh pair, together with
the portio dura (which afterwards runs along the aqueduct of
Fallopius),n having entered the internal acoustic opening,
transmits its medullary filaments into the lower and cribriform
part of it.o These filaments run partly to the vestibule and
semicircular canals, but especially to the base of the cochlea,
where, in the form of a medullary zonula, marked by very
beautiful plexiform striae, they pass between the two laminae
of the septum cochleae.p

253. The oscillatory tremor, which we formerly followed
as far as the fenestra ovalis (248), is propagated to the vesti-
bule, where, by means of the water of Cotugno (251), it
strikes the auditory nerves distributed among the windings of
the labyrinth.

254. Besides the muscles of the malleus and stapes,q that
appear to be voluntary,r the chorda tympani,s passing be-
tween the handle of the malleus and the longer leg of the
incus, is believed to modify the force of sound which is struck
against the membrana tympani and intended to be propagated
along the cavity of the tympanum.t (D)

[Seite 243]

NOTE.

(A) By Hearing we are able to appreciate the vibratory mo-
tions of elastic bodies, when their frequencies are within certain
limits. Some recent experiments by Dr. Wollaston prove that
these limits vary in different individuals; but the average extent
of the scale of sounds perceptible to the human ear has been
estimated to be between 30 and 12,000 vibrations of the sonorous
body per second.

The undulations to which these vibrations give rise may be
transmitted through any substance, either aëriform, liquid, or
solid: but the air is the ordinary medium by which they reach
the ear. The velocity of transmission depends on the specific
elasticity of the substance; according to the latest experiments
sound travels through air at the rate of about 1142 feet per
second.

With regard to the sensation of sound, four independent qua-
lities must be distinguished:u

1st. The tune, or pitch; which depends on the frequencies with
which the vibrations succeed each other.

2d. The loudness, or intensity; which is determined by the am-
plitudes of the vibrations.

3d. The volume, or richness; which depends upon the number
of co-existing undulations that arrive at the ear.

4th. The timbre: – For this word, adopted in France to express
the specific differences of sound which are not comprehended in
any of the preceding definitions, there is no analogous term in our
language; nor have we at present the least idea of the true causes
of these modifications of sound. In some cases the indefinite ex-
pression quality of tone is employed.

When two or more sounds are heard simultaneously, or succes-
sively, the mind by a peculiar faculty perceives the relative fre-
quencies and coincidences of the vibrations. Two sounds are
regarded, as consonant when the ratio of their vibrations is very
simple, and as dissonant when the ratio is more complex. The
rules which determine the most agreeable successions and com-
binations of sounds constitute the science of music.

[Seite 244]

The power of appreciating musical combinations, and conse-
quently the pleasure of listening to them, depends upon a mental
faculty seated in a particular portion of the brain, and not upon
the acuteness of hearing. A person of the quickest ears may have
no music in his soul, and persons of dull ears have often a good
ear for music. In great musicians, that portion of the skull cor-
responding with the part of the brain that Gall declares to be the
organ of music, I have invariably seen large; and in persons
slightly, or not at all sensible to the delights of music, invariably
flat, or even hollow.

(B) The cerumen consists, according to Vauquelin, of albu-
men, which, when burnt, yields soda and phosphate of lime, a
colouring matter, and a very bitter inspissated oil strongly re-
sembling the peculiar matter of bile. Cicero explains one use of
the cerumen: – ‘“Provisum etiam, ut, si qua minima bestiola
conaretur irrumpere, in sordibus aurium, tanquam in visco, inhae-
resceret.”’x The same applies to particles of dust. Its extreme
bitterness, too, deters insects from advancing.

(C) The membrane of the tympanum is not of that importance
which the prevailing hypothesis induced physiologists to believe
formerly. It may be perforated and even obliterated, and yet
the faculty of hearing will remain uninjured. Its uses appear to
be chiefly preservative. The mechanism which has been devised
to bring the membrane to vibrate in unison with different sounds
is entirely imaginary; for it is evident, from the known laws of
vibrating surfaces, that its condition is always such as to render it
susceptible of being influenced by any sound whatever.

When the membrana tympani is stretched by the internal
muscle of the malleus, the amplitudes of its vibrations are dimi-
nished, and the sound is transmitted to the internal ear, through
the fenestra ovalis, with less intensity; when, on the contrary, it
is relaxed, by the action of the anterior muscle of the malleus, the
amplitudes are rendered greater, and the sound is transmitted with
greater intensity. These results, which Dr. Savart has established
by experiment, are in direct opposition to the conjectures of
Bichat.y

[Seite 245]

(D) Some curious and original observations and experiments on
the functions of hearing, will be found in a paper by Dr. Wollaston
‘“On Sounds inaudible to certain Ears,”’z and in Mr. C. Wheatstone’s
‘“Experiments on Audition.”’a Savart’s memoir, already mentioned,
will be found also to contain some facts worthy of notice.

SECT. XVII.
OF SIGHT.

[Seite 246]

255. The instruments of vision, – the eyes,a are two
moveable globes, fixed to the optic nerves, whose decussation
we formerly noticed (211), as it were to stalks, in such a man-
ner, that their insertion is not exactly opposite the centre of
the cornea and iris, but on one side of this imaginary axis, –
rather nearer to the nose.

256. They consist of various coats containing pellucid
humours of different densities, so placed that the rays of light
can pass from the transparent anterior segment of the bulb
to the opposite part of the fundus.

257. The external coat is called sclerotic. It is deficient in
the centre, and that part is filled up by the cornea, which is
transparent, lamellated (lined internally by the membrane of
the aqueous humour,
or of Demours), more or less convex, and
projects like the segment of a small globe from one of rather
larger size.b

258. The interior of the sclerotica is lined by the chorioid,
which abounds in blood-vessels,c especially vorticose veins,
[Seite 247] and is covered on each side by a black pigment, which adheres
but loosely to its concave surface in the form of mucus.d

259. The chorioid is internally coated by the retinae – a
medullary expansion of the optic nerve after this has passed
through the sclerotica and chorioid,f of most beautiful tex-
ture,g and perforated, in the imaginary axis of the eye,
between the two principal twigs of the central artery,h by the
singular central foramen of Sömmerring,i which is surrounded
by a yellow edge.k (A)

260. The anterior edge of the chorioid is terminated by a
cellular belt, called orbiculus ciliaris, by which it adheres
firmly to a corresponding groove in the sclerotic, and from
which two other membranes of a different kind, viz. the iris
and ciliary processes, are expanded in a circular form.

[Seite 248]

261. The iris (whose posterior surface is lined by a brown
pigment, and termed uvea), lies anteriorly to the ciliary pro-
cesses, is flat, and washed on all sides by the aqueous humour;
narrower towards the nose, broader towards the temples.
Its texture is dense and cellular, and contains no vestige of
muscular fibre. We must regard it, with Zinn,l as a mem-
brane sui generis, and not as a prolongation of the chorioid.
The anterior surface is differently coloured in different per-
sons, and, during life, has a flocculent appearance.m

262. The blood-vessels of the iris run chiefly on its anterior
surface, and in the foetus are continued into the membrana
pupillaris,
n which begins to open in its centre at the seventh
or eighth month of pregnancy, – when the eyes have acquired
some degree of size, and when, probably, the elliptic arches
of its vessels begin to be gradually retracted into the inner
ring of the iris,
which ring I have never been able to perceive
distinctly before that period.

263. The posterior of the two circular membranes (260)
bears the name of ligamentum or corpus ciliare; and, inclining
backwards, lies at a distance from the iris. Its external edge
is thicko and adheres to the ciliary circle (260): the internal
is thin, and, together with the adjacent zonula of Zinn,p sur-
rounds the margin of the capsule of the lens. The brown
pigment is copiously diffused over it.

Its anterior surface, lying opposite to the uvea, is striated.

The posterior, lying upon the vitreous humour, is marked
[Seite 249] by about seventy plicae, which are beautifully flocculent, and
remarkable for a set of indescribably minute and elegant blood-
vessels. These flocculi are named ciliary processes, and their
use is still an object of enquiry.q

264. In the bulb of the eye, whose coats we have now de-
scribed, are contained the humours, of three principal kinds.

The posterior, and by far the greater, part of the globe is
filled by the vitreous humour, which is in larger quantity pro-
portionally in the human subject, especially after puberty,
than in other animals, and so dispersed in innumerable drops
throughout the cells of the delicate hyaloid membrane that this
membranaceo-lymphatic body has the singular appearance of
a tremulous jelly.

265. Anteriorly it adheres to, and, the zonula just men-
tioned surrounds, the capsule containing the crystalline lens,
immediately around which lies the water of Morgagni.

The lens itself also very pellucid is cellular, but so much
more dense than the vitreous humour, that in the hand it
seems like a very tenacious, although an amazingly clear,
gluten. Its nucleus is more dense than the exterior laminae.
The laminae may be reduced into extremely delicate fibres,
converging from the circumference to the centre.r

In an adult man the lens is proportionally to the whole
body smaller than in quadruped mammalia; also less convex,
especially on its anterior surface.

266. The remaining space of the eye is filled by the aqueous
humour,
which is very limpid, and divided by the iris into two
chambers: – the anterior and larger separating the cornea
and iris; and the posterior, in which the uvea lies towards
the corpus ciliare, so small, as scarcely believed by some to
exist.

[Seite 250]

267. These most valuable parts are defended from injury
both by the depth of their situation in the orbits and by the
valvular coverings of the eye-lids.

In the duplicature of the palpebrae, lie the sebaceous follicles
of Meibomius,s thickly distributed: and their edges are fringed
by a triple or quadruple series of cilia:t the cartilaginous
tarsi serve for their support and expansion, and also facilitate
their motion upon the eye-ball.

Above the eye-lids, to use the language of Cicero, are
placed the supercilia, which preserve the eyes from the sweat
flowing from the head and forehead, and in some measure
screen them from too strong a light.

268. To lubricate the eyes, to preserve their brightness,
and to wash away foreign matters, is the office of the tears;
the chief source of which is a conglomerate gland placed in
the upper and exterior part of the orbit. It has numerous
but very fine excretory ducts, which are said to discharge
about two ounces of tears upon each eye during the twenty-
four hours: the tears are afterwards absorbed by the puncta
lachrymalia, the function of which may, in a certain sense, be
compared to that of the lacteals in the villous coat of the
small intestines; from the puncta they are conveyed through
the snails’ horns, as they are called, into the lachrymal sac,
and thence pass into the lower meatus of the nostrils.u (B)

269. Thus much it was necessary to premise upon the
structure of the organ of vision. We now come to the func-
tion of the organ, – to the explanation of vision.

Rays of light falling upon the cornea at an angle more
acute than forty-eight degrees, pass through it, and, from
both its density and figure, are considerably refracted towards
the axis of the eye, and on entering the aqueous humour they
experience rather a less degree of refraction.

Those rays which penetrate the pupil and are received by
[Seite 251] the lens, are still more refracted on account of the greater
density of this medium.

The less density of the vitreous humour prevents the focus
of rays from being too short, and allows it to fall upon the
retina and exhibit the image of objects, though, from the laws
of light, necessarily inverted.

270. The focus which thus falls upon the retina, is consi-
dered as a point, not absolutely, but, on account of the different
refrangibility of colours, relatively; yet the latitude necessarily
arising from this aberration of the rays is so small that it not
only does not obscure the distinctness of vision in any per-
ceptible degree, but is the source of many advantages.x

271. The celebrated question – why we behold objects
erect, while their image is inverted upon the retina,y may
be easily answered, by considering that objects are called
inverted relatively only to those which appear erect.

Now, since the images of all objects and of our own bodies
are painted on the retina, each in its relative situation, this
relative situation must correspond as exactly as if they were
viewed erect, so that the mind (to which a sensation excited
by the image and not the image itself is communicated) is
preserved from all danger of error. (C)

272. Since many conditions are requisite for distinct vision,
the Creator has wonderfully ordered the functions of these
organs.

A sufficient, but, at the same time, a definite, quantity of
light, not too intense for distinct vision, is provided in two
modes: – First, according to the greater or less intensity of
the rays, a greater or less number of them pass to the lens; –
Secondly, that portion which is superabundant and injurious
to vision is absorbed.

The first point is effected by the motion of the iris; the
second, by the pigmentum nigrum.

[Seite 252]

273. The iris is endowed with remarkable mobility, and
thus accommodates itself to the intensity and distance of light,
so that, when exposed to a strong light or to near objects it
may expand itself and contract the pupil, but when to a
weaker light or more remote objects it may contract itself and
dilate that opening.z

Physiologists have given different explanations of this
motion. Some ascribe it to the varied impulse of blood into the
vessels, others to contraction of the imaginary muscular fibres
of the iris. I have shown, in a particular treatise, that both
these circumstances are impossible, and that its proximate cause
may be sought for with more probability and reason in the
vita propria of the iris (42); the more remote cause, as we
formerly hinted (56), can be solely the reaction of the sen-
sorium.a

274. The function of the dark pigment, so frequently men-
tioned, (258, 261, 263,) viz. to absorb the superfluous rays,
and, consequently, its importance to the perfection of vision,
are demonstrated, among other modes, by the dissection of
different kinds of animals, and by the diseased condition of
Albinos, whose eyes are very tender and impatient of light
from the absence of this pigment.b

275. The focus of the refracted rays must fall exactly on
the retina, so that the point of vision be neither produced
beyond it nor fall within the vitreous humour.

The latter defect exists in short-sighted persons, from the
too great convexity of the cornea or gibbosity of the lens.

The former is the defect of long-sighted persons, in whom
there is the opposite conformation of parts.

276. Since a perfect and sound eye beholds near and
remote objects with equal distinctness, it must of necessity be
[Seite 253] supplied with appropriate powers of accommodation.c That
these internal changes of the eye are chiefly accomplished by
the pressure of the straight muscles of the ball, I am clearly
convinced, from this among other arguments, – that in the
Greenland whale – an amphibious animal, which must see in
media of such different densities, nature has most accurately
provided for it, in the remarkable structure and obsequious
flexibility of the sclerotica.d (D)

277. During the waking state, the eyes are perpetually,
although unconsciously, agitated, and directed towards the
axes of objects, by these muscles. (E)

For, although the whole of the retina is sensible, it is not
throughout equally calculated to receive the images of objects.

In the first place, the true axis of the humane eye, where
the optic nerve enters, is proved, by the well-known experi-
ment of Mariotte,f to be nearly insensible to light. (F)

The principal focus of the rest of the retina, and which must be
considered as the chief instrument of distinct vision, falls upon
an imaginary axis of the globe, corresponding with the centre
of the cornea and of the whole eye. This, however, as
Kaestner observes in opposition to Boerhaave, is not to be
understood as if only one point of an object could be seen
distinctly at once, the eye being fixed, and that, to behold
another point, the axis of the eye must be changed; for the
sensation of an entire object is simple and complete.g

278. The habit of directing the axes of the eyes rapidly
towards objects is acquired by practice. This is proved by
the example of persons who were born blind but recovered
[Seite 254] their sight after puberty;h and of children, who seldom
acquire this facility of motion before the third month.

279. To habit we must ascribe also the circumstance of
beholding an object singly, although we have two eyes.i For
infants at first see double, and the double vision which occa-
sionally occurs after certain diseases of the eyes may be
removed by practice and experience. (G)

280. The combined power of the two eyes does not exceed,
according to Jurin, that of each, by more than one thirteenth
part.

It is needless to add, what the celebrated painter, Leonardo
da Vinci, long since remarked, – that, in viewing distant
objects, it is preferable to employ but one eye.k

281. An object can never be seen unless the angle of vision
exceeds 34 seconds. This was proved by the very beautiful
experiments of the acute Tob. Mayer, who formerly was one
of our number: and he demonstrated the great perfection of
the human sight, by showing that this still remained the limit
of vision in any light, – in the splendor of the meridian sun
and the faint light of a lantern; so that vision remains almost
equally distinct although the light be considerably dimi-
nished.l

282. We may hence infer the extreme minuteness of the
images of objects projected upon the retina,m and nevertheless
impressed so forcibly upon it, that, under certain circumstances,
their vestiges remain after the removal of the objects from
before the eye.n

[Seite 255]

NOTES.

(A) A delicate transparent membrane has been discovered by
Dr. Jacob, of Dublin, between the retina and chorioid, and ad-
herent to both.o

(B) The tears appear to me to pass over the ball of the eye as
low as the edge of the superior tarsus, which is so applied to the
ball as not ordinarily to allow of their ready escape under it.p As
the upper lid descends and nearly covers the front of the eye dur-
ing sleep, for the lower has but little motion, and the fine inner edges
of both meet, the whole of the ball is at this time readily preserved
moist. But when the eyes are open, the front of the eye between
the lids would not be moistened unless the upper tarsus occasion-
ally descended with the fluid contained behind it. A portion of
the fluid thus brought down upon the front of the eye, remains
after the upper lid rises again after winking, and trickles by its
gravity as far as the inferior tarsus, which, ascending a little as
often as the superior descends, raises it somewhat. Winking thus
preserves the front of the eye constantly moist during the waking
state.

It may be also observed that, when the tarsi approximate, as
they drive before them the moisture of the front of the eye-ball,
they quite inundate the puncta lachrymalia, by which circumstance
the puncta are, of course, enabled to carry off a large quantity of
the secretion, and ordinarily to prevent its overflow, which would
occur at the centre of the lower tarsus. During sleep the puncta
are not so copiously supplied, as they have only the same share
of tears as the eye in general; and there is less occasion for it,
because the removal of the stimulus of air and light by the closure
of the eyelids, lessens the secretion.

Dr. Magendie has found the matter of the tarsal or Meibomian
[Seite 256] glands to be not sebaceous but albuminous, and soluble in the
tears: hence we discover why, during sleep, it accumulates on
the tarsi, – because its solvent – the tears, are not sufficiently
abundant to remove it.

(C) The notion of our originally seeing objects upside-down,
double, and all as at the same distance, till experience lends its
aid, has been satisfactorily refuted by Bishop Berkeley and others.
The organs of sight, and all the others of sense, present, when
perfect, a perfect impression to the inward senses – the faculties
for judging of persons or forms, distance, colour, &c., and nothing
farther: these do the rest. The eyes of infants are not originally
fit for vision: they are at first absolutely insensible to light for
some time, and become qualified for their office gradually. But
those animals who are are born with perfect eyes, see perfectly
the first moment they enter into the world.q Indeed, no expe-
rience will make us perceive objects differently from what the
external organs present them. Experience tells us that the trees
at the end of an avenue are as high as those near us, yet we still
see them diminutive; and that a stick placed in water is straight,
but it continues to appear crooked. My reader must consult
Gall, Dr. Spurzheim, and also Mr. Combe from page 256 to 339.

Persons, all having excellent eyes, and seeing perfectly well,
differ much in their powers of recognising persons, finding their
way, &c. In none of these points is the difference so striking
as with respect to judging of colours. It is by no means un-
common to meet with individuals whose eyes appear excellent,
and whose sight is excellent, and who may judge of form and
distance correctly, but who cannot distinguish certain colours.
Dr. Nicholl describes a boy who confounded green with red, and
[Seite 257] called light red and pink, blue. His maternal grandfather, and
one uncle, had the same imperfection. This uncle was in the
navy, and, having a blue uniform coat and waistcoat, purchased a
pair of red breeches to match.r Dr. Nicholl mentions a gentleman
who could not distinguish green from red. The grass in full ver-
dure always appeared to him what others call red; and ripe fruit on
trees he could not distinguish from the leaves; a cucumber and a
boiled lobster were of the same colour in his sight, and a leek
resembled a stick of sealing-wax. This person had a brother and
a niece – the daughter of another brother – in a similar predica-
ment.s Indeed, the defect has frequently occurred in several
members of the same family, and frequently has been hereditary,
sometimes passing over a generation, like other peculiarities of
structure. It is observed more frequently, perhaps, in men. In
the rarest and most extreme cases, no colour is distinguished, all
objects appearing in this respect alike. In all the cases in which
the point has been examined, the part of the cranium under which,
according to Gall, the organ for judging of the harmony of colours
is placed, is flat, or depressed. I have seen several of these cases,
and in all this was the fact. In painters, remarkable for their ex-
cellence of colouring, this part is full, or prominent. The contrast
between this part of the forehead in a person who has this defect,
and in another excelling in the power of colouring, placed side by
side, is very striking.

Mr. Dugald Stewart remarks, that ‘“in the power of conceiving
colours there are striking differences among individuals;”’ and he
does not ascribe the difference to the eyes. ‘“I am inclined to sus-
pect,”’ he says, ‘“that in the greater number of instances the supposed
defects of sight ought to be rather ascribed to a defect in the
power of conception.”’t Mr. Stewart is correct in exempting the
eye from blame, and ascribing the defect to a defect in conception;
but since he has no idea of a distinct faculty for colours, he means
conception in general. Yet, as the individuals are not deficient
[Seite 258] in other conceptions, some reason must be given for the defi-
ciency of conception in this one point. He thinks it arises ‘“pro-
bably in consequence of some early habit of inattention.”’ Now
this is sad trifling in a philosopher. What particular attention do
children, who distinguish colours accurately, bestow? They dis-
tinguish without effort; and those who cannot, are not only not
proved to have been inattentive, but have, probably, been often
extraordinarily attentive, in the hope of seeing what others can
see. How should want of attention to this one point run in fami-
lies and be hereditary, passing through a generation, &c.? This
is a specimen of the errors of metaphysicians. They see, and
generally acknowledge, that the brain is the organ of the mind,
yet they observe the faculties of the mind without even once
looking at the organ, which possesses, or is employed in the
working of, these faculties. Gall examined the two together, and
we now know, that local deficiency of brain exists where the
power of distinguishing colours is deficient, and is hereditary with
this deficiency.

(D) The most recent opinion on the causes of the adaptation of
the eye to distinct vision, a subject on which innumerable con-
jectures have been made, is that of Jean Mile of Warsaw.u By a
great number of accurate and satisfactory experiments, for which
I refer the reader to the original memoir, he has arrived at the
following conclusions.

The eye does not see with equal distinctness objects at all dis-
tances, but only when they are within a certain distance. This
does not depend on external causes, such as the diminution of the
optic angle, and the obscuration of the object by the intermediate
air; for, to see clearly and to see distinctly are not identical.
The causes of distinct vision are internal, and situated in the eye
itself; they are two in number; one disposes the eye for the con-
tinuous distinct vision, and the other for the transient distinct,
vision of objects at different distances; but neither of them can
act but within certain limits. These limits are greater for the
presbyope than for the myope. These adaptations both depend
on the action of the iris, which can at the same time act in two
ways to produce two effects; first, the contraction of its aperture,
[Seite 259] and, secondly, the flexion of the cornea; the alteration of the size
of the pupil, however, is visible only. The adaptation of the eye
for the continuous distinct vision of objects contained within
certain limits, is owing to the diffraction of the rays of light near
the edge of the aperture of the iris, in consequence of which there
is formed by a single external luminous point, several foci instead
of one, successively ranged in a line of a certain length, so that
the object may change its distance within certain limits, and yet
one of its foci shall always fall on the bottom of the eye. This
focal length is inversely as the magnitude of the pupil. The
borders of indistinct objects appear radiated, and to the pheno-
menon of confusion is added the motion and multiplication of the
image when the edges of bodies are brought near the side of the
fasciculus of rays which enter the eye; prismatic colours also
appear. All these phenomena which are observed in an eye
performing its functions, may be produced by an apparatus, the
structure of which resembles that of the eye, and even by a com-
mon lens, substituting for the motion of the pupil diaphragms of
different sizes. The nature of all these phenomena prove that
diffraction is their common origin, and they may be considered as
constituting a separate kind of optical illusions resulting from
diffraction. The second cause which adapts the eye for the mo-
mentaneous distinct vision of objects, depends neither on the
action of the external muscles of the eye, the advancement of the
bottom of the eye, nor on any alteration of the form or position
of the crystalline lens, but appears to be owing rather to the
change of the curvature of the cornea by the contraction of the
iris, which occurs only when the eye adapts itself to see very
near objects, as is proved by the simultaneous approximation of
the pupil.

(E) The motions of the eyes which result from the actions of
their external muscles have been investigated, and the mental
perceptions attending them have been analysed with considerable
success by Dr. Wells;x and the subject has recently been again
taken up by Mr. C. Bell.y An extensive field of enquiry, how-
ever, still remains. Mr. Charles Wheatstone is about to publish
[Seite 260] some original experiments on this subject that will go a consider-
able way towards completing our knowledge of this intricate and
important subject.

(F) Mariotte’s experiment was to make two spots upon a wall, to
fix the right eye upon the left spot, the other being closed, or v. v.
and gradually to retire till the right spot is no longer distinguish-
able, as occurs when its image falls upon the centre of the
optic nerve. Picard varied this experiment, by placing an object
between the eye and the spot, so that it appeared double, and one
image of it covered one spot completely when one eye was closed.

Mr. C. Wheatstone places two wafers upon a table, and fixing
one eye upon the opposite wafer, and closing the other, moves the
other wafer gradually away till it ceases to be seen: on being
removed still further, it comes into view again.

(G) Although we certainly use both eyes to look generally at
objects before us (those on each side can of course be seen by the
eye of the same side only), yet when we fix our view attentively
on an object, we employ but one if each eye is not of equal
strength. This, at least, is my own case. If I hold up a finger,
and look at distant objects, it appears double, and if I then look
at it, I of course see it single, and the figure now seen is, in my
case, that which was previously seen with the right eye: no dif-
ference occurs in it, if now the left eye is closed. The greater
facility of threading a needle, when both are open, probably
arises from the advantage of increasing the field of vision while
one eye is fixed steadily upon the aperture. Some, however,
who are profoundly skilled in physics, deny that the use of one
eye only in attentive inspection is general.

Many recorded cases prove that one half of the retina may be
paralysed, while the other half remains unaffected; and this effect
may be common to both eyes, or peculiar to one. Dr. Wollastonz
relates, that it twice occurred to him not to be able to see but on
one side of the axis of vision. The first time, the left side of each
eye was affected; he saw but the half of a man’s face or of any
object he looked at; and in attempting to read the name JOHN-
SON over a door, he saw only _....SON, the commencement
of the name being totally obliterated from his view: the com-
plaint was of short duration. About nineteen years afterwards
the phenomenon recurred: this time, the right side of the eye,
[Seite 261] about three degrees from the centre of the retina, was affected,
and its duration was ten minutes. Two analogous cases are also
mentioned by Dr. Wollaston. Desmoulinsa states, that M. Arago
has experienced this affection of vision three times: the first two
times, objects situated to the right of the axis of vision were in-
visible; the third time he saw objects on the right only of this
axis. The same author notices also the following remarkable
case. In consequence of a cerebral fever, the external side of the
left retina of M. de M – became insensible: with this eye he
saw only objects situate to the left of the centre of vision; and,
as at the same time there was an outward deviation of the axis of
this eye, through a paralysis of the nerve of the third pair, when
he employed both eyes, he saw objects double; but, what was
still more singular, the right eye being closed, he saw with the
left eye the objects removed from twenty to twenty-five degrees
to the right of their real position.

Such facts have been thought a reason for believing the decus-
sation of the optic nerves partial, and some say that the outer portion
of the tractus optici goes to the outer part of the corresponding
nerves, and the inner to the inner portion of the opposite; but
Magendie divided from before backwards the junction of the optic
nerves, and found blindness induced.

The decussation of the optic nerves is shown by blindness of
one eye being induced if the nerve on the same side is divided
anteriorly to the union, and of the opposite eye if the division is
made posteriorly to the union: or by destruction of an eye caus-
ing the nerve of the same side to waste as far as the union, and of
the opposite side beyond the union.b Yet cases are on record
where the wasting of the nerve in loss of sight continued through-
out on the same side, but such are probably suspicious.

The thalami optici are improperly named, as they do not give
origin to the optic nerves. These may be traced to the anterior
corpora quadrigemina, pressure or disease of which produces
blindness, and which waste if the nerve wastes.c

If the fifth pair, which gives sensibility to the face, is divided,
the eye, nose, tongue, lose their sense of touch, – ordinary sen-
[Seite 262] sibility, – in common with the skin, and are not excited by me-
chanical or acrid stimulus as before.d In this experiment, the
pupil becomes greatly contracted in rabbits and guinea-pigs,
and dilated in cats and dogs.e The retina has very little ordinary
sensibility, as Magendie showed, by pricking and tearing it with
little or no pain; whence contraction of the pupil does not follow
the application of any stimulus excepting light. The third pair,
which is a nerve of motion, supplies, in common with the fifth pair,
the iris, and therefore, as Mr. H. Mayo has shown, division of
it, at least in cats and pigeons, causes dilatation of the pupil, like
division of the optic nerve; the dilatation arising in the former case
from the cerebral influence being no longer conveyed, and in the
latter from the cerebral influence being no longer excited. On
stimulating the ocular end of the third pair, divided in pigeons,
after removing the brain, the iris suddenly acts.f

SECT. XVIII.
OF THE VOLUNTARY MOTIONS.

[Seite 263]

283. We have seen that the nerves perform two offices
(220) – the one of feeling, the other of moving. The former
we have already considered; we shall now say something with
respect to the latter.

284. All the motions of the body may be divided into
voluntary and involuntary.

The pulsation of the heart, and the peristaltic motion of
the intestines and other viscera, are commonly adduced as
instances of involuntary motion.

The action of by far the greater number of the other
muscles is voluntary.

Respiration, sneezing, the tension of the membrana tympani,
and the action of the cremaster, are regarded by some as be-
longing to the former class; by others, to the latter; and by
others, as of a mixed nature.

285. If this division is narrowly examined, it will be found
embarrassed by so many difficulties that the limits of each
class cannot well be determined.

For, on the one hand, few functions can be termed truly
involuntary, especially if we consider the connection of the
imagination and passions with the will.

Again, on the other hand, there are few voluntary motions
that may not be rendered involuntary by the force of habit,
whose influence upon our animal motions is immense.

286. Of the latter description are those muscular motions
which, although generally voluntary, take place, under certain
circumstances, without the knowledge of the mind, or even in
opposition to its endeavours.

[Seite 264]

Thus we wink involuntarily, if a friend suddenly moves his
finger towards one of our eyes, though it does not come in
contact: and the ring finger generally bends if we bend the
little finger.

We often unconsciously move our limbs, even while sleeping
soundly.

On the contrary, some muscles which are almost always
obedient to the will, cease, under some circumstances, to be
so: an instance of this exists in the difficulty which we ex-
perience in attempting to move the hand and foot of the same
side in different directions, and in all those motions which,
although voluntary and perfectly easy if produced separately,
are found very difficult if attempted together.a

287. Among those motions which are supposed to be
perfectly involuntary, no one is free from exception, as far
as we know, excepting the spasms of the uterus during
labour.b

With respect to the motion of the heart, we have the in-
dubitable testimony of Drs. Baynard and Cheyne, that they
saw the celebrated case of the English officer who could stop
the motion of his heart and arteries at pleasure.c (A)

There is no question that the pulsation of the heart and
arteries may be accelerated or retarded by the varied state of
respiration.d

Rumination shows that the action of the stomach may be
voluntary, and I myself once distinctly found it so, in a man
who had the power of ruminating.

Although the motion of the iris is involuntary in most per-
sons, I am credibly informed that some have been able, by a
[Seite 265] considerable effort, to subject it to the will, and contract the
pupil in a weak light.

And the motions commonly called involuntary, which be-
come voluntary in some particular individuals, especially if
aided by attention and liveliness of imagination, are very
numerous.e

Thus I have seen some able to produce, at any time, a
spasmodic horripilation of the skin, by representing some un-
pleasant sensation to their imagination.

Others have had the power of exciting local sweat in the
hands, &c.f (B)

288. This may, perhaps, be explained on the principle of
sensorial reaction (56), which may be produced by imagina-
tion – a mental stimulus, as easily as by a corporeal stimulus
acting upon the sensorium (52). Many phenomena accord
admirably with this explanation; v. c. the various causes of
the erection of the penis, and of the flow of saliva.

289. The voluntary motions are the distinguishing charac-
teristics of the animal from the vegetable kingdom. For no
plant has been discovered procuring for itself food by means
of voluntary motion; nor any animal incapable of locomotion,
or at least of procuring sustenance by the voluntary motion of
individual members.

290. In ourselves, these motions afford a striking proof of
the intimate harmony which subsists between the body and
the mind, and is demonstrated in the rapid and various mo-
tions of the fingers of a good performer on the harp, and of
the vocal organs whenever we speak.g

[Seite 266]

NOTES.

(A) ‘“Colonel Townshend, a gentleman of excellent natural
parts, and of great honour and integrity, had for many years
been afflicted with a nephritic complaint, attended with con-
stant vomitings, which had made his life painful and miser-
able. During the whole time of his illness he had observed
the strictest regimen, living on the softest vegetables and lightest
animal foods, drinking asses milk daily, even in the camp;
and for common drink Bristol water, which, the summer before
his death, he had drunk on the spot. But his illness increasing
and his strength decaying, he came from Bristol to Bath in a litter,
in autumn, and lay at the Bell Inn. Dr. Baynard and I were
called to him, and attended him twice a day for about the space
of a week, but his vomitings continuing still incessant and obsti-
nate against all remedies, we despaired of his recovery. While
he was in this condition, he sent for us early one morning; we
waited on him with Mr. Skrine his apothecary; we found his
senses clear and his mind calm; his nurse and several servants
were about him. He had made his will and settled his affairs.
He told us he had sent for us to give him some account of an odd
sensation he had for some time observed and felt in himself, which
was, that composing himself, he could die or expire when he
pleased, and yet by an effort, or somehow, he could come to life
again; which it seems he had sometimes tried before he had sent
for us. We heard this with surprise; but as it was not to be ac-
counted for from now common principles, we could hardly believe
the fact as he related it, much less give any account of it; unless
he should please to make the experiment before us, which we
were unwilling he should do, lest in his weak condition he might
carry it too far. He continued to talk very distinctly and sensibly
above a quarter of an hour about this (to him) surprising sen-
sation, and insisted so much on our seeing the trial made, that we
were at last forced to comply. We all three felt his pulse first:
it was distinct, though small and thready, and his heart had its
usual beating. He composed himself on his back, and lay in a
still posture some time; while I held his right hand, Dr. Baynard
laid his hand on his heart, and Mr. Skrine held a clean looking-
glass to his mouth. I found his pulse sink gradually, till at last I
could not feel any by the most exact and nice touch. Dr. Bay-
[Seite 267] nard could not feel the least motion of his heart, nor Mr. Skrine
the least soil of breath on the bright mirror he held to his mouth;
then each of us by turns examined his arm, heart, and breath, but
could not by the nicest scrutiny discover the least symptom of
life in him. We reasoned a long time about this odd appearance
as well as we could, and all of us judging it inexplicable and un-
accountable; and finding he still continued in that condition, we
began to conclude that he had indeed carried the experiment too
far, and at last were satisfied he was actually dead, and were just
ready to leave him. This continued about half an hour, by nine
o’clock in the morning, in autumn. As we were going away, we
observed some motion about the body, and upon examination,
found his pulse and the motion of his heart gradually returning:
he began to breathe gently, and speak softly: we were all
astonished to the last degree at this unexpected change, and after
some further conversation with him and among ourselves, went
away fully satisfied as to all the particulars of this fact, but con-
founded and puzzled, and not able to form any rational scheme
that might account for it. He afterwards called for his attorney,
added a codicil to his will, settled legacies on his servants, re-
ceived the sacrament, and calmly and composedly expired about
five or six o’clock that evening. Next day he was opened (as he
had ordered): his body was the soundest and best made I had
ever seen; his lungs were fair, large, and sound; his heart big and
strong, and his intestines sweet and clean; his stomach was of a
due proportion, the coats sound and thick, and the villous mem-
brane quite entire. But when we came to examine the kidneys,
though the left was perfectly sound and of a just size, the right
was about four times as big, distended like a blown bladder, and
yielding as if full of pap; he having often passed a wheyish liquor
after his urine, during his illness. Upon opening this kidney, we
found it quite full of a white chalky matter, like plaster of Paris,
and all the fleshy substance dissolved and worn away, by what I
called a nephritic cancer. This had been the source of all his
misery; and the symptomatic vomitings from the irritation on the
consentient nerves, had quite starved and worn him down. I have
narrated the facts, as I saw and observed them, deliberately and
distinctly, and shall leave to the philosophic reader to make what
inferences he thinks fit; the truth of the material circumstances
I will warrant.”’

(B) Those muscles, I conceive, are called voluntary, which we
[Seite 268] have ordinarily the power of directly contracting: those involun-
tary, which we have not ordinarily the power of directly contract-
ing. These two definitions appear to me unexceptionable.

The latter does not contradict what is unquestionably true, –
that we can indirectly affect involuntary muscles, as the heart or
stomach, by thinking of certain objects, and thus exciting certain
emotions; nor does the former contradict another truth, – that
voluntary muscles often contract without or against our will.
And this leads me to remark, that the respiratory muscles deserve
the epithet voluntary as much as any in the body, for we directly
contract them:h we feel an uneasy sensation in the chest from
the retardation which occurs to the blood, and we inspire to
remove it; the uneasiness being removed, our effort ceases, and
expiration spontaneously ensues. It is true that respiration con-
tinues while we are asleep, and that the uneasiness is so great that
we are forced to inspire. But the same is true of all voluntary
muscles. If you irritate any part of a person asleep, an effort
of some kind is made to withdraw from the source of uneasiness,
and people turn in their sleep when uncomfortable; fowls perch
on one leg, voluntarily contracting their claws before they go to
sleep, and remain thus supported till they awake; somnambulists
can unconsciously perform astonishing muscular movements; and
while awake, we often continue walking, or performing other actions,
while our minds are totally absorbed in reflecting, and give no
perceptible attention to our corporeal actions. If you cause
strong pain or titillation in a person awake, he will be compelled,
whatever restraint he may attempt upon himself, to cry out or
laugh, and to make an effort to remove it by motion of some part,
as forcibly as he is compelled to remove the uneasiness in the
chest by inspiration; and while history records examples of Chris-
tians and heathens so resolute as to remain motionless and silent,
by the force of their faith or innocence, or their contempt for
their persecutors, in the midst of fire till they were consumed;
we read of suicides so determined as to have accomplished their
purpose by merely holding their breath, when deprived of access
to instruments of destruction.i

SECT. XIX.
OF MUSCULAR MOTION.

[Seite 270]

291. The immediate organs of by far the greater number
of our motions are the muscles, which form the greatest bulk
among all the similar parts.

292. They abound in azote more than other similar animal
parts,a and the departure of this principle from its combin-
ation with hydrogen and carbon that exists during health,
entirely converts them, under particular morbid affections,b
and after death,c into an adipocerous substance, somewhat
resembling soap or spermaceti. (A)

293. The muscles are distinguished from other similar
parts chiefly by two characteristic features, the one derived
from their structure, the other from their singular vital
powers.

294. Their fleshy structure is formed of moving fibres, sui
generis,
and of a very faint red colour, and every muscle may
be resolved into fibrous bands, these into bundles of fibres,
and these again into very fine fleshy fibres and fibrils.

295. Every muscle possesses a covering of cellular mem-
brane,d which is so interwoven with its substance as to sur-
round the bands, the bundles, and even each particular fibre
and fibril.

[Seite 271]

296. Every part of the muscles is amply supplied with
blood-vessels and nervous threads. The latter appear to
deliquesce into an invisible pulp, and unite intimately with
the muscular fibres: the former are so interwoven with the
fibres, that the whole muscle is red, and acquires its own pale-
ness (294) only by being washed.

297. Most muscles terminate in tendons,e which are
fibrousf parts, but so different in colour, texture, elasticity,
&c., as to be readily distinguished from muscles: thus dis-
proving the opinion of some, – that the tendinous fibres
originate from the muscular. This error arose chiefly from
the circumstance of the muscles of infants containing a greater
number of fleshy fibres, in proportion to the tendinous, than
those of the adult.

298. The other exclusive character of muscles (293), is
the irritability of Haller,g the notion of which, and its differ-
ence from contractility, we formerly explained (41), but shall
now prosecute farther.

299. This irritability, muscular power, or vis insita or
propria, is bestowed upon all muscular parts, but in very
different degrees.h

[Seite 272]

300. The highest order are the hollow muscles which per-
form the vital and natural functions, and especially the heart
(124), whose internal surface enjoys a very lively and perma-
nent irritability.

Next to the heart follows the intestinal canal, particularly
the small intestines, which, in warm-blooded animals, contract
after the heart has ceased to show signs of irritability.

Next the stomach.

Then the urinary bladder, &c.

Among the other muscles, the fibres of the tongue display
the greatest irritability (135), then the respiratory muscles,
v. c. the diaphragm, the intercostals, the triangularis sterni.

Then follow the remaining muscles.

Less, but still, however, some, exists in the arteries. (128)

Also in the venous trunks contained in the thorax. (95)

Still less, if it deserve the name of irritability, in the other
blood-vessels. (132)

301. Haller, the great arbitrator in the doctrine of irrita-
bility, has ascribed it improperly (40.58.sq.), we think, to some
parts possessed indeed of contractility, but in which we have
never been able to detect genuine irritability.

Such are the lacteals, glands, gall-bladder, uterus, the
dartos, and the penis. (B)

And others, with no less impropriety, bestow it upon the
iris, the external surface of the lungs, &c. in which it no more
exists than in the cellular membrane and those parts which
are composed of it, – the common integuments, membranes
of the brain, pleura, peritonaeum, periosteum, medullary
membrane, tendons, aponeuroses, &c. or in the proper paren-
chyma of the viscera, (20) – of the liver, spleen, kidneys,
secundines, the brain, and the rest of the nervous system,
[Seite 273] every one of which parts is destitute alike of muscular fibre
and of what is peculiar to it, – irritability.

302. As we find muscular irritability sometimes confounded
with the contractility of the mucous web; so, on the other
hand, some eminent men, particularly in modern times, have
attributed it to the nervous energy.i

Now, although we cannot deny the influence of the nerves
upon the muscles, most strikingly shown of late (225) by the
experiments of the celebrated Galvani and others, and although
no muscular fibril, however minute, can be found absolutely
destitute of nervous pulp, we are not on this account to assert
that irritability is not a power sui generis, as clearly different
from the nervous energy as from contractility. For parts
not muscular are not irritable, however abundantly they may
be supplied with nerves, as the corium, the numerous nervous
viscera; and the muscular texture alone exhibits the genuine
phenomena of irritability. So that from the force of these
united arguments, to omit many others, it appears more just
to assign these phenomena to the muscular fibre alone, than
to ascribe them to the nerves which are common to so many
other parts, but do not in these excite the faintest sign of
irritability. We say nothing of many weighty arguments
derived, for instance, from the facts, – that no proportion
exists between the degree of irritability and the number of
nerves in any part, – that one of these descriptions of vital
powers is often very energetic, while the other is languid in
the same individual, according to national, morbid, or more
especially to sexual variety, &c. (C)

303. The nerves exert their influence upon the muscles, as
remote or exciting causes of their action, but by no means as
[Seite 274] the proximate or efficient, which is the inherent irritability of
the muscles.

The passions, v. c. act upon the sensorium, and this upon
the nerves of the heart, so as to excite its irritability, which
produces palpitation and other anomalous motions.

The will acts upon the sensorium, and this re-acts upon the
nerves of the arm, which excite muscular motion, as remote
causes: but the proximate cause is the irritability of the
muscles themselves.

304. With this distinction of the two causes of muscular
motion, the result of those experiments exactly correspond
which have been so frequently made by dividing or tying the
nerves.k Paralysis ensued, but irritability continued vigorous
for a great length of time afterwards.

There have been cases where one limb was motionless
from paralysis but retained its sensibility, while the other
was insensible but still capable of motion.l Some persons
have had great pain in paralytic parts.m

305. The true efficacy of the blood, so copiously afforded
to muscles, (296) in promoting their action, is not clearly
ascertained.

In the Stenonian experiment,n indeed, paralysis of the hind
legs commonly follows the application of a ligature upon the
abdominal aorta.o (D)

But, after all, we are confirmed in the opinion formerly
mentioned, (125) – that the action of what are commonly
called voluntary muscles, depends less than that of the heart
upon the afflux of blood to the moving fibres; and, on the
contrary, more than it, upon the influence of the nerves which
excite their irritability.

[Seite 275]

306. Besides these inherent powers common to all muscles,
there are some peculiar and adventitious, arising from figure,
situation, &c. and answering their object with perfect ac-
curacy.

307. From the former difference among muscles, they are
in general divided into hollow and solid. The first, as we
have seen, not directly subject to the will, belong more to the
vital and natural functions, and are, consequently, not to be
considered at present, while we are speaking of the voluntary
muscles, which belong to the order of animal functions.

308. Among the second, also, there is much variety. For,
not to allude to difference of size, there is great diversity in
the disposition of their bands and fasciculi, the direction of
their fibres, the proportion of the fleshy to the tendinous part,
their course, mode of insertion, &c.

309. The greatest number are long, and their fleshy bellies
terminate at each extremity in tendinous chords, inert, and
destitute of irritability, and fixed to the bones, which they
move in the manner of levers.

310. While a very few muscles are destitute of tendons,
such as the latissimus colli, an equally small number are not
inserted into bones; such are the cremaster, as we generally
find it, the azygos uvulae, most of the muscles of the eye, &c.

311. The muscles endowed with those common (298. sq.)
and peculiar (306. sq.) powers, are thus prepared to perform
their actions, which also may be divided into common and
peculiar.

312. A property common to all muscles, and the immediate
consequence of their irritability, is to become shorter, more
rigid, and generally unequal, and, as it were, angular, during
contraction.

To attempt, with J. and D. Bernouilli and other mathe-
matical physicians, to reduce this diminution to a general
admeasurement, is rendered impossible, by the great dif-
ference, among other causes, between the hollow and solid
muscles in this respect, and between the solid muscles them-
[Seite 276] selves, v. c. between straight muscles (such as the intercostals)
and sphincters.

313. The peculiar actions of muscles (311) correspond
with their peculiar powers, and, consequently, vary so much
as to be referable to no general laws.

To cite one instance out of many, that action of certain
muscles is peculiar and anomalous, which seldom occurs
alone, but nearly always subsequently to, or simultaneously
with, the action of some of a different order. Such is that
of the lumbricales, when, during rapid motions of the fingers,
they follow the action of other muscles of the metacarpus and
fore-arm; and of the lateral recti muscles of the eyes, the
adducens of either of which seldom acts, unless simultaneously
with the abducens of the other eye.

The commonly received law – that a muscle during its
contraction draws the more movable point of insertion to the
more fixed, must be considered, as Winslow wisely remarks,p
perfectly relative and subject to various limitations. Thus,
for example, sometimes the one point, and sometimes the
other, may be the more movable, accordingly as the united
action of many different muscles may render the opposite
more fixed.

And, on the other hand, although the action of the flexors
is generally so much stronger than that of their antagonists –
the extensors, that, when the body is at rest, the arms,
fingers, &c. are a little bent, this does not so much depend
upon the strength of the contraction of the flexors, as upon
the voluntary relaxation of the extensors for our own relief.

314. Every muscle has, moreover, a peculiar mechanism,q
adapted to the individual motions for which it is intended.

Besides the determinate figure of each, many other kinds
of assistance are afforded to their peculiar motions, v. c. by the
bursae mucosae, chiefly found among the muscles of the ex-
tremities; the annular ligaments by which some are sur-
[Seite 277] rounded; the fat in which most are imbedded; the lymphatic
vapour around each; and, above all, by the conformation of
the skeleton, chiefly in regard to apophyses, condyles, and
articulations; nay, even whole bones, v. c. the patella, the
pisiform of the carpus, and the sesamoid bones;r are destined
solely to facilitate the actions of certain muscles.

315. In this mode is compensated, or, at least, diminished,
that inevitable loss of power which necessarily takes place
from the conformation and stature of the whole system, as,
from the acute angle at which some muscles are inserted, or
the proximity of their insertion to the centre of motion, much
of that power is lost which would have existed, if their inser-
tion had been more remote or at a more obtuse angle.s

316. The human body, possessing about 450 muscles,
or upwards, according to sexual or individual variety, is
thus furnished with a double advantage, – with an extreme
agility of motion in particular parts and throughout the whole,
and with a surprising degree of strength and endurance of
labour. Both these are accomplished partly by the perfec-
tion of the muscles, which, like the perfection of the bones,
takes place at manhood; and partly by habit and practice,
the power of the former of which in affording strength and
agility to the muscles, is demonstrated in rope-dancers,
leapers, runners, wrestlers, porters, savages, and the examples
of ancient nations.t


NOTES.

(A) Muscle is essentially fibrine, but contains also albumen, ge-
latine, fat, salts, &c. and a peculiar substance termed osmazome,
[Seite 278] upon which the peculiar taste and smell of soup depends, and which
is a yellowish brown substance, soluble in water and in alcohol
hot or cold, and not forming a jelly when concentrated.

(B) Mr. Hare affirms, that in the field of a moderately power-
ful microscope, a muscular fibre evidently appears made up of nu-
merous minute tubes, each exhibiting longitudinal striae; with
transverse bands; the average diameter of each of these ultimate
fibres or tubes being 1/400 of an inch.u Under contraction, the
portions between the transverse bands draw the latter nearer
together, and, swelling out, seem girted by them, so that the
whole fibre somewhat resembles a string of eggs. This appear-
ance, the writer supposes, led Dr. Croon to adopt the idea that the
ultimate fibre of muscle was constituted by a chain of bladders
filled with fluid. In fact Mr. Bauer thinks he discovers muscular
fibres to be chains of globules,x and Prevost and Dumas declare the
same from their microscopic observations,y The muscular tubes
are represented by Mr. Hare as filled with a matter which causes
them to appear solid, till it is liquefied by heat: Mascagni describes
the muscular fibre as a small cylinder, filled with glutinous matter.z
The fibres of tendon are said to be really solid, of infinitely
smaller diameter, and disposed in a reticulated manner. Even
cellular membrane is said to consist of reticulated tubular fibres,
1/1000 of an inch in diameter on the average, and exhibiting trans-
verse contractions.a Fontana, by means of glasses of moderate
powers, found tendon to be composed of bands, which again are
composed of solid spiral cylinders, of uniform size, and pursuing
a tortuous course.b He also asserts that the primitive muscular
fibre is marked by continual minute crispations and nodosities, and
that it pursues a straight course, but is solid like the tendinous.
Meckel and Rudolphi believe the primitive muscular fibre solid.
Dr. Hodgkin found it not to consist of globules, and to be marked
[Seite 279] by transverse lines, which he thinks distinguish muscular from all
other fibres. (supra. p. 3.)

Prevost and Dumas assert, that the muscular fibres, straight
while at rest, approximate each other at intervals, under con-
traction, so as to acquire a zigzag course (
xxx
), and
shorten the distance of their two extreme points.c They ascer-
tained satisfactorily, that during contraction no increase of
volume is acquired. If muscles, while the fibres are straight,
are stretched still more, as continually happens in the muscular
coats of cavities, the subsequent shrinking to the original dimen-
sions, is unattended by the zigzag appearance. Nervous fila-
ments, they also assert, go perpendicularly to the muscular
fibre at the very points where the angles are formed under the
zigzag contraction, and yet not to terminate there or unite with
the muscular fibres, but to return or anastomose with other nerves.
The approximation of the nervous filaments to each other is
thought to draw the muscular fibres into angles, and thus be the
cause of muscular contraction. The approximation of the nervous
filaments is considered an electric phenomenon. Electricity will
effect it, and in whatever way it is effected, electric appearances
are said always to be discoverable.

Muscular power is nowhere more displayed than in some fish.
‘“I have seen,”’ says Sir Gilbert Blane, ‘“the sword of a sword-fish
sticking in a plank which it had penetrated from side to side; and
when it is considered that the animal was then moving through a
medium even a thousand times more dense than that through which
a bird cleaves its course at different heights of the atmosphere,
and that this was performed in the same direction with the ship,
what a conception do we form of this display of muscular
power!”’d Muscular strength is proportionably much greater in
smaller animals. A flea can draw from seventy to eighty times
its own weight, whereas a horse cannot draw with ease more than
three times its own weight.”e

(C) Irritability is the power of contracting upon the application
of a stimulus, and ceases with life. It comprehends animal and
organic contractility (see Note B. Sect. VI.), and we must sup-
pose the lacteals, vessels of glands, gall-bladder, and dartos to be
[Seite 280] possessed of it: the uterus will hereafter be shewn to have mus-
cular fibres, according to many anatomists, and their existence
will be rendered probable in the corpora cavernosa of the human
penis.f

(D) This paralysis does not show the irritability of the muscles
to be impaired; they would doubtless contract immediately after
the experiment, upon the application of a stimulus, as readily as
they do after apoplexy. In torpid brutes, after division of the
nerves and removal of the brain, cold and warmth destroy and
restore the irritability of muscles, as usual. The ligatures act imme-
diately by depriving the nerves of the power of stimulating them;
for a supply of arterial blood is necessary to the functions of the
nervous system,g and the ligature of the abdominal aorta, prac-
tised by Haller, cuts off this from the lower part of the spinal
marrow and what originate from it, – the nerves of the hind legs.
If venous blood is sent to the brain, we have seen that death
ensues, and the function of any part is arrested by forcing venous
blood into its arteries.h

Another source of paralysis must ultimately arise, – the loss of
irritability from the want of circulation in the muscle.

SECT. XX.
OF SLEEP.

[Seite 281]

317. The faculties both of feeling and motion, possessed
by the nervous system whose history we have thus pursued,
are so fatigued by their exertions in the day, that rest is
necessary during the night to recruit them by means of sleepa
– the image of death.

318. Sleep is a completely periodical function, by which
the intercourse of the mind and body is suspended, and whose
phenomena, now to be traced, correspond, if any do, with
the supposition of a nervous fluid.

319. Besides other precursors of sleep, may be enumerated
a gradually increasing dulness of the external senses, and a
relaxation of most, especially of the long, voluntary muscles;
a congestion of venous blood about the heart, and relief
afforded by yawning to the uneasy sensation thus produced;
lastly, a curious kind of short delirium at the moment when
sleep is all but present.b

320. The phenomena of sleep amount to this, – that the
animal functions are suspended, and all the rest proceed more
slowly and inactively. For the pulse is slower, the animal
heat, caeteris paribus, somewhat diminished, perspiration more
sparing, digestion imperfect, and nearly all the excretions
[Seite 282] (except that of the semen, and this, indeed, is rather unusual)
suppressed. (A)

321. The remote causes of sleep are evident.c To say
nothing of narcotics, it is induced by the expenditure of the
animal powers from previous fatigue or watchfulness, also
by habit, and by darkness, silence, rest, &c. which acquire
their somniferous powers in some measure from habit; by
mild, continued, and uniform impressions upon certain senses,
v. c. the murmur of a rivulet or the view of a field of standing
corn agitated by the wind, (B) a previous meal, intense cold
applied to the surface, and other modes of deriving blood from
the head, as pediluvia, clysters, profuse hemorrhages, &c.

322. These remote causes may induce the proximate cause,
which, upon mature consideration, we think probably consists
in a diminished or impeded flow of oxygenated (arterial)
blood to the brain; for that fluid is of the highest importance
during the waking state, to the re-action of the sensorium upon
the functions of the senses and upon the voluntary motions.d

The influx of blood is diminished by its derivation from
[Seite 283] the brain and congestion in other parts; it is impeded by
the pressure of foreign matter upon the brain, whether from
serous or purulent collections, from depression of fractured
bones, &c.

This diminution of, or impediment to, the flow of blood to
the brain, causes a deficiency of water in the ventricles and a
collapse of them, upon which that acute and profound physio-
logist, David Hartley, whom we have already praised, ex-
plains the various phenomena of dreams.e

Besides other phenomena which accord with this explana-
tion, especially those of hybernating mammalia,f is a very
remarkable one which I witnessed in a living person whose
case was formerly mentioned, – that of the brain sinking
whenever he was asleep, and swelling again with blood the
moment he awoke.

This opinion is likewise strengthened by the production
of continued watchfulness from congestion of blood in the
head. (C)

323. The quantity of sleep depends much upon age, con-
stitution, temperament, &c.; generally speaking, much sleep
is the attendant of weakness, as we find in infants born pre-
maturely, and in superannuated persons, and is a very frequent
source of fatuity and torpor. (D)

324. We awake refreshed with sleep; and this return to
life is attended by the same phenomena as the approach of
sleep, – by gaping, to which is generally associated stretch-
ing, by some degree of dulness of the senses, &c.

325. The causes of waking correspond with those of going
to sleep.

The proximate is the more free return of blood to the
head.

The remote are (besides the power of custom, which is in
this respect very great) various stimuli applied to the external
or internal senses, either immediately affecting the nervous
[Seite 284] system, as the distension of the bladder, or mediately, by the
intervention of the imagination, as in dreaming.

326. Dreamsg are a sporting, as it were, of the imagination,
in which it recalls the ideas of objects formerly perceived,
especially of objects of sight, and appears to employ and
interest itself with them.

It has been disputed whether dreams are natural during
health. Some believe that sleep never occurs without them,
although they may escape our memory.h Others conceive
them the consequence only of derangement in some of the
abdominal viscera.i Very healthy adults have asserted that
they never dreamt.k

Dreams are generally confused and irregular, but occasion-
ally discover extraordinary marks of reason.l

The power of corporeal stimulants is very great in pro-
ducing dreams; v. c. of the semen in producing lascivious
trains of ideas, of excessive repletion in causing frightful ap-
pearances. There is an instance on record of a man, in
whom any kind of dreams could be induced, if his friends, by
gently addressing him, afforded the subject-matter.m This,
however, appears to be a preternatural state between sleeping
and waking; as does also the truly diseased case of sleep-
walkers, and the very different, though morbid, affection of
somnambulists seized with what is termed magnetic ecstasis.n

Locke and others have regarded all dreams as a species of
this mixed state. (E)

[Seite 285]

NOTES.

(A) Respiration also proceeds more slowly. The lessened
power of evolving heat is strikingly shown by the greater cooling
power of a cool air, and the facility with which persons take cold.
It is generally thought wise in this country to cover the head
preparatively to a nap in the day-time. Noxious agents would
appear more powerful during sleep.

(B) Gentle motion might also be mentioned as illustrative of
the effect of a mild and uniform impression on another sense. A
combination is of course still more effective, whence experience
has taught nurses to rock and otherwise gently agitate infants
while they hum them to sleep.

(C) It is certain that the supply of arterial blood to every part,
and especially to the nervous system, is requisite to its functions
and its life, and that in proportion to the activity of a part is the
activity of its supply of arterial blood. Analogy, therefore,
renders it extremely probable that, during the inactivity of sleep,
the brain, having less occasion for arterial blood, has a less
vigorous circulation than during the waking state; and we know
that whatever diminishes the ordinary determination of blood to
the brain (321), or impairs the movement of the blood through it,o
disposes to sleep,p But, although this be granted, it must be
[Seite 286] viewed, not as the cause, but as a circumstance, or, in fact, a
consequence, of ordinary sleep. Increase the activity of an
[Seite 287] organ, you increase its circulation; diminish its activity, you
diminish its circulation. The alteration of circulation is usually
not the cause but the consequence; necessary, indeed, to the
continuance of the altered degree of activity in the organ, but
not the cause. The degree of activity of any part, and the
degree of its circulation, are exactly and unalterably corre-
spondent. If the circulation through a part be mechanically
increased or diminished, the sensibility and activity of the part
will, doubtless, be proportionally increased or diminished. This
example occurs in hemorrhage. Frequently both are affected
simultaneously,– when diarrhoea renders the surface pale and
cold, both the blood is sent more sparingly to it, and the energy
of its vessels is diminished by the increase of energy in those of
the intestines. (Sect. VI. Note B.) But in ordinary sleep, the
diminished circulation appears only the consequence, for activity
is always followed by inactivity. Stimulate a muscle separated
from the body, it contracts, but it soon refuses to do so; after a
little rest, it again contracts upon the renewal of the stimulus. The
case of the brain is analogous; and when, after its daily activity,
[Seite 288] it falls asleep, the diminution of its circulation consequently
ensues. The influence of sleep upon the cerebral circulation is
shown by the head-ache and other marks of congestion which
follow too much sleep. Boerhaave mentions a physician who
took a fancy that sleep was the natural state of man, and so slept
eighteen out of the twenty-four hours, till he died of apoplexy.
The horizontal posture will not explain these ill effects, because
persons with spinal disease will lie a year upon the back without
them.

The notion of Hartley’s is a mere hypothesis, totally unworthy
of notice. Dreaming is imperfect sleep, – sleep in which some
portions of the brain are more or less active, and the circulation of
such portions is no doubt more active at the time than that of the
rest.

(D) In some diseases of the nervous system persons may pass
many days, and even entire weeks, with little or no sleep. I have
also heard a man declare he never took more than three hours
sleep during the most active period of his life. Sir Gilbert Blane
states, that General Pichegru informed him, that, ‘“in the course
of his active campaigns, he had for a whole year not more than
one hour of sleep, on an average, in twenty-four hours.”’q Sleep
varies so much in intensity that a dead sleep of an hour may be
an equal repose to an ordinary sleep of many hours. Sleep
appears much more profound at the beginning than towards the
end, and, I presume, because the fatigue is then greatest and
gradually lessens as sleep continues. Thus transpiration, we have
seen, is at first greatest, and gradually lessens as the body loses
its excess of fluid, and absorption gradually lessens as the body
becomes charged with fluid.

I believe that most adults require from six to eight hours sleep.
The longer the waking state is protracted the greater the ex-
haustion, whence one advantage of early hours, which is ex-
pressed by the adage, – one hour’s sleep before twelve is worth
two after. If a person rises proportionally late, he certainly can-
not suffer from this course, and if he suffers, it must be ascribed,
provided there is no debauch in the case, to his loss of the
influence of so much solar light and morning air. The oc-
currence of that delirium which is mentioned by Blumenbach,
at the near approach of sleep, when we do not fall asleep in a
[Seite 289] moment, and of which we are sensible by slightly recovering our-
selves, is a much surer sign that we are about to get to sleep than
the greatest drowsiness. The circumstance of our resisting sleep
as long as we can keep our eyelids open, and falling asleep, when
very sleepy, the moment we allow the eye-lids to drop, is very
striking, but explicable on the continuance of voluntary effort
in the former case, and cessation of it in the latter.

Independently of apoplexy, we have cases of extraordinarily
long sleep. A woman in Henault slept seventeen or eighteen
hours a day for fifteen years.r Another is recorded to have slept
once for forty days.s A man named Samuel Chilton, twenty-five
years of age, at Tinsbury, near Bath, once slept for a month. In
two years he slept again for seventeen days, at the beginning
of which period he took food, and had evacuations, but at length
his jaws fixed. When he fell asleep the barley was sowing, and
when he awoke he would hardly believe he saw it reaping. At
the end of a year he fell into such another sleep. His farther
history is not given.t

(E) In sleep the action of the mind is suspended. But the
degree of suspension is extremely various. In ordinary sleep the
mind is sufficiently alert to feel unpleasant sensations and make
an effort to remove their causes; – whether to remove the un-
easiness of impeded circulation in the lungs by breathing, or to draw
away the hand when tickled. One or more faculties is often active,
and one idea associates with it another, constituting dreaming;
but the activity of the mind is partial, and though we are able
occasionally even to reason correctly in our dreams, we are not
sufficiently ourselves to discover the incompatibility of many
circumstances which we fancy. In a higher degree of activity,
we answer questions put to us, although often ridiculously, as our
deficiency of mental power prevents us from keeping our associa-
tions in a proper train; and we sometimes even perform a regular
series of movements. Somnambulism is but imperfect and partial
sleep.u In it persons walk and even perform a variety of other
actions, without hearing or seeing, or consciousness of their situ-
ation, so that they fall over things placed in their way, or down a
[Seite 290] descent. They will sometimes write excellent letters, compose
good verses, and perform accurate calculations, in this state, and
on being roused into consciousness know nothing of what has
happened. This state generally occurs in sleep, but it occasion-
ally seizes persons awake, and is then termed ecstasis.x This is
by no means uncommon at the commencement or termination of
epileptic or hysteric paroxysms. In the opposite morbid affec-
tion, the patient is conscious of every thing around, but unable to
move, or give the least sign of life.y

Night-mare is a cerebral affection, imperfect sleep, a combination
of frightful fancies and fear, with an unusual loss of volition, so
that we cannot excite the common voluntary muscles to action and
with great difficulty move the diaphragm to inspiration.

Brutes dream as well as ourselves. Dogs start and bark in their
sleep.

The great feature of sleep is the deficiency of our active powers.
If we have any external sensation, or if the imagination riots on,
presenting trains of images to our internal senses, we reflect upon
them but weakly, make great mistakes, and however well we may
reason, or whatever corporeal movement we execute, the inferiority
of our active powers is conspicuous.

––––– ‘“Fancy, –’
‘Wild work produces oft, and most in dreams,’
‘Ill-matching words, and deeds long past or late.z”’

But that active power is not suspended, as Mr. Dugald Stewart
maintains in his theory of dreaming,a the simple fact of breathing
during sleep, to say nothing of the voluntary motions of the limbs
and speaking, and the acute, though circumscribed, reasoning
which occasionally occurs, is a sufficient proof.

By certain processes, such as passing the points of the fingers
at a short distance from a person, in a direction from the face down
the arms, trunk, and legs, with a degree of energy, the state of
[Seite 291] somnambulism or ecstasis may actually, we are told, be induced. It
is then termed magnetic, and the whole phenomena, animal mag-
netism.
The patient becomes insensible to all around, but has the
inward senses augmented as in common ecstasis, – may sing well
for the first time in his life, and talk so unguardedly as to disclose
secrets. The external senses become so impenetrable, that a
pistol fired in the ear is not heard, nor melted wax dropped on
the body felt, nor ammonia applied to the mouth or nostrils per-
ceived, although the gentlest word of the operator (magnetiser)
is heard and answered, water similarly treated by him (magne-
tised
) tasted and found ferruginous, and the gentlest touch of him
recognised. A delightful feeling of ease and lightness is expe-
rienced, the body grows warmer, and perspires freely, though some-
times anxiety, palpitation, slight convulsions and wandering pains
take place. On the first attempt these occur generally without
somnambulism, and it is only after many trials (and sometimes they
continue fruitless), that such a state is induced. On coming out
of the somnambulism, the person is unconscious of all that has
occurred; but when thrown into it again, recollects the whole and
converses on it. The magnetiser can put an end to this state at
pleasure. Now some of this is very probable, as we often see the
most extraordinary nervous symptoms induced by mental causes,
and the testimony in favour of it, supported by the probability,
is too numerous and respectable to be doubted.

But this is not all. We are assured that matters often go much
farther; that the patient can often be so highly magnetised, not
only as to taste magnetised water and recognise the magnetiser
by hearing and touch, but even to perceive objects of sight by the
organ of touch, so as to read a book by the epigastrum;b nay more,
to discover a person in the next room, though a wall intervene; to
see the interior structure of his own body, and describe the seat
and appearance of a diseased organ, and point out the remedy,
though I am not aware of any anatomical discoveries having ever
been made, and presume that blood would never have been seen
flowing up the cava and down the aorta, unless Harvey had first
taught the circulation; and I suppose the remedies always depend
upon the country and the period, – that leeches and ptisans would
be called for in France, calomel in the Indies, and iodine for bron-
[Seite 292] chocele not before Dr. Coindet had made known its virtues.
Having never seen the magnetic phenomena, I have no right to
pronounce judgment: but before I can believe these wonders
I must see them.

The most zealous magnetist must allow that deception has
frequently been detected; that women have appeared to be in so
deep a magnetic sopor that they have borne sinapisms and
melted wax without the least agitation of the countenance, and
yet the whole has been proved an imposture. The effects of
which none can doubt – Blumenbach says some are undeniable (225),
– one would at once ascribe in common language to the imagin-
ation. The magnetised person is generally a weak, delicate fe-
male; the magnetiser strong and a male. Great earnestness and
energy must be manifested on his part; repeated operations are
required before a high degree of magnetism occurs: not the least
effect is produced if the magnetiser is weak and the patient strong,
nor if the patient is incredulous; while a mere look, or mere prox-
imity, without a single manipulation, is sufficient when the full
effects have been once attained on previous occasions.

Yet, to prove that there is something more than imagination,
we are assured that the magnetiser can succeed though shut in a
closet and the patient totally ignorant of what is intended. As
collusion is very easy, I must examine this point also myself before
I believe. Water, they not only say, can be magnetised so as to
taste chalybeate, but inanimate bodies made conductors.

Magnetism has been successfully applied to the cure of diseases
of excitability. It is said to have been discovered by Mesmer,
near the end of the last century, who, knowing that the magnet
was much employed as a remedy, and hearing from M. Hell, the
professor of astronomy at Vienna, that he had cured himself by
magnetic plates of a severe cardiaglia, opened a house for curing
every disease in this way, and began to imagine the existence of an
universal magnetic power, distinct from that of the common
magnet, depending upon a fluid pervading all living and mineral
matter, and the source of all in art and nature. To throw this
fluid into persons, – to magnetise them, he manipulated as we
have mentioned, and employed other processes which are now
omitted. He travelled, performed many great cures, and often
failed; was extolled and abused; but such results appeared as
caused a commission of enquiry to be ordered by the government
of France. The whole was ascribed to imagination, and the matter
dropped. Of late the subject has been revived among some of
[Seite 293] the best informed physicians of Germany and France, and a com-
mission is now sitting in Paris to enquire into it anew. Those who
ascribe all to imagination, consider the agitations and prophecies
of the priestess of Apollo, the ecstasies of Dervishes and Santons,
and of Shakers and Quakers, and the pretended miraculous cures of
all ages, from the days of Serapis of Egypt to those of the blessed
Paris of Paris,c as only of a piece with animal magnetism, showing
how strongly fear or enthusiasm will work upon the brain and
all the organs; discover the expression magnetise in Paracelsus
and Van Helmont, and adduce a passage from Plautus to show
that manipulations were used in Rome to send persons to sleep.
Mercury, thinking of sending a person to sleep, says, – ‘“Quid si ego
illum tractim tangam ut dormiat.”’ Sosia replies, – ‘“Servaveris,
nam continuas has tres noctes pervigilavi.”’d The hypothesis of a
magnetic fluid is relinquished by many of the most enlightened
magnetisers.e They assert the phenomena only. But by means of
this fluid, some believers explain why a person cannot tickle himself;
why, proverbially, when a friend is near, we think of him (‘“talk of
the devil, &c.”’); and why, at the moment of death, distant friends
have been said to see or hear the dying who happen to be
thinking intensely of them so as magnetically to influence them!

SECT. XXI.
OF FOOD AND HUNGER.

[Seite 294]

327. As sleep repairs the loss of the animal powers, so
food repairs that of the natural, and supplies fresh elementary
particles in the room of those which are constantly wasting.

328: We are most effectually induced to procure and take
food by calls of nature, different in kind, but tending to the
same end: on one hand, by the intolerable torment of hunger
and thirst; and on the other, by the equally powerful allure-
ments of appetite.

329. Some ascribe hunger to an uneasiness arising in the
stomach from its being empty and unoccupied; others to the
mutual friction of its rugae; others not only to the stimulus
of its fluids, now secreted in abundance, – of the saliva and
gastric juice, but to an acrimony which they acquire when
food is not taken in proper time. (A)

330. Thirst appears referable both to a very unpleasant
dryness of the fauces, and to the particular stimulus of acrid
matters, especially of salts, taken by the mouth. It may be,
therefore, the consequence of excessive absorption in the
cavity of the mouth, such as occurs when the mother applies
her infant to the breast, or, what is not uncommon, when
venesection or purging have been ordered. Violent passions
frequently induce thirst. (B)

331. The necessity of obeying these stimuli is greater or
less according to age, constitution, and especially according to
habit, and nothing can therefore be positively affirmed re-
specting its urgency; but thus much is certain, that an healthy
adult, in whom all the calls of nature are felt in their usual
[Seite 295] force,a cannot abstain from food a whole day without great
prostration of strength, nor scarcely beyond eight days with-
out danger to life. (C)

332. Although thirst is a violent desire, drink appears not
very necessary to life and health; for many warm-blooded
animals, – mice, quails, parrots, &c. do not drink at all; and
some individuals of the human species have lived in perfect
health and strength without tasting liquids.b (D)

333. It has been disputed whether our food, by which we
satisfy these stimuli, is derived more advantageously and the
more consistently with nature from the animal or from the ve-
getable kingdom.c

334. Some contend that man is herbivorous, from the shape
of his teeth,d the length of his intestines,e the difference be-
tween the structure of the small and large intestines, and
from the cells of the colon, &c. Rousseau ingeniously urges
the circumstance that woman is naturally uniparous and pro-
vided with two breasts.f To these arguments it may be
added, that some men have ruminated, – a power peculiar to
herbivorous animals, (E) and that tame vegetable feeders are
easily accustomed to animal food, whereas carnivorous animals,
excepting the dog, can very seldom be brought to feed on ve-
getables.

The arguments of those who, with Helvetius,g regard man
as carnivorous, are derived from the conformation of his sto-
mach, the shortness of his coecum, &c.

[Seite 296]

335. More careful observation, however, proves that man
is not destined for either kind of food alone, but for both.
His teeth, particularly the molares,h (F) and the peculiar
structure of his intestines just alluded to, (G) hold a middle
rank between the same parts in the ferae and in herbivorous
animals. The mode in which the condyles of the lower jaw
are articulated with the temporal bones, demonstrates it in the
most striking manner. (H)

336. As the human race exists in more parts of the globe
than any other kind of animal, we should have been but ill
provided for, if we had been destined to subsist on either de-
scription of food alone; whereas man now inhabits some
countries which afford either vegetable or animal food only.

337. Man is by far the most omnivorous of all animals,
capable not only of feasting on luxurious combinations de-
rived from each kingdom, but of subsisting with health and
vigour on nearly one kind of the most simple food.

Thus, to mention a very few instances, many at present
live on vegetables only, as the tubera of solanum (potatoes),
chesnuts, dates, &c. The first families of mankind most
probably subsisted for a long period merely on fruits, roots,
corn, and pulses.i

The nomadic Moors have scarcely any other food than
gum senega.k (I)

The inhabitants of Kamtschatka and many other shores
scarcely any other than fish.

The shepherds in the province of Caracas in South America
[Seite 297] on the banks of the Oronoko,l and even the Morlachsm in
Europe, live almost entirely on flesh.

Some barbarous nations devour raw animals. This cannot
be denied to have formerly been the case with the Samojedes,n
the Esquimaux,o and some tribes of South America.p

Other nations are no less remarkable in their drink.

The inhabitants of many intertropical islands, especially in
the Pacific Ocean, can procure no sweet water, and instead
of it drink the juice of cocoa-nuts.

Others take only sea-water, and innumerable similar facts
clearly prove man to be omnivorous.


NOTES.

(A) If hunger arise from merely a sense of vacuity in the sto-
mach, why should it be increased by the application of cold to the
surface, and instantly by the deglutition of cold liquids, &c.?

The explanation by friction of the rugae is equally unsatisfac-
tory; because the friction of these, if it does really occur, cannot
be greater than the friction of the stomach against its contents
immediately after a meal, when the organ is in great action, but
at which time hunger does not exist.

Nor can the presence of the gastric juice explain the matter:
because, as every one knows, no sensation arises in any other
organ, which is not excrementory, from the peculiar stimulus of
its natural fluid, and I presume that this is the stimulus intended,
for the mechanical stimulus, from the bulk of the gastric juice,
occurs equally from the presence of food, which does not excite
hunger; because if the hungry stomach is evacuated by vomiting,
as in sea-sickness, the appetite is even greater than before, when
[Seite 298] the sickness has ceased; and because hunger often ceases after
a time, though the gastric juice still remains in the stomach, and
is probably more abundant than ever.

The supposition of an acrimony generated in the gastric juice, &c.
being a cause of hunger, is absurd. The fluid would be unfit for
its purposes, and would be more likely to destroy than produce
appetite.

Hunger has been attributed by some to a sympathy of the sto-
mach with a general feeling of want in the system. But hunger
is removed immediately that a due quantity of food is swallowed, –
long before the general system can have derived benefit from the
meal; fowls are satisfied when their crops are filled, although
their food is not even ground, preparatorily to digestion, till it has
passed from the crop into the gizzard; and ruminating animals leave
off eating before they begin to chew the substances with which they
have distended their stomachs. Again, persons unable to obtain food
in sufficient quantity, lessen their hunger by swallowing any unnu-
tritious and indigestible matter. The circumstance giving rise
to this opinion is the continuance of hunger, although food be
taken in abundance, in cases of scirrhus pylorus and enlarged me-
senteric glands. Here, it is urged, the hunger continues, because
the body receives no nourishment. But, in scirrhus of the pylorus,
vomiting soon follows the reception of food into the stomach, and
therefore this organ is reduced to the condition in which it was
previously, and the return of hunger is easily explicable. In dis-
eases of the mesenteric glands, there is in fact no obstruction to
the course of the chyle. They are found permeable (427), and
the continued hunger appears rather a part of the diseased state
of the chylopoietic viscera. Besides, many cases of imperfect
nutrition, from various causes, occur without any increase of ap-
petite: – and where there is an increase of appetite, the process
of digestion seems to proceed with unusual rapidity, so that the
stomach becomes empty sooner than in health. – In continued ab-
stinence, although the system is daily more in want, hunger usually
ceases after a few days, whether from the stomach falling into a
state of relaxation, becoming distended with wind, or from other
circumstances.

If hunger arose from fatigue of the stomach, it should be
greatest immediately after the laborious act of digestion, and gra-
dually decrease; but it on the contrary increases.

[Seite 299]

Were irritation the cause, hunger should be greatest when the
stomach is filled with food.

On the whole, hunger may perhaps be regarded as a sensation
connected with the contracted state of the stomach.

It occurs when the stomach, being empty, must be contracted;
and is increased instantaneously by a draught of cold liquid, which
cannot but contract the stomach and corrugate its inner coat;
acids, bitters, and astringents, have the same effect, and from their
nature they may be supposed to act in the same way. Cold air
applied to the surface increases it, and, in all probability, by a
similar operation, for the impression of cold upon the skin excites
an attempt at evacuation in the urinary bladder, and when all
other means fail to induce the intestines to expel their contents,
or the uterus to contract after delivery, the affusion of cold water
so frequently succeeds, that the omission of the practice in obsti-
nate cases is highly censurable. It is diminished by heat and
every thing which relaxes. Again, it ceases immediately that the
stomach is filled, and thus the stomach dilated and all corru-
gation removed, and the more the contents of the stomach are of
a nature to be absorbed or passed into the duodenum, the sooner
it recurs. Distension of the stomach is universally acknowledged
to be incompatible with hunger; whence the proverb, – ‘“a full
belly loathes the honey-comb.”’

The Otomacs during the periodical innundation of the rivers of
South America, when the depth of the waters almost entirely pre-
vents fishing, appease their hunger for two or three months by
distending their stomach with prodigious quantities, a pound a day
and upwards, of a fine, unctuous, strong-smelling, yellowish-grey
clay, slightly baked, and destitute of all organic substance, oily or
farinaceous.q The savages of New Caledonia, in the Pacific Ocean,
in times of scarcity, do the same by eating a friable lapis ollaris,
consisting of equal parts of magnesia and silex, with a little oxide
of copper. The wolves, rein-deer, and kids of Siberia, when
pressed by hunger in winter, also devour clay or friable steatites.
The Kamschatkans sometimes appease their hunger by distending
their stomach with saw-dust, for want of something better.

Being, in this view, a sensation connected with a local state of
[Seite 300] the stomach, it will be affected not only by whatever affects this
state, but by whatever affects also the sensibility to this state, and
therefore be subject to the common laws of sensation. Hence
uncivilized tribes enable themselves to traverse large tracts with-
out food by swallowing pills containing tobacco or opium. The
pain of all excessive muscular contraction is lessened by pressure;
whence the uneasiness of hunger is lessened by a belt fixed
tightly over the stomach, and some Northern Asiatic tribes place
a band there, and lace it behind with cords drawn tighter ac-
cording to the degree of the uneasiness. Thus, the state of the
stomach remaining the same, hunger may diminish from the
occurrence of other feelings which attract our attention more
forcibly, by passions of the mind, &c.: as is exactly the case with
all other sensations, even with those that are morbid. Under
strong attention of the mind to pursuits of either intellect or
passion, to delightful or painful sensation, all other feelings cease
to be felt, although really violent; and frequently, from being
unattended to, do not recur. Passions, however, and the narcotic
pills of savages, may affect hunger, not only by increasing or
diminishing the sensibility to the state of the stomach, but by in-
creasing or decreasing this state – the cause of the sensation.

(B) As hunger appears to depend upon the local condition of
the stomach, so does thirst more evidently upon that of the mouth
and fauces. Every consideration renders it probable that thirst is
the sensation of the deficiency of moisture in the parts in which it
is seated. Whatever produces this, either by causing the fluids of
the mouth and fauces to be secreted in small quantity or of
great viscidity, or by carrying off the fluid when secreted, pro-
duces thirst; and vice versa. To be dry means to be thirsty, be-
cause the state is removed by directly wetting the parts, or by
supplying the system with fluid that they may be moistened by
their own secretions. Being a sensation, the same may be re-
peated in regard to it as was observed respecting hunger. Rage
or terror dry up the mouth and throat and cause violent thirst.
Thirst is only momentarily assuaged by wetting the mouth and
throat, because they presently grow dry again. Fluids must be
swallowed to be effectual, that they may be absorbed and the
parts thus preserved moist by constant secretion.

(C) Hippocrates says that most of those who abstain from food
for seven days, die within that period; and if they do not, and are
[Seite 301] even prevailed upon to eat and drink, that still they perish.r Sir
William Hamilton, however, saw a girl, sixteen years of age, appar-
ently not in bad health, who was extricated from the ruins of a
house at Oppido, in which she had remained eleven days without
food: an infant in her arms, but a few months old, had died on
the fourth day, as the young are never so able to endure abstin-
ence.s A moderate supply of water lengthens life astonishingly.
Dr. Willan was called to a young gentleman who had voluntarily
abstained from every thing but a little water, just flavoured with
orange juice, for sixty days: death ensued a fortnight afterwards.t
Redi cruelly found that of a number of starved fowls deprived of
water, none lived beyond the ninth day; whereas one indulged
with water lived upwards of twenty.u If the water is not swal-
lowed, but imbibed by the surface or lungs, it may also prolong
life. Fodéré mentions some workmen who were extricated alive
at the end of fourteen days from a cold damp cavern in which they
had been buried under a ruin.x

A hog, weighing about 160. lbs was buried in its stye under
thirty feet of the chalk of Dover Cliff for 160 days. When dug
out, it weighed but 40 lbs., and was extremely emaciated, clean,
and white. There was neither food nor water in the stye when
the chalk fell. It had nibbled the wood of the stye and eaten
some loose chalk, which from the appearance of the excrement
had passed more than once through the body.y

In abstinence equally great imbecility of mind takes place as
of body; extreme emaciation and oedema of the legs present a
frightful spectacle; urine may still be secreted, but the alvine
discharge is greatly diminished or suppressed altogether; the pain
of hunger ceases in a few days,z probably from relaxation of the
stomach through debility. But when hunger has ceased, though
no food has been taken, weakness and sinking at the pit of the
stomach are still felt.

[Seite 302]

A poor diet, even of vegetable matter, sometimes gives rise to
symptoms of scurvy,a and famine is soon attended by epidemic
fever.

The torment of thirst increases until drink is procured or
moisture applied to the surface or inhaled: inflammation of the
mouth and throat and intense fever at length ensue.b

If abstinence is not forced upon the system, but is absolutely a
part of disease, it may, like suspension of respiration in morbid
states of insensibility,c and like immense doses of powerful medi-
cines in various diseased states, be borne with wonderful indiffer-
[Seite 303] ence, and this occurs chiefly among females. But the most
extraordinary case that I recollect, stated upon unquestionable
authority, is that of a young Scotch woman, who laboured under
an anomalous nervous affection, and, excepting that on two occa-
sions she swallowed some water, received no nourishment what-
ever for eight years. She passed urine enough twice a week to
wet a shilling, and for three years had no intestinal evacuation.d

[Seite 304]

For every example of extraordinary abstinence among females,
we have a counterpart in voraciousness among males. When the
appetite is so great it is seldom nice, and not only all animals in
all states are devoured, but glass, flints, metals, sand, wood, &c.
A Frenchman named Tarare, and described by Drs. Percy and
Laurent in some measure from their own observation,e will form
a good contrast to the Scotch girl. When a lad he once swal-
lowed a large basket of apples after some person had agreed to
pay for them; and at another time a quantity of flints, corks, and
similar substances. The colic frequently compelled him to apply
at the Hotel Dieu; he was no sooner relieved, however, than he
began his tricks again, and once was but just prevented from
swallowing the surgeon’s watch, with its chain and seals. In
1789 he joined the mob and obtained sufficient food without
devouring for money. He was then about seventeen, weighing a
hundred pounds, and would eat five-and-twenty pounds of beef
a day. When the war broke out he entered into the army, and
devoured his comrades’ rations, as long as better supplies from
other sources rendered them of little value. But when at length
his comrades stood in need of them themselves, he was nearly
famished, fell ill, and was admitted into the hôpital ambulant at
Sultzer. He there ate not only a quadruple allowance, the
broken food of the other patients, and the waste of the kitchen,
but would swallow the poultices and any thing else that came in
his way. He devoured so many dogs and cats alive that they fled
at the sight of him. Large snakes he despatched with the greatest
facility, and once gobbled up in a few moments all the dinner
that was provided for fifteen German labourers, viz. four bowls
of curd, and two enormous dishes of dough boiled in water with
salt and fat. At another time, he disposed of thirty pounds of
raw liver and lights in the presence of some general officers, who,
finding that he could swallow a large wooden lancet case, took
the partitions out, enclosed a letter in it, and made him swallow
it and proceed to the enemy’s quarters for the purpose of dis-
charging it by stool, and delivering the letter to a French colonel
who had fallen into the hands of the Prussians. This he contrived
[Seite 305] to do, enclosed the answer in it, swallowed it again, made his
escape, discharged the case again from his bowels, washed it, and,
presented it to Beauharnois and the other officers. Having,
however, been well drubbed by the enemy, he refused any further
secret service, and was readmitted into the hospital to be cured
of his hunger. Being no longer a novelty, he excited less in-
terest, and felt it necessary to have recourse to sheep-folds,
poultry-yards, private kitchens, slaughter-houses, and bye places
where he had to contend with dogs and wolves for their filthy
food. He was detected drinking blood that had been taken from
his fellow-patients, and eating bodies in the dead house. The
disappearance of a young child excited strong suspicions against
him, and he was at length chased away and unheard of for four
years, at the end of which time he applied at the Hospice de Ver-
sailles, wasted, no longer voracious, and labouring under a puru-
lent diarrhoea, and he soon died, aged twenty-six. The body
immediately became a mass of putridity. During his life he was
always offensive, hot, and in a sweat, especially at intervals. His
breath rolled off like steam, and his dejections were constantly
very copious and intolerably foetid. He was of the middle height,
thin, and weak.

All the abdominal viscera were found full of suppurations.

His stomach was of immense size, and this has usually been the
case in persons habitually gluttonous. A polyphagous idiot
opened by the same writers displayed an enormous stomach, more
resembling that of a horse than of a human being: the intestines
also formed several large pouches in succession, which appeared
like additional stomachs. Cabrol dissected a glutton of Toulouse,
and found the oesophagus terminating in an excessively large
cavity, and the intestines running, without a single convolution,
but with merely a gentle sygmoid flexure, to the anus. A large
pylorus, or a very depending position of it, have been found in other
cases. We thus learn the common causes of constitutional vora-
ciousness, and obtain an additional reason for referring hunger to
the want of distention of the stomach: – a great quantity of food
is required to fill these stomachs. If hunger were independent
of the distention of this organ, and connected solely with the
want of the system, an ordinary meal would suffice where the
stomach is very large, as the extraordinary quantity of food can-
not be demanded for nourishment, – when food enough for
[Seite 306] support is taken, hunger should cease. But hunger continues
till the stomach is filled, and the prodigious collection in the
case of Tarare, was disposed of by abundant stools, sweating,
and copious pulmonary exhalation.

The large capacity of the stomach is generally ascribable to
original conformation, but some account for it occasionally by
repeated over distention and the deglutition of indigestible sub-
stances, – an opinion rather improbable when we reflect that city
gluttons, who give a very fair trial to the distensibility of their
idol, never acquire such appetites and capaciousness of stomach
as qualify them for a show. The power of deglutition may be
very much increased by practice. We have all seen the Indian
jugglers, and I frequently conversed with a poor man who had
swallowed nineteen large clasped knives at different times, having
found in a drunken fit that he could get one down his throat for
a wager:f yet in him the appetite and capacity of stomach were
not augmented. Knife and stone eaters are seen in all countries.

Some great eaters are prodigies of strength; as Milo, who killed
an ox with a blow of his fist and devoured it; and the fellow
mentioned in a thesis published at Wittemberg in 1757, who once,
in the presence of the Senate, ate up a sheep, a sucking-pig, and
sixty pounds of plums, stones and all, and could carry four men a
whole league upon his shoulders.

Voraciousness is of course sometimes, like depraved appetite,
as in chlorosis and pregnancy, but temporary, and referable to
merely disordered function. Dr. Satterly details the case of a
lad in whom, while labouring under typhus with marked inflam-
mation in the head, the exacerbations of fever were accompanied
by such hunger, that he ate every day four regular meals, each
sufficient for the stoutest labourer’s dinner, and many pounds of
dry bread, biscuit, and fruit between them. He had no sooner
finished a meal than he denied having tasted any thing,
[Seite 307]

‘“––––– cibus omnis in illo,’
‘Causa cibi est, semperque locus fit inanis edendo,”’

and would suck and bite the bed-clothes or his fingersg if refused
more, cared nothing about the quality of what he ate, would pass
six or seven large solid motions a day by means of physic, and
ultimately recovered.h The stomach here executed its office with
excessive rapidity, and was too soon empty again.

The ant-lion will exist without the smallest supply of food, ap-
parently uninjured, for six months; though when he can get it,
he will daily devour an insect of his own size. A spider has lived
without food under a sealed glass for ten months, and at the end
of that time appeared as vigorous as ever. Reptiles have often
lived upwards of a century enclosed in trees or stones.

On the other hand, herbivorous larvae, as caterpillars, (for in-
sects are carnivorous, herbivorous, and omnivorous, like their
superiors,) will eat twice their weight of food daily.i

(D) Sauvages mentions a member of the Academy of Toulouse
who never thirsted, and passed whole months of the hottest sum-
mer without drinking; and a woman who passed 40 days without
liquids or thirst.k

(E) A striking instance of this occurred at Bristol. A man
twenty years of age, had, as long as he could remember, chewed
his food a second time, after swallowing it. The process began
in a quarter of an hour if he had taken liquid at his meal: later,
if he had not. What had passed down first, always came up first.
Before the second chewing his food appeared to lie heavy in the
lowest part of his throat: after it, the food ‘“passed clear away.”’
He found the taste of the food on its return to be chewed, rather
pleasanter than at first. If this faculty left him it signified sick-
ness, and he was never well till it returned.l

Blumenbach has seen four examples of this kind. In two, the
[Seite 308] process was compulsory; in two, it was optional. These subjects
also were males, and had a real gratification in ruminating.m

(F) In carnivorous animals, the incisors are very large; and
the molares generally of an irregular wedge form, those of the
lower jaw closing in those of the upper like scissors, and being
adapted for lacerating. In the herbivorous, the surface of the
molares is horizontal or oblique, adapted for grinding.

(G) As the food of herbivorous animals requires more prepar-
ation before it becomes the substance of the animal, their stomach
is adapted to retain it for a length of time. The oesophagus
opens nearer the right extremity of the stomach, and the pylorus
nearer the left, so that a blind pouch is left on either side. In the
carnivorous, the reverse is the case, and the stomach cylindrical,
to favour the quick passage of the food. For the same reason, the
intestines in the latter, even among insects, are generally shorter,
and have fewer valvulae conniventes, and, in some instances, no
coecum.

(H) In animals which subsist on animal food, the condyles of
the lower jaw are locked in an elongated glenoid cavity, and all
rotatory motion thus prevented, as motion upwards and down-
wards is sufficient for the laceration of the food. In vegetable
feeders the joint is shallow, so that a horizontal motion is
allowed for grinding the food. For its nature in man, see
paragraph 339.

(I) In 1750, a caravan of Abyssinians had consumed all their
provisions, and would have starved but that they discovered
among their merchandise a stock of gum arabic, on which alone
above a thousand persons subsisted for two months.n Yet M.
Magendie says he finds that dogs perish if fed only with gum or
sugar, olive oil, butter, and similar articles, regarded as nutritious,
which contain no azote.o But although such substances be alone
unable to nourish, yet when united with others they may afford
some support, for persons accustomed to a mixed diet generally
grow thinner if they confine themselves to vegetable food, which
is indubitably good nourishment, and even if we grant that such
substances are not nutritious to dogs, they may be proper food for
other species; and to render it probable even that these are not
nutritious to dogs, the animals should have been gradually brought
[Seite 309] to feed on them only. For animals may be brought to live on food
the most opposite to what their nature inclines them, if the change
is made insensibly: – Spallanzani made a pigeon live on flesh
and an eagle on bread;p if fresh-water molusca are put at once
into sea water, or sea-water molusca into fresh water, they perish;
but if the change is gradually made, they live very well;q a
spider has fed upon sulphate of zinc;r we have seen that the
Otomacs eat little else some months of the year than large
quantities of earth, and that some brutes devour earth. I may
here add that not only the Otomacs are so fond of it, as, when
well supplied with food, to take a little, but that many nations of
the torrid zone have a propensity to geophagism. The negroes
of Guinea, the Javanese, the New Caledonians, and many South
American tribes, eat clay as a luxury, and the Guajeroes,
on the west of Rio da la Hache, carry a little box of lime
as sailors do a tobacco-box. German workmen at the mountain
of Kiffhönser spread clay instead of butter on their bread, and
call it stein butter, and find it every satisfying and easy of
digestion. The Otomacs do not suffer by the practice, but
in some tribes the people grow sick and thin by indulging too
freely in this luxury. Africans who geophagised with impunity
at home on a yellow clay, severely suffer from it in the West
Indies.s The red-clay eaten in Java destroys the appetite and
wastes the body.

It appears that matter which has never belonged to an animated
system is calculated to afford nourishment to animals in some
degree, but subordinately to matter which has belonged to
vegetables or animals, and that it alone will in some instances
support life for a time. Vegetables will indisputably live for a time
with facility on such alone, but eventually they will not thrive
and perfect their seed, unless animal or vegetable remains exist
in the soil; whence the necessity of this kind of manure, which
must have likewise been so changed by putrefaction that its
carbon has formed a compound resembling the extractive princi-
ple, and thus capable of solution in water. It has been contended
[Seite 310] that some animals, as fish, and that vegetables, readily subsist,
growing equally with others, and perfecting their seed, on simple
water, but the experiments in support of this assertion are not at
all decisive.t

The articles of diet generally employed by every nation and
class of society are much determined by the facility with which
they are procured. Generally, too, animal food is preferred in
cold climates and vegetable in warm; a mixture, however, of the
two is usually preferred to either exclusively, and appears better
suited to our necessities. Animal food is chiefly muscle and fat,
milk and eggs; vegetable food, chiefly, seeds and roots, fruits and
leaves, with more or less of the stalks. These articles, which are
rendered more or less masticable or digestible by heat, are
previously subjected to high temperatures in various ways; and
as many saline and aromatic substances are taken, not so much for
their nutritive qualities and their undoubted assistance when the
stomach is weak or chiefly vegetables are eaten, as for their sapid
qualities, and since the admixture of these, and the combination
of various nutritive substances together, often highly increases the
exquisiteness of taste and flavour, the culinary art is cultivated
not only for health, but also for luxury.

The chief proximate principles of animal food are fibrine,
albumen, gelatine, ozmazome, oil, and sugar; of vegetable,
gluten, fecula, mucilage, oil, and sugar. My not less excellent
than distinguished friend, Dr. Prout, in the paper which has just
been honoured with the Copley medal of the Royal Society,u
reduces all the articles of nourishment among the higher animals
to three classes: the saccharine, oily, and albuminous. The
first comprehends sugars, starches, gums, acetic acid, and
some other analogous principles; the second, oils and fats,
alcohol, &c.; the third, other animal matters, and vegetable
gluten, so abundant in wheat. He has favoured me with the
following remarks, which are chiefly an abstract from a work on
digestion, commenced by him in 1823, but not yet published.

‘“Observing that milk, the only article actually furnished and
intended by nature as food, was essentially composed of three
ingredients, viz. saccharine, oily, and curdy, or albuminous
[Seite 311] matter, I was by degrees led to the conclusion that all the
alimentary matters employed by man and the more perfect ani-
mals, might, in fact, be reduced to the same three general heads;
hence I determined to submit them to a rigorous examination in
the first place, and ascertain, if possible, their general relations
and analogies. An account of the first of these classes, viz. the
saccharine matters, has been just published in the Philosophical
Transactions,
and the others are in progress. The characteristic
property of saccharine bodies is that they are composed simply of
carbon united to oxygen and hydrogen in the proportions in which
they form water; the proportions of carbon varying in different
instances from about 30 to 50 per cent. The other two families
consist of compound bases (of which carbon constitutes the chief
element) likewise mixed with and modified by water, and the pro-
portion of carbon in oily bodies, which stand at the extreme of the
scale in this respect, varies from about 60 to 80 per cent.; hence,
considering carbon as indicating the degree of nutrition, which,
in some respects may be fairly done, the oils may be regarded in
general as the most nutritious class of bodies; and the general
conclusion from the whole is, that substances naturally containing
less than 30 or more than 80 per cent. of carbon are not well, if
at all, adapted for aliment.’

‘“It remains to be proved whether animals can live on one of
these families exclusively, but at present experiments are decidedly
against this assumption, and the most probable view is, that a
mixture of two at least, if not of all three of the classes of nutriment
is necessary. Thus, as has been stated, milk is a compound of
this description, and almost all the gramineous and herbaceous
matters employed as food by animals, contain at least two of the
three. The same is true of animal aliments, which consist, at least,
of albumen and oil; in short, it is, perhaps, impossible to name a
substance employed by the more perfect animals as food, which
does not essentially constitute a natural compound of at least
two, if not of all three of the above three great classes of
alimentary matters.’

‘“But it is in the artificial food of man that we see this great prin-
ciple of mixture most strongly exemplified. He, dissatisfied with
the productions spontaneously furnished by nature, culls from every
source, and, by the power of his reason, or, rather, his instinct,
forms in every possible manner, and under every disguise, the
[Seite 312] same great alimentary compound. This, after all his cooking
and art, how much soever he may be inclined to disbelieve it, is the
sole object of his labour, and the more nearly his results approach
to this, the more nearly they approach perfection. Thus, from
the earliest times, instinct has taught him to add oil or butter
to farinaceous substances, such as bread, and which are naturally
defective in this principle. The same instinct has taught him to
fatten animals, with the view of procuring the oleaginous in con-
junction with the albuminous principle, which compound he finally
consumes, for the most part in conjunction with saccharine matter,
in the form of bread or vegetables. Even in the utmost refine-
ments of his luxury and in his choicest delicacies, the same great
principle is attended to, and his sugar and flour, his eggs and
butter, in all their various forms and combinations, are nothing
more nor less than disguised imitations of the great alimentary
prototype, milk, as presented to him by nature.”’

More or less of common salt exists in the food of all animals.
It is equally desired by the greater number, and many traverse
immense tracts and encounter great difficulties to obtain it. Dr.
Prout, I may mention, considers it, or the muriatic acid which it
affords, of the highest importance in the animal economy.

SECT. XXII.
OF MASTICATION AND DEGLUTITION.

[Seite 313]

338. The lower jaw is the chief organ of mastication,
and is supplied, as well as the upper, with three orders of
teeth.

With incisores, generallya scalpriform for the purpose of
biting off small pieces, and not placed in the lower jaw, as in
other mammalia, more or less horizontally, but erect, – one
of the distinctive characters of the human race.

With strong conical canine teeth, by which we divide hard
substances, and which in man neither project beyond the rest,
nor are placed alone, but lie closely and in regular order with
the others.

With molares of various sizes, adapted for grinding, and
differing conspicuously from those of other mammalia, by
possessing gibbous apices excessively obtuse.

339. The lower jaw is connected with the skull by a
remarkable articulation, which holds a middle rank between
arthrodia and ginglymus, and, being supplied with two car-
[Seite 314] tilaginous menisci of considerable strength, has easy motion
in every direction. (A)

The digaster, assisted somewhat by the geniohyoidei and
mylohyodei muscles, draws the lower jaw down, when we
open the mouth.

The masseters and temporal chiefly raise it again when we
bite off any thing, and are most powerfully contracted when
we break hard substances.

Its lateral motions are accomplished by the internal and
external pterygoid.

The latter can also draw it forwards.

340. Substances are retained, directed, and brought under
the action of the teeth by the buccinator, and by the tongue,
which is very flexible and changeable in form. (235)

341. During manducation, there occurs a flow of saliva,b
which is a frothy fluid, consisting of a large portion of water
united with some albumen, and holding in solution a small
quantity of phosphate of lime – the source of the tartar of the
teeth and of salivary calculi. From being constantly applied
to the tongue, it is insipid, although it contains some micro-
cosmic salt (phosphate of ammonia), as well as muriatic and,
invariably, a small portion of oxalic acid. It is antisepticc
and very resolvent. (B)

342. The saliva flows from three orders of conglomerate
glands, placed laterally and interiorally with respect to the
lower jaw.

The parotids,d are the largest, and pour forth the saliva
behind the middle molares of the upper jaw, through the
Stenonian ducts.e

The submaxillary,f through the Whartonian.g

[Seite 315]

The sublingual,h – the smallest, through the numerous
Rivinian.i

343. The excretion of saliva, amounting, according to the
arbitrary statement of Nuck,k to a pound in twelve hours, is
augmented by stimuli and by mechanical pressure, or, if the
expression may be allowed, emulsion.

The latter cause, greatly favoured by the situation of the
parotids, at the articulation of the jaws, occurs when we chew
hard substances, which thus become softened.

The former occurs when acrid substances are taken into
the mouth, which are thus properly diluted; or arises from
imagination (288), as when the mouth waters during the
desire for food.

344. The mucus of the labial and buccal glandsl and of
the tongue, as well as the moisture which transudes from the
soft parts of the mouth, is mixed with the saliva.

345. The mixture of these fluids with a substance which
we are chewing, renders it not only a pultaceous and easily
swallowed bolus, but likewise prepares it for further digestion
and for assimilation.

346. The mechanismm of deglutition, although very com-
plicated, and performed by the united powers of many very
different parts, amounts to this. The tongue being drawn
towards its root, swelling and growing rigid, receives the
bolus of food upon its dorsum, which is drawn into a hollow
form. The bolus is then rolled into the isthmus of the fauces,
and caught with a curious and rather violent effort by the
infundibulum of the pharynx, which is enlarged and in some
measure drawn forward to receive it. The three constric-
[Seite 316] toresn muscles of the pharynx drive it into the oesophagus.
These motions are all performed in very rapid succession, and
require but a short space of time.

347. Nature has provided various contrivances for opening
and securing this passage.o

The important motion of the tongue is regulated by the os
hyoides.

The smallest particle of food is prevented from entering the
nostrils or Eustachian tubes, by means of the soft palate,p which,
as well as the uvula suspended from its arch, and whose use
is not clearly understood, is extended by muscles of its own,
and closes those openings.q

The tongue protects the glottis, for the larynx at the
moment of deglutition is drawn upwards and forwards, and in
a manner concealed under the retracted root of the tongue
and applied to the latter in such a way, that the glottis, being
also constricted and protected by the epiglottis, is most
securely defended from the entrance of foreign substances. (C)

348. Deglutition is facilitated by the abundance of mucus
which lubricates these parts, and which is afforded not only
by the tongue (237), but by the numerous sinusesr of the
tonsils and muciparous cryptae of the pharynx.

349. The oesophagus, through which the food must pass
previously to entering the stomach, is a fleshy canal, narrow
and very strong, mobile, dilatable, very sensible, and con-
sisting of coats resembling, except in thickness, the coats of
the other parts of the alimentary canal.s

[Seite 317]

The external coat is muscular, and possesses longitudinal
and transverse fibres.

The middle is tendinous, lax, and more and more cellular
towards each of its surfaces, by which means it is connected
with the two other coats.

The interior is lined, like all the alimentary tube, with an
epithelium analogous to cuticle (176), and is lubricated by a
very smooth mucus.

350. This canal receives the approaching draught or bolus
of food, contracts upon it, propels it downwards, and, in the
case of the bolus, stuffs it down, as it were, till it passes the
diaphragm and enters the stomach. (D)


NOTES.

(A) The condyles of the lower jaw are prevented from descend-
ing very deeply into the glenoid cavity, and thus being confined
to vertical movements, by a cartilage which is hollow on each sur-
face, and moveable, and permits the condyle to move from the
glenoid cavity to a tubercle which stands before this, and thus to
acquire still greater mobility.

(B) Saliva is composed of

Water 992.9
A peculiar animal matter 2.9
Mucus 1.4
Alkaline muriates 1.7
Lactate of soda and animal matter 0.9
Pure soda 0.2
––––––
1000.0t
––––––

What Berzelius calls mucus, Professor Thomson and Dr. Bos-
tock regard as albumen: This mucus is insoluble in water, and,
when incinerated, but not before, yields a large portion of phos-
[Seite 318] phate of lime. The tartar of the teeth arises from its gradual de-
composition upon them, and consists of

Earthy phosphates 79.0
Undecomposed mucus 12.5
Peculiar salivary matter 1.0
Animal matter soluble in muriatic acid 7.5
–––––
100.0u
–––––

According to a recent examination by Tiedemann and Gmelin,
saliva, mixed with more or less mucus, consists of –

A peculiar matter termed salivary; osmazome; mucus: – all
essential to its composition.

Sometimes a little albumen.

A little fatty matter, united with phosphorus.

Potass united with acetic, phosphoric, sulphuric, hydrochloric,
and sulpho-cyanic acid: – all soluble salts.

A large quantity of phosphate, and a smaller of carbonate, of
lime: a minute quantity of magnesia: – all three insoluble.x

The solid contents amount to about 1/25 per cent. The alkaline
properties of saliva were before ascribed to a free alkali. and that
alkali was supposed to be soda. In the dog the alkali is soda,
very little potass being discoverable.

(C) The glottis, when sound, may be sufficiently closed inde-
pendently of the epiglottis. Dr. Magendie says that he saw two
persons perfectly destitute of epiglottis who always swallowed
without difficulty.y Targioni also met with one, and in that case
neither deglutition nor speech was impaired.z

(D) Professor Hallé observed in a woman, the interior of whose
stomach was exposed by disease, that the arrival of a bolus of
food in the stomach was followed by an eversion of the mucous
membrane of the oesophagus into it, as we observe in the case of
the rectum when a horse has finished discharging its faeces.a

SECT. XXIII.
OF DIGESTION.

[Seite 319]

251. The stomach is the organ of digestion. It exists,
what cannot be affirmed of any other viscus, in perhaps all
animals without exception; and, if the importance of parts
may be estimated in this way, evidently holds the first rank
among our organs.

352. The human stomacha resembles a very large leathern
bottle, is capable in the adult of containing three pints and
upwards of water, and has two openings.

The superior, called cardia, at which the oesophagus, folded
and opening obliquely, expands into the stomach, is placed
towards the left side of its fundus.

The inferior, at which the right and narrower part of the
stomach terminates, is called pylorus, and descends somewhat
into the cavity of the duodenum.

353. The situation of the stomach varies accordingly as it
is in a state of repletion or depletion. When empty, it is
flaccid, and hangs into the cavity of the abdomen, its greater
curvature inclining downwards, while the pylorus, being
directed upwards, forms, by doubling, an angle with the duo-
denum.b

When full, the larger curvature is rolled forwards,c so that
the pylorus lies more in a line with the duodenum, while the
cardia, on the contrary, is folded, as it were, into an angle and
closed.

[Seite 320]

354. The stomach is composed of four principal coats, se-
parated by the intervention of three others, which are merely
cellular.

The external is common to nearly all the alimentary canal,
and continuous with the omentum, as we shall presently
mention.

Within this, and united to it by cellular membrane, lies
the muscular coat, which is particularly worthy of notice from
being the seat of the extraordinary irritability (300) of the
stomach. It consists of strata of muscular fibres,d commonly
divided into three orders, one longitudinal and two circular
(straight and oblique), but running in so many directions that
no exact account can be given of their course.

The third is the chief membrane. It is usually termed
nervous, but improperly, as it consists of condensed mucous
tela, more lax on its surfaces, which are united on the one
hand with the muscular and on the other with the internal
villous coat. It is firm and strong, and may be regarded as
the basis of the stomach.

The interior (besides the epithelium investing the whole
alimentary canal), improperly called villous, is extremely soft,
and in a manner spongy, porous, and folded into innumerable
rugae,e so that its surface is more extensive than that of the
other coats; it exhibits very small cells,f somewhat similar to
those larger cells which are so beautiful in the reticulum of
ruminants.

Its internal surface is covered with mucus, probably se-
creted in the muciparous crypts which are very distinct about
the pylorus.

355. The stomach is amply furnished with nervesg from
each nervous system (214), whence its great sensibility, owing
to which it is so readily affected by all kinds of stimuli,
whether external, as cold, or internal, as food and its own
[Seite 321] fluids, or mental; whence also the great and surprising sym-
pathy between it and most functions of the system; to which
sympathy are referable the influence of all passions upon the
stomach, and of the healthy condition of the stomach upon
the tranquillity of the mind.h

356. The abundance and utility of the blood-vessels of the
stomach are no less striking. Its arteries, ramifying infinitely
upon the cellular membrane and glands, secrete the gastric
juice,
which would appear to stream continually from the
inner surface of the stomach.i

357. In its general composition this fluid is analogous to
the saliva, equally antiseptic, very resolvent,k and capable of
again dissolving the milk which it has coagulated.l (A)

358. Digestion is performed principally by it. The food,
when properly chewed and subacted by the saliva, is dis-
solvedm by the gastric fluid, and converted into the pultaceous
chyme, so that most kinds of ingesta lose their specific qua-
lities, are defended from the usual chemical changes to which
they are liable, such as putridity, rancidity, &c. and acquire
fresh properties preparatory to chylification.n (B)

359. This important function is probably assisted by
various accessory circumstances. Among them, some parti-
cularly mention the peristaltic motion, which, being constant
and undulatory, agitates and subdues the pultaceous mass of
[Seite 322] food.o The existence of a true peristaltic motion in the stomach
during health, is, however, not quite certain; indeed, the
undulatory agitation of the stomach that occurs, appears in-
tended for the purpose of driving the thoroughly dissolved
portions downwards, while those portions which are not com-
pletely subacted are repelled from the pylorus by an antipe-
ristaltic motion.

360. The other aids commonly enumerated, are the pres-
sure on the stomach from the alternate motion of the abdomen,
and the high temperature maintained in the stomach by the
quantity of blood in the neighbouring viscera and blood-
vessels, which temperature was at one time supposed to be of
such importance, that the word coction was synonymous with
digestion.

361. To determine the time requisite for digestion is evi-
dently impossible, if we consider how it must vary according
to the quality and quantity of the ingesta, the strength of the
digestive powers, and the more or less complete previous mas-
tication.

During health, the stomach does not transmit the digestible
parts of the food before they are converted into a pulp. The
difference of food must therefore evidently cause a difference
in the period necessary for digestion.p It may, however, be
stated generally, that the chyme gradually passes the pylorus
in between three and six hours after our meals. (C)

362. The pylorusq is an annular fold, consisting, not like
the other rugae of the stomach, of merely the villous, but also
of fibres derived from the nervous and muscular, coats. All
these, united, form a conoidal opening at the termination of
the stomach, projecting into the duodenum, as the uterus
does into the vagina, and, in a manner, embraced by it.

[Seite 323]

NOTES.

(A) Seven grains of the inner coat of a calf’s stomach were
found by Dr. Young of Edinburgh to enable water poured upon it
to coagulate 6857 times its weight of milk.r

(B) It was once imagined that fermentation, and once that tri-
turation, was the cause of digestion, but, as neither can produce
the same effects on food out of the body that occur in the stomach,
these opinions fell to the ground. Besides, no signs of ferment-
ation appear when digestion is perfect; and food, either defended
from trituration by being swallowed in metallic spheres perforated
to admit the gastric juice,s or immersed in gastric juice out of
the body,t is readily digested.

(C) The digestive process does not go on equally through the
whole mass of food, but takes place chiefly where this is in contact
with the stomach, and proceeds gradually from the surface to
[Seite 324] the centre of the mass, so that the food at the centre is entirely
different in appearance from that at the surface, and, as soon as a
portion is reduced to a homogeneous consistence, it passes into
the duodenum without waiting till the same change has pervaded
the whole.u

The cardiac portion of the stomach is the chief seat of the pro-
cess, and when a part of the food is tolerably digested it passes
along the large curvature to the pyloric portion, where the pro-
cess is completed. As the cardiac half is the great digesting
portion, it is this half that is found sometimes to have been dis-
solved by the gastric juice after death; its contents are much
more fluid than those of the pyloric half; and Dr. Philip, who by
the dissection of about a hundred and thirty rabbits has been
enabled to furnish the completest account of what goes on in the
stomach, relates the case of a woman who had eaten and properly
digested to the last, but whose stomach was ulcerated every
where except at the cardiac end. Sir Everard Home says he
found that fluids which had been drunk were chiefly contained in
the cardiac portion, and, like many others, for upwards of a cen-
tury and a half,x that, if the body was examined early after death,
the two portions of the stomach were frequently in fact divided
by a muscular contraction.y Dr. Haighton observed the same
hour-glass contraction in a living dog, and remarked the peristaltic
motion to be much more vigorous in the pyloric half.z

Van Helmont asserted that the food becomes sour by digestion,
but this was afterwards denied, and acidity said never to happen
except in cases of disorder. Sir Gilbert Blane, many years ago,
however, declared that he had ‘“satisfied himself that there is
such an acid (the gastric) by applying the usual tests to the
inner surface of the stomach of animals. This property in rumin-
[Seite 325] ating animals,”’ he added, ‘“is confined to the digesting stomach.”’a
Dr. Prout has discovered that the acid generated is the muriatic,
both free and in combination with alkalis.b Tiedemann and
Gmelin soon afterwards found the same thing, though without
knowing, they assure us, Dr. Prout’s discovery. They assert the
clear ropy fluid of the stomach without food to be nearly, or
entirely, destitute of acidity, while the presence of food or of the
most simple stimulus to the mucous membrane, occasions it to be-
come acid, and more so, according to the greater indigestibility of
the food. The acid is very copious. They also assert the presence
of acetic acid; but Dr. Prout believes this neither necessary nor
ordinary, and derived from the aliment when it is observed. The
general change of the aliment in the stomach appears a greater
or less approach to the nature of albumen, but Dr. Prout has been
unable to detect true albumen there when none has been taken.

Brutes have been the subjects of these experiments; chiefly the
rabbit, horse, dog, and cat.

Besides the labours of Dr. Prout and of the professors of Heidel-
berg, a work has lately been published on all the subjects of
chymification and chylification by MM. Leuret and Lassaigne,
contradictory in many respects to the results of the others; but,
knowing as I do the extreme accuracy of Dr. Prout in experi-
menting and deducing, and seeing that Tiedemann and Gmelin
have bestowed infinite labour in repeating, varying, and extend-
ing their experiments, and have detailed all their proceedings,
while the French writers merely give results and appear to have
bestowed far less pains, I must be excused for merely mentioning
their work.c

An immense number of curious facts respecting different
articles of food, and many points on the subject of digestion, will
be found in the German work, and a good history of opinions in
the French.

In granivorous birds the food passes into the crop, and from this
into a second cavity, from which it enters the gizzard, – a strong
muscular receptacle, lined by a thick membrane, in which,
[Seite 326] instead of having been masticated, it is ground by means of
pebbles and other hard bodies swallowed instinctively by the
animal; hence true salivary glands do not exist about the mouth
of birds, but abound in the abdomen, opening into the lower part
of the oesophagus and into the crop and gizzard. In carnivorous
birds, the gizzard is soft and smooth. The fluids of both crop
and gizzard contain a free acid, according to Tiedemann and
Gmelin, which is the muriatic or acetic.

Some graminivorous quadrupeds with divided hoofs have four
stomachs, into the first of which the food passes when swallowed,
and from this into the second. It is subsequently returned by
portions into the mouth, chewed, and again swallowed, when, by
a contraction of the openings of the two first stomachs, it passes
over them into the third, and from this goes into the fourth.
The process can be delayed at pleasure when the paunch is quite
full. Some birds and insects also ruminate. The same chemists
found the fluids of the two first stomachs alkaline, and of the
third and fourth, acid. The stomachs of some insects and crus-
tacea contain teeth. Some zoophytes are little more than a
stomach: others have several openings on the surface leading by
canals that unite and run to the stomach, – a structure called by
Cuvier, mouth-root. Between the most distinct kinds of stomach
we see numerous intermediate varieties. The cardiac half of
the interior of the stomach of the horse, for example, is covered
by cuticle, and appears merely recipient, while the pyloric half
is villous and digestive, and the state of the contents in each half
is, therefore, very different: a link thus existing between such
stomachs as the human and the ruminating.

Vomiting cannot occur unless the stomach have the resistance
of the diaphragm and abdominal muscles, or of something in
their stead. Different persons have made the horrid experiment
of giving an emetic to an animal, and, after the abdominal muscles
were cut away, observing how fruitless were all the efforts of
the stomach to reject its contents till they applied their hands
in place of these muscles, when the stomach, being forced by
the diaphragm against the resistance, instantly accomplished
vomiting.

‘“In vomiting, the muscles of the cavity of the abdomen act,
in which is to be included the diaphragm; so that the capacity of
the abdomen is lessened, and the action of the diaphragm rather
raises the ribs, and there is also an attempt to raise them by their
[Seite 327] proper muscles, to make a kind of vacuum in the thorax, that the
oesophagus may be rather opened than shut, while the glottis is
shut so as to let no air into the lungs. The muscles of the
throat and fauces act to dilate the fauces, which is easily felt by
the hand, making there a vacuum, or what is commonly called a
suction.”’d

It is generally accompanied by more or less of a peculiar sensa-
tion in the stomach, called nausea: this frequently exists alone,
and sometimes in a high degree; but where it increases to a cer-
tain amount, usually ends in vomiting. During nausea the pulse
is small, the temperature low, and the head giddy, and a large
quantity of fluid is secreted in the mouth and fauces. It is ex-
cited by disgust, certain articles, pain, sympathy of the stomach
with other organs not in health; by general derangement or disease
of the stomach; by turning round, swinging, or the motion of a
ship, and from the latter cause takes its name.

The stomach has been called the grand centre of sympathy.
Its sympathies are great, but there is no reason for considering it
the centre of sympathy. Blows upon the head or testicle, and dis-
eases of the kidney and uterus, nay, the mere pregnant state of
the latter, severe pain in any part, or a disgusting sight, will often
cause vomiting. Any depressing passion deranges the stomach,
but anxiety is a common source of stomach complaints, although
the stomach generally bears the whole blame, and is in vain
drugged and dieted, or want of exercise or great mental occu-
pation is regarded as the cause, while the anxiety is overlooked.
Pleasurable mental exertion, ‘“constant occupation without care,”’
must be very excessive to injure the stomach.

The stomach itself, except as far as its inner surface is very
extensive and sensible, and therefore highly adapted for the
influence of ingesta, appears to affect other organs, by mere
sympathy, far less than it is influenced by them.

The effects of the division of the par vagum upon the lungs
and stomach were mentioned at page 224; but I should remark,
that Mr. Brodie found even digestion uninfluenced, if the division
was made not in the neck, but close to the stomach.e

SECT. XXIV.
OF THE PANCREATIC JUICE.

[Seite 328]

363. The chyme, after passing the pylorus, undergoes
new and considerable changes in the duodenuma – a short
but very remarkable portion of the intestines, before the
nutrient chyle is separated. To this end, there are poured
upon it various secreted fluids, the most important of which
are the bile and pancreatic juice.

364. Of these we shall treat separately, beginning with the
pancreatic fluid, because it is closely allied both in nature and
function to the saliva and gastric juice already mentioned.

365. Although it is with difficulty procured pure from
living and healthy animals, all observations made in regard to
it establish its close resemblance to the saliva. At the present
day, it would scarcely be worth while to mention the er-
roneous hypotheses of Franc. Sylviusb and his followers –
Regn. De Graaf,c Flor. Schuyl,d and others, respecting its
supposed acrimony, long since ably refuted by the celebrated
Pechlin,e Swammerdam,f and Brunner,g unless they afforded
a salutary admonition, how fatal the practice of medicine may
become, if not founded on sound physiology.

[Seite 329]

366. The source of this fluid is similar to that of the saliva.
It is the pancreas,h – by much the largest conglomerate gland
in the system, excepting the breasts, and extremely analogous
to the salivary glands in every part of its structure, even in
the circumstance of its excretory ducts arising by very minute
radicles and uniting into one common duct, which is deno-
minated, from its discoverer, Wirsüngian.

This duct penetrates the tunics of the duodenum, and sup-
plies the cavity of this intestine with a constant stillicidium of
pancreatic juice.

367. The excretion of this fluid is augmented by the same
causes which affect that of the saliva, – pressure and sti-
mulus.

By the former it is emulged, whenever the stomach lies in
a state of repletion upon the pancreas.

The stimuli are the fresh and crude chyme entering the
duodenum, and the bile flowing through the opening common
to it and the pancreatic fluid.

368. Its use is to dissolve the chyme, especially if imper-
fectly digested in the stomach, and at all times, by its great
abundance, to assimilate the chyme more to the nature of the
fluids and render it fitter for chylification.


NOTE.

Brunner, about 150 years ago, removed almost the whole pan-
creas from dogs, and tied and cut away portions of the duct; and
they lived apparently as well as before. From one he was not
contented with removing the spleen at one time and the pancreas
at another, after which the poor animal pancratice valebat; but,
to render it celebrated for experiments, he on a third occasion laid
bare the intestines and wounded them for an inch and a half,
sewed up the wound, made a suture in the abdominal parietes so
badly that the intestines were found hanging out on the ground one
[Seite 330] morning, purple and cold, and then allowed the animal to lick the
wound into healing. He also performed the operation for aneurism
in the artery of its hind leg, and paracentesis of its chest, inject-
ing a quantity of milk into the pleura and pumping it out again.
This even was not enough for the gentle Brunner; he gave the
dog such a dose of opium, when it had recovered from the oper-
ation on the spleen, that it was seized with tetanus. But this also it
got the better of, and lived upwards of three pleasant months with
its master, ‘“gratus mihi fuit hospes,”’ after all these indulgencies,
and was at last lost in a crowd; stolen, no doubt, because ‘“celebris
ab experimentorum multitudinem, – vivum philosophiae experi-
mentalis exemplum, et splene mutilus, variis cicatricibus notabilis.”’
Brunner offered any money for it again, but to no purpose, (p. 6.
13.)

The pancreatic juice, at least in the sheep, according to Tiede-
mann and Gmelin, has twice as much solid contents as the saliva,
and conversely a large quantity of albumen and fatty matter, with
a small quantity of salivary matter and mucus; is neutral, or has
only a little alkaline carbonate, and no sulpho-cyanic acid.

The use of the pancreatic juice is unknown, but Blumenbach’s
opinion, that it ‘“assimilates the chyme more to the nature of the
fluids,”’ is more precisely given by Tiedemann and Gmelin, who
conceive that it animalises the unazotised principles of vegetable
food. It is certainly much larger proportionately in herbivorous
than in carnivorous animals. They assign the same purpose to
the saliva.

The quantity of the pancreatic juice cannot be accurately as-
certained. It is, no doubt, produced copiously during chylifi-
cation, and cannot be expected to flow readily at other times, or
naturally under the torments of an experiment.

The weight of the human pancreas is about three times that of
all the salivary glands together.i

SECT. XXV.
OF THE BILE.

[Seite 331]

369. The bile is secreted by the livera – the most pon-
derous and the largest of all the viscera, especially in the
foetus,b in which its size is inversely as the age. The high
importance of this organ is manifested, both by its immense
supply of blood-vessels and their extraordinary distribution,
as well as by its general existence, for it is not less common
to all red-blooded animals than the heart itself.c (A)

370. The substance of the liver is peculiar, easily distin-
guished at first sight from that of other viscera, of well-known
colour and delicate texture,d supplied with numerous nerves,e
lymphatics (most remarkable on the surface),f biliferous ducts,
[Seite 332] and, what these ducts arise from, blood-vessels,g which are
both very numerous and in some instances very large, but of
different descriptions, as we shall state particularly.

371. The first blood-vessel to be noticed is the vena porta-
rum,
whose dissimilarity from other veins, both in its nature
and course, was formerly hinted at. (97) Its trunk is formed
from the combination of most of the visceral veins belonging
to the abdomen, is supported by a cellular sheath called the
capsule of Glisson,h and, on entering the liver, is divided into
branches which are subdivided more and more as they pene-
trate into the substance of the organ, till they become ex-
tremely minute, and spread over every part. Hence Galen
compared this system to a tree whose roots were dispersed in
the abdomen, and its branches fixed in the liver.i

372. The other kind of blood-vessels belonging to the
liver, are branches of the hepatic artery, which arises from
the coeliac, is much inferior to the vena portae in size, and in
the number of its divisions, but spreads by very minute rami-
fications throughout the substance of the organ.

373. The extreme divisions of these two vessels terminate
in true veins, which unite into large venous trunks running to
the vena cava inferior.

374. These extreme divisions are inconceivably minute and
collected into very small glomerules,k which deceived Mal-
pighi into the belief that they were glandular acini, hexagonal,
hollow, and secretory.l

375. From these glomerules arise the pori biliarii – very
delicate ducts, secreting the bile from the blood, and discharg-
ing it from the liver through the common hepatic duct, which
is formed from their union.

376. It has been disputed whether the bile is produced
from arterial or venous blood.

[Seite 333]

Although the former opinionm is countenanced by the
analogy of the other secretions which depend upon arterial
blood, nevertheless more accurate investigation proves that
the greater part, if not the whole, of the biliary secretion is
venous.

With respect to arguments derived from analogy, the vena
portae, resembling arteries in its distribution, may likewise
bear a resemblance to them in function. Besides, the liver is
analogous to the lungs, in which the great pulmonary vessels
are intended for their function, and the bronchial arteries for
their nourishment; and if we are not greatly mistaken, the
use of the hepatic artery is similar. We would, however,
by no means completely deny its importance in the secretion
of bile, but must regard it as inconsiderable, adventitious, and
not well established. (B)

377. The bile flows slowly, but constantly, along the hepatic
duct. The greater portion runs constantly through the ductus
communis choledochus into the duodenum, but some passes
from the hepatic into the cystic duct, and is received by the
gall-bladder, where it remains for a short period, and acquires
the name of cystic bile.n

378. The gall-bladder is an oblong sac, nearly pyriform,
adheres to the concave surface of the liver, and consists of
three coats.

An exterior, not completely covering it, derived from the
peritonaeum.

[Seite 334]

A middle, called nervous, and, as in the stomach, intestines,
and urinary bladder, the source of its firmness and tone.

An interior,o which may be, in some measure, compared to
the inner coat of the stomach, (359) as it contains a net-work
of innumerable blood-vessels, abounds in mucous glands,p and
is marked by rugae,q which occasionally have a beautifully
cancellated and reticulated appearance.

379. Its cervix is conical, terminates in the cystic duct, is
tortuous, and contains a few falciform valves.r

380. The bile which has passed into the gall-bladder is
retained until, from the reclined or supine posture of the
body, it flows down from it spontaneously, or is squeezeds
out by the pressure of the neighbouring jejunum, or ileum, or
of the colon when distended by faeces.

The presence of stimuli in the duodenum may derive the
bile in that direction.

The great contractility of the gall-bladder, proved by ex-
periments on living animals, and by pathological phenomena,
although it has no irritability (301), probably assists the
discharge of bile, especially when this fluid has, by retention,
become very stimulating.

381. For the cystic bile, though very analogous to the
hepatic, (377) becomes more concentrated, viscid, and bitter,
by stagnation in the gall-bladder; the cause of which is, in
all probability, the absorption of its more watery parts by the
lymphatic vessels.t (C)

382. Our attention must now be turned to the bile itself –
a very important fluid, respecting the nature and use of which
[Seite 335] there has been more controversy for these thirty years than
about any other fluid.

The cystic bile, being more perfect and better calculated
for examination, will supply our observations.

383. Bile taken from a fresh adult subject is rather viscid,
of a brownish green colour,u inodorous, and, if compared
with that of brutes, scarcely bitter.

384. Its constituent parts, obtained by chemical analysis,
are, besides a large proportion of water, albumen, resin,
soda,x partly united with phosphoric, sulphuric, and mu-
riatic acid, a small portion of phosphate of lime and iron, and
a variable quantity of a remarkable and peculiar yellow matter.y

385. The composition of the bile varies greatly both from
the proportion of its parts, particularly of the albuminous and
resinous, differing under different circumstances, and also
from the addition of other constituents, during morbid states,
especially of adipocerous substance, which gives origin to
most biliary calculi; for these consist either of it alone, or of
it combined with the yellow matter just mentioned. (D)

386. The nature of the bile is not saponaceous and capable
of effecting a combination between water and oils, as Boer-
haave supposed, but which opinion the excellent experiments
of Schröder,z who was formerly of this university, both con-
firmed and extended by other physiologists,a have disproved.
It even decomposes a combination of those substances.b

[Seite 336]

387. The important and various use of the bile in chylifi-
cation is self-evident.

In the first place, it gradually precipitates the faeces, and
separates the milky chyle from the mixed and equable pul-
taceous chyme, while this is passing through the tract of the
small intestines, after being propelled from the stomach into
the duodenum and diluted by the pancreatic juice.c

It separates itself into two portions, the one serous, the
other resinous. The latter combines with the faeces, tinges
them, and is discharged with them; the former is probably
mixed with the chyle and carried back to the blood. (E)

The bile seems to act as a stimulus to the peristaltic mo-
tiond of the intestines.

We shall omit other less probable uses assigned to the bile,
v. c. of exciting hunger by regurgitating into the stomach, –
a circumstance which we think can hardly happen during
health.


NOTES.

(A) The liver exists not only in all red-blooded animals, but in
the invertebral with colourless blood, whenever a heart and blood-
vessels are present. The pancreas exists in all the mammalia,
birds, reptiles, and fishes.

(B) Two instances have occurred in London, of the vena portae
running, not to the liver, but immediately to the vena cava in-
ferior. The bile must have been secreted entirely from the blood
[Seite 337] of the hepatic artery. One of these is described by Mr. Aber-
nethy,f and the other is mentioned by Mr. Lawrence.g

We must not forget that, in the mollusca, there is no vena
portae, and the liver receives its blood from the aorta. M. Simon
informs us, that, after tying the hepatic artery in pigeons, the bile
was secreted as usual; but after tying the vena portae none was
produced.h A. Kaau found water injected into either the vena
portae or hepatic artery, exude on the surface of the liver;i but
this might be mere imbibition.

(C) Many animals have no gall-bladder; v. c. the horse, goat,
&c. All the carnivorous among the mammalia possess it, and all
reptiles, most of which also are carnivorous; while those of the
class mammalia that are destitute of it, are, with the exception of
the porpoise and dolphin, vegetable feeders. Hence, Cuvier
thinks that it is intended as a reservoir of bile where the
animal is subject to long fasting from the uncertain supply
of food. The gall-bladder is sometimes absent in the human
subject. I have read of five instances of this.k

(D) Berzeliusl stated, that bile contains alkali and salts in the
same proportion as the blood, and that no resin exists in it, but
‘“a peculiar matter, of a bitter and afterwards somewhat sweet
taste, which possesses characters in common with the fibrin, the
colouring matter, and the albumen of the blood.”’ This forms,
with an excess of acid, a perfectly resinous precipitate. What
was considered albumen in the bile, Berzelius regarded as the
mucus of the gall-bladder.

[Seite 338]

Bile contained, according to him, of

Water 907.4
Biliary matter 80.0
Mucus of the gall-bladder dissolved
in the bile

} 3.0
Alkalies and salts common to all
secreted fluids

} 9.6
––––––
1000.0m
––––––

Of the weight of alkalies and salts more than one half was pure
soda.

Tiedemann and Gmelin make the bile of the ox to consist of
91.51 water, with 7.30 proximate principles, and 1.19 salts. The
biliary matter, or picromel, they find a compound of resin and
a sweet crystallisable substance, which, together with another,
termed by them biliary asparagin, renders the resin soluble in
water. They discover also ozmazome, and a new acid – the
cholic, also cholesterin, gliadine, casein, the oleic, acetic, phos-
phoric, sulphuric, and muriatic acids, and colouring matter. The
soda, they say, is not pure, but a bicarbonate, and mixed with a
little potash.

(E) Fourcroy first explained the chemical operation of the bile
in chylification.n According to Dr. Prout, during the precipit-
ation of the chyle and the decomposition of the bile, a gaseous
product is usually evolved, the mass becomes neutral, and traces
of an albuminous principle commence, strongest at a certain dis-
tance from the pylorus, – below the point at which the bile
enters the intestine, and gradually fainter in each direction. On
mixing bile with chyme out of the body, a distinct precipitation
takes place, and the mixture becomes neutral; but the formation
of an albuminous principle is doubtful, probably from the want of
the pancreatic fluid.o

The bitter and bilious yellow matter passes off with the faeces,
while the alkali (soda) of the bile probably combines with the
acid, and contributes to the formation of the chyle. The loss
of the alkali which preserved the picromel in solution, causes
the separation of the latter; and Dr. Prout found the distinctive
[Seite 339] qualities of it the more evident the further from the intestine it
was examined.

It is no longer wonderful that in jaundice, so intense that no bile
is seen in the faeces, and, according to Dr. Fordyce, even in artificial
obstruction of the choledochus by ligature, nutrition continues,
though, no doubt, less perfectly than in health. For Tiedemann
and Gmelin, after tying the biliary duct, which proved on dissection
to have continued impervious,p found the thoracic duct still con-
taining an abundance of matter, yellowish, indeed, from the jaun-
dice, but coagulating, and its coagulum becoming red, precisely
like chyle; the small intestines had the soft flakes usually con-
sidered chyle, but thought mucus by them, and both large and
small intestines contained nearly all the principles, except those
of the bile, seen in sound animals; but the contents of the large
intestines were exceedingly offensive. In the less satisfactory
[Seite 340] experiments of MM. Leuret and Lassaigne, the thoracic duct
was still full of chyle.

Although the bile is seen by experimenting upon the contents
of the duodenum, to cause a precipitation (Tiedemann and Gmelin
deny it, but Dr. Prout has almost constantly seen it,) the chyle
may thus be separated without it; but probably, Dr. Prout con-
ceives, in less quantity and perfection.

The neutralising effect of the bile, he informs me, is evident
on laying a piece of litmus paper through the pylorus, when the
portion in the stomach becomes red, and that in the intestines is
unaffected, or even shows alkaline agency.

The further down the intestinal contents are examined, the
more do all traces of albuminous matters disappear, as well as of
all the highly azotised principles of the pancreatic juice, these
being supposed to convert the unazotised principles of the vege-
table food into albumen: in man and carnivorous brutes no traces
of either are discoverable so low down as the caecum.

The hypothesis, that one great use of the liver was, like that of the
lungs, to remove carbon from the system, with this difference, that
the alteration of the capacity of the air caused a reception of calo-
ric into the blood, in the case of the lungs, while the hepatic excre-
tion takes place without introduction of caloric, – was, I recollect,
a great favourite with me when a student, principally from the
facts that a supply of venous blood – blood which has been used
by the system, – runs to both liver and lungs, and to no other
organs; that the higher the temperature the less carbon passed
off by the lungs (less caloric being demanded by the body), and
the more abundant, or more acrid, became the bile; so that bilious
diseases are most prevalent in hot seasons and climates. The
Heidelberg Professors have adduced many arguments to the same
effect. In the foetus, for whose temperature the mother’s heat
must be sufficient, the lungs perform no function, but the liver is
of great size, and bile is secreted abundantly, so that the meco-
nium accumulates considerably during the latter months of preg-
nancy. We shall see, indeed, that at the very time the functions
of the lungs suddenly begin at birth, the liver suddenly loses
much of its supply of blood. Warm-blooded animals with large
lungs, living in the air, have the liver proportionally smaller
than those which live partly in water: in cold-blooded animals,
and reptiles, which have lungs with such large cells as but
[Seite 341] slightly to decarbonise the blood; in fish, which get rid of
carbon but slowly by the gills; and in the mollusca, which
decarbonise still more slowly by gills or lungs, – the liver is
proportionally large. More blood flows to the liver, accord-
ingly as the lungs are less active organs. In the mammalia and
birds it receives the blood of only the stomach, intestines, spleen,
and pancreas; but in the cold-blooded, of many other parts; in
the tortoise, of the hind legs, pelvis, tail, and vena azygos; in
serpents, of the right renal, and all the intercostal veins; in fish,
of the renal veins, the tail, and genitals. They assert, that in
pneumonia and phthisis more bile is secreted, and in the blue dis-
ease,
and other affections of the heart, that the liver is enlarged.
The constituents of the bile contain a large quantity of carbon,
which is chiefly in union with hydrogen, and under the form of
resin or fatty matter, and resin is most abundant in the bile of
herbivorous animals, whose food contains a very large proportion
of carbon and hydrogen. In the lungs the carbon may be said to
be burnt, whence animal heat; in the abdomen it passes off still
combustible.

SECT. XXVI.
OF THE FUNCTION OF THE SPLEEN.

[Seite 342]

388. The Spleena lies to the left of the liver, with which
it has considerable vascular communications; with its oblong
figure,b it accommodates itself, as it were, to the contiguous
viscera, but is liable to great varieties in point of form, num-
ber, &c.c

389. Its colour is livid, its texture peculiar, soft, easily
lacerated, and therefore surrounded by two membranes, the
interior of which is proper to the spleen, and the exterior
derived from the omentum.

390. The situation and size of the spleen are no less
various than its figure, and depend upon the degree of the
stomach’s repletion; for, when the stomach is empty and lax,
the spleen is turgid; when the stomach is full, the spleen,
being compressed, is emptied.

It undergoes a continual, but gentle and equable, motion,
dependent upon respiration, under the chief instrument of
which – the diaphragm, it is immediately situated.

[Seite 343]

391. Its texture was formerly supposed to be cellular, and
compared to the corpora cavernosa of the penis. This
opinion was proved to be erroneous by more careful examin-
ation of the human spleen,d which consists entirely of blood-
vessels, of enormous size in comparison with the bulk of the
organ. They are, in fact, proportionally more considerable
than in any other part of the body.

392. The experiments of Wintringham demonstrate the
great tenuity and strength of the coats of the splenic artery.
It is divided into an infinite number of twigs, the termina-
tions of which resemble pulpy penicilli and give rise to the
splenic veins, which gradually unite into large, loose, and
easily dilatable, trunks.

393. This immense congeries of blood-vessels is connected
and supported by a sparing cellular parenchyma, from which
the absorbents arise. The trunks of these run along the
lower surface of the spleen between the two coats just
described.e

394. This loose structure of the spleen, easily becoming
distended with blood, admirably confirms what we formerly
remarked respecting the turgor of this organ (390). The
congestion and slow return of the splenic blood, if the nature
of the neighbouring organs is also taken into consideration,
illustrates its peculiar properties, which may throw some light
upon the function of this enigmatical viscus – the source of
so much controversy.

395. The splenic blood is very fluid, coagulates with great
difficulty, separates the serum from the crassamentum imper-
fectly, and is of a livid dark colour, like the blood of the
foetus. These circumstances clearly demonstrate the abun-
dance in it of carbonaceous matter; which is likewise proved
indisputably by an easy experiment. Whenever I have ex-
[Seite 344] posed sections of a recent spleen to oxygen gas, they have
acquired a very bright red colour, while the air, losing its
oxygen, has become impregnated with carbon.

396. But since the spleen is the only organ of that descrip-
tion quite destitute of an excretory duct excepting its veins
which run ultimately to the liver, its function is probably
subservient to that of the latter. This opinion has appeared
strengthened by the observation, that in animals from which
the spleen has been removed, – a remarkable experiment very
frequently made from the most remote period,f the cystic bile
is sometimes found pale and inert.

397. Besides at least twenty hypotheses respecting the use
of the spleen, two of more weight have been lately advanced,
both supposing a connection between the spleen and stomach,
but the oneg regarding the spleen as a diverticulum to the
arterial blood destined to form the gastric juice; (A) the
other,h supported by excellent arguments and experiments,
making the spleen to receive a great portion of our drink from
the cardiac extremity of the stomach, so that these may pass
through a short cut, hitherto unknown, from the stomach to
the spleen, and thus into the mass of blood. The latter hy-
pothesis, especially if a few objections were removed,i is highly
deserving of further examination. (B)

[Seite 345]

NOTES.

(A) This opinion was proposed a century ago, by Dr. Stukely.k

Considering the spleen to consist entirely of complications and
inosculations of arteries, veins and cells, nerves, and (as Malpighi
asserted) ‘“a muscular net-work of fibrillae,”’ he supposed that it
contracted and propelled its blood through the splenic vessels
into those of the stomach, when this organ required a larger
supply during digestion. (p. 37.) He maintained, likewise, that it
accelerated the motion of the blood in the mesenteric veins when
the circulation in the vena portae was sluggish, and that it answered
various other purposes. The whole is an hypothesis now forgotten:
the spleen has no muscularity.

Some have thought it a diverticulum for the blood whenever
this fluid is obstructed in any part of the body, as in the cold
stage of fever, great efforts, &c. To prevent too much being
thrown upon organs that might be injured, the spleen, they con-
tend, is formed to allow an accumulation in its substance. This is
ingeniously defended by Dr. Rush.l

Dr. Haighton (Lectures at Guy’s Hospital), and Mr. Saumarez
(New System of Physiology), have explained its operations as a
diverticulum in a very different manner. When the stomach is
full, the compression experienced by the spleen impedes its cir-
culation, and the blood makes its way the more copiously into the
arteries of the stomach, liver, &c. But we have no proof that the
repletion of the stomach compresses the spleen materially, and thus
can impede its circulation: a fact, indeed, which will be mentioned
presently, renders this improbable. Besides, in ruminating animals,
as Blumenbach observes, it lies next the first stomach or paunch,
and if compressed, must be so before digestion begins; and in
proportion as the fourth stomach fills and digestion proceeds more
actively, is the distension of the paunch diminished. It varies
in situation in different animals, not being always attached to the
stomach. The excitement, too, which the liver must experience
[Seite 346] when chyme irritates the extremity of the ductus choledochus,
and still more the provision of a gall-bladder, must render such
aid from the spleen superfluous to the liver. The infinite blood-
vessels and excerning orifices of the stomach cannot, likewise,
but furnish sufficient gastric juice, from the mere excitement
which they must experience whenever the stomach contains food.
No other glands habitually excited to occasional great activity
have such a diverticulum.

A third view of its influence as a diverticulum is, that it serves
for receiving a great part of the venous blood of the intestines
during chymification and especially during chylification. When
this process is going on, there must be a great increase of blood
flowing to the alimentary canal; the vena portae, through which it
all flows, can dilate to only a certain extent, and in order to pre-
vent such a congestion in the mesenteric veins as would retard
the circulation in the organs, the spleen allows an accumulation
in itself. Leuret and Lassaigne found the spleen of a dog weigh
a pound and a half in two hours after the application of a ligature
to the vena portae, while it ordinarily weighs but two ounces; and
observe that it has a vermillion tint when an animal is fasting,
but grows turgid and of a dark purple when the chyme has passed
the pylorus.

If the opinion of Erasistratus that the spleen is useless, was a
little atheistical, the notion of Paley was not much better, – that
the viscera contained, and the abdomen containing, are so clum-
sily adapted to each other, that a pad is necessary to make them
fit, just as hatters put stuffing under the leather of a hat which is
made too big for the head, – ‘“It is possible, in my opinion, that
the spleen may be merely a stuffing, a soft cushion to fill up a
vacuum or hollow, which, unless occupied, would leave the
package loose and unsteady.”’m When I consider the stupendous
power and design displayed throughout nature, Tinstantly revolt
at such an explanation as Paley’s, to say nothing of its anatomical
absurdity.

(B) Sir Everard Home’s friends having, among other experiments,
passed a ligature around the pyloric extremity of the stomach of
a dog, injected into this receptacle a solution of rhubarb; and,
on killing the animal some few hours afterwards, none of the ab-
sorbents of the stomach were found distended, nor could any
[Seite 347] trace of rhubarb be detected in the liver, but evident traces
existed in the spleen and in the urine. When fluids had been
drunk, the spleen was turgid and exhibited cells full of a colour-
less liquid that were at other times collapsed and almost imper-
ceptible, – a circumstance rendering it unlikely that the spleen
is diminished in bulk by the distention of the stomach; for, first,
compression sufficient to prevent the artery from sending into it
the usual quantity of blood, would prevent the entrance of fluids
by any other vessels; and, secondly, we learn that the spleen is
actually distended by the fluid portion of the contents of the
stomach.

During the distention of the spleen, when the pylorus was not
tied, the rhubarb appeared more strongly in the blood of the
splenic than in that of other veins. If coloured solids without
fluids were introduced into the stomach, the cells of the spleen
were not distended, nor did this organ or its veins give more
signs of the colouring matter than others.

From later experiments, published in 1811, the writer com-
pletely changes his opinion. It seems that traces of rhubarb were
discoverable in the bile as well as in the spleen: and that it
tinged the urine if the spleen had been removed before the
experiment: so that he abandons what he had before advanced
as a discovery.

SECT. XXVII.
OF THE FUNCTION OF THE OMENTUM.

[Seite 348]

398. The omentum gastro-colicum or magnuma (to dis-
tinguish it from the parvum or hepato-gastricum),b is a
peculiar process of peritonaeum, arising immediately from the
external coat of the stomach.

399. Although there are innumerable continuations of the
peritonaeum in the abdomen,c and every abdominal viscus is
so covered by it that on opening the abdomen nothing is
found destitute of that membrane, nevertheless, it is afforded
in different ways, which may be reduced to classes.

Over some the peritonaeum is merely extended as a smooth
membrane, or it affords to them only a partial covering, as is
the case with respect to the kidneys, rectum, urinary bladder,
and, in some measure, with respect to the pancreas and gall-
bladder.

To some which project into the cavity of the abdomen,
although adhering to its parietes, it affords a covering for the
greater part of their surface; v. c. to the liver, spleen, stomach,
uterus, and the testes of the very young foetus.

The intestinal tube, with the exception of the rectum, pro-
jects so much into the Cavity of the abdomen, that it is, as it
were, suspended in loose processes of the peritonaeum, called
[Seite 349] mesentery and mesocolon: the broad ligaments of the uterus
are similar to these.

400. The longest and most remarkable process of perito-
naeum, is the omentum – a large, empty, delicate, sac, hanging
from the large curvature of the stomach, extended over the
greater part of the small intestines, applying itself closely to
their convolutions, and, in some measure, insinuating itself
into their interstices.

401. Besides the blood-vessels seen upon the omentum, it
is marked by fatty striae or bands, which are every where
reticulated (whence the German name (Netzhaut) of this
membrane), and in corpulent persons increase occasionally
to a large and even dangerous size, and, by their means, the
whole omentum is lubricated with a halitus, which one might
almost call adipose.

402. On the latter circumstance depends the use commonly
ascribed to the omentum, – of lubricating the intestines and
assisting their continual movements: this also appears the
use of those analogous small bursae which are foundd in such
numbers about the rectume and colon.f

The omentum also prevents the adhesion of the intestines
to the peritonaeum, and the consequent impediment to the
functions of the primae viae.

403. There is another two-fold office attributed with great
probability to the omentum,g viz. that of facilitating the
dilation of the viscera to which it is contiguous, and of
acting as a diverticulum to their blood during their state of
vacuity.

404. If we reflect on the singular structure of the omentum
parvum or hepato-gastricum especially, we may be inclined to
believe that there is another, and, perhaps, principal office
attached to it, unknown at present, and discoverable by com-
parative anatomy.

SECT. XXVIII.
OF THE FUNCTION OF THE INTESTINES.

[Seite 350]

405. The intestinal tube, over which the omentum is ex-
tended, and which receives the chyme to elaborate it further
(362, 363), and separate the chyle from the faeces, is divided
into two principal portions – the small and large intestines,
of whose functions we shall speak separately.

406. The smalla intestines are again divided into three:
the duodenum, jejunum, and ileum.

The first is named from its usual length.

The second from generally appearing collapsed and empty.

The third from its convolutions: it is the longest of the
three, fuller, and, as it were, inflated, and sometimes resem-
bling the large intestines by the appearance of bullae.

407. The coats of the small intestines correspond with
those of the stomach. (354)

The external is derived from the mesentery.

The muscular consists of two orders of fibres: the one lon-
gitudinal, interrupted, external, and found especially about
the part opposite the mesentery; the other, annular and falci-
form, possessing the power of narrowing the canal, while
the former shortens it. Upon both depends the very great
and permanent irritability of the intestines, formerly men-
tioned. (300)

The nervous coat is condensed cellular membrane, easily
reduced by handling, or more particularly by inflation, into a
spumous tela;b in it the intestinal blood-vessels, which arise
[Seite 351] from the mesenteric,c are distributed in a beautifully arbor-
escent form;d the intestines, no less than the stomach, are
indebted to it for their tenacity and strength.

The interior, lined by its delicate epithelium, and deserving
the name of villous in the small intestines more than in any
other part of the canal, forms, in conjunction with the inner
surface of the former coat, here and there, undulated ridges
and rugous plicae, which, in dried and inflated intestines, re-
semble the blade of a scythe, and are termed the valvulae
conniventes or Kerkringhianae.e

408. The villi, which are innumerablef upon the inner
surface of the intestines, and whose beautiful and minute
vascular structure was first carefully investigated, though de-
scribed with exaggeration, by Lieberkühn,g may be, perhaps,
compared, while destitute of chyle, to little loose pendulous
bags, internally soft and spungy; but, when distended with
chyle, they have the appearance of a morel.

409. The base of these villi is surrounded by innumerable
glandular follicles, adhering chiefly to the nervous coat, and
opening into the intestinal canal by a very small orifice,
through which they discharge the mucus that lines the whole
tract of the intestines.

These are distinguished into three orders. The Brun-
nerian, largest, distinct, found in most abundance in that part
of the duodenum which is contiguous to the pylorus.h The
[Seite 352] Peyerian, smaller, aggregated, found chiefly at the termin-
ation of the small intestines, – about the valve of the colon.i
Lastly, the Lieberkühnian, the smallest, said to be distributed
in the proportion of about eight to each villus.k The two
former orders are so inconstant, that I am inclined to consider
the view given of them in the plates alluded to, as morbid;l
for I have more than once been unable to discover the
slightest trace of fungous papillae with a single pore, in the
small intestines of healthy adults; while, on the contrary, in
aphthous subjects, I have found nearly the whole intestinal
tube beset with them in infinite numbers, both solitary and
aggregated.m

410. As the gastric juice is poured into the stomach, so an
enteric or intestinal fluid is poured into the small intestines,
demonstrated, among other ways, by the common experiment,
first, we believe, instituted by Pechlin.n It is probably of a
nature similar to that of the gastric liquor, but an accurate in-
vestigation of it is a physiological desideratum. We can say
nothing respecting its quantity, but Haller’s estimate, – eight
pounds in the twenty-four hours, is certainly excessive. (A)

411. The intestines agree with the stomach in this par-
ticular, that they have a similar, and, indeed, a more un-
questionable, or, at least, a more lively, peristaltic action,o
which occurs principally when the chymous pulp enters them.
This it agitates by an undulatory constriction of different
parts of the canal, and propels from the duodenum towards
the large intestines. Although the existence of an antiperis-
taltic motion, causing a retrograde course to their contents,
[Seite 353] cannot be disproved, it is in health much weaker, and less
common and important, than the former.

412. By these moving powers and by these solvents which
are afforded by means of secretion, the chyme undergoes re-
markable changes.p In the jejunum it becomes a more liquid
pulp, equally mixed, of a grey colour, and acidulous odour:
in the ileum it begins to separate into two parts – into the
faeces, of a pale, yellowish, brown colour,q and nauseous
smell – and the genuine chyle, swimming upon the former,
extracted from the chyme, separated by the bile from the
faeces, and destined for absorption by the lacteal vessels, as
we shall find in the next section. (B) At present, we shall
enquire what course is taken by the faeces.

413. These, after becoming more and more inspissated in
their long course through the ileum, have to overcome the
valve of the colon and pass into the large intestines. To fa-
[Seite 354] cilitate this, the extremity of the ileum is lubricated very
abundantly by mucus.

414. The valve of the colon,r or, as it may deservedly be
termed after its discoverer, the valve of Fallopius,s is a short
process or continuation of the portion of the ileum that pene-
trates into and is surrounded by the cavity of the large in-
testine. Its external lips, while a neighbouring fold of the
large intestine at the same time projects considerably, are
composed,t not like other similar folds, merely of the interior
and nervous coats, but of fibres from the muscular coat also.
Hence it performs the double office of preventing the passage
of too great a quantity of faeces into the large intestines, and
regurgitation into the small.

415. The large intestines, divided like the small into three
parts, commence by the caecum (which has a vermiform process
whose use in man is unknown),u and afford a very ample
[Seite 355] receptacle, in which the faeces may be collected and retained,
till an opportunity for discharging them arrives.

416. They exceed the small intestines in thickness and
strength, as well as in capacity. The muscular coat has this
peculiarity – that its longitudinal fibres, excepting at the
extremity of the rectum, are collected into three bands, called
ligaments of the colon;x and the intestines themselves are
divided into a kind of bulbous segments. The inner coat is
not so beautifully flocculent as that of the small intestines, but
more similar to that of the stomach.

417. Their peristaltic motion is much fainter than that of
the small intestines. On the other hand, they experience to
a greater degree the pressure of the abdominal parietes, to
which the whole length of the colon is contiguous.

418. They gently propel the faeces into the rectum, which
thus becomes internally stimulated to discharge its contents.
The discharge is facilitated by the absence of transverse
rugae, and especially by the great quantity of mucus at the
extremity of the bowels.

419. It is principally effected by the pressure of the abdo-
men downwards, overcoming the resistance of the os coccygis
and of both sphincters, the inner of which is a remarkable
bundle of circular fibres, the outer, a truly cutaneous muscle.
After the excretion, the effort of the abdomen having ceased,
the levator ani chiefly retracts the intestine, which is again
closed by its sphincter.y (C)


NOTES.

(A) Pechlin’s experiment was simply to include a portion of
intestine between two ligatures, so that the fluid secreted into the
canal might be collected.

[Seite 356]

(B) A great part of the chyle is generally formed and absorbed
before the digested mass reaches the ileum.z On arriving in the
large intestines, the mass undergoes fresh changes, at present un-
explained, and is converted into excrement.a Here it is that the
true succus entericus must be poured forth, for the secretion into
the small is probably nothing more than mucus and a simple
watery fluid. Tiedemann and Gmelin support, in some measure,
the old idea of the caecum being a subsidiary stomach, from its
contents being acid, although acidity had disappeared higher up
in the canal, and more acid as the aliment is less digestible; and
from albumen often reappearing suddenly in this part of the canal.
Dr. Prout found the fluids of the large intestines coagulate lymph
even as low as the rectum. The excrementitious mass, consisting
of the indigestible part of the food, the resin, and colouring and
fatty matter of the bile, with intestinal mucus, loses its fluids
gradually as it descends, and in the rectum becomes particularly
dry.

The gas of the stomach contains, besides azote and carbonic
acid gas, oxygen, and very little hydrogen; while that of the
small intestines contains, besides the two former gases, no oxygen,
and abundance of hydrogen: that of the large intestines has less
hydrogen and carbonic acid, and likewise no oxygen. Little or
no gas is found in the stomach during chymification.

The following are the results of MM. Magendie’s and Che-
vreuil’s analysis of the gases of the alimentary canal:

In the stomach of a man just executed, –

Oxygen 11,00
Carbonic acid 14,00
Pure hydrogen 3,55
Azote 71,45
––––––
100,00
––––––

In the small intestines of a subject, four-and-twenty years of
age, who had eaten, two hours before execution, bread and
Gruyère cheese, and drunk eau rougie, –

[Seite 357]
Oxygen 0,00
Carbonic acid 24,39
Pure hydrogen 55,53
Azote 20,08
––––––
100,00
––––––

––––– twenty-three years of age, who had eaten the same
food, and was executed with the former, –

Oxygen 0,00
Carbonic acid 40,00
Pure hydrogen 51,15
Azote 8,85
––––––
100,00
––––––

––––– twenty-eight years of age, who, four hours before
execution, had eaten beef, bread, lentils, and drunk red wine, –

Oxygen 0,00
Carbonic acid 25,00
Pure hydrogen 8,40
Azote 66,60
––––––
100,00
––––––

In the large intestines of these three criminals, were found, –

Oxygen 0,00
Carbonic acid 43,50
Carburetted hydrogen and some
traces of sulphuretted hydrogen

5,47
Azote 51,03
––––––
100,00
––––––
Oxygen 0,00
Carbonic acid 70,00
Hydrogen and pure carburetted
hydrogen

11,06
Azote 18,04
––––––
100,00
––––––

The gas of the caecum and rectum of the third was examined
separately.

[Seite 358]
Caecum,
Oxygen 0,00
Carbonic acid 12,50
Pure hydrogen 7,50
Carburetted hydrogen 12,50
Azote 67,50
––––––
100,00
––––––
Rectum,
Oxygen 0,00
Carbonic acid 42,86
Carburetted hydrogen 11,18
Azote 45,96
––––––
100,00
––––––

Some traces of sulphuretted hydrogen appeared upon the mer-
cury before the last analysis was commenced.

Berzelius finds human excrement to consist of

Water 73,3
Remains of vegetable and animal
matter

7,0
Bile 0,9
Albumen 0,9
Peculiar extractive matter 2,7
Matter composed of altered bile,
resin, animal matter, &c.

14,0
Salts 1,2
–––––
100,0
–––––

The gases are probably disengaged from the contents of the
canal; but I believe, with John Hunter,b that it often secretes
gaseous fluids. For mental emotion will suddenly cause extreme
discharges of air from the stomach, and the intestines to swell
with wind. In many diseases the same will occur, although no
fermentation or unusual change is discernible in the contents of
the canal. Emphysema has occurred without any wound of the
lungs; and air in the serous membranes, or in the cellular, is
known to be absorbed.c

[Seite 359]

The excrements of brutes have been analysed, but not to an
extent capable of affording general views.

(C) Every one knows that the intestines are usually relieved
once in twenty-four hours, but that some little variety occurs in
this respect. In cases of extreme abstinence, they of course
discharge their contents very rarely, as I mentioned formerly.
Heberden, however, mentions a person who naturally had a mo-
tion once a month only, and another who had twelve motions
every day during thirty years, and then seven every day for seven
years, and rather grew fat than otherwise.c

Pouteau’s young lady, mentioned at page 303, had no stool, he
says, for upwards of eight years, although during the last year
she ate abundantly of fruit, and drank coffee, milk, and tea, and
broth with yolks of eggs: but she had copious greasy sweats.

SECT. XXIX.
OF THE FUNCTION OF THE ABSORBENT VESSELS.a

[Seite 360]

420. The chyle, which we left in the ileum just separated
from the faeces, must evidently be a mixture of different fluids.
The proportion derived from the secretions – the saliva, the
gastric, pancreatic, and enteric fluids, the bile, &c., surpasses,
without the least doubt, that which is derived from the ali-
ment, although this cannot be accurately ascertained. Hence
must be derived the solution of the problem, – how ingesta
of such various kinds can be converted into the chyleb – a
fluid constantly of the same appearance, homogeneous, and of
an animal nature.

421. The course of the chyle from the intestines to the
blood, is through a part of the absorbent system, which we
have hitherto only hinted at, but shall now speak of particu-
larly. It is divided into four parts – lacteal and lymphatic
vessels, conglobate glands, and the thoracic duct. Each of
these will now fall under consideration.

422. It is certain that the lacteals originate among the villi
of the internal coat of the intestines; but whether they are an
immediate continuation of these villi, or merely connected
with them by a cellular medium, admits a question. I myself
have never been able to trace them so far as to discover their
immediate connections with the villi, but they appear to arise
here and there in the coats of the intestines, by a conspicuous
[Seite 361] trunk, and we may conjecture that they take up the chyle
from the cellular structure into which it is first drawn by the
villi. This I have in fact observed repeatedly in puppies,
after making them swallow a solution of indigo, according to
the celebrated experiment of Lister,c an hour or two before
opening them alive.d (A)

423. The trunks just mentioned run some inches along the
surface of the intestines, under the external coat, sometimes
meandering in an angular course, before they reach the me-
sentery.

424. In their course through the mesentery they run into
the mesenteric glands, of which there are two series. The
one nearer the intestines, dispersed, small, and resembling
beans in shape; the other, nearer the receptaculum chyli,
large, and aggregated.

425. Both appear nothing more than closely-compacted
collections of lacteals, interwoven with innumerable blood-
vessels,e and retarding the course of the chyle; to the end,
perhaps, that it may be more intimately and perfectly assimi-
lated to an animal nature, previously to its entrance into the
thoracic duct, and its mixture with the blood. (B)

426. It has been inquired whether lacteals exist also in
the large intestines, and their existence has been advocated,
from the effects of particular injections, nutrient, inebriating,
&c., and also from the circumstance that the faeces, if retained
for any length of time, become hard and dry. Although
these arguments do not demonstrate the absorption of genuine
chyle below the valve of Fallopius, nevertheless it is rendered
probable by the visible existence of an abundance of lymph-
atics, in the large intestines,f having the same structure and
[Seite 362] function with the lacteals; for these absorb lymph from the
intestines,g during the absence of chyle.

But the very different structure of the internal coat of the
large intestines from that of the villous coat of the small,
strongly argues that they are not naturally intended to absorb
chyle.

427. There is another question more important and diffi-
cult of solution, – whether all the chyle absorbed from the
small intestines passes through the thoracic duct, or whether
some enters the blood by more secret passages.h

The latter opinion rests upon very unstable arguments.
Thus the assertion of Ruysch, – that the mesenteric glands
become, in advanced life, indurated and unfit for continuing
their functions, was long since disproved: and affections of
these glands, swellings, &c., are improperly called obstruc-
tions,i as the glands remain pervious, readily allowing a pas-
sage to quicksilver. The well-known phenomenon of tepid
water, injected after death into the mesenteric veins, passing
into the cavity of the intestines, has little weight with me in
regard to a function which occurs during life; and much less
weight can be allowed to the brass tube with two legs and two
branches invented by Lieberkühnk to prove the existence of
[Seite 363] these passages. (C) The assertion – that chyle has been
seen in the mesenteric veins,l requires farther investigation
and proof; so that I cannot believe that they, at least after
birth,m carry any thing more than blood, very carbonised and
destined for the formation of bile.n (D)

428. The ultimate trunks of the lacteals, arising, like the
lymphatics, from the combination of a great number of small
twigs,o unite into the receptaculum or cisterna chyli, – the
appellation by which the lower and larger part of the thoracic
or Pecquetian duct is distinguished.

429. This duct isp a membranous canal, slender, strong,
more or less tortuous, subject to great varieties in its course
and division,q destitute of muscular fibre and nerves, and
possessing here and there valves. At about the lowest cer-
[Seite 364] vical vertebra, after passing the subclavian vein, it turns back
again,r and is inserted into this, being furnished with a pecu-
liar valve at the point of insertion.

430. The motion of the chyle throughout its course is to
be ascribed to the contractility of its containing vessels, to
their valves, and to the vis-a-tergo. (E)

431. The use of the valve placed at the opening of the
thoracic duct, is probably not so much to prevent the influx of
blood, as to modify the entrance of the chyle into the vein, –
to cause it to enter by drops.

By this contrivance, fresh chyle is prevented from having
access to the blood so rapidly as to stimulate the cavities of
the heart too violently and be imperfectly and difficultly
assimilated; for fresh chyle consists of very heterogeneous
elements, brought not only from the primae viae by the lacteals,
but from every part of the body by the lymphatics.

432. These lymphatics,s which constitute the third part of
the absorbent system, and resemble the lacteals in their struc-
ture and function, are much more, and perhaps, indeed, uni-
versally, diffused.t They arise principally from the mucous
web, which we therefore called the grand bond of connection
between the sanguiferous and absorbing system; (27) but in
great numbers likewise from the external common integuments,u
from the fauces and oesophagus, (330) the pleura and perito-
naeum, and from the thoracic and abdominal viscera.x

433. Their origin is similar to that of the lacteals in the
intestines, so that the radicle of each lymphatic absorbs the
[Seite 365] fluid from the neighbouring cellular membrane, as from its
territory, and propels it onwards.

434. The lymphatics have double valves, set more or less
thickly in different parts; they almost all enter conglobate
glands; those which are contiguous to each other anastomose
here and there; and those found on the surface of certain
viscera, as the lungs, liver, &c. form a most beautiful
network.

435. Besides other aids to their functions, evident from
what has already been said, no inconsiderable assistance is
derived from the combination of great strength with thinness
in their coats, by which they are enabled to support a heavy
column of quicksilver. In the limbs, especially, the motion
of the muscles, pressing them on every side, is highly useful in
increasing their power.

436. But their principal action, by which they take up
fluids more or less rapidly, eagerly absorbing some and abso-
lutely rejecting others,y depends upon the peculiar modification
of their vitality, and is ascribed by the very acute Brugmans
to a certain vita propria. (42)z

437. The far greater part of these lymphatics terminate in
the thoracic duct; except, however, those of the right arm,
the right side of the neck, the right lung, and the right por-
tion of the diaphragm and liver, which terminate in the sub-
clavian vein of the same side.

438. From the universal existence of the lymphatics, and
especially from their great number on the surface capable of
absorbing fluids from without, the heterogeneous nature of
the lymph must be obvious; and this is further proved by
[Seite 366] accurately examining it in different parts of a subject; v. c.
that contained in the hepatic or splenic lymphatics is perfectly
different from that in the uterine.

439. We will enumerate the principal fluids which are
continually absorbed during health, to say nothing of many
different kinds of substances taken up during disease. There
is, besides the chyle separated from the faeces in the small
intestines, the halitus of the cavities, properly so called, espe-
cially that of the fauces and of all the mucous tela, the more
watery part of those secreted fluids which are retained for
some time in their ducts, v. c. in the breast, the vesiculae se-
minales, the gall-bladder, &c. and not a small portion of the
stillatitious fluids which are applied to the common integu-
ments.a

440. The solids, after performing their purpose in the eco-
nomy, insensibly melt away and are absorbed, as is proved by
the absorption of the greater part of the thymus gland during
infancy, of the roots of the first teeth, and of the alveoli after
the second teeth have fallen out. The constant change of
the whole osseous system, arising from the insensible renova-
tion of the bony matter, of which we have treated elsewhere
professedly,b may also be adduced.

441. It is therefore evident, since so great a variety of
matter is absorbed, and at the same time nothing crude or
improper allowed to enter the blood, that there is a necessity
for some peculiar medium to previously subact and assimilate
the various substances.

442. It appears to be the chief office of the conglobate glands,
which constitute the last part of the absorbent system, to pre-
vent the ill effects upon the heart of the improper admixture
of crude fluidc with the blood, by assimilating the extremely
[Seite 367] various fluids more and more to an animal nature, by retard-
ing their motion, and perhaps also by superadding to them
some fresh secreted fluid. (F)

443. Those glands which are dispersed generally through
the body, and aggregated here and there, as in the groin
and axillae, are perfectly similar to those found in the mesen-
tery, consisting, like them, in a great measure, of convoluted
absorbent vessels, supplied with an immense number of
blood vessels, and liable to the same diseases.d (G)


NOTES.

(A) Dr. W. Hunter, Mr. Cruikshanks, and others, are said to
have seen the villi of the intestines perfectly white in a person
who had died soon after eating, and twenty or thirty orifices, in a
single villus, forming tubes that ran to its base and united into
one trunk.e

(B) If a gland is well injected, the numerous ramifications of
the absorbents prevent cells from appearing, but if injected less
minutely, cells are very evident, and distinct from the convolu-
tions and ramifications of vessels. ‘“If an absorbent gland of a
horse is filled with quicksilver and dried, and then carefully slit
open, the cells will be seen of a large size, and bristles may with
ease be passed through the openings by which they communi-
cate.”’ It is imagined that the vasa inferentia pour their contents
into these cells, and that the efferentia afterwards absorb it from
them.f

[Seite 368]

(C) Lieberkühn’s tube was of this shape: –

xxx

Water propelled into A, passed out at B and C, but not at F.
Even if F was immersed in a coloured fluid, this ascended to H,
and passed out at B with the water.

A G may represent an artery, and G C a branch of it, opening
into the cavity of the intestines; B H a vein, and H F one of its
branches, doing the same.

(D) Dr. Magendieg contends that the lacteals absorb nothing
but chyle, asserting that neither he nor Hallé have ever seen the
chyle in these vessels tinged by coloured ingesta, and that neither
he nor the veterinary surgeon Flandrin ever found any thing but
chyle enter the lacteals. Lister’s experiment has succeeded with
Blumenbach, John Hunter, Fordyce,h and numerous others, and
Hunter in the presence of several persons poured milk into the
intestines of a dog, and they all observed it quickly to fill the
lacteals. Among other insignificant objections, Dr. Magendie
urges that Hunter should have first noticed whether the vessels
contained chyle, whereas it is expressly mentioned that before the
milk was poured into the intestine, the lacteals were seen dis-
tended by a nearly colourless and pellucid fluid.i

Tiedemann and Gmelin, however, have made an abundance of
these experiments with the same result as Magendie, though in
some few instances the substance introduced into the canal was
discovered in the chyle.

He also revives the old opinion – that the lymphatics arise
from arteries only, and are destined to convey lymph from them.k
[Seite 369] John Hunter, after pouring water coloured by indigo into the
peritoneum of an animal, saw the lymphatics filled with a blue
fluid. In the hands of MM. Magendie, Flandrin, and Dupuytren,
this experiment likewise has failed. Magendie does, however,
allow, that, in a woman who died with a collection of pus in the
thigh, the surrounding lymphatics were distended with pus to the
size of a crow’s quill; – a pretty decisive fact. The absorbents of
fish have no valves except at their termination in the red veins,
and may therefore be injected from the principal trunks: the
injection passes out of the mouths of the absorbents in numerous
streams, and especially on the back, if the skate is employed; –
another decisive fact. Peyer, Fallopius, and Kerkring saw bile in
lymphatics about the liver. Down to Boerhaave and Haller the
doctrine that the lymphatics absorb was maintained, and it
was first seriously attacked by Dr. William Hunter. Dr. Munro
soon afterwards did the same, and commenced a very acrimo-
nious quarrel with Dr. William Hunter for the honour of priority
of attack. Dr. Baillie expressly states, that Dr. Hunter had de-
livered such opinions six years before Dr. Munro professes to
have made his discovery, and the world has generally given
priority to Dr. Hunter. Dr. Munro had also an equally acrimo-
nious dispute with Mr. Hewson for the honour of the discovery of
the lymphatics in fish, but the Royal Society adjudged Hewson
the Copley medal in 1769 for the discovery. It is amusing
to reflect that the very doctrine, for the honour of having first
attacked which so much violence was shown, is now again in high
favour, and that Dr. Munro would be now lauded had he shown
that Dr. Hunter only had attacked it.

The ancient doctrine of veins being organs of absorption forms
a prominent feature in Dr. Magendie’s physiology.l John Hunter
deposited various fluids in the intestines, but, although he found
manifest traces of them in the absorbents, he could discover none
in the mesenteric veins. Dr. Magendie, however, relates two
experiments in which a decoction of nux vomica, introduced into
the alimentary canal, produced its usual effects, notwithstanding
the thoracic duct was tied and ascertained to be single. In fact,
Sir Everard Home, many years ago found substances to be taken
into the circulation and into the urine from the stomach, though
[Seite 370] the thoracic duct was tied.m In a similar experiment, instead
of the thoracic duct being tied, the portion of intestine containing
the solution was totally separated from the body, except in one
artery and one vein: but here it may be said, that the poison
might be conveyed by absorbents in the coats of the vessels.
Another experiment appears at first sight unobjectionable, because
not only was every part of a limb separated from the body except
the large artery and vein, but even these were cut asunder, quills
having been previously introduced into them and fixed to carry on
the circulation, and yet some upas plunged into the paw of the
animal exerted its peculiar influence, which besides was suspended
and permitted at pleasure by compressing or liberating the vein
under the finger and thumb. But to all these experiments an ob-
jection presents itself: – 1. Many connections have been seen be-
tween absorbents and veins, v. c. Mr. Bracy Clarke discovered com-
munications in the horse between the thoracic duct and lumbar
veins,n and Mr. Abernethy traced lymphatic vessels to veins;
Tiedemann and Gmelin, and many before them, propelled mercury
into the vena portae by absorbents; Mr. Cruikshanks long ago
remarked, that in animals destroyed by violence the lymphatics
about the spleen and in the cavity of the abdomen, in peritoneal
inflammation sometimes the lacteals, and in peripneumony the lym-
phatics of the lungs, are tinged with blood, though no extravasa-
tion has occurred, and therefore he believed that lymphatics arise
from the internal surface of arteries and veins;o the connection
of the lymphatics with the veins, in the four classes of vertebrated
animals has of late years been demonstrated by Lippi, Fohmann,
and Louth, and in the Anatomical Museum of Heidelberg are
numerous beautiful specimens, showing this fact:p and, 2. Dr.
Magendie allows that the absorbents communicate with arteries,
and may frequently be injected from them. Consequently, his
poison might be imagined to be taken up by absorbents, carried
into blood-vessels, and conveyed with the blood through the body.
Indeed, when the poison was placed in a wound, it might contami-
nate the blood without being taken up by absorbing extremities of
[Seite 371] vessels, and if Magendie is right in believing that fluids soak
through even living solids, another objection is thus afforded. It
is universally known, that, after death, fluids penetrate through the
various textures of the body; – the aqueous humour diminishes in
the eye, which consequently becomes flat, the intestines near the
gall-bladder become yellow,q and water poured into the stomach or
intestines exudes.r Dr. W. Hunter contended that this imbibi-
tion occurs also during life, although not in the case of blood-
vessels, and others admitted it.s Dr. Magendie supports the same
opinion. After separating a blood-vessel from the surrounding
cellular membrane, and laying tincture of nux vomica upon it,
the animal was poisoned, and the blood within tasted bitter; ink
placed in the pleura of a young dog, dyed, in less than an hour,
the pericardium, heart, and intercostal muscles. Dr. Fodera in-
troduced a solution of prussiate of potass into the pleura, and of
sulphate of iron into the abdomen of a living animal, when the
two fluids became blue by union at the diaphragm, in five or six
minutes, and instantaneously if a galvanic current was established.t
Still there is not the slightest reason to imagine that the natural
fluids of parts penetrate their substance during life and in a sound
condition.u Dr. Magendie found absorption (of poisonous matters,
for example, applied to surfaces) greatly impeded on rendering the
vascular system turgid by injecting water into the veins, and
equally accelerated on lessening the repletion by blood-letting.
We should expect that the greater the repletion of the sanguineous
system, the more difficulty must the contents of the absorbents
have to advance, and v. v.; and from the wise arrangements
observed in every function, we should conceive, that supposing
absorption a vital action (as I cannot but believe it to be, as soon
as a substance has fairly entered the vessel perhaps by mere phy-
sical attraction), the vessels would be less disposed to propel their
contents in proportion as repletion existed. How it favours the
idea of absorption being a mere imbibition through the coats of
[Seite 372] the absorbents, – a notion unsupported and contradictory to
established facts, I cannot see.x

Against the result of an experiment in which, after a solution
of prussiate of potass was swallowed, the salt was discoverable in
the urine and not in the lymph, Dr. Magendie himself supplies an
objection when treating of the urine. For he states, that a minute
portion of this substance may be readily detected in the urine,
while the quantity in the blood must be large to be discoverable.
As the contents of the thoracic duct so nearly resemble blood, he
should have ascertained whether it is not difficult to detect in
them also a portion of the prussiate which would be easily mani-
fest in the urine. A similar experiment with a decoction of
rhubarb, lies under the same difficulty.

In starting all these doubts, I am only desirous of showing that
Dr. Magendie’s experiments are not so unobjectionable as he
believes, and readily grant that John Hunter’s experiments deserve
repetition, and the whole subject farther investigation. I am not
prepared to deny that veins absorb, or, what comes to nearly the
same thing, that there are lymphatics which do not form trunks,
but convey their contents to small blood-vessels; and I have
nothing to suggest against the following facts.

‘“Three ounces of diluted alcohol were given to a dog; in a
quarter of an hour the blood of the animal had a decided smell
of alcohol; the tymph (of the thoracic duct) had none.”’y

‘“In the horse, the usual contents of both the large and small
intestines are mixed with a large quantity of fluid that gradually
decreases towards the rectum, and is therefore absorbed as it
passes along the canal. Now, Flandrin, having collected the
contents of the lacteals, did not find them smell like this intestinal
fluid, whereas the venous blood of the small intestines had a taste
distinctly herbaceous; that of the caecum a sharp taste and a
slightly urinous smell; and that of the colon the same qualities
in a more marked degree. The blood of other parts presented
nothing analogous.’

‘“Half a pound of assafoetida dissolved in the same quantity of
honey was given to a horse, which was afterwards fed as usual and
killed in sixteen hours. The smell of assafoetida was perceptible
in the veins of the stomach, small intestines, and caecum; but not
in the arterial blood, nor in the lymph.”’z

[Seite 373]

Dr. Segalas cut a portion of living intestine from the rest of the
canal, and passed a ligature around its blood-vessels, leaving the
absorbents free, and introduced a solution of nux vomica for an
hour without ill effect: he then liberated the vein, and the animal
was poisoned in six minutes.

In Tiedemann and Gmelin’s experiments, among a variety of
substances taken, coloured, odorous, or saline, very few could be
detected in the chyle, but many were found in the blood.

(E) The force of their contraction is shown by the rupture of
the thoracic duct from over-distention when a ligature is passed
around it.a Tiedemann and Gmelin saw the thoracic duct con-
tract from exposure to air.

(F) Although some albumen is discovered actually in the duo-
denum, and, as Dr. Prout allows, even in the stomach if animal
food has been taken, and some fibrin in the first lacteals, the con-
tents of the absorbents are found to possess more and more of
these substances in proportion to their progress towards the left
subclavian vein. The chyle contains a certain fatty matter, which
is considered as incipient albumen, and, in proportion as this de-
creases, does the quantity of fibrin and albumen increase.b

The use of the conglobate glands is elucidated by the observ-
ations of Tiedemann and Gmelin, mentioned, p. 381. Amphibia
and fish are said to have no lymphatic glands.c Dr. Magendie
denied the existence of lymphatics in nearly all birds, but has
been amply refuted by Dr. Louth and many others.

Dr. Carson argued that the thoracic vacuum would not only
draw the blood along the veins, but draw it into their open mouths,
thus being an agent of absorption. He concluded that the blood of
the corpora cavernosa penis entered the veins in this way, but, as
the lymphatics only were believed the organs of absorption, pro-
perly so called, when he wrote, he had not a more extended idea
[Seite 374] of the co-operation of the vacuum in producing venous absorption.
It must, however, evidently extend to every absorbing vein, and if
the veins absorb generally, as is now believed, it must be general.
As the great trunk of the absorbents terminates in a vein, they must
be circumstanced in this respect exactly like veins, and equally
subject to the influence of the thoracic vacuum. Indeed, Dr. Barry
found that while a cupping-glass was applied over a wound to which
poison was applied, no absorption occurred, no poisonous effects
ensued: nor did they, even for some time afterwards; and when
they became apparent, they instantly subsided on the re-applica-
tion of the glasses. The pressure of the rim of the glass was not
the cause of the non-appearance of poisoning, because if the
deleterious substance was passed under the skin beyond the
boundary of the glass, no ill effect occurred as long as the glass
remained over the wound: an incision between the site of the
poison and the rim, destroyed the efficacy of the glass.d

These experiments, however, do not prove that atmospheric
pressure is the cause of absorption: they merely show its co-
operation, and that the propulsive powers of the absorbents are
insufficient when opposed by the removal of it. Pecquet, nearly
two centuries ago, considered whether the chyle was absorbed by
suction, and concluded against the opinion, by observing, that, if
a ligature was placed upon the thoracic duct, or the lacteals of the
mesentery, and all effect of vacuum thus prevented, the lacteals
swelled on the intestinal side; therefore, said he, ‘“non trahitur
chylus sugiturve.”’e The pressure of ordinary respiration and of
muscular efforts is also seen to drive the chyle forwards in the
lacteals.

(G) A short account of the first discovery of the absorbent
system may be acceptable at the close of this section.

Hippocrates knew that the nutritive portion of the contents of
the alimentary canal was conveyed by certain vessels to the
system. Erasistratus actually saw the lacteals containing chyle –
[Seite 375] ἀρτηριας, γαλαϰτος πλήρεις. From Galen we learn that they were
known also to Herophilus. From the year 150 to 1622 no advance
was made, except that in 1563 Eustachius discovered the thoracic
duct, but he remained ignorant of its use. In 1622 Aselli in Italy
saw the lacteals by chance when demonstrating the recurrent
nerves to some friends. Thinking they were nerves, he at first
paid no attention to them; but soon observing that they did not
pursue the same course as the nerves, and ‘“astonished at the
novelty of the thing, he hesitated for some time in silence,”’ while
all the circumstances of the controversy and quarrels of anatomists
passed before his view. He had by chance been reading Costaeus
on this subject the day before, and, in order to examine the matter
further, he ‘“took a sharp scalpel to cut one of those chords, but
had scarcely struck it when,”’ he continues, ‘“I perceived a liquor
white as milk, or rather like cream, to leap out. At this sight, I
could not contain myself for joy, but, turning to the bystanders,
Alexander Tadinus and the senator Septalius, I cried out ἕυρηϰα!
with Archimedes, and at the same time invited them to look at so
rare and pleasing a spectacle, with the novelty of which they
were much moved. But I was not long permitted to enjoy it, for
the dog now expired, and, wonderful to tell, at the same instant
the whole of that wonderful series and congeries of vessels, losing
its brilliant whiteness, that fluid being gone, in our very hands
and almost before our eyes, so evanished and disappeared, that
hardly a vestige was left to my most diligent search.”’ The next day
he procured another dog, but could not discover the smallest white
vessel. ‘“I now,”’ he says, with the same admirable naïveté, ‘“be-
gan to be downcast in my mind, thinking to myself that what had
been observed in the first dog, must be ranked among those rare
things which according to Galen are sometimes seen in anatomy.”’
At length he recollected that the dog had been opened ‘“athirst
and unfed,”’ and therefore opened a third, after feeding him ‘“to
satiety.”’ ‘“Every thing was now more manifest and brilliant than
in the first case.”’ He gave his whole attention to the subject,
and was so diligent that not a week, or certainly not a month,
passed without a living dissection of dogs, cats, lambs, hogs, and
cows, and he even bought a horse and opened it alive. ‘“A
living man, which Erasistratus and Herophilus of old did not fear
to anatomise, I confess I did not open.”’

Notwithstanding this discovery of distinct chylous vessels, a
large number of high authorities adhered firmly to the old
[Seite 376] opinion of Galen, that they were only mesenteric vessels. ‘“There
is not one among the doctors,”’ we read in a letter of Thomas Bar-
tholin written at Montpellier, during his journey to Italy, ‘“who ac-
knowledges the lacteal veins, so wedded are they to the authority
of Galen, for which they contend as pro aris et focis, and disregard
the experiments of the moderns.”’ Unluckily, he did not trace
the lacteals to the left subclavian vein, but fancied they went
to the liver, distributing the chyle through it for sanguification;
this organ, according to the established doctrine, receiving the
chyle from the mesenteric arteries and veins to convert it into
blood.

In 1649, Pecquet, a physician at Dieppe, was removing the
heart of a dog, when he noticed a quantity of white fluid pouring
from the upper cava mixed with blood. He at first thought
he had opened some strange abscess, and, after pressing first
upon one part and then upon another, he compressed the me-
sentery, whose lacteals were full of chyle, when instantly a large
quantity of this poured from the superior cava. He traced the
lacteals to the thoracic duct, and thus overthrew the doctrine of
the liver being the great seat of haematosis.

Of course, there was as great an outcry against this innovation
in doctrine, as there had been against the existence of lacteals,
and even Harvey, who was now nearly eighty years of age,
could not at once loosen himself from the bonds of early pre-
judice, and Thomas Bartholin, whose eyes had always been open
to improvement in medicine, still thought that perhaps the finer
parts of the chyle went by the new ducts to the chest, ‘“while
the grosser, needing a larger concoction, enter the liver.”’

About eighty years after the discovery of Asellius, Rudbeck,
professor at Upsal, or Thomas Bartholin who was professor at
Copenhagen and son of Caspar Bartholin, or Joliff, an English
student, discovered the lymphatics.f

SECT. XXX.
OF SANGUIFICATION.

[Seite 377]

444. There is scarcely occasion to remark that we employ
the term sanguification to denote the assimilation of the chyle
to the blood, and the constant reparation, by means of the

former, of the constant loss sustained by the latter.

445. The division of all our fluids into three classes (45) –
crude, sanguineous, and secreted, turns upon this; – that the
middle class contains the stream of the vital fluid itself, from
which the numerous secreted fluids are perpetually withdrawn,
and to which, on the other hand, there is a constant afflux of
chyle and lymph from the absorbent system.

446. But since the blood is a peculiar fluid, sui generis,
without its fellow in nature, various assistances and media are
evidently requisite to subact and assimilate the heterogeneous
and foreign fluids which pass to it from the thoracic duct.

447. This is, in the first place, especially in the mesenteric
and other conglobate glands, favoured by those windings,
mentioned formerly, of the lacteals and lymphatics, which are,
at the same time, gradually more impregnated, as it were,
with an animal nature.

448. We must also take into consideration, that a great
part of the lymph which enters the left subclavian after its
admixture with the intestinal chyle in the thoracic duct, has
been derived from the substance of the viscera and other soft
parts, formerly secreted from the blood, and, therefore, already
imbued with an animal nature, and easily, without doubt,
again miscible with the mass of blood, to which it does but
return.

449. Something is contributed by the slow and almost
stillatitious manner in which the chyle joins the blood through
[Seite 378] the last valve of the thoracic duct, these very minute portions
becoming thus the more intimately combined with the blood.

450. The heart, too, by means of the remarkable papillary
muscles of the ventricles, agitates and mingles the blood just
impregnated with fresh chyle.

451. The great importance of the lungs which receive the
blood immediately after its addition of fresh chyle, and also
of respiration, in the business of assimilation,a will be evident
on considering the extraordinary vascularity of those organs,
(140) and their constant and regular alternate motion.

452. The remaining part of sanguification is accomplished
by the general circulation and the powers which aid it, par-
ticularly by muscular motion, &c.

453. Although so many means are provided for the com-
bination of the chyle with the blood, and although the consti-
tuents of the chyle somewhat resemble those of this fluid;
nevertheless, it is commonly asserted that many hours are re-
quired for the complete change of the colour of the chyle and
for its assimilation. Besides other arguments in favour of this
assertion, the pathological fact is urged, that chyle is fre-
quently seen in blood drawn many hours after digestion. I
myself have witnessed this appearance in cases where the
blood too evidently bore an inflammatory disposition, to use
a common phrase; but I am persuaded that no inference can
be hence deduced in regard to the healthy state, which alone
is the object of physiology.


NOTE.

The fluid collected from the thoracic duct is opake and white;
without smell; sweetish, and slightly acid to the taste; and re-
[Seite 379] stores the blue colour of litmus paper reddened by acetic acid,
proving the presence of an alkali. It separates, like the blood,
into a solid and a serous portion. If formed from vegetable food
only, it is nearly transparent, may be kept weeks or even months
without putrefying, and affords a faintly pink coagulum. If from
animal food, it is white and opake, begins to putrefy in a few days,
affords an opake coagulum which acquires a more marked pink
hue by the influence of the atmosphere, and throws upon its sur-
face a white creamy substance. The former gives three times as
much carbon as the latter; but the latter being so much richer
gives much more carbonate of ammonia and heavy fixed oil, when
subjected to the destructive distillation.b

Chyle collected from lacteals is whiter, coagulates less perfectly,
or not at all, and does not acquire a red colour by exposure to the
air,c so that sanguification proceeds gradually, as the chyle passes
towards the left subclavian vein, – a circumstance already stated
in the last section, Note (F). The pink colour, acquired by the
coagulum of chyle when exposed to the atmosphere, shows the
use of the lungs in sanguification.

White globules exist in the chyle even at a very early period
of its formation, and these most probably it is that become
coloured when the chyle grows pink by the action of the air.
There are also much larger white particles in the chyle, appearing
to be formed of the caseous-like and oily principles, and, being in-
soluble in the serum, naturally assume the globular form.d

Dr. Marcet had reason to believe that the appearance of creamy
matter floating in the serum of blood occurs most frequently when
the food is chiefly animal, and when therefore rich chyle is poured
into the blood faster than it can be assimilated. The serum at first
appears milky; but it gradually becomes clear, from the creamy
matter separating and rising to the surface.

The coagulum of the fluid of the thoracic duct is much less
firm than that of blood, and after a few days, if allowed to remain
in a separate vessel, it passes almost entirely to the fluid state.
Vauquelin regards it as unfinished fibrin, something between
albumen and fibrin.

[Seite 380]

I once saw a young married woman whose urine contained
very large coagula of chyle. She always dined at noon. In the
evening the coagula were white; in the morning pale with pink
streaks. After fasting twenty-four hours at my request, the coa-
gula still appeared in the urine, extremely pale, and showing more
pink streaks. She had been some months in this way, was in
very fair health, and had a great appetite, and perhaps some other
general symptoms of diabetes; but there was no sugar in the urine.
Notwithstanding the fluid discharged seemed to present as much
coagulum as urine, the quantity of chyle proved on drying to be
very minute, and from its looseness to have been extremely dis-
tended by the urine. As this was a state of disease, I draw no
inference from the case respecting the time necessary for the
change of chyle to blood. She would not allow me to take any
blood from the arm for observation.

I know that similar cases have been seen by Dr. Prout and
other gentlemen now practising in London, and there may be
several on record, but the only one of which I have read is quoted in
Shenkius. ‘“I saw,”’ says the author whom he quotes (in Castro
Itri, Comitatus Sundorum), ‘“a young man, thirty years of age, who
daily made a considerable quantity of urine, depositing a white
substance like the curd of milk, sufficient to fill a common pot de
chambre,
besides the urine which was above it. He was in perfect
health, not experiencing the slightest ill effect.”’e

Shenkius is generally thought a credulous collector of incredible
cases, and no doubt some of his histories as well as of his opinions
are ridiculous. But careful modern observation discovers facts
precisely similar to the greater number that he has collected.
I should have doubted the history just related, more especially
the good health of the patient, had not the case of the woman
occurred to me. He gives some instances of black urine made
by persons in perfect health, and Dr. Marcet has published two
such in the Transactions of the Medical and Chirurgical Society.f
Dr. Prout showed me a specimen of urine from one of these.

[Seite 381]

Lymph from the hind extremities of a horse was found by Em-
mert to be white, with straw-coloured globules, to contain rather
less albumen, to coagulate more imperfectly, and become less
easily red on exposure to air, than the contents of the thoracic
duct.g

According to the recent observations of Tiedemann and Gmelin,
the chyle has no fibrin, so as scarcely to coagulate, nor any red
particles, before it passes through the mesenteric glands; but im-
mediately afterwards, and especially after it is mixed with the
lymph of the spleen, – a fluid abounding both with them and
fibrin, – presents both, still more copiously than the lymph of the
extremities.

No fatty matter is discoverable in the lymph, nor indeed in the
chyle if the animal fasts or takes food destitute of fat. The fatty
matter is merely diffused through the chyle, and found even in
the blood after butter has been eaten.

The serum of the chyle they observed to be nearly always
alkaline.

Ligature of the choledochus they found to augment the quan-
tity of fibrin and red particles, and to diminish that of fatty mat-
ter, in the chyle.

SECT. XXXI.
OF NUTRITION.

[Seite 382]

454. Besides the function of the blood formerly inves-
tigated, – of distributing oxygen (as is probable) through the
system and removing carbon, its principal use is to afford
nourishment to the body in general, and to the secreting
organs the peculiar fluids which they possess the power of
deriving from it. Nutrition shall be first examined.

455. Nutrition is the grandest gift of nature, and the com-
mon and highest prerogative of the animal and vegetable
kingdoms, by which they, beyond measure, surpass, even at
first sight, all human machines and automatons. Upon these
no artist can bestow the faculty, not to say of increasing and
of coming to perfection, but even of existing independently
and repairing the incessant losses incurred from friction.a

456. By the nutritive faculty of the body, its greatest and
most admirable functions are performed; by it we grow from
our first formation and arrive at manhood; and by it are
remedied the destruction and consumption which incessantly
occur in our system during life.b

457. Respecting the nature of this consumption, there has
been much dispute whether it affects the solids,c or, whether,
[Seite 383] according to some very acute writers,d these, when once
formed and perfected, remain invariably entire.

458. There can be no doubt that some of the similar
solids, v. c. the epidermis and nails, are gradually destroyed
and renewed; and the same is proved respecting even the
bones, by the well-known experiment of dyeing them, in
warm-blooded animals, with madder root, (A) and by the
frequently surprising attenuation of the flat bones, espe-
cially of the skull, from defective nutrition, in old age.e

459. If I am not mistaken, those solid parts undergo
this successive change, which possess the reproductive power
an extraordinary faculty, by which not only the natural loss
of particles, but even the accidental removal of considerable
parts through external injuries, is repaired and perfectly sup-
plied, as the bonesf and a few other parts sufficiently demon-
strate.

460. On the other hand, I have been led by many expe-
riments, upon man and other warm-blooded animals, to the
conclusion – that this genuine reproductive power appears
completely bestowed upon scarcely any similar solid part which
possesses any other vital power
besides contractility, i. e.
irritability, sensibility, or a vita propria.g (B)

[Seite 384]

461. In those parts, therefore, whose vital powers are, as it
were, of a higher order, the parenchyma, constituting their
base, appears permanent, and is liable to this change only,
– that the interstices of the fibres and parenchyma, while nu-
trition is vigorous, are constantly full of nutrient animal gela-
tine; but, when nutrition languishes, are deprived of the
gelatine, collapse, and consequently become thin.

462. For as the plastic lymph, the importance of which
has been frequently mentioned, is readily converted into cel-
lular membrane, so it appears to constitute the principal
material of the body, and, as it were, the animal gluten,
which is nourished by its means.

463. During the growth of the body, peculiar powers
are exerted, by which the lymph deposited in the cellular
membrane from the blood-vessels is properly distributed and
intimately assimilated to the substance of each organ, &c.

This is referable both to the laws of affinity, by which we
imagine particles attract, and, as it were, appropriate others
which are similar and related to themselves; and to the nisus
formativus, which we shall enlarge upon hereafter, and to
which the proper application of shapeless elementary matter
and its modification to particular forms must be ascribed.

464. The union of both these powers, we conceive, must
be the source of the nutrition of such similar parts as are not
supplied with blood itself, but are, nevertheless, at first gene-
rated by a most powerful and infallible nisus, grow, are
nourished throughout life, and, if destroyed by accident, are
very easily reproduced;h such are the nails, hairs, &c.

465. As this appears to be the true account of nutrition in
general, so, on the other hand, this function evidently has great
varieties of degree and kind, especially where, from the more
[Seite 385] or less lax apposition of the nutritious matter, the structure of
the similar parts is more or less dense, and the specific weight
of the whole body more or less considerable.i In this respect,
not only individuals, but whole nations, differ from each other.
The Yakuts and Burats, who are remarkable for the lightness
of their bodies, are a sufficient example of this.


NOTES.

(A) The redness imparted to the bones by feeding animals
with madder, does not prove that the matter of the bones is con-
stantly changing; because the opinion that the madder unites
with the phosphate of lime in the blood, and thus reddens all the
bony matter subsequently deposited, is erroneous. Mr. Gibson
proved, by numerous experiments, that the serum has a stronger
affinity than the phosphate of lime, for madder. The serum being
charged with madder, the phosphate of lime of the bones, al-
ready formed, seizes the superabundant madder, and becomes
red. If the madder is no longer given to the animal, as it is
continually passing off with the excretions, the stronger attraction
of the serum draws it from the bones, and they re-acquire their
whiteness.k

(B) The constant renewal of the epidermis is demonstrated
by wearing black silk stockings next the skin. That the hair
and nails not only grow perpetually, but are even reproduced, is
certain from the great quantity of the former which falls off
the head whole if worn long, while a good head of hair still
continues; and from the renewal of the latter, after the loss of
a great part of a finger. I once attended a middle-aged woman,
in St. Thomas’s Hospital, who had lost nearly the whole of the
first phalanx of a finger, and yet the stump was tipped by a nail,
though certainly a clumsy one. An instance of a nail at the end
of the stump, after the complete removal of the first phalanx,
[Seite 386] may be seen in the London Medical and Physical Journal.l
Tulpius declares he has seen examples after the loss of both the
first and second phalanges – in secundo et tertio articulo.m The
glans penis (in truth a mere continuation of the corpus spongiosum
urethrae) was entirely renewed in one case.n Nothing more can,
I apprehend, be said, respecting the entire restoration of organs
in the human body. Portions of cutis, bone, membrane, blood-
vessels, absorbents, and nerves, are replaced. That portions
of large nerves, fully capable of all the functions of the destroyed
pieces, are reproduced, is now a matter of certainty. Minute
blood-vessels and absorbents are of course allowed on all hands to
be produced in the cure of most solutions of continuity, whether
by wounds, ulceration, or whatever else;o but Dr. Parry, senior,
has shown, that in the ram, at least, when a blood-vessel which
proceeds some way without giving off a branch is obstructed, new
branches sprout forth and establish a communication on each side
of the obstruction.p The continuance of circulation was previously
[Seite 387] attributed solely to the enlargement of the small anastomosing
vessels. Muscle is supplied by tendinous matter. The substance
formed in the situation of destroyed cellular membrane is so
little cellular, that it does not become distended in emphysema
or anasarca.q

Brutes far surpass man in both the ordinary renewal of the
integuments and appendages, and in the extraordinary restoration
of destroyed organs. The horse periodically sheds its hair, the
bird its feathers,r the stag its horns, the serpent its cuticle,
the lobster its shell and the teeth which are in its stomach.s
The fall of the leaves of trees is an analogous circumstance. In-
sects not only change their coats frequently, but undergo com-
plete metamorphoses, are first worms, then grubs, and finally
winged beings. The crystalline lens extracted from an healthy
eye is speedily reproduced in cats, dogs, and rabbits,t and probably
in other brutes. The extraordinary reproductive power of some
brutes is almost incredible. A lobster can reproduce a claw, a
water-newt an extremity: Blumenbach actually observed the
reproduction of the whole head with its four horns in a snail, and
the complete eye, – cornea, iris, crystalline lens, &c. in a water-
newt.u Besides greater powers of reproduction than man, brutes
generally possess greater also of reparation – will survive injuries
which would prove fatal to us, perhaps under any circumstances,
or at least without great care. I related Brunner’s numerous
attempts upon the life of a dog, of which, violent as they were,
‘“vim elusit, vegetusque evasit,”’ as an illustration of this. Less
violent injuries are recovered from with far less danger and incon-
venience than we experience. The lower we descend in the scale,
the greater tolerance of violence and the greater powers of repar-
ation and renewal do we observe. If the polype, which is a
gelatinous tube, with one end closed and the other fringed for
[Seite 388] the purpose of receiving food and conveying it, is divided,
the two halves change at one end, the one closing, the other
acquiring fringes, so that both halves become perfect animals; or,
if a polype is inverted, the outer surface forms a digesting cavity.

Vegetables endure extreme violence. A log of mulberry-tree
has sent forth shoots on being placed in the ground as a post,
after many years of neglect; a gooseberry-bush will grow if
planted with its branches in the earth and its roots in the air.

SECT. XXXII.
OF THE SECRETIONS IN GENERAL.

[Seite 389]

466. Besides the nutritious fluids, others of extremely
various descriptions are produced from the blood by means
of secretion, which Haller, no less than his predecessors, with
truth and regret declared to be among the most obscure parts
of physiology.a

467. The secreted fluids differ, on the one hand, so con-
siderably among themselves, and, on the other, have so many
points of resemblance, that their classification cannot but be
extremely arbitrary. If we arrange them according to the
degree of difference between them and the blood from which
they are formed, they will stand in the following order. –

First, the milk, which may be in some degree considered
as chyle reproduced, and appears formed by the most simple
process from the blood newly supplied with chyle.

Next, the aqueous fluids, as they are commonly denomi-
nated from their limpid tenuity, although the greater part
differ importantly from water in the nature of their consti-
tuents, and especially in the proportion of albumen: such are
the humours of the eye, the tears, in all probability the
vapour contained in the cellular interstices and the cavities of
the abdomen and thorax; nearly similar, also, is the fluid of
the pericardium and of the ventricles of the brain.

The liquor amnii of pregnancy, and the urine, remarkable
for the peculiar nature and mixture of its proper constituents,
are generally enumerated among these.

[Seite 390]

The salivary fluids, concerned in mastication, digestion, and
chylification, appear more elaborated.

Next the mucous, which line the cavities of most of the
organs performing the natural and genital functions, and like-
wise the tract of the nostrils, larynx, and trachea.

The mucus within the eye, and under the epidermis, is
nearly similar.

In the same class may be included the cerumen of the
ears, the unguent of the Meibomian glands and of the joints,
and, perhaps, the ambiguous and nameless fluid commonly
poured forth by the vagina during the venereal oestrum.

The adipose are, besides the common fat, the medulla of
the bones and grease of the skin.

Related to these are the secretion of the corona glandis
under the preputium, and of the external female genitals.

The truly serous, or albuminous, are the fluid of the ovarian
vesicles of De Graaf, and the liquor of the prostate.

The semen virile and the bile are each sui generis. (A)

468. It is obvious that so great a variety of secreted fluids
cannot be secreted from the mass of blood in the same way,
nor by similar organs. They differ extremely from each
other in the simplicity or complexity of their preparation.

469. The most simple mode of secretion is diapedesis, or
transudation: which is the case with the fat and the bony
fluid.b

[Seite 391]

470. Secretion by glandsc is more complicated. Such is
considered the secretion even by follicles and cryptae, which
are found, v. c. in some parts of the corium, the fauces, and
aspera arteria, and denominated the most simple glands.

Properly speaking, the conglomerate (as they are called to
distinguish them from the lymphatic conglobate) are the only
true secreting organs; such as the salivary and lachrymal
glands, the pancreas and breasts. They are provided with
an excretory duct coming immediately from the large lobes,
which are composed of others, smaller, and whose interior
structure was once the source of warm disputes in the schools
of medicine. Malpighid considered the miliary globules,
which are easily discoverable in most glands, as acini, according
to his expression, internally excavated. Ruysch, on the con-
trary, contended that these supposed hollow acini were nothing
more than glomerules of blood-vessels, – an opinion shown
to be far more consistent with nature by microscopical ob-
servation and the effects of minute injection.

471. The structure of some secreting organs, especially of
the liver and kidneys, the latter of which strikingly exhibit
the glomerules of Ruysch or the acini of Malpighi, are not,
excepting in their peculiar parenchyma, very dissimilar from
this structure, and indeed throw considerable light upon the
question. On the outer part of these, small twigs arise from
the sides of the capillary arteries and run into vascular glo-
merules, hanging from them like granules as from stalks:
from these arterial glomerules spring both very minute co-
[Seite 392] lourless secreting vessels whose origin from the extremities
of arteries was formerly alluded to (92), and the radicles of
veins into which the arteries are continued, and which convey
back into the venous trunks the remaining blood deprived of
the secreted fluid.e

472. The organisation of some other secreting parts is
evidently peculiar, v. c. of the testes, which are composed of
very long and numerous vessels, closely compacted, &c.

473. That the different nature of the secreted fluids de-
pends not so much on the size and external form of the se-
creting organs as upon their interior structure and corre-
sponding vital powers, is rendered probable by the example of
many of our fluids, which, although secreted by organs at
first sight very different, have considerable resemblance to
each other in nature; v. c. the saliva and gastric juice. And
comparative anatomy teaches us, that the same fluids are
formed by organs very different in external appearance, in
different animals.f

474. We shall now investigate the causes why particular
fluids are found in particular organs, – the most difficult
part of the doctrine of secretion, and still open to very many
doubts.

475. There can be no question that the absolute cause of
most secretions is the intimate structure of the secreting
organ. This depends, in the conglomerate glands and se-
creting viscera especially, both upon the peculiar direction
and distribution of the extreme blood-vessels, and upon the
peculiar parenchyma of each secreting organ, in some instances
distinguishable at first sight from the substance of every other
part. (20)

476. It is likewise probable, and indisputable arguments in
favour of the opinion have been continually afforded in the
[Seite 393] course of this work, that secreting organs have not only a
peculiar parenchyma, but a vita propria – a peculiar species
of vitality distinct from the common vital powers of con-
tractility, irritability, and sensibility.

477. The absorbent system seems to us of much import-
ance in the business of secretion. In every secreting organ,
it absorbs, for the purpose of transmission to the blood, a
fluid which is, as it were, contaminated by the secretion of
the part: v. c. a bilious fluid in the liver; a spermatic in the
testes.

A constant circle would, therefore, appear to exist in the
secretory system, so that the elements of the secretions are
incessantly carried to the blood from the secreting organs,
and, when they return to the organs, are the more easily at-
tracted by a species of affinity, and draw with them those
parts of the blood whose nature is related to their own.

478. The blood, from which some secretions are produced,
is endowed with peculiar qualities. The bile, for example, is
derived from blood which contains an abundance of carbon-
aceous element.

479. We omit other assistances afforded to certain secre-
tions; v. c. congestion and derivation, so striking in the se-
cretion of milk, &c. (B)

480. There is this difference among the various fluids
secreted by the organs and powers now described, – that
some pass to the place of their destination immediately, while
others are deposited in receptacles, and detained there for a
length of time, becoming more perfect before their excretion.
The milk in its ducts, the urine, bile, and semen in their re-
spective bladders, and in some degree the serum of the vesi-
cles of De Graaf, are examples of this.

[Seite 394]

NOTES.

(A) Dr. Bostock arranges the secretions as the aqueous, albu-
minous, mucous, gelatinous, fibrinous, oleaginous, resinous,
and
saline.h

The aqueous are the perspiration and pulmonary halitus, in
which the proportion of water is so great as to give the chief
character.

The albuminous, – all the membranous or white parts of animals,
the fluids of serous membranes and of the cellular membrane, the
former differing from the albumen of the blood chiefly in being
freed from extraneous matter and coagulated; the latter from
serum, chiefly in containing much less albumen.

The mucous are the mucus of all mucous membranes, the saliva,
gastric juice, tears, and semen. The animal matter which is their
basis, much resembles coagulated albumen, and their salts are
neutral, while those of the albuminous fluids are alkaline.

The gelatinous are named from containing jelly, – a substance
not found in the blood nor any of the fluids, but abundantly in
membranes, and particularly in the skin; and as albumen may be
converted into it by digestion in dilute nitric acid, it appears to
be the albumen of the blood with an addition of oxygen. It
abounds in the young, so that those parts which at the beginning
of life are almost entirely jelly, consist chiefly of albumen as age
advances: Since it is not found in the fluids, it must be deprived of
its oxygen again, and, probably, reduced to the state of albumen.

The fibrinous are the muscular fibres, abounding in azote, and
thus more completely animalised, resembling the fibrin of the
blood, – apparently their source.

The oleaginous are the fat, marrow, and secretions of sebaceous
glands, and perhaps the milk, as its properties depend so consi-
derably upon oily matter.

The resinous are the bile, cerumen, and urea, very similar to
the former, but owing their specific characters to a kind of resin.
Osmazome, an animal principle in all parts of the body, is referred
to this class.

The saline are the acids, alkalis, and neutral and earthy salts of
the various solids and fluids; generally more copious in the fluids
[Seite 395] than in the solids, absent in the simple oleaginous secretions, and
abundant in the compound; and still more so in the resinous
secretions. Their quantity is greatest in the bones, which are
principally phosphate of lime; but, with this exception, the urine
possesses the greatest proportion, as well as the most variety.
1. In some secretions they are absent; as the fat. 2. In some
they exist in definite quantity, and this different from that in the
blood; as the saliva. 3. In others, they are found in the same
quantity, and of the same nature as in the blood; as the fluid of
serous membranes. 4. In some, they are different from the salts of
the blood, and of variable quantity; as the urea. These four divi-
sions are, i. The solid albuminous, the gelatinous, and simple
oleaginous. ii. The mucous, fibrinous, and compound oleaginous.
iii. The liquid albuminous. iv. The aqueous and resinous.

This arrangement is certainly good; but, like every ar-
rangement of natural objects, convenient for general views and
memory rather than correct. The semen is mucous, but unlike
every other fluid: the gastric juice and cerebral substance are
equally sui generis. Fibrous matter as well as mucus exists in
semen, and is probably, indeed, its specific part: albumen exists
abundantly in milk, united into an emulsion with the oleaginous
portion. The bile and urine have few properties in common;
and urea is certainly not a resinous substance.

Berzelius adopts the old division of secretions and excretions,
and makes the following remarks.

‘“There are two classes of secreted fluids, viz. the secretions,
properly so called, or the fluids intended to fulfil some ulterior
purpose in the animal economy, and the excretions, which are
directly discharged from the body. The fluids of the former class
are all alkaline, and of the latter all acid. The excretions are the
urine, the perspired fluid, and the milk. All the other fluids
appear to belong to the former class.’

‘“The alkaline secreted fluids may be divided into two very
distinct species. The former of these contains the same quantity
of water as the blood, so that the change induced by the nervous
influence, seems to be confined to that of altering the chemical
form of the albuminous materials,i without affecting their relative
proportion to the water and other substances dissolved in the
[Seite 396] blood. The bile, spermatic fluid, &c. are of this kind. The latter
species consists of fluids, in which the influence of the nervous
system has separated a large portion of the albuminous matter,
and left the remaining liquid proportionally watery. The saliva,
the humours of the eye, and the effused serum of membranes, are
of this species, and in these the quantity of salts, and in general
also of alkali, is the same as in the blood.’

‘“The influence of the chemical agent of secretion is, there-
fore, chiefly spent upon the albuminous materials of the blood,
which seem to be the source of every substance that peculiarly
characterises each secretion, each of which is sui generis, and is
its principal constituent. All the other parts of the secretion
seem to be rather accidental, and to be found there only because
they were contained in the blood out of which the secretion was
formed. Therefore, in examining the secreted fluids, the chief
attention should be paid to the peculiar matter of the fluid, which
varies in all. This matter sometimes retains some of the pro-
perties of albumen, at other times, none; and hence an accurate
analysis, showing the quantity and nature of this peculiar matter,
is above all to be desired.’

‘“If the several secretions be supposed to be deprived of their
peculiar matter and the remainders analysed, the same residue
would be found from them all, which also would be identical
with the fluid separated from the serum after its coagulation.
Thus we should find, first, a portion soluble in alcohol, consisting
of the muriates of potash and soda, lactate of soda, and of an ex-
tractive animal substance, precipitable by tannin; and secondly,
of a portion soluble only in water, containing soda (which acquires
carbonic acid by evaporation, and is separable by acetic acid and
alcohol) and another animal substance, not extract, precipitable
from its solution in cold water, both by tannin and muriate of
mercury. Sometimes a vestige of phosphate of soda will also be
detected.’

‘“The excretions are of a more compound nature. They all
contain a free acid, which is termed lactic, and in the urine this is
mixed with the uric acid. Urine seems to contain only a single
peculiar characteristic matter; but milk has as many as three,
viz. butter, curd, and sugar of milk, which, however, seem to be
produced by different organs that mingle their fluids in the same
receptacle. The perspired fluid appears to have no peculiar
matter, but to be a very watery liquid, with hardly a vestige of
[Seite 397] the albumen of the blood, and, in short, is the same as the other
excretory fluids would be when deprived of their peculiar matter.
If we suppose this matter taken away from those excretions which
possess it, the remaining fluid will be found to have properties
very different from the fluid part of the secretions, when equally
freed from their peculiar matter. That of the excretions is acid,
contains earthy phosphates, and when evaporated, leaves a much
larger residue than the fluid of the secretions. This residue is
yellowish-brown, of the consistence of syrup, with an unpleasant,
sharp, saline taste of the salt that it contains. It reddens litmus,
is most soluble in alcohol, and this spirituous solution contains the
muriates of the blood, together with free lactic acid, much lactate
of soda (the soda being the free alkali of the blood, neutralised by
this acid), and the extractive matter, which always accompanies
this neutral salt. The part insoluble in alcohol contains a dis-
tinguishable quantity of phosphate of soda, a little of a similar
animal matter to that found in the secretions, and also the earthy
phosphates which were held in solution by the lactic acid, and
were precipitated by the action of the alc