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BY XAVIER BICHAT, 
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PHYSICIAN OF THE GREAT HOSPITAL OF HUMANITY AT PARIS, AND 
PROFESSOR OF ANATOMY AND PHYSIOLOGY. 
CranslateO from tfjc jFrencI), 
BY GEORGE HAYWARD, M.D. 
FELLOW OF THE AMERICAN ACADEME OF ARTS AND SCIENCES, 
AND OF THE MASSACHUSETTS MEDICAL SOCIETT. 
m THREE VOLUMES. 
\ 
VOLUME I. 
BOSTON: 
PUBLISHED BY RICHARDSON AND LORD, 
J. H. A. FROST, PRINTER 
1822. DISTRICT OF MASSACHUSETTS, to wit : 
District Clerk’s Office. 
BE IT REMEMBERED, that on the seventeenth day of April, A. D. 1822, in the 
forty-sixth year of the Independence of the United States ot America, Richardson &r Lord, 
of the said District, have deposited in this office the title of a book, the right whereof they 
claim as proprietors, in the words following, to wit: 
“ General Anatomy, applied to Physiology and Medicine; by Xavier Bichat, Physician 
of the Great Hospital of Humanity at Paris, and Professor of Anatomy and Physiology. 
Translated from the French, by George Hayward, M. D. Fellow of the American Acade- 
my of Arts and Sciences, and of the Massachusetts Medical Society. In three Volumes. 
Volume I. 
In conformity to the Act of the Congress of the United States, entitled, “ An Act for the 
Encouragement of Learning, by securing the Copies of Maps, Charts and Books, to the 
Authors and Proprietors of such Copies, during the times therein mentioned and also to 
an Act entitled, “ An Act supplementary to an Act, entitled, An Act for the encouragement 
of Learning, by securing the Copies of Maps, Charts and Books, to the Authors and Pro- 
prietors of such Copies during the times therein mentioned ; and extending the Benefits 
thereof to the Arts of Designing, Engraving and Etching Historical and other Prints.” 
JOHN W. DAVIS, 
Clerk of the District of Massachusetts. PREFACE BY THE TRANSLATOR. 
I commenced the present translation while pursuing the 
study of medicine in Paris in the winter of 1813—14. It was 
then my intention to have completed and published it imme- 
diately upon my return to the United States ; but I learnt in 
England in the spring following, that a translation of this 
work was about to appear from the London press. This infor- 
mation induced me to abandon my undertaking, but after wait- 
ing more than six years for the appearance of the English edi- 
tion, and finding from letters received from London, that there 
was but little if any expectation of its being published there 
at all, I was led to pursue my original plan and complete the 
translation which I now offer to the public. In doing this, I 
was influenced more by the intrinsic value of Bichat’s work 
than by any and every other motive. I was unwilling that so 
many of my professional brethren should be any longer denied 
access to this admirable production, because it was in a foreign 
language, and though I could have wished that another had 
undertaken the task, yet I was resolved to go through the 
labour rather than it should not be performed at all. 
Some of the writings of Bichat are so well known and so 
justly appreciated in this country, that it is perhaps unneces- 
sary for me to speak of his merits as an author, or offer an 
apology for translating the present work. Every thing which 
he gave to the public bore unequivocal proofs of being the 
production of a mind of the most original and powerful cast, PREFACE BY THE TRANSLATOR. 
IV 
and it is impossible to estimate what the influence of his la- 
bours might have been upon medical science if a longer 
career had been permitted to him. As it was, he accomplish- 
ed much, and as his writings are more known, their influence 
will be more sensibly felt. Ilis manner of investigating phy- 
siological subjects was characteristic of his strong and original 
mind, and it is difficult to determine which is the most admira- 
ble, his acute and accurate reasoning, or his ingenious and 
well conducted experiments. Nor were these experiments 
the result of preconceived opinions, he seems to have brought 
his mind perfectly unbiassed to every subject that he investi- 
gated, and to have been guided in every instance by the most 
rigorous laws of induction. To these high qualifications he 
added great perspicuity in his arrangement, remarkable pu- 
rity and beauty of style, and an extensive knowledge of 
disease, which enabled him to enrich his work with much 
valuable practical information. It is not pretended, but that 
his experiments upon living animals may have in some few 
cases led him to erroneous conclusions, but how numerous 
were the instances in which he obtained from them the most 
satisfactory and important information. It has, I know, be- 
come fashionable of late to undervalue these experiments, 
and to deny that any useful application can be made of them. 
It is no doubt true, that the sufferings which animals some- 
times undergo in these experiments, are such as to destroy 
entirely the order and regularity of all the functions, and of 
course to prevent us from determining any thing as to these 
functions in health. This probably was the case with some 
of the experiments of Magendie on vomiting, and Legallois 
on the principle of life ; but let us not condemn this mode of 
investigation because it has been sometimes injudiciously em- 
ployed, let us not forget that the argument is wholly directed 
against the abuse of it, and that these experiments have PREFACE BY THE TRANSLATOR. 
V 
already led to some practical consequences of immense value. 
Would the carotid artery have ever been tied in a living hu- 
man subject, if it had not been first ascertained that it could 
be done with safety in animals ? 
In translating this work, I have studiously endeavoured to 
give with precision the meaning of the author, and have, I 
fear, by this means frequently employed French idiomatic ex- 
pressions. From the great originality of many parts of the 
General Anatomy, Bichat found it necessary in some instances 
to employ new terms, to which there were no corresponding 
words in our language ; in such cases, I have either made use 
of several, or adopted the term, as one or the other seemed 
i 
best calculated to render the meaning more clear and exact. 
A few notes only have been given, and these for the most part 
for the purpose of explaining what was obscure, rather than 
of controverting any thing contained in the original. Upon the 
whole, I trust that this work will be a valuable acquisition to 
our stock of medical literature, and I shall feel as if my 
labour has not been in vain, if I shall have been the means of 
making my countrymen better acquainted with the writings 
of its illustrious author. 
Boston, Aprils 1822. PREFACE BY THE AUTHOR. 
THE work which I now offer to the public, will appear to 
them new, I trust, in three points of view; 1st, in the plan 
that has been adopted ; 2d, in most of the facts which it con- 
tains ; and 3d, in the principles which constitute its doctrine. 
1st. The plan consists in considering separately and pre- 
senting with all their attributes, each of the simple systems, 
which, by their different combinations, form our organs. The 
basis of this plan is anatomical, hut the details that it em- 
braces belong also to medicine and physiology. It has nothing 
in common, but the name, with what has been lately advanced 
upon the anatomy of systems; my Treatise on the Membranes 
alone gives an outline of it. 
2d. The facts and observations in this work, in addition to 
what is already known, form a very numerous series. I shall 
not give an analysis of them ; the reader will supply it, how 
little soever he may know of works on Anatomy and Physio- 
logy. Experiments on living animals, trials with different re- 
agents on organized textures,* dissection, examinations after 
death, observations upon man in health and disease, these are 
sources whence I have drawn them, and they are the sources 
*1 have ia this and every other instance translated the French word 
fissu by the English word texture. I know many writers have adopted 
the French term, but I think it unnecessary, to say the least, to employ 
a foreign word, when one of our own language can be used with quite 
as much precision. Tr. PREFACE BY THE AUTHOR. 
VII 
of nature. I have not, however, neglected authors, those 
especially who make the science of the animal economy a 
science of facts and experiments. 
I will make but one remark upon the experiments con- 
tained in this work ; amongst them will be found a series upon 
the simple textures, which 1 subjected successively to desicca- 
tion, putrefaction, maceration, ebullition, stewing, and to the 
action of the acids and the alkalies. It will be easily seen, 
that it was not the object of these experiments to determine 
the composition, or ascertain the different elements, and con- 
sequently give a chemical analysis of simple textures ; for 
this purpose they would have been insufficient; but their ob- 
ject was to establish the distinctive characters of these simple 
textures, to show that each has a peculiar organization, as 
each has a peculiar life, and to prove by the different results 
which they gave, that the division which I have adopted is 
not speculative, but that it rests upon the diversity of their 
intimate structure. The different re-agents, which I used, 
were only to assist me where the scalpel was insufficient, and 
on this account, therefore, 1 presume these experiments will 
have some influence upon Anatomy. 
3d. The general doctrine of this work has not precisely the 
character of any of those which have prevailed in medicine. 
Opposed to that of Boerhaave, it differs from that of Stahl 
and those authors who, like him, refer every thing in the 
living economy, to a single principle, purely speculative, 
ideal, and imaginary, whether designated by the name of soul, 
vital principle, or archeus. The general doctrine of this work 
consists in analyzing with precision the properties of living 
bodies, in showing that every physiological phenomenon is 
ultimately referable to these properties considered in their 
natural state ; that every pathological phenomenon derives 
from them augmentation, diminution, or alteration; that every VIII 
PREFACE BY THE AUTHOR. 
therapeutic phenomenon has for its principle the restoration 
of the part to the natural type, from which it has been chang- 
ed ; in determining with precision the cases in which each 
property is brought into action; in distinguishing accurately 
in physiology as well as in medicine, that which is derived 
from one, and that which flows from others ; in ascertaining 
by rigorous induction the natural and morbific phenomena 
which the animal properties produce, and those which are 
derived from the organic; and in pointing out when the 
animal sensibility and contractility are brought into action, 
and when the organic sensibility and the sensible or insen- 
sible contractility. We shall be easily convinced upon re- 
flection, that we - cannot precisely estimate the immense in- 
fluence of the vital properties in the physiological sciences, 
before we have considered these properties in the point of 
view in which I have presented them. It will be said, per- 
haps, that this manner of viewing them is still a theory; I 
will answer, that it is a theory like that which shows in the 
physical sciences, gravity, elasticity, affinity, &c. as the primi- 
tive principles of the facts observed in these sciences. The 
relation of these properties as causes to the phenomena as 
effects, is an axiom so well known in physics, chemistry, astro- 
nomy, &c. at the present day, that it is unnecessary to repeat 
it. If this work establishes an analogous axiom in the phy- 
siological sciences, its object will be attained. GENERAL OBSERVATIONS. 
THERE are in nature two classes of beings, two 
classes of properties, and two classes of sciences. The 
beings are either organic or inorganic, the properties 
vital or non-vital, and the sciences physiological or phy- 
sical. Animals and vegetables are organic—minerals 
are inorganic. Sensibility and contractility are vital 
properties ; gravity, elasticity, affinity, &c. are non-vital 
properties. Animal and vegetable physiology, and medi- 
cine form the physiological sciences ; astronomy, physics, 
chemistry, &c. are tne physical sciences. These two 
classes of sciences have relation only to different phe- 
nomena ; there are two other classes that correspond to 
these, which relate to the internal and external forms of 
bodies and their description. Botany, anatomy, and 
zoology, are the sciences of organic bodies ; mineralogy, 
&c. of the inorganic. The first will occupy us, and we 
shall fix our attention especially upon the relations of 
living bodies with one another, and their relations with 
those that do not live. 
I. General remarks upon physiological and physical sci- 
ences. 
The differences between these sciences are derived 
essentially from those existing betweeu the properties 10 
GENERAL OBSERVATIONS. 
that preside over the phenomena, which are the object 
of each class of sciences. So immense is the influence 
of these properties, that they are the principle of all 
phenomena; whether we examine those of astronomy, 
of hydraulics, of dynamics, of optics, of acoustics, &c. 
we shall finally arrive by a connexion of causes to gra- 
vity, to elasticity, Sic. as the end of our researches. So 
the vital property is the primum mobile to which we must 
ascend, whether we consider the phenomena of respira- 
tion, of digestion, of secretion, circulation, inflammation, 
fevers, &x.—In giving existence to every body, nature 
has imprinted upon it a certain number of properties, 
that particularly characterize it, and by means of which 
it contributes in its own manner, to all the phenomena 
that are developed, succeed, and continually connect 
themselves in the universe. Cast your eyes upon that 
which surrounds you ; turn them upon objects the most 
distant; whether, aided by the telescope, they examine 
those that swim in space, or, armed with the microscope, 
they enter the world of those, whose minuteness almost 
evades our view, every where you will find on one side 
physical properties, on the other vital properties, brought 
into action ; every where you will see inert bodies gravi- 
tating upon each other, and reciprocally attracting; 
living bodies gravitate also, but above all they feel, and 
possess a motion which they owe only to themselves. 
These properties are so inherent in bodies, that we 
cannot conceive of their existence without them. They 
constitute their essence and their attribute. To exist 
and to enjoy them are two things inseparable. Suppose 
that of a sudden they are deprived of them ; instantly 
all the phenomena of nature cease, and matter alone 
exists. Chaos was only matter without properties; to 
create the universe, God endowed it with gravity, elas- 
ticity, atfinity, &c. and to a part he gave sensibility and 
contractility. GENERAL OBSERVATIONS. 
11 
This mode of considering the vital and physical pro- 
perties, sufficiently shews, that we cannot ascend above 
them in our explanations, that they afford the principles, 
and that these explanations are to be deduced from them 
as consequences. The physical sciences, as well as the 
physiological, then, are composed of two things; 1st. 
the study of phenomena, which are effects ; 2d. the re- 
search into the connexions that exist between them and 
the physical or vital properties, which are the causes. 
For a long time these sciences have not been so 
considered ; every fact that was observed, was made the 
subject of a particular hypothesis. Newton was the first 
to remark, that however variable the physical phenomena 
were, they could all be referred to a certain number of 
principles. He analyzed these principles and found 
that attraction enjoyed the most important place among 
them. Attracted by each other and by their sun, the 
planets describe their eternal courses ; attracted to the 
centre of our system, the waters, air, stones, &c. move 
or tend to move towards it: it is truly a sublime idea, 
and one that serves as the basis to all the physical sci- 
ences. Let us render homage to Newton ; he was the 
first who discovered the secret of the Creator, viz. A 
simplicity of causes reconciled with a multiplicity of 
effects. 
The epoch of this great man was the most remarkable 
of human wisdom. Since that period, we have had prin- 
ciples from which we draw facts as consequences. This 
epoch, so advantageous to the physical sciences, was 
nothing to the physiological; what do I say? it retarded 
their progress. Mankind soon saw nothing but attraction 
and impulse in the vital phenomena. 
Boerhaave, though brilliant in genius, suffered himself 
to be dazzled by a system which misled all the men of 
learning of his age, and which made a revolution in the 
physiological sciences, that may be compared to that 12 
GENERAL OBSERVATIONS. 
effected in the physical, by the vortices of Descartes. The 
plausibility of the theory and the celebrated name of its 
author, gave to this revolution an empire, which, though 
rotten in its foundation, was not easily overthrown. 
Stahl, less brilliant than profound, rich in the means 
that convince, though deficient in those that please, 
formed for the physiological sciences an epoch more wor- 
thy of notice than that of Boerhaave. He perceived the 
discordance between the physical laws and the functions 
of animals; this was the tirist step towards the discovery 
of the vital laws, but he did not discover them. The 
soul was to him every thing in the phenomena of life; 
it was much to neglect attraction and impulse. Stahl 
perceived that these were not true, but the truth escaped 
him. Many authors, following his steps, have referred 
to a single principle, differently denominated by each, 
all the vital phenomena. This, called the vital princi- 
ple by Barthez, archeus by Van Ilelmont, &lc. is a specu- 
lation that has no more reality than that which would 
refer to a single principle all the physical phenomena. 
Among these we know that some are derived from gravity, 
some from elasticity, others from affinity, &c. The same 
in the living economy, some are derived from sensibility, 
others from contractility. 
Unknown to the ancients, the laws of life have begun 
to be understood during the last age only. Stahl had 
already remarked the tonic motions, but he did not gen- 
eralize their influence. Haller was engaged particularly 
with sensibility and irritability; but in limiting one to 
the nervous system, and the other to the muscular, this 
great man did not consider them in the correct point of 
view; he made them almost insulated properties. Vicq 
d’Azyr changed them into functions in his physiological 
division and ranked them with ossification, digestion, &,c. 
that is, he confounded the principle with the consequence. 
Thu you see, notwithstanding the labours of a crowd of GENERAL OBSERVATIONS. 
13 
learned men, how much the physiological sciences still 
differ from the physical. In these, the chemist refers all 
the phenomena that he observes to affinity: the natural 
philosopher, in his science, every where sees gravity, 
elasticity, &c. In the others, we have not as yet ascend- 
ed, at least in a general manner, from the phenomena to 
the properties from which they are derived. Digestion, 
circulation, or the sensations, do not bring the idea of 
sensibility or contractility to the mind of the physiolo- 
gist, as the movement of a watch proves to the mechani- 
cian that elasticity is the primum mobile of its motion; 
or as the wheel of a mill or of any machine, which run- 
ning water sets in motion, proves to the natural philoso- 
pher that gravity is the cause. To place upon the same 
level in this respect these two classes of sciences, it is 
evidently necessary to form a just idea of vital properties. 
If their limits are not accurately assigned, we cannot with 
precision analyze their influence. I shall present here 
only general considerations on this point, which has been 
treated sufficiently in my Researches upon Life; what I 
shall add now will be but as a supplement to what has 
been explained in that work. 
II. Of vital properties, and their influence upon all the 
phenomena of the physiological sciences. 
To assign the limits of these properties, we must follow 
them from bodies that are hardly developed, to those 
which are the most perfect. In the plants that seem to 
form the transition from vegetables to animals, you dis- 
cover only an internal motion that is scarcely real; their 
growth is as much by the affinity of particles and con- 
sequently by juxta-position, as by a true nutrition. But 
in ascending to vegetables better organized, you see 
them continually pervaded by fluids, that circulate in 
numerous capillary canals, which mount, descend, and 
run in a thousand different directions, according to the 
state of the forces that regulate them. This continual 14 
GENERAL OBSERVATIONS. 
motion of fluids is foreign to the physical properties, the 
vital ones only direct it. Nature has endowed every por 
tionof a vegetable with a faculty of feeling the impression 
of fluids, with which their fibres are in contact, and of re- 
acting upon them in an insensible manner, to favour their 
course. The first of these faculties I call organic sensi- 
bility, the other, insensible organic contractility. This 
is very obscure in most vegetables; it is the same in the 
bones of animals. These two properties govern not only 
the vegetable circulations, which correspond in some 
measure to the capillary system of animals, but also the 
secretion, absorption, and exhalation of vegetables. Re- 
mark, in fine, that these bodies have only functions rela- 
tive to their properties; that all the phenomena that 
animals derive from properties which they have more 
than vegetables, as the great circulation and digestion, 
for which there must be sensible organic contractility ; as 
the sensations, for which there must be animal sensibility; 
and locomotion, the voice, &c. for which animal con- 
tractility is necessary ; remark, I say, that these func- 
tions are essentially foreign to vegetables, since they have 
not vital properties to place them in action. 
For the same reason the catalogue of their diseases is 
less extensive. They have not the class of nervous dis- 
eases, in which the animal sensibility takes so great a 
part; they have not those of convulsions or paralysis, 
which are formed by an augmented or diminished animal 
contractility; they have not those of fevers, or gastric 
diseases, which evidently arise from a disorder in the 
sensible organic contractility. The diseases of vegeta- 
bles are tumours of various kinds, increased exhalations, 
marasmus, &c.; they all indicate a derangement in the 
organic sensibility and in the corresponding insensible 
contractility. 
If we pass from vegetables to animals, we see the 
lowest of these, the zoophites, receive into a sac, which GENERAL OBSERVATIONS. 
15 
is alternately filled and emptied, the aliments that are to 
nourish them ; we see them begin to unite sensible organic 
contractility or irritability to the properties which they 
have in common with vegetables, and consequently com- 
mence the performance of different functions, digestion 
in particular. 
Thus far the organized bodies live wholly within them- 
selves ; they have no relation with that which surrounds 
them; animal life is wanting in them, or at least if it has 
commenced in these animo-vegetables, its rudiments are 
so obscure that we can hardly discover them. But this 
life begins to display itself in the superior classes, in 
worms, insects, mollusca, &c. On the one hand, the 
sensations, and on the other, locomotion, which is insepa- 
rable from them, are more or less fully developed. Then 
the vital properties necessary to the exercise of these 
new functions, are added to the preceding. Animal sen- 
sibility and contractility, obscure in the lower species, 
become more perfect, as we approach quadrupeds, and 
locomotion and the sensations become also more exten- 
sive. Sensible organic contractility then increases, and 
in proportion to that, digestion, circulation of the great 
vessels, &c. which are governed by it, receive a develope- 
rnent which is constantly growing more perfect. 
If we strictly examine the immense series of living 
bodies, we shall see the vital properties gradually aug- 
menting in number and energy, from the lowest of plants 
to the first of animals, man ; we shall see the lowest plants 
obedient to vital and physical properties ; all plants are 
governed only by these, which, in them, consist of insen- 
sible contractility and organic sensibility; the lowest 
animals begin to add sensible organic contractility to these 
properties, afterwards animal sensibility and contractility. 
We know the expression of Linnaeus, which he has used 
to characterize minerals, vegetables, and animals. The 
following would be more correct: 1st. physical properties 16 
GENERAL OBSERVATIONS. 
for minerals; 2d. physical properties and organic vital 
properties, except* sensible contractility, for vegetables ; 
3d. physical properties, all the organic vital properties, 
and the animal vital properties, for animals. 
Man and the neighbouring species, which are the par- 
ticular object of our researches, enjoy then evidently, 
all the vital properties, some of which belong to organic 
life, the others to animal life. 1st. Organic sensibility 
and insensible contractility have all the phenomena of 
the capillary circulation, of secretion, of absorption, ex- 
halation, nutrition, &c. evidently dependant upon them 
in a state of health. In treating, therefore, of these 
functions, we must always ascend to these properties. In 
the state of disease, all the phenomena that suppose a 
disorder in these functions, are clearly derived from an 
injury of these properties. Inflammation, formation of 
pus, induration, resolution, hemorrhage, unnatural aug- 
mentation or suppression of secretions ; increased exhala- 
tion, as in dropsies; diminished, or wholly wanting, as in 
adhesions; absorption, disordered in some way or other; 
nutrition, altered more or less, or presenting unnatural 
phenomena, as in the formation of tumours, cysts, cica- 
trices, &c.: these are morbid symptoms, that evidently 
suppose some injury or disorder in these two preceding 
* Several plants certainly possess a considerable degree of sensible 
organic contraetility; the mimosa pudica (sensitive plant) is a well 
known example, though there are several others that enjoy this pro- 
perty to almost as great an extent; particularly the hedysarum gyrans, 
the oxalis sensitiva, and the berberis vulgaris. “ A very remarkable 
degree of irritability, not exceeded by the sensitive plant, exists in the 
flowers of the barberry, (berberis vulgaris.) When these are fully 
expanded, the stamens are found spread out on the inside of the co- 
rolla. In this situation, if the inside of the filament be touched with 
a pin or straw, it instantly contracts and throws the anther violently 
against the stigma. This fact, which has been particularly described 
by Dr. Smith, in the English barberry, is not less remarkable and dis- 
tinct in the American varieties of the shrub.” Bigelow’s Florida 
Bostoniensis. Tr. GENERAL OBSERVATIONS. 
17 
properties. 2d. Sensible organic contractility, which, 
like the preceding, is not separated from the sensibility 
of the same nature, governs especially in a state of health, 
the movements necessary to digestion and the circulation 
of the great vessels, at least for the red and black blood 
of the general system, for the excretion of urine, &c. 
In the state of disease, all the phenomena of vomiting, 
of diarrhoeas, and a great part of those numberless ones 
of the pulse, may ultimately be referred to a disorder of 
the sensible organic contractility. 3d. All the external 
sensations, those of seeing, hearing, smelling, tasting, and 
feeling, and the internal, as those of hunger, thirst, &c. 
are derived in a state of health from the animal sensi- 
bility. In disease, what part does not this property per- 
form ? pain and its innumerable modifications, itching, 
smarting, tickling, the sensation of heaviness, weight, 
lassitude, throbbing, pricking, pulling, &c. &c. are not 
these only different alterations of animal sensibility ? A 
hundred different words would not express the diversity 
of painful sensations that morbid affections bring with 
them. 4th. Animal contractility is the principle of loco- 
motion and the voice; convulsions, spasms, palsies, &lc. 
are derived from an augmentation or diminution of this 
property. Examine all the physiological and all the 
pathological phenomena, and you will see that there is 
no one which cannot be ultimately referred to some 
one of the properties of which I have just spoken. 
The undeniable truth of this assertion, brings us to 
a conclusion not less certain in the treatment of dis- 
eases, viz. that every curative method should have for 
its object the restoration of the altered vital proper-* 
ties to their natural type. Every remedy, which, in 
local inflammation, does not diminish the augmented or- 
ganic sensibility; w'hich, in oedema and dropsy, does 
not increase this weakened property; and which does 18 
GENERAL OBSERVATIONS. 
not reduce animal contractility in convulsions, and 
elevate it in paralysis, fails in its object, and is contra- 
indicated. 
To what errors have not mankind been led in the em- 
ployment and denomination of medicines? They created 
deobstruents, when the theory of obstruction was in 
fashion, and incisives, when that of the thickening of the 
humours prevailed. The expressions of diluents and 
attenuants, and the ideas that are attached to them, were 
common before this period. When it was necessary to 
blunt the acrid particles, they created inviscants, incras- 
sants, &c. Those who saw in diseases only a relaxation 
or tension of the fibres, the laxum and strictum as they 
called it, employed astringents and relaxants. Refrige- 
rant and heating remedies were brought into use by those 
who had a special regard in diseases to an excess or a 
deficiency of caloric. The same identical remedies have 
been employed under different names according to the 
manner in which they were supposed to act. Deobstru- 
ent in one case, relaxant in another, refrigerant in another, 
the same medicine has been employed with all these dif- 
ferent and opposite views ; so true is it that the mind of 
man gropes in the dark, when it is guided only by the 
wildness of opinion. 
There has not been in the materia medica, a general 
system; this science has been governed by the different 
theories that have successively predominated in medicine; 
each has, if I may so express myself, flowed back upon 
it. Hence the vagueness and uncertainty that it presents 
at this day. An incoherent assemblage of incoherent 
opinions, it is perhaps of all the physiological sciences, 
that which best shows the caprice of the human mind. 
What do 1 say? It is not a science for a methodical mind, 
it is a shapeless assemblage of inaccurate ideas, of obser- 
vations often puerile, of deceptive remedies, and of for- 
mulae as fantastically conceived as they are tediously GENERAL OBSERVATIONS. 
19 
arranged. It has been said that the practice of medi- 
cine was disgusting; I add further, that it is not in some 
respects the study of a reas6nable man, when its principles 
are derived from the greatest part of the works on the 
materia medica. Take away those medicines, the effect 
of which is known only by accurate observation, as evaeu- 
ants, diuretics, sialagogues, anti-spasmodics, &.c. those 
consequently that act upon a particular function; what 
knowledge have we of the remainder ? 
It is, without doubt, extremely difficult at present to 
class remedies according to their modus operandi; but 
it is undeniable that all have for their object, the restora- 
tion of the vital forces to the natural type, from which 
they have been driven by disease. Since the morbid 
phenomena may be considered as different alterations of 
these forces, the action of remedies should also be viewed 
as the means by which these alterations are to be brought 
back to the natural type. Upon this principle, each of 
the properties has its class of appropriate remedies. 
1st. We have seen that there is in inflammations an 
increase of organic sensibility and insensible contractility; 
diminish then this increase by cataplasms, fomentations, 
and local baths. In some dropsies, in white-swellings, 
Slc. there is a diminution of these properties ; raise them 
by the application of wine and all those substances that 
are called tonics. In every species of inflammation, 
suppuration, tumours of different kinds, ulcers, obstruc- 
tions; in every alteration of secretion, exhalation, or nu- 
trition, the remedies act peculiarly upon the insensible 
contractility, to increase, diminish, or alter it in some 
way. All those that are called resolvents, tonics, stimu- 
lants, emollients, &c. act upon this property. Observe, 
that these remedies are of two kinds: 1st. general; as 
wine, ferruginous substances, oftentimes the acids, &c.; 
these re-animate insensible contractility, and give tone to 
the whole system: 2d. particular; thus this property is 20 
GENERAL OBSERVATIONS. 
separately excited by nitre in the kidnies, mercury in the 
salivary glands, &c. 
2d. Many remedies act particularly upon the sensible 
organic contractility; such are emetics, which produce 
a contraction of the stomach ; cathartics, and drastics 
especially, which create a strong contraction of the intes- 
tines. Art does not excite the heart in the same manner 
as these viscera ; we do not artificially increase its move- 
ments as we do those of the stomach in gastric diseases. 
It will, perhaps, hereafter be attempted, especially if it is 
true that fever may often be a method of cure, and then 
it will not, I think, be difficult to find the means of ef- 
fecting it. At other times, we have to diminish sensible 
organic contractility, and then remedies are employed 
that act in a manner opposite to the preceding, as in 
stopping vomitings, in diminishing intestinal irritation, &c. 
3d. Animal sensibility has also remedies that are pecu- 
liar to it. But they act in two ways—1st. in diminish- 
ing pain in the part where it is seated, as different appli- 
cations upon tumours, obstructions, &lc. : 2d. in acting 
upon the brain that perceives the pain; thus all narcotic 
preparations, taken internally, remove the sensation of 
pain, while the cause still subsists. In cancer of an ul- 
cerated uterus, the disease continues its progress with 
activity, but the prudent physician stupifies the brain so 
much, that it is incapable of perceiving it. It is essential 
to distinguish accurately these two actions of remedies 
upon the animal sensibility. They are totally different 
from each other. 
4th. Medicinal substances have also their influence on 
animal contractility. Every thing that produces an active 
excitement on the external surface of the body, as vesi- 
catories, frictions, smarting, &,c. tends to re-animate in 
paralysis this benumbed faculty7. AH those substances 
that paralyze the cerebral action, prevent the brain from 
governing the muscles of animal life; when these mus- GENERAL OBSERVATIONS. 
21 
cles, therefore, are convulsively agitated, these substances 
are true anti-spasmodics. 
In presenting these observations, I do not mean to offer 
a new plan for the materia medica. Medicines are too 
complicated in their action to be arranged anew, without 
more reflection than l profess as yet to have bestowed on 
the subject. Moreover, an inconvenience common to 
every classification, would here present itself: the same 
medicine acts often upon many vital properties. An 
emetic, while it brings into action the sensible organic 
contractility of the stomach, excites the insensible con- 
tractility of the mucous glands, and oftentimes the ani- 
mal sensibility of the nervous villi. The same observa- 
tion may be made with regard to the stimulants of the 
bladder, of the intestines, &c. My only object is to 
show, that in the action of substances applied to the body 
to heal it, as in the phenomena of diseases, every thing 
must be referred to the vital properties, and that their 
augmentation, diminution, or alteration, are ultimately 
the invariable object of our curative method. 
Some authors have considered diseases only as increas- 
ed strength or weakness, and have consequently divided 
medicines into tonics and debilitants. This idea is true 
in part, but it is false when we generalize it too much. 
For every vital force there are means proper to raise it 
when too much diminished, and to lessen it when too 
much elevated. But tonics and debilitants are certainly 
not applicable to every case. You would not weaken 
animal contractility, augmented in convulsions, as you 
would insensible organic contractility increased in in- 
flammation ; neither would you increase them by the 
same means. The morbid phenomena that organic con- 
tractility and animal sensibility experience, are not cured 
by the same method. There are medicines proper for 
each vital force. Moreover, it is not only in increase or 
diminution that the vital forces err, but they are besides 22 
GENERAL OBSERVATIONS. 
disordered; the different modifications that insensible 
contractility and organic sensibility can undergo, produce 
in wounds and ulcers a diversity of suppuration, in glands 
a diversity of secretion, in exhaling surfaces a diversity 
of exhalations, &c. It is necessary, therefore, that medi- 
cines should not only diminish or increase each of the 
vital forces, but that they should moreover restore them 
to the natural modification from which they have been 
altered. 
What I have just said is particularly applicable to the 
strictum and laxum of many authors, who every where 
see but these two things. The strictum may be properly 
applied to inflammation, the laxum to dropsies, &c.; but 
what have these two states of the organs in common 
with convulsions, with disorder of the intellect, with 
epilepsy, with bilious affections, &c. ? It is the peculiarity 
of those who have a general theory in medicine, to en- 
deavour to bend every phenomenon to it. The fault of 
generalising too much, has been perhaps more injurious to 
science, than that of viewing each phenomenon separately. 
These observations are, I think, sufficient to show, that 
every where in the physiological sciences, in the phy- 
siology of vegetables and of animals, in pathology, in 
therapeutics, &c. there are vital laws, that govern the 
phenomena which are the object of these sciences; and 
that there is not one of these phenomena that does not 
flow from these essential and fundamental laws, as from 
its source. 
If I should take a survey of all the divisions of phy- 
sical sciences, you would see that the physical laws were 
ultimately the sole principle of all their phenomena ; but 
this is so well known that it is not necessary to do it. 1 
will consider an important subject, and one to which we 
are naturally led by the preceding observations. I mean, 
a parallel between physical and vital phenomena, and 
consequently between physical and physiological sciences. GENERAL OBSERVATIONS. 
23 
III. Characteristics of the vital properties, compared with 
those of the physical. 
When we consider, on one side, the phenomena which 
are the object of the physical sciences, and those that 
are the object of the physiological, we see how immense 
is the space that separates their nature and their essence. 
But this difference arises from that which exists between 
the laws of the one and the other. 
Physical laws are constant and invariable; they are 
subject neither to augmentation or diminution. A stone 
does not gravitate towards the earth with more force at 
one time than another; in every case marble has the 
same elasticity, &c. On the other hand, at every instant, 
sensibility and contractility are increased, diminished, or 
altered ; they are scarcely ever the same. 
It follows, therefore, that the physical phenomena are 
never variable, that at all periods and under every influ* 
ence they are the same ; they can, consequently, be fore- 
seen, predicted, and calculated. We calculate the fall of 
a heavy body, the motion of the planets, the course of a 
river, the ascension of a projectile, &c.: the rule being 
once found, it is only necessary to make the application 
to each particular case. Thus heavy bodies fall always 
in a series of odd numbers; attraction is in the inverse 
ratio of the square of the distances, &c. On the other 
hand all the vital functions are susceptible of numerous 
variations. They are frequently out of their natural 
state ; they defy every kind of calculation, for it would 
be necessary to have as many rules as there are different 
cases. It is impossible to foresee, predict, or calculate, 
any thing with regard to their phenomena; we have only 
approximations towards them, and even these are often 
very uncertain. 
There are two things in the phenomena of life, 1st. the 
state of health; 2d. that of disease; hence there are 
two distinct sciences; physiology considers the pheno- GENERAL OBSERVATIONS. 
24 
mena of the first state, pathology those of the second. 
The history of the phenomena in which the vital forces 
have their natural type, leads us to consider as a conse- 
quence, those phenomena that take place when these 
forces are altered. But in the physical sciences there is 
only the first history ; the second is never found. Phy- 
siology is to the movements of living bodies, what astro- 
nomy, dynamics, hydraulics, hydrostatics, &,c. are to those 
of inert ones; hut these last have no such correspondent 
sciences as pathology. There is nothing in the physical 
sciences that corresponds to therapeutics in the physio- 
logical. For the same reason, every idea of medicament 
is absurd in the physical sciences. The object of a 
medicament is the restoration of properties to their natu- 
ral type ; but, the physical properties, never losing this 
type, have of course no need of restoration. 
We see then that the peculiar instability of the charac- 
ter of the vital laws is the source of an immense series 
of phenomena, which form a peculiar order of sciences. 
What would become of the universe, if the physical 
laws were subject to the same commotions and the same 
variations as the vital ? Much has been said of the revo- 
lutions of the globe, of the changes that the earth has 
undergone, of the overthrows that ages have gradually 
brought about, and upon which ages have accumulated 
without producing others : but you would see these over- 
throws and these general commotions in nature at every 
instant, if <he physical properties had the same character 
as the vital. 
For the same reason, that the phenomena and laws of 
the physical and physiological sciences are unlike, the 
sciences themselves are essentially different. The man- 
ner of presenting the facts and of prying into their 
causes, the experimental art, &c. every thing bears a 
different stamp ; and it is absurd to confound them. As 
the physical sciences were perfected before the physiolo- GENERAL OBSERVATIONS. 
25 
oical, mankind thought that they could illustrate the lat- 
ter by connecting them with the former; but they have 
confused them; and this was inevitable, for the application 
of the physical sciences to physiology, was the explica- 
tion of the phenomena of living bodies by the laws of 
the inert. Here then is a false principle, and all the 
consequences drawn from it must be erroneous. Let us 
leave to chemistry its affinity, and to physics its elasticity 
and gravity, and let us employ in physiology only sensi- 
bility and contractility ; I except, however, those cases 
where the same organ becomes the seat of vital and 
physical phenomena, as the eye and the ear, for exam- 
ple. It is on this account, that the general character of 
this work is wholly different from those on physiology, 
and even that of the celebrated Haller. The works 
of Stahl illustrate well the advantage of neglecting all 
those pretended accessory aids, which overthrow the sci- 
ence in attempting to support it. But as this great phy- 
sician had not analyzed the vital properties, he could not 
present their phenomena in their true point of view. 
Nothing is more vague and indefinite than the words, 
vitality, vital action, vital influx, &c. when we do not pre- 
cisely limit their meaning. Suppose that mankind had 
created some general and vague words, which were to 
correspond to all the non-vital properties, and which 
gave no precise or definite ideas; if you were every 
where to use these terms, if you did not determine that 
which belonged to gravity, that which depended on af- 
finity, and that which was the result of elasticity, you 
would never be understood. Let us sayr as much in re- 
gard to the physiological sciences. The art is much 
indebted to many physicians of Montpellier for having 
deserted the theory of Boerhaave, and having followed 
in preference that given by Stahl. But in leaving a bad 
path, they have taken another so tortuous, that they will 
never, I think, find its termination. 26 
GENERAL OBSERVATIONS. 
Ordinary minds, in reading, stop at insulated facts that 
are presented; they do not embrace, at one view, the 
principles of the work. Oftentimes the author himself 
incautiously follows the impression given to a science in 
the age in which he writes. But the man of genius 
every where pauses at this impression, which should 
be henceforth entirely different in physical and physiolo- 
gical works. It is necessary to use a different language; 
for most of the words that are carried from the physical 
into the physiological sciences, continually refer to ideas 
that have no connexion with them. You see the living 
solids constantly undergoing composition and decomposi- 
tion, every moment taking and rejecting new substances; 
on the other hand, inert bodies remain the same, and keep 
the same constituent principles, until friction and other 
causes destroy them. So in the elements of inert bodies, 
there is a constant uniformity, and an invariable identity 
in their principles, which is known when they have been 
once analyzed; whilst the pripciples of the living fluids 
are so continually changing, that it is necessary that 
many analyses should be made, under every possible cir- 
cumstance. We shall see the glands and exhaling sur- 
faces pour out, according to the degree of their vital 
forces, a great variety of modifications of the same fluid ; 
what do I say? they pour out a variety of fluids really 
different; for are not the sweat and the urine poured out 
under one circumstance, and the sweat and the urine 
under another, twro distinct fluids ? There are a thou- 
sand examples that wmuld incontestably establish this 
assertion. 
It is the nature of vital properties to exhaust them- 
selves; time wastes them. Elevated in the commence- 
ment of life, they remain stationary at the adult age, and 
afterwards are debilitated and become nothing. Prome- 
theus, it is said, having formed some statues of men, 
snatched fire from heaven to animate them. This fire is GENERAL OBSERVATIONS. 
27 
the emblem of the vital properties ; while it burns, life is 
supported; when it is extinguished, it ceases. It is, then, 
a part of the essence of these properties, to animate 
matter for a determinate time only ; hence there are ne- 
cessary limits to life. On the other hand, the physical 
properties, constantly inherent in matter, never abandon 
it; so that inert bodies have no limits to their existence, 
but what accident gives to them. 
By nutrition the particles of the matter of inanimate 
bodies pass into living bodies, and vice versa; and we 
can evidently conceive that this matter has been endowed 
through an immense series of ages with physical proper- 
ties. These properties are given to it at the creation, 
and will leave it only when the world shall end. This 
matter, in passing into living bodies, in the space that 
separates these two epochs, a space that immensity only 
can bound, this matter, I say, becomes possessed, at inter- 
vals, of vital properties, which are then united to physical 
properties. Here, then, is a great difference in matter, 
with regard to these two kinds of properties; one it 
enjoys by intermissions only, the other it possesses con- 
stantly. 
I could add many other considerations, that would still 
further establish the difference between the physical 
and vital laws, and consequently between the physical 
and vital phenomena, and as a consequence from these, 
the difference of the general character and methods of 
the physical and physiological sciences. I could show, 
that inert bodies are formed at hazard, by juxta-position 
or a combination of their particles, while living bodies, 
on the contrary, exist in consequence of a certain func- 
tion, viz. generation ; that the first increase in the same 
manner as they are formed, by juxta-position or the 
combination of new particles; the others by an inter- 
nal movement of assimilation, which requires different 
preliminary functions ; these constantly experiencing 28 
GENERAL OBSERVATIONS. 
composition and decomposition; those remaining always 
internally in the same condition, undergo no other modi- 
fications than such as are derived from chance and the 
physical laws. The existence of inert bodies ceases 
as it commenced, by mechanical laws, by friction, or by 
new combinations ; living bodies afford in their natural 
destruction, a phenomenon as uniform as in their pro- 
duction; they pass suddenly to a new state when life 
abandons them, and undergo putrefaction, desiccation, 
&c. which they did not before, because the physical pro- 
perties being restrained by the vital, could not produce 
these phenomena; inert bodies, on the other hand, 
always preserve the same modifications. Though a stone 
or a metal, when broken or dissolved, ceases to exist, 
their particles will always be the same. But some au- 
thors have already presented a great part of this parallel; 
let us content ourselves with drawing from it a consequence 
often deduced from other facts, I mean the difference of 
the laws that preside over the two classes of functions. 
But there is an essential difference between vital and 
physical properties ; I refer to sympathies. 
All inert bodies show no communication in their dif- 
ferent parts. Though the extremity of a stone, or of a 
metal, may be altered in any way by chemical dissolu- 
tion, or by mechanical agents, the other parts are not 
affected; it is necessary to touch them by a direct action. 
On the contrary, every thing is so connected and tied 
together in the living body, that no one part can be dis- 
ordered in its functions, without being immediately per- 
ceived by the rest. All physicians have known the sin- 
gular consent that exists between our different organs, 
both in a state of health and disease, but principally in 
the latter. How easy would be the study of diseases, if 
they were stripped of every thing derived from sympa- 
thy ! Who does not know that these complaints often 
predominate over those that arise from the injury of GENERAL OBSERVATIONS. 
29 
the diseased organ ? Who does not know that the cause 
of sleep, of exhalation, of absorption, of secretion, 
of vomiting, of diarrhoea, of retention of urine, of con- 
vulsions, &,c. is oftentimes very far from the brain, from 
the exhalants, from the absorbents, from the glands, from 
the stomach, from the intestines, from the bladder, from 
the voluntary muscles, &,c. ? 
How little soever we reflect on the sympathetic phe- 
nomena, it will be evident that they are only unnatural 
developments of vital forces which are called into ac- 
tion in an organ by the influence that it receives from 
those that have been directly excited. In this view all 
the systems are dependant upon each other. This impor- 
tant point of doctrine will be treated at so much length, 
in this work, particularly under the article on the ner- 
vous system that it is useless to insist much upon it here. 
We shall see sympathies call into action always those 
vital properties especially that prevail in a system; ani- 
mal sensibility in the nerves, contractility of the same 
kind in the voluntary muscles, insensible organic con- 
tractility in the involuntary, sensible contractility in the 
glands, in the serous, mucous, synovial, cutaneous sur- 
faces, &x. We shall see them assume the character of 
the vital properties of the organs in which they are de- 
veloped, their progress will be chronic in the bones, car- 
tilages, &c. acute in the muscles, skin, &c. We shall 
s *e them observe in the frequency of their development, 
t! e laws of nutrition and growth, to appear oftener in the 
nervous and vascular system of the child, in the pulmo- 
nary organs in youth, and in the abdominal contents in 
adult age. But let us pass to other subjects. 
IV. Of the vital properties and their phenomena, consid- 
ered in relation to the solids and fluids. 
Every organized body is composed of fluids and of 
solids. The first are, in one point of view, the materials, 
and in another the residue of the second. 1st. They 30 
GENERAL OBSERVATIONS. 
are the materials, for from the aliments which convey 
through the intestines, the elements of nutrition, even to 
the interior of the organs where these elements are de- 
posited, they form evidently a part of the chyle and 
the blood. 2d. They are the residue, for after having 
remained some time in the organs, these nutritive parti- 
cles are taken up, enter again into the blood, and after- 
wards make a part of the secreted fluids, and of those 
that form cutaneous and mucous exhalations, which are 
thrown out externally. 
There are then fluids for composition and others sub- 
servient to decomposition. The solids are the termina- 
tion of the first, which come from without, and the place 
from which the second are sent back. The fluids of 
composition and decomposition are not all insulated ; the 
chyle, the materials that enter by cutaneous absorption, 
the principles that the lungs draw from the air, &c. are 
especially of the first kind. The fluids secreted and 
exhaled upon the mucous and cutaneous surfaces, appear 
to be exclusively of the second. But the blood is a com- 
mon centre, in which the elements that enter, and those 
that go out, circulate together. 
This being admitted, let us see what part the fluids 
and the solids enjoy in the vital phenomena. This 
must evidently depend on the properties they possess ; 
and in reflecting on the vital properties which we know, 
it is evident, that every idea of fluidity is foreign to them, 
that fluidity cannot be the seat of any contraction nor of 
organic and animal sensibility, &c. 1 will not speak here 
of the pretended spontaneous movements of the blood, 
of the subtle fluids that it contains, according to some 
authors, and which can on occasion expand or contract 
it; all this is but an assemblage of vague ideas, that are 
confirmed by no experiment. Moreover, all the pheno- 
mena of the living economy show us manifestly the 
fluids in a state almost passive, and the solids, on the GENERAL OBSERVATIONS. 
31 
other hand, always essentially active. It is the solids 
that every where receive the excitement, and act in con- 
sequence; the fluids are only the excitants. This con- 
stant impression of the second upon the first, constitutes 
every where continual sensations that are not referred to 
the brain, and which are consequently not perceived ; 
this is organic sensibility, and differs from the animal in 
this, that the mind has no consciousness of these sensa- 
tions, which do not go beyond the organs in which they 
take place. 
Since, on one side, the vital properties are essentially 
seated in the solids, and on the other, the morbid phe- 
nomena are but alterations of these properties, it is evi- 
dent that these phenomena reside especially in the solids, 
and that to a certain limit the fluids are foreign to them. 
Every kind of pain, all spasms and irregular movements 
of the heart, that constitute the innumerable variations of 
the pulse, have their seat in the solids. 
Let us not believe, however, that the fluids are nothing 
in diseases; they oftentimes carry the fatal principle of 
them. They possess, then, in disease, the same place as 
in the state of health, in which the solids are the active 
agents of all the phenomena that we observe, but their 
action is inseparable from that of the fluids. That the 
heart may contract, that the capillary system may close 
itself, it is necessary that fluids should first go there. In 
proportion as the fluids are in their natural state, the ex- 
citement is natural; but when this is changed from any 
cause, as by the introduction of foreign substances, at that 
instant they become unnatural excitants; the functions 
are disordered, and diseases supervene. You see, then, 
that the fluids can oftentimes be the principle of diseases, 
and the vehicle of morbific matter. But this subject 
merits further consideration. 
Here we can apply the distinction of fluids into those 
of composition and those of decomposition. The first, 32 
GENERAL OBSERVATIONS. 
which enter the system in various ways, go into the 
blood, which, on one account, belongs to them, but on 
another, to the fluids of decomposition. It is incontesta- 
ble, 1st. that the chyle can be loaded with a variety of 
foreign substances, and carry into the blood the fatal 
principles of disease, as when putrid and badly digested 
matter, principles of contagion mixed with our aliment, 
&,c. are found in the primae vise. 2d. Is it not established 
by many proofs, that cutaneous absorption oftentimes in- 
troduces into the blood the causes of disease, and, 3dly. 
that substances foreign to the constituent principles of the 
air, and adapted to excite disease, may accidentally get 
into that fluid through the medium of the lungs? these 
things we cannot doubt. Here, then, there are already 
three ways open to the principles of morbific matter, as 
we shall moreover have reason to be convinced in the 
course of this work. 4th. There is another accidental 
one, that arises from wounds, cuts, bites, lacerations, &c. 
by means of which destructive principles are oftentimes 
conveyed into the animal economy. Under these four 
we might produce a variety of cases, in which the fluids 
are the first causes of diseases, by conveying their essen- 
tial principles and becoming unnatural excitants to the 
solids, in which they produce phenomena contrary to the 
natural order. But it is evident, that it is those fluids 
especially destined to the composition of the organs that 
thus carry morbific principles; these are especially their 
vehicle, and convey the disease. On the other hand, the 
fluids destined to the decomposition tend to carry the 
disease out of the system. We have seen that these 
fluids are every where poured upon the mucous and cu- 
taneous surfaces, either by exhalation or secretion, as 
the sweat, the urine, &c.: and it is by these fluids that a 
crisis is produced. Physicians have exaggerated to an 
infinite degree the influence of these morbific humours, 
thus driven out; but we cannot doubt that this doctrine GENERAL OBSERVATIONS. 
33 
has oftentimes a real foundation. If these fluids are some- 
times the vehicles of disease, it is when they enter unnat- 
urally into the system, as when the bile passes into the 
mass of blood, w hen the absorbed urine enters this fluid, 
&c. 
After all that has just been said, it is evident, that 
it is necessary to distinguish accurately diseases them- 
selves, or rather the whole of the symptoms that charac- 
terize them, according to the principles that produce or 
support them. Almost all the symptoms are in the solids, 
but the cause can be in them as well as in the fluids. An 
example will render this more clear; the heart can con- 
tract unnaturally; 1st. because its organic sensibility is 
increased whilst the blood itself remains the same; 2d. 
because the blood is either augmented, as in plethora, 
or altered in its nature, as in putrid fevers, &c. while the 
organic sensibility of the heart does not vary. The ex- 
citement may be double, or the organ may be twice as 
susceptible as common, the effect is the same; an accele- 
ration of the pulse takes place. The solid always takes 
the principal part in the disease; it is always that which 
contracts, but in the first case the cause was in the solid, 
in the second it was not. 
This example gives an idea of what occurs in diseases, 
in all of which the solids are especially in action ; but the 
cause of this action, sometimes exists in them, and some- 
times not. It is no doubt essentially necessary to seek 
the distinction of these cases. The following reflections 
are made with this view. 1st. I distinguish, in the present 
question, diseases into two classes; 1st. into those which 
especially affect animal life; 2d. into those that particu- 
larly disorder organic life. 1 say particularly, for such is 
the connexion of these tw > lives, that the one can hardly 
be altered without the other; thus fevers that affect or- 
ganic life, produce cerebral effects that agitate the ani- 
mal : thus also primitive cerebral affections influence sym- 34 
GENERAL OBSERVATIONS. 
pathetically the circulation, respiration, &c. But cer- 
tainly we cannot deny, that there are some affections, 
whose principal and primitive character is a disorder of 
the animal life; such are convulsions, spasms, paralysis, 
mania, epilepsy, catalepsy, &c. But it appears that the 
cause of these diseases is almost always in the solids, and 
that the fluids most commonly are not affected. There- 
fore you see that crises, in every case are foreign to these 
diseases. Hypochondria, hysteria, melancholia, &c. 
though they appear to reside more particularly in the 
solids, can yet be in a degree dependant on the fluids, 
as different examples will prove. 
Diseases, on the other hand, that particularly affect or- 
ganic life, as fevers, inflammations, &c. may have their 
principle as well in the fluids as in the solids. Hence the 
reason, that these diseases are subject to crisis, and are 
cured by evacuants, alteratives, &c. 
2dly. It is necessary in order to resolve the question 
of the affection of the solids or the fluids in diseases, to 
distinguish their phenomena into those which are sympa- 
thetic, and those that are the product of a direct excite- 
ment. Every sympathetic phenomenon has its seat essen- 
tially and necessarily inherent in the solids. In fine, the 
solids alone act upon each other and correspond together 
by means yet unknown. All sympathetic vomiting, febrile 
agitation of the heart, exhalation, secretion, and absorp- 
tion, arise from a change effected, by the influence of a 
part more or less remote, in the solids of those which are 
the seats of these phenomena. When cold acts upon the 
3kin covered with sweat, immediately the pleura becomes 
affected. If cold water is conveyed into the stomach 
while the body is hot, an effect is oftentimes produced 
upon a distant organ. This is sympathy, and not the re- 
percussion of the humours. In this work I have cited a 
great number of examples of sympathy under each system; GENERAL OBSERVATIONS. 
35 
but in none of them I think is it possible to conceive of 
an affection of the fluids. 
3dly. The division of diseases into organic, or those 
which alter the texture of the organs, and into those which 
leave this texture untouched, is still essential here. The 
first have their seat evidently in the solids. 
4thly. The division into acute and chronic, ought not 
to be neglected in resolving the problem. 
5thly. In fine, it would be necessary to make another 
distinction not less important, viz. that of diseases which 
are independent of every principle inherent in the econo- 
my and of those which proceed from a similar principle, as 
when the virus of the venereal, the tetters, scrofula or 
scurvy predominates in the whole system, and alternately 
attacks the different organs. 
How little soever you may examine diseases under dif- 
ferent points of view, you will perceive that what is 
true of one class cannot be so of another. It is evident 
from this, that it is improper to resolve this question in a 
general manner, as it has been too often done, and that a 
theory of diseases founded upon the principle of the affec- 
tion of the solids or fluids alone, is a pathological absur- 
dity, equal to that in physiology which would place in ac- 
tion the fluids or solids only. I think there are two errors 
that should be equally feared, that of particularizing and 
that of generalizing too much. The second leads us to 
false conclusions as well as the first. 
Though the vital properties reside especially in the 
solids, it is not necessary to consider the fluids as entirely 
inert. It is undeniable, that those of them which form 
the composition of the body, increase in vitality as they 
advance from the aliments of which they are formed, to 
the solids which they compose. The alimentary mass is 
less animalized than the chyle, and this is less so than 
the blood. It would undoubtedly be a subject of very cu- 
rious research, to determine, how the particles, from being 36 
GENERAL OBSERVATION'S. 
foreign to the vital properties, and enjoying only physical 
ones, become by degrees possessed of the rudiments of 
the first. I say the rudiments, for certainly the vital 
elaboration that the fluids experience in circulating as 
such in the body, and before they penetrate the solids to 
become a part of them, is the first degree of their vital 
properties. In the same manner, if you should inject into 
this fluid the materials of those that are exhaled or secret- 
ed, the exhalant and secretory organs would repulse these 
materials, if life had not made them undergo a previous 
elaboration. 
It is evidently impossible to say what this vitality of 
the fluids is; its existence however is not less real, and the 
chemist who wishes to analyze the fluids, has, like the 
anatomist who dissects the solids, only the dead body upon 
which he can operate. You will observe, that when the 
principle of life has left the fluids, they go immediately 
into a state of putrefaction, and are decomposed like the 
solids, deprived of their vital powers. This alone pre- 
vents that internal movement, which undoubtedly enters 
much into the alterations of which the fluids are suscepti- 
ble. Observe what takes place after a meal; ordinarily 
a slight increase of the pulse, the effect of the mixture of 
the nutritive piinciples with the blood, is the consequence 
of it. If you have made use of acrid or spicy aliments, to 
which you are unaccustomed, a general heat, a thousand 
different sensations of lassitude and heaviness, accompany 
digestion. Shall I speak of the various kinds of wine, and 
their effects, even to intoxication ? Who has not a hundred 
times paid dearly for the pleasures of a repast by a gene- 
ral disorder, an universal agitation, a heat in every part 
during the whole time that the wine circulates with the 
blood ? Who has not observed that one kind of wine pro- 
duces one effect and another a different? The solids are 
then without doubt the seat of every thing we experience; 
but is not the cause of it in the fluids? It is the blood, GENERAL OBSERVATIONS. 
37 
which carrying with its own particles others that are 
foreign to it, excites all the organs, and especially the 
brain, because there is a particular relation between this 
viscus and spirituous liquors, as there is between cantha- 
rides and the bladder, and mercury and the salivar 
glands. That which I say is so true, that if you infuse 
wine into the open vein of an animal, you will product 
analogous effects. The experiments made upon this sub- 
ject are so well known that 1 have not even repeated 
them. 
I will relate a fact here which disproves what has lately 
been advanced upon the incorruptibility of the blood in 
diseases. A short time since, in examining a body at 
the Hotel Dieu, with Mess. Peborde, l’Herminier, and 
Bourdet, we found instead of the black abdominal blood, 
a real grey sanies, which filled all the divisions of the 
splenic vein, the trunk of the vena porta, and all the 
hepatic branches, so that by cutting the liver in slices, 
we could distinguish by the flow of this sanies, all the 
ramifications of the vena porta from those of the vena 
cava, which contained ordinary blood. This body was 
so remarkable for its size, that I do not recollect to have 
ever seen one equal to it. Certainly this sanies was not 
the effect of death, and the blood had circulated, if not 
thus altered, at least very different from its natural state, 
and really decomposed. 
Consider the immense influence of aliments upon health, 
structure, and even character. Compare the people who 
live only on milk and vegetables with those who are in 
the constant use of spirituous liquors. See how alkohol, 
carried into the new world, has modified the manners 
and habits of the savages; consider the slow and gradual 
influence of regimen in chronic diseases, and you will 
pe rceive that in health, as in disease, the alteration of 
the fluids is frequently before that of the solids, w hich 
consequently become changed ; for it is an inevitable 38 
GENERAL OBSERVATIONS. 
circle. But the alteration of the fluids appears to depend 
essentially upon the mode of the mixture of parts not 
animalized with those that are so. 
We should have a very inaccurate idea of the mixture 
with the blood of the foreign substances brought by the 
way of the intestines, the skin, or the lungs, for the'pur- 
poses of sanguification, if we compared it to the mixture 
of inert substances, or chemical combinations. The 
blood enjoys, if we may so say, the rudiments of organic 
sensibility ; and as the life which it enjoys places it more 
or less in relation to the fluids that enter it, it is more or 
less disposed to combine with them and to endow them 
with the life with which it is animated. Sometimes it 
repulses for a long time substances that are foreign to it. 
I am persuaded that a great number of the phenomena 
that we experience after taking food, especially acrid 
substances, and spirituous liquors, arises in part from the 
general disorder that the blood undergoes when its vitality 
begins to communicate itself to these foreign substances 
from the kind of struggle which takes place in the vessels, 
between the living fluid and that which does not live. 
Thus we see all the solids rise, as it were, against a 
stimulant they are unaccustomed to. Who knows but 
that the vitality of the fluids has an influence upon their 
motions? I think it is very probable. I doubt whether 
fluids purely inert could, if they were alone in animated 
vessels, circulate like living fluids. In the same manner, 
animated fluids could not move themselves, if they w?ere 
in vessels deprived of life. Life then is equally necessary 
to one and the other. But these subjects are too ob- 
scure to occupy us longer. 
V. Of the properties independent of life. 
These are what 1 call properties of texture. Foreign 
to inert bodies, inherent in the organs of living bodies, 
they arise from their texture, from the arrangement of 
their particles, but not from the life that animates them. GENERAL OBSERVATIONS. 
39 
Thus death does not destroy them. They remain in the 
organs when life is gone; that, however, adds much to 
their energy. Putrefaction and the decomposition of the 
organs, alone destroy them. The two first of these pro- 
perties are extensibility and contractility of texture. I 
have explained these sufficiently in my Treatise on Life. 
I shall have occasion in this work to explain the influence 
they have in each system. I shall now speak of a pro- 
perty of which as yet very little has been said ; which 
chemists have proved by their experiments, and which 
physiologists have confounded often with irritability, but 
which is as distinct from it as it is from the contractility 
of texture ; I mean the property of being* hardened like 
horn, and contracted by the action of different agents. 
This will be examined particularly in each system; 1 
shall now describe it in a general manner only. 
Every organized part, submitted either after death or 
during life, to the action of fire and of certain concen- 
trated acids, is contracted and wrinkled in different ways, 
and is affected almost like irritable organs when they are 
excited. Now this property is to be considered as to the 
agents which put it in action, as to the organs which are 
the seat of it, and as to its phenomena. 
1st. Fire is the principal agent of this horny harden- 
ing. Every living organ, placed upon burning coals, is 
suddenly raised to the highest degree. 2d. Next to fire, 
the strongest acids, the sulphuric first, then the nitric, 
then the muriatic, make the animal fibres contract most 
suddenly. As they are diluted, they lose this power, and 
the acids that are naturally very weak have hardly any 
of it. 3d. Alkohol is much less powerful in producing 
this effect, though it may be highly concentrated. It con- 
* There are no words in English that correspond exactly to the 
words racomir, and racomissement, and I have therefore been compel- 
led to employ the terms, to harden like horn, and homy hardening, to 
express the precise meaning. Tr. 40 
GENERAL OBSERVATIONS. 
tracts, however, the texture of parts, which it condenses 
and even twists. So that those who preserve anatomical 
specimens, find it necessary to dilute the alkohol. 4th. 
The neutral salts, after being moistened by the humidity 
of animal substances, condense and harden them wonder- 
fully after the lapse of a considerable length of time. 
5th. When the air has taken away, by drying, the aque- 
ous particles of the solids, these continuing exposed to 
its action, contract, wrinkle, and twist in a slow and gra- 
dual manner. 6th. The alkalies, however strong they 
may be employed, do not produce any kind of horny har- 
dening. 7th. Water appears to act in a manner opposite 
to this horny hardening; it dilates, spreads the organs by 
maceration, and separates their particles. It is when it is 
combined with much caloric that it produces horny hard- 
ening. This phenomenon takes place at some degrees 
below boiling, and is very remarkable at that point. 
The different agents of which I have just spoken, pro- 
duce, then, two species of horny hardening: 1st. the first 
is prompt, sudden, almost like the motion which results 
from the irritation of a living muscle : 2d. the other slow, 
gradual, and even insensible. Fire and the strong acids 
are in a special manner the agents of the first. The ac- 
tion of the neutral salts, of the air, of alkohol, princi- 
pally produce the second. 
These two species differ very much in their results. 
The state to which the first reduces the organ, is soon 
changed if the hardening cause continues. 1st. Fire con- 
tinuing to act upon the solids, reduces them to a hard 
and coaly mass. 2d. Boiling water, after a length of 
time, destroys by degrees the hardness the solids had 
suddenly acquired, by being plunged into it. As the 
hardness diminishes, the effect of the boiling increases, 
and it arrives at the greatest extent, when the solid, 
having lost all consistence, becomes pulpy. 3d. Animal 
organs that have been acted upon suddenly by the acids.. GENERAL OBSERVATIONS. 
41 
and become consequently hard, soon grow soft and 
change into a true pulp. This double phenomenon, 
that is presented on the one hand by boiling, and on 
the other by the strong acids, has a great analogy, and 
seems to be derived from the same principle. 
The slow and ipsensible horny hardening, the effect of 
the contact of neutral salts, such as alum, the muriate of 
soda, &lc. of the air and of alkohol, offers a very different 
phenomenon from the first. It is not altered by the con- 
tinued action of the cause that produced it, however long 
it may be; it does not soften in a slow and insensible 
manner, as it has hardened, but remains always firm and 
contracted. 
Are these two species only different degrees of the 
same, or are they derived from separate principles? I 
know not. I have only observed, that when the living 
solids have undergone the slow and gradual horny harden- 
ing, they are still susceptible of the other. We know that 
after many years drying, animal textures are hardened, 
a9 in a recent state, by the action of fire ; I have made 
the same observation with regard to boiling and the acids. 
Textures that have been contracted for a long time by 
alkohol and the neutral salts present the same pheno- 
menon. 
Ail animal textures are susceptible of sudden harden- 
ing, except the hair, the epidermis, and the nails ; these, 
if we may so say, exhibit only the rudiments of it. In 
general the hardening is more sensible, in proportion as 
the fibrous texture predominates in the organs. Hence 
the muscles, the tendons, and nerves, are the most sus- 
ceptible of it. The organs not fibrous, as the glands, show 
the least degree of it. The slow and insensible horny 
hardening is almost the same in every part. Both exist 
in textures deprived of animal contractility, of sensible 
organic contractility, and of contractility of texture, as 
well as in those which enjoy them in the highest degree. GENERAL OBSERVATIONS. 
42 
Thus the tendons, the aponeuroses, the bones, even when 
their calcareous substance has been removed by acids, 
may be hardened as well as the muscles and the skin. 
This single circumstance would suffice to distinguish the 
contractility arising from hardening from all others, if a 
variety of differences, which 1 shall point out hereafter, 
under the article of the muscles in particular, did not. 
When a texture is suddenly hardened, it loses more 
than half its length, and becomes twisted in various ways. 
Taken suddenly from the acid or boiling water, it remains 
hardened; but if it is pulled, it becomes elongated, and 
then contracts again, when the force applied ceases, so 
that it has acquired a real elasticity by the process of 
hardening. This elasticity is remarkable in the tendons, 
nerves and muscles, which before this are absolutely des- 
titute of it. This elasticity is not an effect of the slow 
and insensible hardening of alkohol ard the neutral salts. 
By macerating for a length of time the organized tex- 
tures, they gradually lose the power of contracting sud- 
denly, which does not, however, entirely disappear, until 
the maceration has reduced the textures to mere pulp. 
If the textures are softened by boiling, and stretched 
out to their original length, after having been hardened, 
this cannot be produced again by any agent that we may 
employ. 
When the textures are in a state of putrefaction, they 
no longer possess this kind of contractility. 
Slow and insensible hardening cannot take place dur- 
ing life; this is an insurmountable obstacle to it. But 
that which is sudden may, when its agents have over- 
come the resistance that vitality offers. Oftentimes we 
see the skin hardened by burns. When it is stripped of 
its epidermis, and a very strong acid is poured upon it, 
the same,effect is produced as upon any other organ. 
When a part has been hardened upon a living subject, 
it almost inevitably dies; it cannot be restored to the GENERAL OBSERVATIONS. 
43 
suppleness that it possessed before ; suppuration separates 
it from the sound parts. 
The fluids do not present the phenomenon of hardening, 
the fibrine only excepted. Separated from the blood, it 
crisps and contracts. 
After what has been said, it is evident that the so- 
lids possess the faculty of contracting or shortening. 
This is brought into action in many different ways. 
During life it appears, 1st. in the influence of the nerves 
upon the voluntary muscles; this is animal contractility". 
2d. In the involuntary muscles by the action of stimuli ; 
this is sensible organic contractility. 3d. In the mus- 
cles, the skin, the cellular texture, the arteries, the veins, 
&c. from a want of extension. This is the contractility 
of texture, which is not found, or at least is very obscure, 
in many of the organs, as the nerves, the fibrous bodies, 
the cartilages, the bones, &c. 4th. By the action of fire, 
and the strong acids; this is the contractility of the 
horny hardening, and is general. 
When the muscles are deprived of life, they lose the 
two first kinds of contractility ; but the third remains 
with them as it does with all the organs that enjoy it. 
When they are dried or remain in water a little time, 
they lose that also; but the fourth still continues with 
them ; it is the last that abandons the animal textures ; 
it is perpetuated for a length of years. When I have 
exposed to the action of fire the cartilaginous parenchyma 
of bones found in cemeteries, they have become harden- 
ed. I am persuaded that this faculty would last for many 
ages, if we could preserve the organic textures. 
Contractility is, then, a common and general property, 
inherent in all animal textures, but which, according to 
the manner that it is brought into action, presents essen- 
tial differences, which divide it into many species, that 
have no analogy. It would certainly be impossible to 
avoid distinguishing the difference between the four 44 
GENERAL OBSERVATIONS. 
species I have pointed out, and that insensible contrac- 
tion, or kind of oscillation, which forms during life the 
insensible organic contractility, or tonic motions. 
Among the causes that bring contractility into action, 
some belong, then, to life, others are independent of it, 
and are derived only from organization. All the organs 
are essentially contractile ; but each of the causes which 
makes them contract acts only upon this or that texture : 
the horny hardening alone has a general effect. 
VI. Observations upon the organization of animals. 
The properties, whose influence we have just analyzed, 
are not absolutely inherent in the particles of matter 
that are the seat of them. They disappear when these 
scattered particles have lost their organic arrangement. 
It is to this arrangement that they exclusively belong; 
let us treat of it here in a general way. 
All animals are an assemblage of different organs, which, 
executing each a function, concur in their own manner, 
to the preservation of the whole. It is several separate 
machines in a general one, that constitutes the individual. 
Now these sepaiate machines are themselves formed by 
many textures of a very different nature, and which really 
compose the elements ot these organs. Chemistry has 
its simple bodies, which form, by the combinations of 
which they are susceptible, the compound bodies; such 
are caloric, light, hydrogen, oxygen, carbon, azote, phos- 
phorus, &lc. In the same way anatomy has its simple 
textures, which, by their combinations four with four, six 
with six, eight with eight, &e. make the organs. These 
textures are, 1st. the cellular; 2d. the nervous of animal 
life; 3d. the nervous of organic life; 4th. the arterial; 
5th. the venous; 6th. the texture of the exhalants; 7th. 
that of the absorbents and their glands ; 8th. the osseous; 
9th. the medullary; 10th. the cartilaginous; 11th. the 
fibrous; 12th. the fibro-cartilaginous; 13th. the muscular 
of animal life; 14th. the muscular of organic life; 15th. general observations. 
45 
the mucous; 16th. the serous; 17th. the synovial; 18th. 
the glandular; 19th. the dermoid ; 20th. the epidermoid; 
21st. the pilous. 
These are the true organized elements of our bodies. 
Their nature is constantly the same, wherever they are 
met with. As in chemistry, the simple bodies do not alter, 
notwithstanding the different compound ones they form. 
The organized elements of man form the particular object 
of this work. 
The idea of thus considering abstractedly the different 
simple textures of our bodies, is not the work of the imag- 
ination ; it rests upon the most substantial foundation, 
and I think it will have a powerful influence upon phy- 
siology as well as practical medicine. Under whatever 
point of view we examine them, it will be found that they 
do not resemble each other ; it is nature and not science 
that has drawn the line of distinction between them. 
1st. Their forms are every where different; here they 
are flat, there round. We sec the simple textures arrang- 
ed as membranes, canals, fibrous fasciae, &c. No one has 
the same external character with another, considered as 
to their attributes of thickness or size. These differences 
of form, however, can only be accidental, and the same 
texture is sometimes seen under many different appear- 
ances ; for example, the nervous appears as a membrane 
in the retina, and as cords in the nerves. This has noth- 
ing to do with their nature; it is then from the organiza- 
tion and the properties, that the principal differences 
should be drawn. 
2dly. There is no analogy in the organization of the 
simple textures. We shall see that this organization re- 
sults from parts that are common to all, and from those 
that are peculiar to each ; but the common parts are all 
differently arranged in each texture. Some unite in abun- 
dance the cellular texture, the blood vessels and the 
nerves; in others, one or two of these three common 46 
GENERAL OBSERVATIONS. 
parts are scarcely evident or entirely wanting. Here 
there are only the exhalants and absorbents of nutrition; 
there the vessels are more numerous for other purposes. 
A capillary net-work, wonderfully multiplied, exists in cer- 
tain textures, in others this net-work can hardty be de- 
monstrated. As to the peculiar part, which essentially 
distinguishes the texture, the differences are striking. 
Colour, thickness, hardness, density, resistance, &c. 
nothing is similar. Mere inspection is sufficient to show 
a number of characteristic attributes of each, clearly dif- 
ferent from the others. Here is a fibrous arrangement, 
there a granulated one; here it is lamellated, there circular. 
Notwithstanding these differences, authors are not agreed 
as to the limits of the different textures. I have had re- 
course, in order to leave no doubt upon this point, to the 
action of different re-agents. I have examined every tex- 
ture, submitted them to the action of caloric, air, water, 
the acids, the alkalies, the neutral salts, &c. drying, putre- 
faction, maceration, boiling, &,c. the products of many of 
these actions have altered in a different manner each kind 
of texture. Now it will be seen that the results have 
been almost all different, that in these various changes, 
each acts in a particular way, each gives results of its 
own, no one resembling another. There has been con- 
siderable inquiry to ascertain whether the arterial coats 
are fleshy, whether the veins are of an analogous nature, 
&c. By comparing the results of my experiments upon the 
different textures, the question is easily resolved. It would 
seem at first view that all these experiments upon the 
intimate texture of systems, answer but little purpose ; 1 
think however that they have effected an useful object, in 
fixing with precision the limits of each organized texture ; 
for the nature of these textures being unknown, their dif- 
ference can be ascertained only by the different results 
they furnish. GENERAL OB 2RVATI0NS. 
47 
3d!y. In giving to each system a different organic 
arrangement, nature has also endowed them with differ- 
ent properties. You will see in the subsequent part of 
this work, that what we call texture presents degrees in- 
finitely varying, from the muscles, the skin, the cellular 
membrane, &,c. which enjoy it in the highest degree, to 
the cartilages, the tendons, the bones, &,c. which are al- 
most destitute of it. Shall 1 speak of the vital properties ? 
See the animal sensibility predominant in the nerves, con- 
tractility of the same kind particularly marked in the vol- 
untary muscles, sensible organic contractility, forming the 
peculiar property of the involuntary, insensible contrac- 
tility and sensibility of the same nature, which is not sep- 
arated from it more than from the preceding, character- 
izing especially the glands, the skin, the serous surfaces, 
&c. &,c. See each of these simple textures combining, in 
different degrees, more or less of these properties, and 
consequently living with more or less energy. 
There is but little difference arising from the number 
of vital properties they have in common; when these 
properties exist in many, they take in each a peculiar and 
distinctive character. This charac ter is chronic, if I may 
so express myself, in the bones, the cartilages, the ten- 
dons, &,c.; it is acute in the muscles, the skin, the glands, 
&c. 
Independently of this general difference, each texture 
has a particular kind of force, of sensibility, &,c. Upon 
this principle rests the whole theory of secretion, of ex- 
halation, of absorption, and of nutrition. The blood is a 
common reservoir, from which each texture chooses, that 
which is adapted to its sensibility, to appropriate and keep 
it, or afterwards reject it. 
Much has been said since the time of Bordeu, of the 
peculiar life of each organ, which is nothing else than that 
particular character which distinguishes the combination 
of the vital properties of one organ, from those of another. 48 
GENERAL OBSERVATIONS. 
Before these properties had been analyzed with exactness 
and precision, it was clearly impossible to form a < or- 
rect idea of this peculiar life. From the account I have 
just given of it, it is evident that the greatest part of the 
organs being composed of very different simple textures, 
the idea of a peculiar life can only apply to these simple 
textures, and not to the organs themselves. 
Some examples will render this point of doctrine which 
is important, more evident. The stomach is composed 
of the serous, organic muscular, mucous, and of almost all 
the common textures, as the arterial, the venous, &c. 
which we can consider separately. Now if you should 
attempt to describe in a general manner, the peculiar life 
of the stomach it is evidently impossible that you could 
give a very precise and exact idea of it. In fact the mu- 
cous surface is so different from the serous, and both so 
different from the muscular, that by associating them 
together, the whole would be confused. The same is 
true of the intestines, the bladder, the womb, &c.; if 
you do not distinguish what belongs to each of the tex- 
tures that form the compound organs, the term peculiar 
life will offer nothing but vagueness and uncertainty. 
This is so true, that oftentimes the same textures alter- 
nately belong or are foreign to their organs. The same 
portion of the peritoneum, for example, enters or does not 
enter, into the structure of the gastric viscera, according 
to their fulness or vacuity. 
Shall l speak of the pectoral organs ? What has the life 
of the fleshy texture of the heart in common with that of 
the membrane that surrounds it ? Is not the pleura indepen- 
dent of the pulmonary texture? Has this texture nothing 
in common with the membrane that surrounds the bron- 
chia? Is it not the same with the brain in relation to its 
membranes, of the different parts of the eye, the ear. &c. ? 
When we study a function, it is necessary carefully to 
consider in a general manner, the compound organ that GENERAL OBSERVATIONS. 
49 
performs it; but when you wish to know the properties 
and life of this organ, it is absolutely necessary to decom- 
pose it. In the same way, if you would have only general 
notions of anatomy, you can study each organ as a whole; 
but it is essential to separate the textures, if you have a 
desire to analyze with accuracy its intimate structure. 
VII. Consequences of the preceding principles relative to 
diseases. 
What I have been saying leads to important conse- 
quences, as it respects those acute or chronic diseases that 
are local; for those, which like most fevers, affect almost 
simultaneously every part, cannot be much elucidated by 
the anatomy of systems. The first then will engage our 
attention. 
Since diseases are only alterations of the vital proper- 
ties, and each texture differs from the others in its pro- 
perties, it is evident there must be a difference also in the 
diseases. In every organ then, composed of different 
textures, one may be diseased, while the others remain 
sound; now this happens in a great many cases; let us 
take the principal organs, for example. 
1st. Nothing is more rare than affections of the mass of 
the brain ; nothing is more common than inflammation of 
the tunica arachnoides that covers it. 2d. Oftentimes one 
membrane of the eye only is affected, the others preserv- 
ing their ordinary degree of vitality. 3d. In convulsions 
or paralysis of the muscles of the larynx, the mucous sur- 
face is unaffected; and on the other hand the muscles 
perform their functions as usual in catarrhs of thi3 sur- 
face. Both these affections are foreign to the cartilages, 
and vice versa. 4th. We observe a variety of different 
alterations in the texture of the pericardium, but hardly 
ever in that of the heart itself; it remains sound while 
the other is inflamed. The ossification of the com- 
mon membrane of the red blood does not extend to the 
neighbouring textures. 5th. When the membrane of the 50 
GENERAL OBSERVATIONS. 
bronchia is the seat of catarrh, the pleura is hardly affect- 
ed at all, and reciprocally in pleurisy the first is scarcely 
ever altered. In peripneurnony, when an enormous infil- 
tration in the dead body shows the excessive inflamma- 
tion that has existed during life in the pulmonary texture, 
the serous and mucous surfaces often appear not to have 
been affected. Those who open dead bodies know that 
they are frequently healthy in incipient phthisis. 6th. 
We speak of a bad stomach, a weak stomach; this most 
commonly should be understood as applying to the mucous 
surface only. Whilst this secretes with difficulty the nu- 
tritive juices, without which digestion is impaired, the 
serous surface exhales as usual its fluid, the muscular coat 
continues to contract, &c. In ascites, in which the serous 
surface exhales more lymph than in a natural state, the 
mucous oftentimes performs its functions perfectly well, 
&c. ,7th. All authors have said much of the inflammation 
of the stomach, the intestines, the bladder, &c. For my- 
self I believe that this disease rarely ever affects at first 
the whole of any of these organs, except in the case where 
poison or some other deleterious substance acts upon them. 
There are for the mucous surface of the stomach and intes- 
tines, acute and chionic catarrhs, for the peritoneum se- 
rous inflammations, perhaps even for the layer of organic 
muscles that separates the two membranes, there is a par- 
ticular kind of inflammation, though we have as yet hardly 
any thing certain upon this point; but the stomach, the 
intestines, and the bladder are not suddenly affected with 
these three diseases. A diseased texture can affect those 
near it, but the primitive affection seizes only upon one. 
I have examined a great number of bodies in which the 
peritoneum was inflamed either upon the intestines, the 
stomach, the pelvis, or universally; now very often when 
this affection is chronic, and almost always it is 
acute, the subjacent organs remain sound. 1 have never 
seen this membrane exclusively diseased upon one organ, GENERAL OBSERVATIONS. 
51 
while that of the neighbouring ones remain untouched; its 
affection is propagated more or less remotely. I know 
not why authors have hardly ever spoken of its inflamma- 
tion, and have placed to the account of the subjacent vis- 
cera that which most often belongs only to this. There 
are almost as many cases of peritonitis as of pleurisy, and 
yet while these last have been particularly noticed the 
others are almost entirely overlooked. Oftentimes that 
part of the peritoneum corresponding to an organ, is much 
inflamed ; we see it in the case of the stomach ; we ob- 
serve especially after the suppression of the lochia or the 
menses, that it is the portion that lines the pelvis that is 
first affected. But soon the affection becomes more or 
less general; at least examinations after death prove 
it satisfactorily. 8th. Certainly the acute or chronic 
catarrh of the bladder, or womb even, has nothing in com- 
mon with the inflammation of that portion of the perito- 
neum corresponding with these organs. 9th. Every one 
knows that diseases of the periosteum have oftentimes no 
connexion with the bone, and vice versa, that frequently 
the marrow is for a long time affected, while both the 
others remain sound. There is no doubt that the osseous, 
medullary and fibrous textures have their peculiar affec- 
tions which we shall not confound with the idea we may 
form of the diseases of the bones. The same can be said 
of the intestines, of the stomach, &c. in relation to their 
mucous, serous, muscular textures, &c. 10th. Though the 
muscular and tendinous textures are combined in a muscle, 
their diseases are very different. 11th. You must not 
think that the synovial is subject to the same diseases as 
the ligaments that surround it, &c. 
I think the more we observe diseases, and the more 
we examine bodies, the more we shall be convinced of 
the necessity of considering local diseases, not under 
the relation of the compound organs, which are rarely 52 
GENERAL OBSERVATIONS. 
ever affected as a whole, but under that of their different 
textures, which are almost always attacked separately. 
When the phenomena of diseasesare sympathetic, they 
follow the same laws as when they from a direct affec- 
tion. Much has been said of the sympathies of the stom- 
ach, the intestines, the bladder, the luniks, &c. But it is 
impossible to form an idea of them, if they are referred to 
the organ as a whole, separate from its different textures. 
1st. W hen in the stomach, the fleshy fibres contract by 
the influence of another organ and produce vomiting, they 
alone receive the influence, which is not extended either 
to the serous or mucous surfaces; if it were, they would 
be the seat, the one of exhalation, the other of sympathetic 
exhalation and secretion. 2d. It is certain that when the 
action of the liver is sympathetically increased, so that it 
pours out more bile, the portion of peritoneum that covers 
it dues not throw out more serum, because it is not affect- 
ed by it. It is the same of the kidney, the pancreas, &c. 
3d. For the same reason, the gastric organs upon which 
the peritoneum is spread, do not partake of the sympa- 
thetic influences that it experiences. 1 shall say as much 
of the lungs in relation to the pleura, the brain in relation 
to the tunica arachnoides, the heart to the pericardium, &c. 
4th. It is undeniable that in all sympathetic convulsions, 
the fleshy texture is alone affected, and that the tendinous 
is not so at all. 5th. What has the fibrous membrane of 
the testicles in common with the sympathies of its peculiar 
texture? 6th. No doubt a number of sympathetic pains 
that we refer to the bones, are seated exclusively in the 
marrow. 
1 could cite many other examples to prove, that it is not 
this or that organ which sympathizes as a whole, but only 
this or that texture in the organs; besides, this is an im- 
mediate consequence of the nature of sympathies. In fact 
the sympathies are but aberrations of the vital properties; GENERAL OBSERVATIONS. 
53 
now these properties vary according to each texture; the 
sympathies of these textures then would do the same. 
Observe what takes place in fever, accompanying the 
different kinds of inflammation. That attending the mu- 
cous is slight, that with the serous severe, and that with 
the cutaneous has the peculiar character of showing itself 
some days before the eruption, as has been noticed by 
Pinel. If we attentively observe the fever which attends 
the inflammations of all the systems, we shall find as many 
differences, as many peculiar characters, as there are sys- 
tems. Whence does this arise? From the difference of 
the relations that unite the heart to each kind of texture; 
now this difference of relations is the result of the differ- 
ence of the vital forces peculiar to each. 
Observe the itch, herpes, cancer, venereal disease, &c. 
when they have ceased to be local affections, they spread 
themselves universally; they alternately attack different 
textures, according to the relation which they have with 
the organic sensibility of these textures. But it is almost 
always separately that they attack them; an organ is 
never as a whole influenced by them in all its parts. 
What do I say ? If two of these diseases exist at the same 
time, one seizes upon one texture, the other upon a differ- 
ent one of the same organ. Thus the stomach, the intes- 
tines, the lungs, &,c. can be attacked by two different dia- 
theses, and each will be independent of the other, because 
each will be fixed upon a different texture, one upon the 
mucous, for example, the other upon the serous, &c. 
Let us not, however, exaggerate this independence of 
the textures of the organs in diseases, lest experience 
should contradict us. We shall see that the cellular 
system is oftentimes a medium of communication, not 
only from one texture to another in the same organ, but 
from one organ to a neighbouring one. Thus in many 
chronic diseases, all the parts of the same organ are 
gradually changed, and at the examination of this organ 54 
GENERAL OBSERVATIONS. 
after death, the whole of it appears to have been affect- 
ed. though one of its textures only was so at first. In 
the cancer of the breast, you find at first only a small 
gland that rolls under the finger; finally the glandular, 
the cellular, and even the cutaneous textures are con- 
founded in one common cancerous mass. Cancer of the 
stomach, the intestines, the penis, &c. follows the same 
course. Observe phthisis, exhibiting in the beginning 
some small tubercles in the pulmonary texture, at length 
invading oftentimes the pleura, the bronchial membrane, 
&c. How little soever you may examine bodies with a 
view to the same chronic disease, and at different periods, 
you will be convinced of the truth of this assertion, viz. 
that a texture being at first affected in an organ, commu- 
nicates its affection gradually to others, and that you will 
be deceived in judging of the primitive seat of the dis- 
ease, if you attempt to determine it from the parts found 
affected at the time of the examination. 
In acute diseases, continuity is oftentimes sufficient to 
explain the different symptoms that appear in textures 
that are not affected. The peritoneal coat only being 
inflamed, vomiting is produced. We cough and some- 
times expectorate considerably when the pleura alone is 
diseased. Delirium comes on when the tunica arachnoides 
is inflamed, though the intellectual functions are not con- 
nected with it. Frequently the diseases of the pericar- 
dium are sufficient to disturb the motion of the heart, &c. 
We cannot deny alter this, that oftentimes an alteration 
in one of the textures alone of an organ is sufficient to 
disturb the functions of all the others; but still it is in 
one only, that the primitive source of the evil exists. 
1 now pass to some other considerations relative to the 
influence of the anatomy of systems in diseases. 
Since every organized texture has every where the 
same arrangement; since, whatever be its situation, it 
has the same structure and the same properties, it is GENERAL OBSERVATIONS. 
55 
evident that its diseases must be every where the same. 
It makes no difference, that the serous texture is connect- 
ed with the brain by the tunica arachnoides, with the 
lungs by the pleura, with the heart by the pericardium, 
with the gastric viscera by the peritoneum, &,c. every 
where it is inflamed in the same manner ; every where 
dropsies take place in the same way; every where it is 
subject to a species of eruption of little whitish tubercles, 
like the miliary, of which I believe there has been no 
description, but which deserves great attention ; I have 
already many times observed this peculiar eruption of the 
serous texture, which is generally of a chronic character, 
like most of the cutaneous eruptions; I shall speak of it 
hereafter. Whatever may be the organ that the mucous 
texture invests, its affections have in general the same 
character, excepting the difference only that arises from 
variety of structure. I will say the same of the fibrous, 
cartilaginous textures, &c. Mr. Pinel appears to me to 
have done much for the art, in being the first who ar- 
ranged inflammations in the order of the systems, and 
embracing in one general view' all those of the same sys- 
tem, whatever may be the organs in which it is found. 
There are always two orders of symptoms in inflam- 
mations; 1st. those that belong to the nature of the dis- 
eased textures; 2d. those which depend upon the affect- 
ed organ, in which the inflammation exists. For example, 
the kind of pain, the nature of the accompanying fever, 
the duration, the termination, &c. are almost always the 
same, whatever serous surface is affected. But difficulty 
of breathing, dry cough, &c. prove it to be the pleura ; 
diarrhoea, constipation, vomiting, &c. that it is the peri- 
toneum ; injury of the intellectual functions, that it is the 
tunica arachnoides; irregular pulse, that it is the peri- 
cardium, &,c. The first belong to the whole class, the 
second set of symptoms is confined exclusively to this or 
that particular sort; now the second are, if we may so 56 
GENERAL OBSERVATIONS. 
say, accessory, depending upon the proximity of the af- 
fected texture with some other texture. The first are 
particularly important. 
Medicine has yet much to do, in its researches upon 
the inflammation of the different textures. We are well 
acquainted with that of the cellular, the cutaneous, the 
serous, and the mucous; but that of the others is very 
obscure. It is yet to be ascertained, which is attacked, 
the fibrous or muscular, in rheumatism. I am inclined 
to think that it is the first. Almost every thing remains 
to be known in the cartilaginous, the synovial, the arte- 
rial, the venous, &c. as it respects their inflammatory 
phenomena. 
In making these researches, it will be necessary to 
establish one important distinction ; that is, 1st. that cer- 
tain textures, as the osseous, the muscular of animal life, 
Sic. are precisely the same in all the organs in which 
they are found, and consequently that their diseases must 
be the same ; 2d. that others, as the cutaneous, the serous, 
the mucous, &c. experience, according to the organs to 
which they belong, some variety of structure and vital 
properties, which necessarily modify the general pheno- 
mena of the class of diseases that belong to these tex- 
tures; 3d. that others, as the glandular, the muscular of 
organic life, &c. are very different in each organ ; and 
that their general symptoms and class of diseases must 
consequently differ considerably. 
After having shown most of the local diseases, as af- 
fecting almost always, not an individual organ, but some 
texture in an organ, it is necessary to show the differences 
they present according to the textures they affect. As 
under each system, this subject will be treated more or 
less fully, I shall only refer to it here. 
We shall see, then, that pain is modified differently in 
each texture, according to the degree of sensibility that 
it possesses. No one excites the same sensations as the GENERAL OBSERVATIONS. 
57 
others when it is inflamed. Compare the burning of 
erisy pdas with the throbbing of phlegmon, the pain of 
rheumatism with that of inflamed lymphatic glands, &c. 
We shall see also that the sense of heat, developed in 
each inflamed texture, has a particular character; here 
it is sharp and biting, there like the feeling produced by 
fire, &,c. There are two general causes that produce a 
variation in the symptoms of diseases : 1st. the nature of 
the affected texture ; thus, as I have just said, the inflam- 
mation of each produces a different kind of suffering. 2d. 
The nature of the disease ; we know that cancer, whatever 
texture it may affect, has a pain that is peculiar to it; that 
syphilis and scurvy have also a peculiar character, that 
is, however, modified in a slight degree in each texture. 
The difference of textures not only modifies the symp- 
toms, but affects the duration of them also. Nothing in 
medicine is more vague, in this point of view, than the 
terms acute and chronic, in relation to inflammations of 
the different textures. Most commonly they run their 
course rapidly in the dermoid, cellular, serous, mucous 
textures, &c.; on the other hand, they are slow in the 
bones, the cartilages, and the fibro-cartilages. If we 
apply this distinction to the same texture, it is very well; 
thus there are catarrhs, serous and cutaneous inflamma- 
tions, &c. that are acute and chronic. But if we gene- 
ralize it, it cannot be understood. A catarrh would be 
chronic if it lasted two months; but this is the common 
term of an acute inflammation of the bones; a chronic 
one continues for a whole year or more. Cutaneous, 
mucous wounds, &,c. last only five or six days if they heal 
by the first intention ; while it requires thirty or forty for 
a bone, a cartilage, &c. to be cicatrized by the juxtapo- 
sition of its different parts. A disease cannot be classed, 
then, by its duration, as an acute or chronic one, except 
in relation to the same system ; when we describe it then 
in a general way, this distinction becomes void* GENERAL OBSERVATIONS. 
58 
Physicians consider abstractedly almost all diseases, 
When they speak of inflammation they describe the red- 
ness, swelling, throbbing and pain, as general attributes, 
always uniform. If of suppuration, they take for a general 
standard that of the cellular texture, in phlegmon, with- 
out thinking that it is only one of the modifications of sup- 
puration and its product. The same may be said of gan- 
grene, scirrhus, &c. Nothing is more vague and uncer- 
tain than the general ideas that are given concerning a 
disease; they scarcely agree in one or two of the tex- 
tures. 
It is not only the history of diseases that the anatomy 
of systems will elucidate ; it will change in part the 
method of treating morbid anatomy. Morgagni, to whom 
we owe so much in this respect, and many others, to 
whom the art is indebted, have adopted the general ar- 
rangement used in descriptions. They have examined 
the diseases of the head, the chest, the abdomen, and the 
extremities. In following this method, they can only 
form to themselves a general idea of the alterations com- 
mon to all the textures. The ideas are necessarily too 
much contracted, when there is presented only an insu- 
lated part of a system, which is composed of a great 
many others. If, besides this, you obtain a general 
knowledge of the affections of each system, you must 
bear in mind, with regard to each, the general ideas con- 
cerning the affections of the parts they compose. 
It appears to me to be infinitely more simple to con- 
sider at first all the affections common to each system, 
and then to observe what every organ has peculiar to 
itself in the part that it occupies. 
I divide, then, morbid anatomy into two great parts. 
The first contains the history of the alterations common to 
each system, whatever may be the organ in the structure 
of which it is concerned, or whatever may be the place 
it occupies. It is necessary to show at first the different GENERAL OBSERVATIONS. 
59 
alterations of the cellular, arterial, venous, nervous, osse- 
ous, muscular, mucous, serous, synovial, glandular, cuta- 
neous textures, &c. to examine the kind of inflammation, 
suppuration, gangrene, &,c. peculiar to each ; to speak of 
the different enlargements of which they are susceptible, 
the changes in their nature, which they undergo, &c. 
Some, as the mucous, the cutaneous, the serous, the glan- 
dular, &c. afford in this respect an immense field to 
morbid anatomy. The others, as the fibrous, the nervous, 
the muscular, &c. are more rarely changed in their tex- 
ture. We shall see hereafter that nutrition alone is per- 
formed in these, and that the others are particularly the 
seat of exhalation, absorption, secretion, &c. functions 
which suppose much energy in the insensible contractility 
and organic sensibility, which are connected with all the 
alterations of texture. 
After having thus pointed out the alterations peculiar 
to each system, in whatever organ it is found, an exami- 
nation should be made of the diseases peculiar to each 
region; as those of the head, the chest, the abdomen, 
and the extremities, after the common method. Here 
they may be divided, 1st. into diseases which can espe- 
cially affect an organ as a whole, and not one of its tex- 
tures alone, which is very rare. 2d. Into the characters 
peculiar to each portion of this or that texture; for ex- 
ample in the head, the peculiar symptoms which are seen 
in diseases of the serous surface of the tunica arachnoides, 
those in affections of the mucous surface of the pituitary 
membrane, &c. 
This course is incontestably the most natural, though, 
as in all divisions in which we wish to copy nature, there 
are many cases which it almost excludes. 
It seems to me that we live at a period, when morbid 
anatomy should take a higher stand. This science is not 
only that of organic derangements, that take place slowly, 
as the principles or consequences of chronic diseases, 60 
GENERAL OBSERVATIONS. 
it consists in the examination of all the alterations our 
organs can undergo, at any period in which we may ob- 
serve their diseases. With the exception of certain kinds 
of fevers and nervous affections, every thing in pathology 
is within the province of this science. How weak ap- 
pears the reasoning of many great physicians, when we 
examine it, not in their works, but on the dead body. 
Medicine was for a long time excluded from the circle 
of the exact sciences; it will have a right to be associated 
with them, at least in the diagnostics of diseases, when 
we shall every where unite to accurate observation, an 
examination of the changes our organs undergo. This 
course is beginning to be that of all rational minds; it 
will without doubt soon be general. What is observation 
worth, if we are ignorant of the seat of the disease ? 
You may take notes, for twenty from morning to 
night at the bedside of the sick, upon the diseases of the 
heart, the lungs, the gastric viscera, &c. and all will be 
to you only a confusion of symptoms, which, not being 
united in one point, will necessarily present only a train 
of incoherent phenomena. Open a few bodies, this ob- 
scurity will soon disappear, which observation alone 
would never have been able to have dissipated. 
VIII. Remarks upon the classification of functions. 
The plan that I have followed in this work, is not the 
most favourable to the study of the functions. Many of 
them, such as digestion, respiration, &e. would find no 
place here, because they do not belong especially to the 
simple systems, but to a combination of them, an union 
of many systems, and even of many organs. Thus what 
I have said upon the functions, is introduced only 
incidentally in this work, the particular object of which 
is the analysis of the different simple systems that 
form the compound organs. However, as some would 
wish to connect the different facts of physiology that 
it contains, with a physiological classification, 1 will now GENERAL OBSERVATIONS. 
61 
explain that which I have adopted in my course of lec- 
tures. 
We know how different the kinds of classification are. 
The ancient division, into animal, vital, and natural func- 
tions, rests upon so weak a foundation, that a methodical 
superstructure could not be raised upon it. Vicq d’Azyr 
has substituted one for it which offers hardly any more 
advantages, as it separates phenomena that are connect- 
ed, and changes into functions, properties, such as sensi- 
bility, irritability, &c. Since this author, others have 
made divisions which are not more methodical, and are 
equally removed from the natural arrangement of the 
phenomena of life. 
1 have endeavoured, as far as possible, in classing the 
functions, to follow the path marked out by nature herself. 
1 have laid, in my work upon Life and Death, the founda- 
tions of this classification, which I pursued before I pub- 
lished this work. Aristotle, Buffon, &c. have seen in man 
two kinds of functions, one which connects him with ex- 
ternal bodies, the other, which serves for his nourishment. 
Grimaud brought forward again this idea, which is as great 
as it is true, in his course of physiology and in his memoir 
upon nutrition ; but by considering it in too general a 
manner, he did not analyze it with sufficient exactness, he 
ranked among the external functions, only sensation and 
motion, he did not describe the brain as the centre of these 
functions, nor place the voice among them, which is how- 
ever one of the great means of communication, with the 
bodies that surround us. He did not analyze more accu- 
rately the internal functions. He did not point out their 
connexion in the elaboration of nutritive matter, where 
each works in its turn, if 1 may so express myself; nor 
show the distinctive characters, which separate generation 
from all the other functions relating to the individual 
alone. Besides, the distinction of internal and external 
functions was only presented as a general sketch in his 62 
GENERAL OBSERVATIONS. 
Memoir upon Nutrition, and not as a means of classifica- 
tion. He did not avail himself of it, in the division of the 
functions, in his lectures, of which many manuscripts ar- 
ranged by himself, are to be met with at the present time; 
in these he examined, 1st. osteogony, which was treated 
at much length; 2d. the action of the muscles; 3d. the 
action of the vessels or the circulation; 4th. generation; 
5th. the action of the organs of the senses; 6th. the action 
of the brain and nerves; 7th. digestion; 8th. secretion; 
9th. respiration, &c. From this it may be perceived, that 
Grimaud, like preceding authors, mixed together all the 
functions without referring them to certain general heads. 
In reflecting upon the division pointed out above, I soon 
saw that it was not only one of those general views, one 
of those great outlines, that are oftentimes made by men 
of genius who cultivate physiology, but that it might be- 
come the permanent basis of a methodical classification. 
To come at this classification I observed that it was neces- 
sary at first to refer all the functions to two great classes, 
one relating to the individual, the other to the species; 
that these two classes had nothing in common, but the 
general connexion that unites all the phenomena of living 
bodies; but a variety of distinctive attributes characterize 
them, which cannot be separated from them. 
These two first classes being rigorously defined, and 
their limits established by nature, I sought to discover in 
each, orders equally natural; this was easy in the func- 
tions relating to the individual. In fact, this was the place 
for the general outline of Aristotle and Buffon; but it was 
not to be presented in too general a manner; the nature 
and connexion of the functions peculiar to each order, 
were to be accurately assigned. 
I called the order of functions that connects us with ex- 
ternal bodies, animal life, thus indicating that this order 
belongs alone to animals, that it is more with them than 
with vegetables, and that it is the addition of these func- GENERAL OBSERVATIONS. 
63 
tionsthat particularly distinguishes them from vegetables. 
I called organic life, the order that serves for the constant 
composition and decomposition of our bodies, because this 
life is common to all organized beings, vegetables as well 
as animals; and because the only condition of enjoying it is 
organization; so that it forms a boundary between or- 
ganic and inorganic bodies, as animal life serves to separate 
the two classes that form the first. 
Animal life is composed of the action of the senses which 
receive impressions, of the brain which perceives them, 
reflects, and wills, of the voluntary muscles and larynx 
that execute this volition, and of the nerves which are the 
agents of transmission. The brain is truly the central 
organ of this life. Digestion, circulation, respiration, ex- 
halation, absorption, secretion, nutrition, calorification, 
compose organic life, which has the heart for its principal 
and central organ. 
I place calorification here, because it is evident from what 
I have said under the article upon the capillary systems, 
that it is a function analogous to secretion, exhalation and 
nutrition. It is truly a separation of combined caloric, 
from the mass of blood. It is, if the expression is prefer- 
red, a secretion or exhalation of that fluid in every part of 
the body. I have not even at present given this place to 
heat in my physiological classification : but in reflecting 
upon the method of its production, it will be seen that it 
ought to have it. 
The two orders of the first class being established, it 
was easy to assign those of the second, which are three in 
number: 1st. functions belonging to the male; 2d. those 
belonging to the female ; 3d. those arising from an union 
of the two sexes and the product of this union ; these are 
the three orders. > 
Such is the classification that I made in my Lectures on 
Physiology; it has evidently nothing in common with any 
of those that are found in physiological woiks; and if you 64 
GENERAL OBSERVATIONS. 
reflect upon it a little, it will appear I think infinitely pre- 
ferable to any of them. Observe in fine, that each class 
and each order have general and characteristic attributes 
that particularly distinguish them, and which being appli- 
cable to all the functions of that order, mark a difference 
between them and all the functions of any other order. 
I have pointed out moreover the distinctive attributes of 
animal and of organic life; I have shown that the organs 
of one are symmetrical, those of the other irregular ; that 
there is a harmony in the functions of the first, a discord- 
ance in those of the second; that one commences sooner 
and terminates later, &c. 
I have demonstrated, that the cerebral nerves belong 
especially to animal life, the nerves of the ganglions to 
the organic, which appears to me to be a remarkable dif- 
ference, and which has induced me to make two systems 
of the nerves, that anatomists have united in one. The 
first, belonging to animal life, is composed of the cerebral 
nerves, the other to organic, is formed of the nerves of 
the ganglions, or what is commonly called the great sym- 
pathetic. 
But it is the vital powers especially that distinguish one 
life from another. I have shown that one kind of sensi- 
bility and contractility belongs to animal life, and another 
to organic. Now as these vital properties are the princi- 
ple of the functions, it is evident that the division of these 
properties demonstrates that that of the two lives is not an 
abstraction, but that it is nature herself that has fixed the 
limits, since she has made particular properties for each. 
It is impossible to form a precise idea of the vital pro- 
perties, without admitting the division I have made. How 
many disputes there have been, upon the subject of sen- 
sibility! Not one of them would have taken place, if the 
attributes of animal life had been properly distinguished 
from those of the organic. Certainly no one will here- 
after confound in one view, as frequently has been done, GENERAL OBSERVATIONS. 
65 
the faculty that the heart has of being sensible to the en- 
trance of the blood, without transmitting that impression, 
and the faculty that the skin, the other senses, the nerves, 
&,c. have, not only of feeling the impression of external 
bodies, but of transmitting it to the brain, so that the sen- 
sation may be perceived. 
If you include under one common name of irritability, 
the motions of muscles that contract only by stimuli, and 
those which the cerebral influence puts in action, it is 
impossible that you should be understood. 
There has been much discussion during the last age, 
upon the point, whether sensibility is the same as con- 
tractility, or if these two properties can be separated. 
Each of the two opinions seem to have rested upon an 
equally solid foundation. But all these disputes will be 
done away, by admitting the distinction I have made in 
the vital properties. 1st. In animal life, then, it is evi- 
dent, that contractility is not a necessary consequence of 
sensibility; thus frequently external objects make for a 
long time an impression upon us, and yet the voluntary 
muscles remain unmoved. 2d. On the other hand, in or- 
ganic life, these two properties are never separated. In 
the involuntary motions of the heart, the stomach, the in- 
testines, &c. there is first an excitement of the organic 
sensibility, and then an action of the sensible organic con- 
tractility. In the same manner, in the motions necessary 
to secretion, exhalation, &c. when the organic sensibility 
has been brought into action, immediately insensible or- 
ganic contractility takes place. It is that they may be 
studied better, and appreciated more accurately, that in 
organic life, I separate these two kinds of contractility from 
sensibility. In the natural state they are inseparable. 
Hence why the passive sympathies of animal sensibility 
are very different from those of animal contractility, and 
make two distinct classes, whilst the passive sympathies 
of organic sensibility can never be separated from the 66 
GENERAL OBSERVATIONS. 
corresponding contractilities. We suffer by sympathy, 
and are sympathetically convulsed in a distinct manner: 
these two things are almost always separate. On the con- 
trary, sensation and motion in the organic sympathies are 
inseparable. 
I could prove by many examples, that all the disputes, 
and all the diversities of opinion, upon the subject of the 
vital properties, proceed only from this cause, that those 
which preside over the functions of one life, have not 
been distinguished from those which put into action the 
functions of the other. 
Let us return to my physiological division; I will now 
give a table of it, which, presenting it under one point of 
view, will give a more precise idea of the classification. 
This table comprehends, 1st. the prolegomena of the 
science ; 2d. the exposition of the functions. In the prole- 
gomena, every thing is referred to two great considera- 
tions; on the one hand to organic texture, described in a 
general manner, and on the other to life, considered in 
relation to its great attributes. GENERAL OBSERVATIONS. 
67 
* In a subsequent part of this work, the author defines appareil, which I have translated by the word apparatus, to be an 
assemblage of many systems. It will be perceived that the English word in this and some other instances is in the plural number. 
I should certainly have preferred some other term more conformable to the idiom of our own language if I had known any one 
that would so well have conveyed the sense of the author. Tr. 
Jlst. By want of extension. 
2d. By horny hardening. 
GENERAL OBSERVATIONS ON ORGANIC TEXTURE. 
TABLE OF PHYSIOLOGY. 
< Extensibility. 
\ Contractility .... 
PROLEGOMENA.- 
C 1st. Of the properties of texture. 
/ 2d. Division of the properties of texture. 
* 3d. Characters of the properties of texture. 
f 1st. Of the organic texture of animals, 
2 2d. Of simple textures, in general. 
j3d. Of organs, in general. 
( 4th. Of the apparatus, in general.* 
Section II. 
Section I. 68 
General observations. 
Functions of the male. 
Functions of the female. 
Functions relating to the union of the 
sexes, and the product of this union. 
Sensibility. 
Sensible and insensible contractility. 
Habit. 
Of that which is called individual life. 
Of sensible contractility. 
Of insensible contractility. 
Animal functions. 
Organic functions. 
1st. Of life and its functions. 
2d. Classification of functions .... 
3d. Of the differences and relations that exist between the two classes of functions. 
4th. Of the differences and relations that exist between the two orders of the first class. 
5th. Of the differences and relations that exist between the three orders of the second class. 
Of temperament. 
Of the passions. 
Of the character. 
Of sensibility. 
Of contractility. 
Sensibility. 
Contractility. 
Sex. 
Climate. 
Seasons. 
Age, &c. 
GENERAL OBSERVATIONS UPON LIFE. 
Of those relating to the 
individual. 
Of those relating to the 
species. 
1st. Of the vital properties. 
2d. Division of the vital properties . . 
3d. Characters of the vital properties. 
4th. Of the causes which modify the vital properties 
5th. Of the peculiar differences of the vital properties, in each simple 
texture, in each individual 
6th. Of the general differences of the vital properties in different indi- 
viduals 
7th. Sympathies of vital properties. 
Division of sympathies .... 
Animal properties . . 
Organic properties . 
Animal sympathies . . 
Organic sympathies . . 
Section I. 
Section II. GENERAL OBSERVATIONS. 
69 
Of the opposition of 
these two causes. 
Of concussion. 
Of apoplexy, &c» 
the judgment. ( 
the passions. \ 
FIRST CLASS.—functions relative to the individual. 
Of attention. 
Of the ideas. 
Of the judgment. 
Of the reasoning faculty, &c. 
ORDER FIRST.—Functions of Animal Lift. 
1st. Relative to sensation 
/ 
2d. Relative to the understanding 
3d. Relative to motion 
.4th. Connexion of the cerebral functions with life ...... . . 
!Of perception. 
Of imagination. 
Of memory. 
Of the will, which < 
is determined by \ 
OF THE FUNCTIONS. 
t external. 
[ internal. 
r Hearing. 
Seeing. 
Smelling. 
Tasting 
Feeling. 
1st. Of the general sensations, or feeling, . . . . 
2d. Of particular sensations 
,3d. Of pleasure and of pain. 
Genus I. 
Sensations. 
Genus II. j 
- 
Cerebral 
Functions. 70 
GENERAL OBSERVATIONS. 
1st. Gestures of the face, 
i 2d. Gestures of the head in general. 
I 3d. Gestures of the superior extre- 
mities. 
Support, raising weights. 
Swimming. 
. Prepulsion. 
I Repulsion. 
Diduction. 
| Pressure. 
. Elevation, Sec. 
, on the feet . . Standing.. 
i on the knees. 
: on the pelvis. 
I on the head, &c. Sec. 
s — Prostration. 
Walking. 
Running. 
* Leaping. 
general. 
particular. 
to the locomotive organs, 
to the vocal organs. 
Of the superior ex- * 
tremities. . . * 
Of the inferior ex-1 
tremities. . . 
Of the trunk . . 
Of the whole body. 
Of gesture consid- 
ered as an auxili- < 
. ary to the voice ( 
Dumbness. 
; Of stuttering, 
i Of lisping, Sec. 
[ true. 
false. 
'1st. Of the immoveable attitudes ....... 
l.2d. Motion 
"1st. Of the voice of brutes . . . 
2d. Of speech 
3d. Of singing 
i_4th. Of declamation. 
1st. Transmission to the brain of sensations . . . < 
2d. Transmission of motion ........ 
3d. Mode of transmission. 
Genus III. 
Locomo- 
tion. 
Genus IV. 
Voice. 
Genus V. 
Nervous 
transmis- 
sion. GENERAL OBSERVATIONS-. 
71 
Action of the liquor of the oesophagus. 
Action of the gastric liquor. 
Action of the bile. 
( Action of the pancreatic liquor. 
Action of the intestinal liquor. 
of the senses. 
of the brain ... Of sympathetic sleep, 
of the muscles. 
OF THE INTERMISSION OF THE FUNCTIONS OF ANIMAL LIFE. 
■ the pharynx and oesophagus. 
) the stomach, 
the small intestines. 
| the large intestines. 
11 — Sympathetic vomiting. 
Of the peristaltic motion. 
! Of the fecal matter. 
Of the intestinal gas. 
ORDER SECOND.—Functions of organic life. 
1st. Of hunger and thirst. 
2d. Of aliments. 
3d. Of taking of aliments 
4th. Of mastication, of lubricating with saliva and deglutition. 
* 
5th. Alteration of the alimentary mass 
6th. Separation of the substances that are nutritive from those that are not. 
7th. Absorption of the nutritive substance ; course of 
the chyle in 
8th. Excretion of the non-nutritive substance . . . 
,9th. Of vomiting, as it has its seat in 
in the oesophagus, 
in the stomach . 
in the small intes- 
tines ... 
the lacteals. 
the mesenteric glands, 
the thoracic duct, 
the blood vessels. 
solid. 
fluid. 
partial 
general. 
1st. natural 
2d. unnatural. 
3d. Dreams and somnambulism. 
Sleep. 
Genus I. 
Digestion. 72 
GENERAL OBSERVATIONS. 
Circulation of red blood. 
Circulation of black blood. 
Action of the heart. 
Action of the arteries. 
Action of the veins. 
-Connexion of the circulation with life. Of syncope, &c. 
( phenomena of the motion of the blood. 
\ change of red to black. 
Iits relation with the general. 
[ change of black to red blood. 
in the middle of the long bones, 
in the extremities of the long bones, in 
the short and flat ones. 
in the grooves of the tendons, 
in the articulations. 
' of their agents. 
I of their phenomena. 
| of their alterations. 
— Sympathetic exhalations. 
j of fat. 
| of serum. 
i Inspiration. 
[ Expiration. 
J to the air. 
[ to the blood. 
Of asphyxia, &c. 
general . . 
pulmonary . 
serous, 
cellular . . 
synovial . . 
..medullary , 
• 1st. Of the air. 
2d. Mechanical phenomena 
3d. Chemical phenomena relative ...... 
-4th. Connexion of respiration with life. 
1st. general . . 
2d. abdominal. 
L.3d. capillary . . . • . 
j' 1st. in general 
i 
| 
L2d. m particular* Exhalations 
.Genus II. 
Respira- 
tion. 
Genus III. 
Circulation. 
Genus IV. 
Exhala- 
tions. GENERAL OBSERVATIONS. 
73 
in the middle of the long bones, 
in the extremities of the long bones, in the 
short and flat ones. 
I the chyle. 
. the blood. 
f the organs themselves. 
infancy Of increase in height. 
I youth ....... Of increase in thickness. 
I adult age. 
old age ....... Decrease. 
in the grooves of the tendons, 
in the articulations. 
Of their agents. 
Of their phenomena. 
Of their alterations. 
— Sympathetic absorptions* 
' Of their agents. 
(Of their phenomena. 
Of their alterations. 
— Sympathetic secretions. 
Nutritive matter, considered 
in 
— Assimilation. 
t of fat. 
\ of serum. 
'lachrymal. 
salivary and pancreatic. 
hepatic. 
renal. 
mucous. 
.sebaceous. 
serous, 
cellular . . 
synovial . . 
medullary. 
'1st. in general 
.2d. in particular. Absorptions ....... 
f 1st. in general . . . 
l.2d. in particular. Secretions 
1st. Of the double nutritive motion. 
I 
2d. Composition of organs 
I 
3d. Decomposition pf organs. 
4th. Causes that modify nutrition. 
5th. Of nutrition considered in J 
u6th. Of natural death. 
Genus V. 
Gbnus VI. 
Secretions. 
Genus VII. 
Absorp- 
tions. 
vYutrition. GENERAL OBSERVATIONS. 
74 
ORDER SECOND.—Functions peculiar to the female. Phenomena of puberty in woman. 
SECOND CLASS.—functions relative to the species. 
A COMPARISON OF THE TWO SEXES. HERMAPHRODISM. 
ORDER FIRST.—Functions peculiar to the male. Phenomena of puberty in man. 
, 1st. Secretion in the testicle. 
i 2d. Residence in the vesiculae. 
‘ 3d. Excretion Of erection and its phenomena. 
) 4th. Of the semen. 
■ 5th. Of eunuchs. 
! respiration, 
digestion, 
absorption. 
'1st. Phenomena of animal heat. 
2d. Entrance of caloric by 
< 
3d. Its latent state in the blood. 
4th. Its disengagement in the capillary system. 
5th. Its exit from the body. 
J>th. Of the sympathies of heat, and of sympathetic heat. 
' 1st. Of its seat. 
| 2d. Of its periodica] return. 
| 3d. Of its alterations. 
[ 4th. Of its cessation. 
Genus VIII. 
Calorifica- 
tion. 
Production 
of the 
semen. 
Genus I. 
Genus I. 
Menstrua- 
tion. GENERAL OBSERVATIONS. 
75 
( in the womb. 
( in the tubes and ovaries. 
Functions that it wants. 
Activity of assimilation. 
Difference of this secretion from others. 
Relation between the breast and womb. 
ORDER THIRD.—Functions relative to the union of the sexes, and the product of this union. 
Of its animal life ; it is almost nothing. 
| Of its organic life . . 
[ Of monsters. 
s 
.2 
V 
a 
a 
u 
Qs . 
•C XJ 
S 
O o 
0) £ 
ca o 
go 
O rt) 
§15 
OuS 
i Development of its animal life. 
( Functions added to its organic. 
Its phenomena . . 
Hypotheses. 
spontaneous, 
by suckling. 
1st. Secretion in the breast 
2d. Excretion 
3d. Of the milk. 
■ 1st. Sexual intercourse. 
I2d. Conception 
1st. to the mother . . 
2d. to the foetus 
l 1st. Causes and mechanism of parturition, 
j 2d. Of the lochia. 
’ 3d. Phenomena of the new bom infant 
What these fluids are. 
What is their influence. 
Genus II. 
Production of 
milk. 
Genus III. | 
Of the fluids of 
women proper 
for generation. I 
Genus I. 
Generation. 
Gejtcs II. 
Gestation, rela- 
tive 
Ge.vds III. 
Parturition and 
subsequent phe- 
nomena. 76 
GENERAL OBSERVATIONS. 
This is a sketch of the general plan that I have adopt- 
ed in my lectures. Those who have attended them, will 
find here some changes in one part, and additions in 
another. But they can easily arrange under it all the 
facts that are contained in this work, if they wish to refer 
them to a physiological classification, instead of distri- 
buting them according to the anatomical order in which 
I present them here. 
Though aline of demarcation separates each order of 
functions, it is not necessary, however, to take, in too exact 
a sense, the divisions pointed out above. Each order is 
connected with the others, more or less intimately. For 
example, in the first class, when one order ceases, another 
is soon annihilated. It is thus that 1 have shewn else- 
where that the heart, which is the principal agent of or- 
ganic life, being interrupted, the brain, which is the cen- 
tral organ of animal life, is immediately stopt for the 
want of excitement, and the functions over which it pre- 
sides are destroyed. It is thus also, as I have shown, 
that the brain, having under its immediate superintend- 
ance, respiration, by the means of the diaphragm and in- 
tercostals, which receive the cerebral nerves, has the cir- 
culation directly under its control, and thus the whole of 
organic life, which ceases when its action is interrupted. 
Jt is on this account that I have considered respiration 
as the link that connects animal with organic life, and 
have proved that a foetus without a brain, or without 
something to supply its place, cannot live out of the womb 
of its mother. Every thing is connected, every thing is 
united in the animal economy. We live without and 
within in a distinct manner, but one life cannot be pre- 
served as a whole, independent of the other. Thus, 
though the functions should be studied abstractedly, we 
should always have in view their connexion, when we 
consider the whole of them as simultaneously in opera- 
tion. GENERAL OBSERVATIONS. 
77 
It will be seen that in the Descriptive Anatomy, I 
have adopted a classification analogous to that of physio- 
logy. The one differs, however, a little from the other, 
because the same organs often serve for many functions, 
and especially because certain functions, such as exhala- 
tion, nutrition, calorification, have not, to speak correctly, 
any distinct and determinate organs. GENERAL ANATOMY. 
SYSTEMS 
COMMON TO ALL THE APPARATUS. 
GENERAL OBSERVATIONS. 
THE organized systems of the living economy may be 
divided into two great classes. One, generally distributed 
and every where present, concurs not only in the forma- 
tion of all the apparatus, but even in that of the other sys- 
tems, and offers to every organized part a common and 
uniform base; this includes the cellular, arterial, venous, 
exhalant, absorbent, and nervous systems. The other, on 
the contrary, placed in certain determinate apparatus, 
foreign to the rest of the economy, has a less general and 
oftentimes an almost insulated existence; this embraces 
the osseous, cartilaginous, fibrous, muscular, mucous, serous 
systems, &c. &c. 
The first part of this work will be devoted to the exam- 
ination of the general systems, of the generative systems, 
if I may so express myself, systems which are not how- 
ever of such importance that all the organized parts are 
necessarily provided with these six. In fine, in some there 
are neither arteries nor veins; in others nerves; in some 
but little cellular texture ; but they concur to form the 
greatest number, and some are always found where others 80 
GENERAL OBSERVATIONS. 
are wanting. Thus in the tendons, in the cartilages, &c. 
which are deprived of blood, there are exhalants, absorb- 
ents, &c. 
In general, it appears that the exhalant and absorbent 
systems are the most universally diffused. Nutrition sup- 
poses this; in fact this function is the result of a double 
movement; one of composition, which brings to the or- 
gans, the other of decomposition, that carries from them 
the nutritive matter; now the exhalants are the agents of 
the first movement, and the absorbents of the second. As 
every organ is nourished, and as the mechanism of nutri- 
tion is uniform, it follows that these two systems belong 
to all the organs. After them the cellular system is the 
most generally found. Where there are no blood vessels, 
it is sometimes met with, and it always exists where these 
vessels are. Next to this, the arteries and veins are 
spread to the greatest number of parts. Oftentimes no 
nerve is discoverable, where they penetrate, as in the 
aponeuroses, the fibrous membranes, &c. &c. The ner- 
vous is of all the generative systems, that which is found 
by dissection in the smallest number of parts. The serous 
membranes, the whole fibrous system, the cartilaginous, 
the fibro-cartilaginous, the osseous, &,c. appear to be de- 
prived of it. 
Particularly destined to form a part of the structure of 
other organs, the generative systems perform the same 
office for one another ; thus the cellular texture enters 
into the composition of the nerves, and the arteries and 
veins; and the arteries and veins are ramified in the 
cellular texture, &x. It is a general intermixture of one 
with the other. 
It may be imagined, from what has now been said, that 
the generative systems, considered under the relation of 
organs, forming a common and uniform base for all, ought 
to be sooner developed than others; and this, observation 
proves. While there is hardly an outline of the others GENERAL OBSERVATIONS. 
81 
in the first months of the foetus, these predominate in a 
remarkable manner. The nerves, and their centre, w hich 
is the brain, the arteries, the veins and their central organ, 
which is the heart, the cellular texture, the exhalants and 
the absoi bents, exhibit this phenomenon in a striking de- 
gree. Mere inspection suffices to prove this in the ner* 
vous, arterial, venous and cellular systems; in the ether 
two it is proved by the wonderful activity of absorption 
and exhalation, at this period of life. 
From what has just been said of the general systems of 
the economy, it is easy to perceive that they perform the 
most important part of nutrition. They form the nu- 
tritive parenchyma of each organ; now I call the nutri- 
tive parenchyma, the cellular, vascular and nervous out- 
line of that organ. It is in this outline that the nutritive 
matter is deposited. This matter being different for each 
organ, establishes a difference between them. For the 
bones, it is phosphate of lime and gelatine; it is gelatine 
alone for the cartilages, tendons, &c.; fibrin for the mus- 
cles, albumen for certain other organs; so that if the nu- 
tritive parenchyma of a bone was filled with fibrin, it 
would be a muscle in the form of a bone, and vice versa, 
a muscle would become a bone with a muscular form, if 
its parenchyma was filled up with earthy and gelatinous 
substances. We should know the nature of all the living 
parts, it their nutritive substances were known to us ; but 
the most of them are unknown, it is chemistry that must 
enlighten us upon this subject. All the organs resemble 
each other in their parench)ma, or at least have a great 
analogy. If it were possible to remove from all, the nu- 
tritive matter and leave this parenchyma untouched, we 
should see only among them, varieties oi form, of size, of 
deposition of cellular layers, of vascular or nervous 
branches, but not of nature and composition. 
In the first period alter conception, the mucous mass 
that represents the foetus, appears to be only a compound 82 
GENERAL OBSERVATION'S. 
of the general systems. Each organ has as yet only its 
nutritive parench)ma, the parenchyma upon which nature 
has imprinted the form of the organ, that is to be developed 
there. In proportion as this outline is increased, the nu- 
tritive substances penetrate it, and then each organ, which 
until that time had been like the rest in its nature, and 
forming with them a homogeneous mass, begins to be dis- 
tinct, and have a separate existence; each one draws from 
the blood the substance that is proper for it. This addi- 
tion gives the attributes of thickness, of density, and of 
nature; but the increase of parenchyma, the augmenta- 
tion of its dimensions are always antecedent to this. 
Whilst all inorganic bodies increase by the addition of 
particles, there is here at first an expansive force, from 
which length and breadth arise, afterwards substances 
are exhaled into the parenchyma, which lengthen and 
widen it. 
By what mechanism is it, that each organ draws the 
materials of its nutrition from the blood, the common 
source ? This depends entirely upon the organic sensibility 
peculiar to each, which places it in relation to this or that 
substance and not to another, and which makes it appro- 
priate it to itself, is penetrated by it, and suffers it to en- 
ter its vessels on all sides while it draws back and con- 
tracts, to prevent what is foreign to it, from being intro- 
duced into its texture. 
After this substance has continued for some time to 
form the organ, it then becomes foreign to it and hetero- 
geneous; by remaining longer it would be injurious; it is 
absorbed and thrown out by the different emunctories; a 
new substance of the same kind, which is brought by ex- 
halation, takes its place. Each organ is then constantly 
in a state of composition and decomposition ; but this 
composition and decomposition vary in their proportion. 
The predominance of the first over the second, constitutes 
growth. Their equilibrium establishes the stationary GENERAL OBSERVATIONS. 
83 
state of the body, which is the ease with the adult. When 
the activity of the second is greater than that of the first, 
then decrease and decrepitude follow. 
Such is, in short, the manner in which the general the- 
ory of nutrition should be considered, a theory which I 
shall explain at length in my physiology, £nd upon which 
I will now offer a few words, to show that it is not a system 
formed by accident, but that it rests upon the laws of the 
economy, and upon its organic phenomena. Now I think 
that this assertion will be demonstrated, if 1 prove, 1st. the 
uniformity of the parenchyma of nutrition; 2d. the vari- 
ety of the nutritive substances; 3d. the faculty which the 
parenchyma of nutrition has of appropriating to itself, 
according to the quantity of its organic sensibility, this 
or that nutritive substance, to the exclusion of others, of 
afterwards throwing out this substance, and of taking 
new'. These are in fact the fundamental principles of 
this theory. 
I say in the first place, that the parenchyma of nutrition 
is the same for all the organs, and that it is an assemblage 
of red vessels, of exhalants, of absorbents, of cellular tex- 
ture, and of nerves ; these are the proofs. 1st. These dif- 
ferent organs are met with in all the others, as 1 have 
observed before, anatomy shows them every where, be- 
tween each fibre, each layer, each point, if I may so say ; 
they are truly the common organs. 2d. When w?e take 
away from the organs their different nutritive substances, 
for example, from the bones the phosphate of lime by 
acid, and the gelatine by boiling, there is a residue which 
is evidently cellular and vascular. 3d. There is no doubt 
but that the mechanism of the union of divided parts is 
the same as that of their natural nutrition. Now in the 
healing of wounds, the parenchyma of nutrition is first 
developed, and is every where the same ; every where 
fleshy points appear, which are cellular and vascular, 
which have the same appearance and same character, 84 
GENERAL OBSERVATIONS. 
whether they arise from a bone or a cartilage, a muscle, 
the skin, a ligament, &lc. All wounds, in healing, like the 
organs, resemble each other in their parenchyma; they 
differ also like the organs, in the nutritive substance that 
is afterwards deposited in its texture, substances which 
vary according to the part where the wound happens to 
be ; thus the deposit of the phosphate of lime gives to the 
callus a different character from that of muscular wounds, 
which are united by the exhalation of fibrin in the fleshy 
points that first arise upon the divided surfaces, &c. 4th. 
The mucous substance which forms the body of the em- 
bryo, appears to be nothing but cellular or mucous texture, 
as Bordeu calls it, which is abundantly supplied with ves- 
sels and nerves. In fact, when the organs are developed 
in this mucous substance, it may be seen in their inter- 
stices for a certain length of time, and exhibits there the 
same appearance as the body of the embryo in the first 
periods; gradually this substance becomes condensed, is 
filled with cells, and assumes the form of cellular texture; 
whence it may be presumed, that in this mucous state of 
the embryo, there is only the nutritive parenchyma of the 
organs; and as the parenchyma is the same in all, it is 
evident that the mass of the embryo must be homogene- 
ous. Nutrition commences, and then each organ appro- 
priates to itself the substance which is proper for it; after 
this it ceases to be homogeneous. From these considera- 
tions, it becomes easy to admit the uniformity of the pa- 
renchyma of nutrition, and its cellular, vascular and, in 
certain cases, nervous texture. 
I am aware, that by admitting this common parenchy- 
ma of nutrition, it becomes necessary that it should be 
nourished itself, and consequently that we must go farther 
back; but in physiology, the art of finding the truth con- 
sists, in searching for it in secondary causes ; here facts 
and experiments enlighten our way, beyond that, imagina- 
tion only is our guide. GENERAL OBSERVATIONS. 
85 
After having demonstrated that the organs resemble 
each other in a common parenchyma of nutrition, it is un- 
necessary to prove that they differ by the substances that 
are deposited there. Animal chemistry has within a few 
years past so much elucidated this point, that it is not 
worth while to waste time in refuting what has been writ- 
ten upon the identity of the nutritive juice. 
In fine, it is easy to conceive, how each parenchyma of 
nutrition appropriates to itself according to the quantity 
of organic sensibility it enjoys, the nutritive substances 
that are proper for it, and which are brought to it by the 
circulation. It is not a phenomenon peculiar to nutrition; 
it is observable in all the acts of the organic economy. 
Thus the secretions take place only in consequence of the 
determined quantity of this sensibility, which, placing 
each gland in relation with the fluid that it should sepa- 
rate, makes it receive this fluid, and reject the others; 
thus the red part of the blood does not ordinarily pass into 
the exhalants, because the serous part is alone in relation 
with their organic sensibility; thus the substances that 
pass the intestines, do not stop in the biliary or pancreatic 
ducts, although their diameter is sufficient to admit them; 
thus cantharides are exclusively in relation with the sen- 
sibility of the kidneys, mercury with that of the salivary 
organs, &c. &c. 
We see from this, that the mechanism by which the 
parenchymas of nutrition appropriate to themselves nutri- 
tive substances, is not an insulated phenomenon, but a con- 
sequence of a general law of organic sensibility. But why 
has this property as many degrees as there are organs in 
the economy ? Why do these degrees establish relations 
so different between the organs and the substances that 
are foreign to them? Let us stop here; let us be content- 
ed with proving this fact by a great number of examples, 
without trying to discover the cause. We could offer 
nothing but conjectures upon this subject. 86 
GENERAL OBSERVATIONS. 
These few notions upon the nutritive phenomena, though 
indirectly connected with the subject of this volume, are 
not misplaced here; because in these phenomena, the 
generative systems upon which we are going to treat, 
perform the greatest part, and because we shall frequently 
have occasion to refer to them in the examination of the 
development of the organs, the development that authors 
have only vaguely examined, upon which the most exact 
and the most judicious of all physiologists, Haller, has 
only slightly glanced, but which however ought to receive 
the particular attention of physicians, of those especially 
who wish to consider diseases under the essential relation 
of the influence that age has upon them. CELLULAR SYSTEM. 
THIS system, which many know still, under the name 
of the cribriform body, the mucous texture, &,c. is an 
assemblage of filaments, and of white soft layers, inter- 
mixed and interwoven in different ways, leaving between 
them spaces communicating together, more or less irreg- 
ular, and which serve as a reservoir for the fat and serum. 
Placed around the organs, the different parts of this sys- 
tem act at the same time as a bond to connect, and as an 
intermediate body to separate them. Carried into the 
interior of these same organs, they essentially contribute 
to their structure. 
The great extent of this system, which, though every 
where spread, is every where continuous, the number of or-, 
gans it surrounds, and the multiplied relations it presents, 
do not allow me to describe it, as has been done, in 
one point of view; in order to give a complete view, it 
is necessary to separate the different points in which it 
may be examined. 
1 shall then at first consider abstractedly the general 
system, as represented by the continuity of all its parts, 
in order to consider it in relation to the organs that it 
surrounds, or to whose composition it concurs. I shall 
examine it afterwards independently of these organs, as it 
is spread every where in the spaces between them. In 
fine, its organization, its properties, its relations with other 
systems, and its development will be the object of my 
researches. 88 
CELLULAR SYSTEM. 
ARTICLE FIRST. 
OF THE CELLULAR SYSTEM CONSIDERED IN RELATION TO THE 
OTHER ORGANS. 
The cellular system, considered in an insulated man- 
ner, and in relation to each organ of the animal economy, 
can be described in two secondary relations. 1st. It 
forms for each organ a covering, a boundary which is ex- 
terior to it. 2d. It enters essentially into the structure of 
each, and forms one of the essential bases of this structure. 
The different conformation of the different organs, es- 
tablishes two very distinct modifications in the relations of 
the cellular texture, that is exterior to them. In one case 
in fact, it is contiguous only to one of their surfaces, in 
the other it envelopes them entirely. The first arrange- 
ment takes place, when these organs have one side free, 
and the other attached, as for example, the skin. The 
second, which is the most general, is observed, when an 
organ is attached every where to those in the vicinity of 
it. Let us describe separately each of these two arrange- 
ments. 
1st. Of the cellular system upon the exterior of each organ. 
Of the cellular system which adheres only to one side of the 
organs. 
There are three membranous organs which are free on 
one side, and clothed on the other by the cellular texture ; 
these are the skin, and the serous and mucous membranes. 
We can also consider here, that which covers the exterior 
of the arteries, the veins, the absorbents and the excreto- 
ries, which are destitute of it in their interior. As this 
texture enters also into the structure of these vessels, most 
authors have examined it, in treating of them. It appears CELLULAR SYSTEM. 
89 
to me more convenient to present under one point of 
view all the parts of the cellular system. 
Sub-cutaneous cellular texture. 
Besides the chorion, into which, as we shall see, a 
great quantity of cellular texture enters, and which anat- 
omists consider as formed by a particular condensation 
of this texture, the skin, every where that we examine 
it, presents a subjacent cellular layer, the quantity and 
density of which vary in the different parts of the body. 
Upon the greatest part of the median line, this texture 
appears more compact, and more adherent to the skin 
than in many other places. We may he convinced of 
this, by dissecting upon the middle of the nose, of the lips, 
of the sternum, upon the linea alba of the abdomen, upon 
the range of the vertebral and sacral spinous processes, 
upon the posterior cervical ligament, &c. From this 
adhesion arises a sort of division of the two great halves 
of the sub-cutaneous cellular texture; a division that I 
have sometimes made very evident in my experiments 
upon emphysema. The air being driven with moderate 
force under the integuments of one side of the body, 
diffuses itself gradually, and is stopped in many instances 
at the median line, so that one side is puffed up and the 
other exhibits the ordinary state of the cells. It is often- 
times necessary to increase the force very much, in order 
to overcome the resistance and render the emphysema 
general. However, we cannot always produce this phe- 
nomenon, and sometimes the air spreads immediately 
every where; this takes place especially if it is forced in 
about the neck, for the sub-cutaneous texture is as loose 
there in front, upon the median line, as it is upon the 
sides. 
It is only from the circumstance, that the sub-cutaneous 
texture immediately under the median line, is somewhat 
more compact than elsewhere, that we can say with Bor* 90 
CELLULAR SYSTEM. 
deu, that this texture divides the body perpendicularly 
into two equal parts. No where, but under the skin, do 
we see any trace of this separation. Besides, 1 have de- 
monstrated in one of my works, that the division of the 
body into two symmetrical parts, is a general attribute of 
the organs of animal life, an attribute which distinguishes 
them from those of the internal life, which seem to be 
characterized by their irregularity; it is under this rela- 
tion, and not under that of Bordeu, which is contrary 
to anatomical facts, that the median line should be de- 
scribed. 
In the other parts of the body, the sub-cutaneous cellu- 
lar texture varies considerably. 1st. The density of this 
texture is remarkable in the hairy scalp, which is with 
difficulty separated on that account from the aponeuroses 
and subjacent muscles. Those who have often exam- 
ined patients who have died of apoplexy, know that 
sometimes their heads and necks are emphysematous; I 
have already seen four. Now whilst considerable air 
is found in the face, little or none is met w ith under the 
hairy scalp. 2d. In the face, the sub-cutaneous texture is 
remarkably loose, it is very abundant there. 3d. Upon 
the trunk this laxity is also very evident; it accommodates 
itself to the motions which the great and broad muscles per- 
form there. 4th. Upon the extremities, the sub-cutaneous 
cellular texture, situated between the aponeuroses and the 
skin, offers almost every where an equal degree of relaxa- 
tion. It is only upon the palm of the hand and the sole of 
the foot that, its texture becoming more compact, the adhe- 
sion of the aponeuroses to the skin is more evident, an ar- 
rangement that is favourable to the use of these two parts, 
which are designed to adapt themselves to the forms of 
external bodies, to grasp and hold them. It is to this com- 
pact texture, that must be referred the difficulty that exists 
of making these parts subject to dropsical ellusions. Long 
after every other part of the sub-cutaneous texture is infil- CELLULAR SYSTEM. 
91 
trated, this preserves its ordinary state. 1 have seen two 
patients affected with elephantiasis, where every part of the 
skin and subjacent texture of the lower extremities was 
enormously swelled, except the sole of the foot. The con* 
trast of this part, remaining in its natural state, with the top 
of the foot, which was raised to an enormous swelling, gave 
that peculiar appearance that all authors have noticed. 
At the place of the annular ligaments, the sub-cutaneous 
cellular texture is very compact, and the adhesion of the 
skin, is also very evident; hence those contractions that 
are seen in the limbs of infants at the place of the liga- 
ments, the fat penetrating but very little into the cells, 
that are very closely drawn together. 
The sub-cutaneous cellular texture has several different 
uses. It furnishes the skin with the great mobility it en- 
joys, a mobility that is particularly observable in the great 
motions of the trunk and extremities, in the collisions it 
experiences with external bodies, in the different tumours 
that get to a great size, as in sarcocele, which is often 
covered at the expense of a part of the integuments of 
the penis, the abdomen and the thigh, which are stretched 
and have a real locomotion. 
It is to this texture also, that the organs subjacent to 
the skin owe in part the facility with which they move in 
the great contractions of which they are susceptible. The 
fat contained in great quantity in its cells, contributes to 
protect the subjacent parts from the impression of the ex- 
ternal air. We know, that in general this fluid is more 
abundant there in winter than in summer, that it is found 
in a very considerable proportion under the skin of ani- 
mals that inhabit cold countries, that in consequence of 
the emaciation that follows great diseases, the impres- 
sion of the external air is often very sensible, &c. 
The serum appears to be in the sub-cutaneous texture, 
considerably more than in other parts; it has a greater 
tendency to accumulate there, no doubt on account of 92 
CELLULAR SYSTEM. 
its laxity. If we compare the quantity of fluid which 
enters this texture in a dropsical limb, with that which 
occupies the intervals between the muscles and the inter- 
stices of the fibres of the different subjacent organs, we 
shall see that it exceeds it considerably, and that the size 
of the limb is in proportion much more increased by the 
dilatation of the portion of sub-cutaneous cellular texture, 
than by that of the portions situated deeper. To be con- 
vinced of this, place at the side of a healthy, lower limb, 
stripped of its integuments and subjacent texture, a drop- 
sical limb prepared in the same manner, and consequently 
having like the other, only its aponeurotic covering, you 
will see that the difference is not very great. 
The mucous membranes have the same relations with 
the cellular texture, that the skin has, of which they are a 
continuation, and with which, as we shall see, they have 
a great analogy in their structure. There is then a sub- 
mucous, as well as a sub-cutaneous texture. But there is 
between them, this essential difference, that the texture of 
the first is infinitely more compact and condensed than that 
of the other, and consequently that the adhesion of the 
mucous system to the neighbouring parts is much greater, 
than that, of the cutaneous system. It is to this difference 
that may be referred, 1st. the difficulty of dissecting the 
mucous membranes and of separating them from the sub- 
jacent parts. 2d. The impossibility that I have always 
found in many successive experiments, of producing an 
artificial emphysema in the sub-mucous texture, whilst I 
have done it almost every where else, by blowing in air. 
3d. The uniform absence of this fluid in this texture, even 
when the natural emphysemas are the most generally 
spread. 4th. The equally uniform absence of serum in the 
sub-mucous cells, in the most general leucophlegmasia ; a 
phenomenon essential to the functions of the hollow or- 
Sub-mucous cellular texture. CELLULAR SYSTEM. 
93 
gans, which would soon be obliterated, if the sub-mucous 
texture swelled as much in dropsy as the sub-cutaneous. 
Is it to the difference of texture of these two portions 
of the general cellular system, that must be referred the 
much greater frequency of phlegmonous inflammation in 
the second than m the first, or is it that this is less ex- 
posed to the exciting causes derived from external bodies? 
Both circumstances may have an effect. I believe much 
more readily in the first, as the throat, in which is seated, 
especially around the amygdalae, the most lax of all the 
parts of the sub-mucous texture, is the most frequent seat 
of phlegmonous inflammation. 
Besides, it is the firm and compact structure of the sub- 
mucous texture, which makes it fit to serve as a point of 
insertion and termination to that number of fleshy fibres 
that compose the muscular membranes of the stomach, 
the intestines, the bladder, &c. and thus to fulfil the uses 
that the tendons have in relation to the muscles of ani- 
mal life. 
Sub-serous cellular texture. 
There is under almost all the parts of the serous system, 
as under the two preceding ones, a cellular layer, which 
is in general very abundant and very loose, as we may be 
convinced by examining it around the peritoneum, the 
pleura, the tunica vaginalis, the pericardium, &.c. This 
quantity of cellular texture is particularly destined to ac- 
commodate the different changes these membranes expe- 
rience, in dilatation, in contraction, and in a species of 
locomotion, of which they are susceptible under many cir- 
cumstances. We shall see the peritoneum, for example, 
belong at one time to the omentum, at another to the 
stomach, according as this last is in a state of fulness or 
vacuity; now for these removals, it was necessary that 
there should be a great degree of laxity in the surround- 
ing texture. It is to this, that we must attribute the ease 94 
CELLULAR SYSTEM. 
with which the sub-serous texture is penetrated with water 
in dropsies, and with air in emphysema. Next to the sub- 
cutaneous texture, no part is more disposed to these infil- 
trations. 
There are, however, some places, where the serous 
membranes adhere in a very intimate manner to the 
neighbouring parts. The pericardium in its two layers, 
the synovial glands with the cartilages and fibrous cap- 
sules, the tunica arachnoides with the dura mater, offer 
examples of this arrangement, which constitutes, when 
it is with a fibrous membrane that it makes the adhesion, 
the sero-fibrous membranes. 
Cellular texture exterior to the arteries. 
There is around each artery an extremely compact, 
condensed, and resisting layer, which at first sight appears 
to he a peculiar membrane, but which evidently belongs 
to the cellular system. It has the greatest analogy with 
that which is under the mucous membranes. It is never 
the seat of serous infiltrations. Fat never accumulates 
there, and it is never attacked with inflammation. It 
arises in an insensible manner from the neighbouring 
cellular texture, which is gradually condensed, and inter- 
mixed in such a manner, that we can detach it as a whole, 
so that it will represent a kind of canal corresponding 
with that of the artery which it surrounds and supports. 
Are the arterial fibres inserted in this compact texture, as 
the muscular fibres of the stomach and intestines are, in 
the sub-mucous texture ? I do not think they are ; for if it 
was the case, we could not so easily remove the cellular 
cylinder that surrounds the arteries; the arterial fibres 
seem to be whole circles, and consequently not to have, 
like the muscular, two inserted extremities. However, 
some of these fibres constantly adhere to the deepest cel- 
lular layer, when we remove it; we distinguish them by 
their direction and yellowish colour. CELLULAR SYSTEM. 
95 
Cellular texture exterior to the veins. 
The veins have an external covering analogous to that 
of the arteries, but it is in general less thick and com- 
pact. It cannot be taken out in an entire cylinder as 
easily as that of the arteries. Moreover, it does not 
contain fat, and but little serum, and is not subject to 
dropsical effusions, but uniformly preserves in all affec- 
tions its original state. When we raise by layers this 
texture which is on the outside of the coats of the veins, 
we easily perceive that it is dryer than in any other part; 
and I have often been tempted to believe, that it does 
not, like that of the arteries, the excretories, and mucous 
surfaces, exhale an albuminous fluid which lubricates the 
other parts of the cellular We shall see that its 
organization, which is entirely different, forms an excep- 
tion in this system. 
In examining the cellular cylinder of the veins and 
arteries, especially that of the first, it is essential not to 
confound it with their filaments, and the numerous ner- 
vous branches which come from the ganglions, and form 
a very thick net-work around them. The cellular tex- 
ture is whiter, the nerves more greyish; this becomes 
very apparent after a few days maceration. 
I do not speak of the texture external to the absorb- 
ents ; without doubt they have one like the veins, but so 
delicate are these vessels, that we can say nothing of 
them founded upon experiment and dissection. 
Cellular texture exterior to the excretory duels. 
All the excretories, the salivary, urinary, spermatic, 
hepatic, pancreatic, &c. are evidently surrounded with 
a layer analogous to the preceding, entirely distinct 
from the neighbouring texture, and which appears to be 
inserted in it without partaking of its nature; it is a dis- 
tinct body, as to its thickness, its form, and its texture. 
The filaments that compose it, not being separated in 96 
CELLULAR SYSTEM. 
their interstices by any fluid, remain in contact with each 
other; so that the whole really makes a membrane in 
the form of a canal, which can be easily raised up like 
that which surrounds the arteries; it is, however, thicker 
than that of the veins. 
Of the cellular system considered in relation to the organs 
that it surrounds on all sides. 
Except the organs of which we have just spoken, all 
parts of the body are surrounded on every side with a 
cellular layer more or less abundant, which forms for 
them, according to the happy expression of Bordet), a 
kind of peculiar atmosphere, an atmosphere in the midst 
of which they are immersed, and which serves to insulate 
them from the other organs, to interrupt to a certain de- 
gree the communications which would unite them in an 
intimate manner, which would identify, if we may so say, 
the existence of one with the other, if they were in im- 
mediate apposition. 
The serous vapour, in which the cellular atmosphere 
of each organ is constantly immersed, and the fat which 
floats there in greater or less abundance, powerfully assist 
in this insulation of vitality ; both form for the different 
organs a line of separation, which, being fluid, enjoys in 
a much less degree than them the vital forces, which also 
in this point of view, is not at their level, if 1 may so 
express myself, and whidi is consequently very proper, 
to interrupt in a certain degree the vital communications 
that would otherwise exist. The essential difference 
that there is between the peculiar life of the cellular tex- 
ture and that of the other organs, renders it also very 
susceptible of performing alone like a solid, an analogous 
use independent of the fluids it contains. 
It is to this insulation of the vitality of the organs by 
their surrounding cellular texture, that we can refer in 
part that of the diseases, which is only an alteration of CELLULAR SYSTEM. 
97 
this vitality. Every day we see an affected part contiguous 
to a sound one, without communicating to it its disease. 
A healthy pleura covering the lungs filled with tubercles, 
or ulcers, in phthisis; an inflamed peritoneum corres- 
ponding with the intestines, the stomach, the liver, the 
spleen, which remain in their natural state; the mucous 
membranes affected with catarrhs approaching without 
danger the numerous parts they cover; the sub-cutane- 
ous organs remaining free from the innumerable erup- 
tions of which the skin is the seat; the tunica arach- 
noides in a state of suppuration enveloping a healthy 
brain, and a thousand other similar facts; these are the 
phenomena that the examination of bodies constantly 
presents. Shall I speak of the different tumours that are 
formed in the midst of organs, without their perceiving 
it, of the numerous excrescences that grow by their side 
without affecting them ? Dissect a muscle under a 
suppurating cutaneous wound, or even a most obstinate 
ulcer; you will not often find it different from the rest, 
the skin only has been affected. No doubt the differ- 
ence of vitality of two neighbouring organs is an essen- 
tial cause of the insulation of their diseases ; but the cel- 
lular atmosphere that protects them is also an important 
one. When an organ sends elongations into another, it 
communicates to it much more easily its diseases, than if 
a thick cellular layer separated them; for example, we 
know that the affections of the periosteum and the bone 
are soon identified. 
Let us not, however, exaggerate this idea, by describ- 
ing the cellular atmosphere as an insurmountable barrier 
to diseases. Fact3 would often contradict us, by showing 
diseases passing from an organ to the texture that sur- 
rounds it, and from this texture to the neighbouring or- 
gans; so that we see it at one time an obstacle, and at 
another the means of their propagation. The atmosphere 
that is formed is in different cases susceptible of being 98 
CELLULAR SYSTEM. 
charged with all the emanations that arise from the or- 
gan, or to speak in language more strictly medical and 
physiological, the vital forces of an organ being altered, 
those of the surrounding texture are often altered by 
communication, and gradually those of the different neigh- 
bouring organs themselves. This kind of influence that 
the organs have upon each other, should be carefully dis- 
tinguished from sympathy, in which, a part being dis- 
eased, another part becomes affected without the inter- 
mediate ones being deranged in their functions. Here 
there is constantly in the communication of diseases, the 
same order as in the position of the organs. 
A great number of local affections affords us examples 
of this dependance, in which an organ and its texture 
being diseased, the neighbouring organs afterwards be- 
come so. In phlegmon, a more or less considerable 
swelling surrounds the red and inflamed place; rheu- 
matism, which affects the white parts of the wrists and 
fingers, produces a painful swelling around them ; a con- 
siderable tumefaction in the neighbourhood of the knee 
is almost always the result of diseases of the joint, 
which affect only the ligaments, &c. Many tumours have 
around them a kind of diseased atmosphere, an atmos- 
phere which extends more or less remotely, which always 
exists in the cellular texture, and which constantly par- 
takes of the nature of the tumour. If it is acute, as in 
phlegmon, it is a simple swelling which disappears almost 
entirely at death ; as I have often seen in dead bodies an 
inflamed part that was very large during life, resume by 
the loss of the vital forces, nearly its ordinary size. Is 
the tumour chronic ? it is an induration more or less 
evident that affects, oftentimes to a distance, the neigh- 
bourhood of the diseased parts, as we see in most cancers. 
This atmosphere of disease is developed not only 
around the affected organ, but embraces also the neigh- 
bouring ones. The inflammations of the pleura spread CELLULAR SYSTEM. 
99 
to the lungs, that of the convex surface of the liver to 
the diaphragm; pericarditis, by the influence it has on 
the fleshy fibres of the heait, produces in this organ the 
irregular motions of an intermittent pulse; peritonitis, 
which is exclusively confined to the peritoneum, in the 
beginning, terminates, when it becomes chronic, by af- 
fecting the subjacent intestines; it is this which forms 
chronic enteritis, &c. 
It should be remarked, however, that mere contiguity 
without cellular texture, is often sufficient to communi- 
cate disease; for example, a carious tooth affects its 
neighbour; the inflamed portion of a serous membrane, 
in contact with healthy ones, soon produces inflammation 
in them; thus it is, that after inflammation has continued 
a short time, though the pain has announced only one 
point to be primarily affected, the whole surface is found 
attacked. 
I am convinced that disease is not the only thing, 
that the cellular atmosphere of the organs serves to pro- 
pagate, but it is also the means of communicating medi- 
cinal effects. Why is a blister often useless that is ap- 
plied to a remote part in rheumatism, whilst one placed 
upon the skin that covers the muscle or the fibrous organ 
that is the seat of the disease, frequently produces a sud- 
den effect? Why has a cataplasm applied to the scrotum 
oftentimes an influence upon a diseased testicle, tho’ugh 
between the cutaneous organ and this gland there is no 
relation of vitality? Why do several other medicines 
applied also to the skin, produce an action upon the sub- 
jacent parts ? The cellular texture is certainly the means 
of communication, as in the different applications made 
to the mucous membranes. A gargle is advantageous in 
inflammations of the tonsils; an emollient enema dimi- 
nishes that of the peritoneum, &c.: now these means are 
not applied directly to the affected organ ; their effects 
are transmitted by the sub-mucous texture. However, 100 
CELLULAR SYSTEM. 
the advantages of these applications have been much 
exaggerated, both when applied to the cutaneous and 
mucous surfaces, with a view of acting upon organs of 
different vitality, and which are subjacent to these sur- 
faces. Practice too often proves that they may be ex- 
cited, and irritated in a certain manner, without the con- 
tiguous organ being affected, because their life and that 
of the organ has no resemblance or correspondence, the 
one is indifferent to the affections of the other, though 
the parts are contiguous. Who does not know, how 
little effect emollients, discutients, &c. have, upon tumours 
of the breast, of the glands of the groin, axilla, &c. ? 
and that they are as often cured without our applications 
as they are with 1 Formerly, when a tumour appeared 
projecting under the skin, if it was seated in the abdomi- 
nal viscera, and consequently separated from the cuta- 
neous organ, by many others of a different and even op- 
posite vitality, they covered it with a poultice. All 
modern surgeons admit the inutility of applications 
made in this way, and now confine them to the most sub- 
cutaneous organs. Perhaps hereafter we shall be suffi- 
ciently acquainted with the degree of vitality of each 
organ, to know when the cellular texture can be the 
means of communication of medicinal effects, between 
two contiguous organs, with different structure and pro- 
perties, and when it is a barrier which stops the commu- 
nication of these effects. At present we go almost al- 
ways groping in the dark. 
Frequently a cutaneous application acts by sympathy 
upon very distant organs, whilst it has no effect upon 
neighbouring ones, with which it has no relation; for 
example, a bath will check a spasmodic vomiting, while 
it will have no sensible effect in diminishing pain which 
has its immediate seat in the sub-cutaneous organs. 
In general, the vital forces of any organized part are 
particularly altered, and consequently its injuries are CELLULAR SYSTEM. 
101 
produced in three ways; 1st. by a direct irritation, as 
when the conjunctiva is inflamed, from fresh air, or that 
filled with irritating exhalations; 2d. by sympathy, as 
when one eye being affected, the other becomes so with- 
out any apparent cause; 3d. by cellular communication, 
as when a bone being carious, the skin that covers it be- 
comes discoloured, livid and swelled. 
Why is the cellular texture, in some cases, the means 
that nature uses to defend organs from the influence of 
that which is diseased, while in others it serves to pro- 
pagate morbid affections ? Let us limit ourselves upon 
this point to the exposition of facts; the research into 
the cause, would only be conjecture. 
The cellular atmosphere of each organ has relation not 
only to the immediate phenomena of its vitality, but also 
to the different movements that the organ executes; as 
this is more abundant, these movements are more extend- 
ed. This observation is made, in comparing that which 
is in considerable quantities around the heart, the great 
arterial trunks, the eye, the womb, the bladder, the great 
articulations, as the axilla, the groin, &c. with that which 
is on the outside of the tendons, the aponeuroses, the 
bones, &c. and of which there is in general only a very 
small quantity. The extension and contraction of which 
its cells are susceptible, make them very proper to accom- 
modate the great movements of the organs, those espe- 
cially of dilatation and contraction, which moreover are 
favoured by the fluids that it contains. The organs, upon 
the external surface of which but little cellular texture is 
found, and which, however, perform many movements, 
as the stomach, the intestines, the brain, &c. have, to 
supply its place, the serous membranes that cover them. 
These membranes and the cellular texture are in fact 
the two great means, and the only ones, by which nature 
has facilitated the movements of these organs. 102 
CELLULAR SYSTEM. 
There are many organized parts with obscure motions, 
but which are however surrounded with a quantity of cel- 
lular texture ; the kidnies are a remarkable example 
of this. The testicle and its membranes are also sur- 
rounded with a great quantity of this texture ; so is the 
thyroid gland ; the pancreas and salivary glands find it 
a thick partition which separates them from the neigh- 
bouring organs. In general, almost all the immoveable 
parts, which are not of much importance, and which are 
not separated from others by serous surfaces, as are almost 
all the thoracic and abdominal viscera, are every where 
surrounded by an abundant cellular texture. 
II. Of the internal cellular system of each organ. 
The cellular texture, after having covered the organs, 
enters every where into their intimate structure; it forms 
one of their principal elements. In an apparatus, which 
is an assemblage of many systems, each of these systems 
is united to the others by it; thus in the stomach, the in- 
testines, the bladder, &c. different layers which belong to 
it separate the serous, muscular and mucous membranes 
of these different hollow organs. In the lungs, between 
the serous surface and the pulmonary parenchyma, be- 
tween this and the divisions of the bronchia, between them 
and their mucous surfaces, it offers a variety of elonga- 
tions more or less compact. 
In the organized systems, the cellular texture at first 
accompanies and surrounds, in their whole course, the 
vascular and nervous branches which enter into their 
composition; then it unites together the different homo- 
geneous parts of each of them. Each fasciculus of a mus- 
cle, every muscular fibre, every nervous filament, every 
portion of aponeurosis and ligament, every glandular par- 
ticle, &lc. are surrounded with a sheath, a particular cel- 
lular layer, which in relation to its parts, is destined to the 
same uses that the greater covering of which we have CELLULAR SYSTEM. 
103 
just spoken, performs for the whole organ. Thus the life 
of each fibre is insulated by this layer, which, like that of 
the whole organ, forms around it a kind of atmosphere, 
destined to defend and protect it, but which can, how- 
ever, like the general layer, and even more than that, be- 
cause the parts are nearer to each other, be the means of 
the communication of diseases from one fibre to another. 
The motion of each of these fibres is peculiarly favoured 
by the cellular texture; thus the organs, which, like the 
muscles, have a very apparent motion in each of their 
parts taken separately, are capable by means of it of a 
much greater internal contraction, than those which, like 
the tendons, the ligaments, and the glands, have no sen- 
sible motion but that which is communicated to them. 
The internal cellular texture of each organ has but 
little of the vital character which distinguishes that or- 
gan ; it preserves almost all its general properties; it is, 
in the structure of different parts, the medium which 
unites without resembling them. We see that it is insen- 
sible in the nerves, without contractility in the muscles, 
or powers of secretion in the glands. It is often affected 
without the participation of the organ. In many organic 
affections of the liver, we meet with steatomatous tu- 
mours, which give this organ a raised and uneven form, 
and which, occupying only the cellular texture, leave un- 
touched the glandular texture, which secretes as usual the 
bile, which undergoes no alteration in its course. It is 
remarkable, that these tumours, oftentimes of enormous 
size, should exist without injuring the secretion of bile. 
They may be compared with those not less remarkable in 
the lungs in phthisis, in which, however, respiration is 
performed almost the same as in health. 
There are many organs, in which the cellular texture 
is hardly apparent, because their structure is so compact; 
some authors have even denied the existence of it in 
(hem. But in many of these organs, maceration, by fill- 104 
CELLULAR SYSTEM. 
ing in an insensible manner the fibres with water, parts 
them by degrees, and makes apparent the cellular texture 
which separates them, as we see especially in the tendons, 
in the fibrous membranes, &c. Ebullition, which takes 
from some their nutritive substance, for example gelatine, 
leaves a membranous residue which is evidently cellular. 
In all, even the bones and cartilages, the production of 
fleshy points, or granulations, which, as we shall see, are 
essentially of a cellular nature, proves the existence of 
this internal texture, of which they are only the elonga- 
tions. The same may be said of the bones becoming 
soft, and fleshy, and of fungous tumours of the other 
systems, diseases in which this texture becomes very 
apparent, because the organ loses by them its compact 
structure, and takes one that is more loose and spongy, 
and which exposes that which is placed in the interstices 
of the fibres. 
ARTICLE SECOND. 
OF THE CELLULAR SYSTEM, CONSIDERED INDEPENDENTLY OF 
THE OROANS. 
After having considered the cellular system in relation 
to the organs, let us consider it separate from all the parts 
that it covers and penetrates, in order to represent it as 
a body continued on all sides, found every where in the 
interstices of the organs and being analogous in this point 
of view to almost all the other primitive systems. Let 
us trace it in the head, the trunk, and extremities. 
I. Of the cellular system of the head. 
The cranium and face differ extremely as it respects 
the cellular texture ; it is found in very small quantity 
in the first, and in great abundance in the second. CELLULAR SYSTEM. 
105 
The interior of the cranium has but very little cellular 
texture; it is even apparently destitute of it. If, how- 
ever, we raise the tunica arachnoides, where the vessels 
enter and where the nerves go out, we shall find a small 
quantity, which is remarkable for its delicacy and trans- 
parency. The pia mater is principally formed by this 
texture, and the texture of this membrane appears to be 
continued with that of the brain; this, however, is ex- 
tremely hard to be demonstrated ; it is not proved by 
maceration, and it is scarcely seen except in fungous 
tumours. 
The communications of the cellular texture of the in- 
terior of the cranium are very numerous. 
1st. In front it enters the orbit by the optic foramen 
and the sphenoidal fissure; hence the redness and heat of 
the eye in paraphrenitis,* the influence of which is pro- 
pagated by these communications, as well as by the con- 
tinuity of membranes. It enters the nostrils by the fora- 
mina in the cribriform plate; to this perhaps we may 
attribute the weight, and pain of the head in coryza. 
2d. Below, the numerous foramina of the base of the 
skull effect communications between the face and the 
cerebral cellular texture, and between it and the top of 
the pharynx, the zygomatic furrow, &c. In many cases 
in which angina is attended with pain, and heaviness in 
the head, vertigo, &ic. 1 am convinced that it is in a great 
measure owing to these communications, though often- 
times it may be wholly sympathetic. 
3d. Above and behind, the cerebral texture is continir- 
ed with that of the corresponding parts of the head, by 
Cellular texture of the cranium. 
* The word paraphrenifis is meant probably to designate the inflam- 
mation of the meninges of the brain, though this term is not usually em- 
ployed by English writers ; but the word used by the author might be 
translated inflammation of the diaphragm, which certainly is not his 
meaning. 7V. 106 
CELLULAR SYSTEM. 
the numerous but small openings in the sutures; it ac- 
companies the vessels that go from the dura-mater to the 
pericranium, and it becomes probably sometimes the 
means of communication, that is so frequently observed 
between these two membranes, when one is inflamed ; 
hence the sudden affection that frequently takes place of 
the dura mater, tunica arachnoides. &c. from a stroke of 
the sun upon the integuments of the cranium, &c. 
The cellular texture, though more abundant on the 
outside of the cranium, is not found in great quantity 
there, no doubt because the muscles are so few and thin. 
Its communications with the face are evident, especially 
upon the forehead ; as a consequence of erisypelas of 
the cranium, nothing is more common than to see the 
eye-lids receive the pus that is formed, and which often 
accumulates in these moveable veils, so as to occasion 
considerable deposits. It is by these communications 
also that serum is deposited there, and blood extrava- 
sated. Behind and upon the sides, the communications 
of the cellular texture of the cranium are also v.ery evi- 
dent. 
Cellular texture of the face. 
It is very abundant in every part. The orbits are fill- 
ed with it ; the excavation of the cheeks, that is bound- 
ed by the buccinator and masseter muscles, the zygoma- 
tic and malar bones, contain much of it: all the neigh- 
bouring parts of the tongue are furnished with it. The 
nasal cavities only and their sinuses, which a mucous sur- 
face covers, that is almost immediately attached to the 
bone, have but a small quantity of it. 
The facial cellular texture contributes to the beauty 
and harmony of the countenance, the features of which, 
examined closely, show that the muscles draw in an un- 
pleasant manner across the skin, when there is no fat, 
and consequently that there is too great a depression. In CELLULAR SYSTEM. 
107 
an opposite state, there is a kind of bloating that is disa- 
greeable; a middle state is the most favourable to the 
beauty of the face. This texture is almost wholly dis- 
connected with expression, which is effected by the mus- 
cles. Thus the different passions are delineated with 
nearly the same features upon a fat and a lean face. 
Only these features are less marked in the first than the 
second, because in the last more wrinkles are formed than 
in the other, by the contraction of the same muscles. 
The cellular texture is in greater or less quantity in 
the face in different people. Every one knows that 
some are always thin in this part, who are fat in the rest 
of the body. From the dissection of the bodies of such 
persons, f have found that it arises from the small quan- 
tity of cellular texture it contains in proportion to the 
other parts. In other individuals, there is an opposite 
state, a fulness of the face with a lean body, a striking 
contrast, and which arises without doubt from a cause op- 
posite to the first. 
It is to the greater proportion of cellular texture, much 
more than to the development of the muscles, that must 
be attributed the evident thickness of certain parts of 
the face, in different species of the human race, that, for 
example, of the lips and the alas of the nose in negroes, 
&c. From the same cause arises the variety in thickness 
in the great and small labia pudendi. 
The principal communications of the facial cellular 
texture are made with the neck by the sub-cutaneous 
portion of this texture, by that which accompanies the 
vessels, and particularly in the triangular space at the 
superior part of which is situated the parotid gland. 
Thus, from deposits made upon the lateral parts of the 
face, effusions of pus take place that often extend to the 
neck. In emphysema, the air of which comes from the 
chest, after the neck is swelled, the air passes to the face 
principally by the sides. There are still great communi- 108 
CELLULAR SYSTEM. 
cations of cellular texture between the neck and the face, 
by the spaces between the muscles that are attached to 
the base of the tongue. 
II. Cellular system of the trunk. 
It varies in its proportions, as we examine the regions 
of the spine, the neck, the chest, the abdomen, and pelvis. 
I so call the cellular texture which is found in the 
neighbourhood of the spine, and in the vertebral canal. 
In the cavity of this canal, there is but very little of 
it. Between the tunica arachnoides and the medulla 
oblongata, between the nervous elongations that go from 
the last, and the sheaths of the arachnoides that accom- 
pany them, we see some filaments that follow the course 
of the vessels, and contribute to the formation of the pia 
mater. There is none of this texture between the arach- 
noides and dura mater. Below this, between it and the 
vertebral canal, in the places where it does not adhere, 
there is more of it, especially below, where it is very 
loose, and always covered with a fluid that is often red- 
dish. 
On the outside of the spine, we see, behind, many mus- 
cles and but little cellular texture in proportion; thus, 
depositions in this part are much more rare and much 
less liable to spread than elsewhere, a circumstance 
which arises also from this, that the muscles being very 
compact in the vertebral canals, keep in a state of de- 
pression the cellular texture that separates them. 
This texture is on the contrary very abundant along 
the whole course of the anterior part of the spine, in 
the neck, where it accompanies the carotids, in the thorax 
and abdomen, where it follows the course of the aorta, 
the great trunks which go from it, the vena cava, azygos, 
&c. There is no part of the animal economy, more fre- 
Vertebral cellular texture. CELLULAR SYSTEM. 
109 
quently exposed to different collections of pus, than this. 
Nothing i9 more common than to see depositions that 
are formed at the anterior part of the thorax and abdo- 
men, projecting at the groin by a channel which we dis- 
cover by the examination of bodies. It is principally 
by these cellular communications, and by those which 
are beneath the integuments, that the superior parts cor- 
respond with the inferior, and vice versa. 
Cervical cellular texture. 
The neck, which is very muscular, has much cellular 
texture, besides that which belongs to the vertebral co- 
lumn. It is especially in the lateral parts, where the 
lymphatic glands are situated, that this texture is remark- 
able. In the space between the sterno-cleido-mastoideus 
and trapezius muscles, where the brachial nerves arise, 
and where the vessels pass that go from the thorax, 
there is a great quantity of it. It communicates with 
that of the thorax, by the large opening that is found at 
the superior part of this cavity ; hence it happens, that 
when the cells of the lungs are ruptured, the escaped air 
occupies first the chest and then the neck, and hence also 
the facility with which we produce the same phenome- 
non by forcing air beneath the pleura of a dead body,&c. 
The cellular texture of the neck communicates also 
with that of the superior extremities above and below the 
clavicle. Hence why the neck and consequently the 
chest, are filled with air, water, and other fluids that are 
forced into the sub-cutaneous and intermuscular texture 
of these extremities. 
Pectoral cellular texture. 
In the pectoral cavity, it is upon the median line that 
the cellular texture is especially found ; it is abundant in 
the space formed by the duplicature of the mediastinum; 
the neighbourhood of the pericardium is supplied with it, 110 
CELLULAR SYSTEM. 
particularly around the great vessels, which it accompa- 
nies a short distance ; the rest of the thorax, occupied by 
the lungs, contains much less of it. 
The pectoral texture communicates with the abdo- 
minal, 1st. by the different openings of the diaphragm, 
by that of the aorta, and particularly of the oesophagus ; 
that of the vena cava being too closely united to that ves- 
sel, to permit these communications easily; 2d. by the 
opening of the diaphragmatic fibres, especially by the tri- 
angular space, through which those pass that are attach- 
ed to the ensiform cartilage; hence the passage of the de- 
posits from the thorax to the abdomen. Desault mentions 
a purulent collection, first formed in the neck, and which 
by the anterior mediastinum, became prominent just 
above the abdomen. Hence the facility with which the 
pleura particularly on the right side receives the influ- 
ence of diseases of the peritoneum, when this is diseased 
on the convex surface of the liver which always keeps its 
place, whilst by the motions of the stomach and the 
spleen, that which covers those two viscera, which are 
constantly changing their situation, has a much less de- 
cided influence upon the left pleura. 
The cellular communications of the chest take place 
also from the interior to the exterior, by the interstices 
between the intercostal muscles, but they are not very 
evident, as these interstices are very small ; thus the dis- 
eases of the breast have rarely any influence out of this 
cavity ; this happens however when in dropsies and 
chronic inflammations of the pleura, the pectoral integu- 
ments have an adhesion to the diseased side. 
The exterior cellular texture of the chest, is very 
abundant above ; it there surrounds the breasts and con- 
tributes in part to those rounded forms that delight us 
in women, and those prominent ones which we admire in 
a well formed man. We see it in great quantities under CELLULAR SYSTEM. 
111 
the pectoral muscles; below it diminishes in a very evi- 
dent manner. 
Abdominal cellular texture. 
The abdomen contains, in proportion a little more cel- 
lular texture than the thorax. In the interior of thi3 
cavity, this texture is found collected in the places where 
the great arteries and veins enter the gastric organs, as in 
the fissure of the liver, the mesentery, &c. It is not abun- 
dant between the peritoneum and the anterior and lateral 
parietes of the abdomen, but it is so on the posterior part 
of this membrane, particularly about the kidnies. This 
interior texture communicates at first with that of the 
pelvis, all around the peritoneum, then with that of the 
lower extremities, by different openings, by the inguinal 
ring and especially by the crural arch. The first of these 
openings establishes also a cellular correspondence be- 
tween the abdomen and genital organs, particularly in 
man. We can easily prove these communications by 
injecting a fluid into the abdominal cellular texture of a 
dead body. This fluid goes spontaneously to the inferior 
extremities, whilst it requires a long continued force to 
drive it to the superior. All practitioners know, that 
there is hardly any case, of ascites, in which the lower 
extremities are not swelled, while the superior are unal- 
tered. It is then with the abdominal cellular texture, 
that that of the inferior extremities has a particular rela- 
tion, as it is with the pectoral that that of the superior 
corresponds, as has been observed by Bordeu and Portal. 
It is to be remarked however, that the first are affected 
much more easily in the diseases of the abdomen, than 
the second are in those of the chest. 
Cellular texture of the pelvis. 
There are but few parts in which the cellular texture is 
more abundant than in the pelvis. Around the bladder, CELLULAR SYSTEM. 
112 
rectum and womb there is a great quantity of it, it is 
found no where more abundantly. This appears to me 
to be the cause of it; that, as these three organs are sub- 
ject to great dilatation, and as the osseous parietes of the 
pelvis cannot yield to these dilatations, like the abdominal 
parietes, it is necessary that something should so act, that 
in whatever state the preceding organs may be, the cavity 
of the pelvis should be always filled. If the motions of 
the brain alternately increased and diminished the size 
of this organ, the bony cavity of the cranium would have 
been lined without doubt with cellular texture. 
Besides we know the effect of this large quantity of 
cellular texture in the pelvis, in deposits which take place 
in the neighbourhood of the anus, in infiltrations of urine 
which accompany ruptures of the urethra and bladder. 
The facility with which pus and urine spread themselves 
in this part and the mischief they occasion, are well 
known. 
This texture communicates with that of the inferior 
extremities by the ischiatic notch, by the arch of the 
pubis, &,c. Different authors mention, that effusions of 
pus and urinous infiltrations extend downwards by these 
communications. We can fill the pelvis with air, by 
blowing this fluid into the inferior extremities, especially 
in their intermuscular texture. 
The exterior of the cavity of the pelvis has also much 
cellular texture, less however behind than upon the sides, 
but in front around the genital organs of man as well as 
woman, there are large masses, particularly upon the great 
labia and the dartos. 
III. Of the cellular system of the extremities. 
In the superior and inferior extremities, the quantity 
of cellular texture decreases from the superior to the infe- 
rior part. Around the two superior articulations, it is 
very abundant. The hollow of the axilla, in which the CELLULAR SYSTEM. 
113 
head of the humerus is situated, and which is spacious, 
is almost entirely filled with it. The groin has also con- 
siderable, though less than the axilla. The arm and the 
thigh have between their muscles large interstices that 
are cellular. At the elbow there is a smaller proportion 
than at the ham, whose deep cavity has a considerable 
quantity ; an arrangement that is consequently the reverse 
of that of the axilla compared with that of the groin. 
In the fore arm and leg, the muscles approach each 
other in a sensible manner ; their cellular lasers are 
much more compact, the whole cellular system is less 
abundant. 
Towards the inferior part of these two portions of the 
limbs, where almost every thing on the hand and foot are 
tendinous and fibrous, the cellular texture diminishes still 
more, and becomes in proportion to the motions, hardly 
sensible. However, the foot, especially on the sole, con- 
tains much more than the palm of the hand, where we 
see but little. 
This successive decrease of the cellular texture of the 
limbs is adapted to the uses of their different parts. In 
fact the extent of motion that exists above, requires in the 
muscles a laxity which they borrow from the quantity of 
cellular texture that surrounds them. Below, the multi- 
plicity and at the same time the limited extent of the 
motions of the hand and the foot, of the hand especially 
which is destined to adapt itself to the form of external 
bodies, require in the organs of these two parts a close 
juxta-position, for which they are indebted to the small 
quantity of cellular texture that exists there. 114 
CELLULAR SYSTEM. 
ARTICLE THIRD. 
OF THE FORMS OF THE CELLULAR SYSTEM, AND THE FLUIDS 
IT CONTAINS. 
I. Of the cells. 
The general conformation of the cellular texture is not 
the same every where. The interstices or cells between 
the different layers, are more or less wide; their size is 
remarkable upon the eyelids and the scrotum, and in gen- 
eral where there is no fat, or w here it is in small quan- 
tity. Moreover the capacity of the cells is extremely 
variable ; nothing definite can be determined upon this 
point, as they are capable of contraction and expansion. 
When fat and serum fill them, they are double, triple or 
even quadruple what they are when they are empty. It 
is the variation in the size of the cells of the system of 
which we speak, which constitutes all the difference of 
the general size of the body in corpulency or emacia- 
tion ; in each state the size of every nervous, tendinous 
fibre, &c. remains nearly the same, and the cellular sys- 
tem only varies. There is the same variety in leuco- 
phlegmasia compared with the ordinary state of the 
body. 
The figure of the cells is so variable, that we cannot 
describe them in a general manner. Round, quadran- 
gular, hexagonal, oval, are found mixed together. The 
best way to see these, is to freeze an infiltrated limb; 
numerous little icicles are then formed, and show by their 
form, that of the cells which they filler!. Artificial 
emphysema is also a good way ; 1 have often determined 
by it in our slaughter houses where they blow meats, the 
forms of the cells. The injection of melted gelatine may 
also be employed ; but the results are less certain, because CELLULAR SYSTEM. 
115 
in going from one cell to another, it breaks the texture; 
and moreover after it is hardened, it is difficult to sepa- 
rate each portion contained in each cell. 
All the cells communicate; so that the cellular texture 
is really permeable throughout the whole extent of the 
body, from the feet to the head. This permeability is 
proved, 1st. by emphysema spontaneously produced ; 
2d. by that which is artificially produced in a living ani- 
mal, by blowing air under any portion of the cutaneous or- 
ganon operation which affects neither the life or health 
of the animal, though oftentimes the whole of the body is 
bloated. We know that some beggars make use of these 
means without danger, for the purpose of exciting compas- 
sion. 3d. If one or two punctures are made in a dropsical 
limb,it is sometimes wholly emptied in this way. 4th. Of- 
tentimes this happens from ruptures taking place sponta- 
neously in limbs of this kind. 5th. Pressure made upon 
them, makes the fluid ascend or descend, according to the 
part upon which it is made. 6th. A rupture of the blad- 
der or the urethra produces an urinous infiltration, which 
sometimes extends even to the sides of the chest. 7th. The 
injection of any fluid into the cellular texture of a dead 
body, produces an artificial leucophlegmasia. 
The permeability of the cellular texture has been much 
exaggerated, or rather it has been presented under a point 
of view different from that in which it is shown by nature. 
It is thus that many physicians, thinking that it could be 
pervaded indifferently by all the fluids of the animal 
ec rnomy. have believed that these fluids formed there, 
currents in different directions more or less irregular. 
Thus the sweat has been console »d as the transmission 
by the skin of the albuminous fluid of the cellular texture, 
which, according to some moderns, is drawn out with the 
caloric that is constantly disengaged. They have thought, 
also, that the permeability of this texture would explain 
the rapid passage of drinks to the bladder. They have 116 
CELLULAR SYSTEM. 
explained by it too, the promptness with which sweat is 
produced by warm liquors, &,c. 
All these theories, that examination never proves, are 
repugnant to the known laws of our economy7, laws which 
show us the fluids constantly circulating in the vessels, 
in consequence of the vital forces, of organic sensibility 
and contractility which they possess, and not as being 
extravasated to move irregularly in the cellular texture. 
Moreover, I have never found any portion of drink in 
the cellular texture of animals immediately after they 
have taken it. 1 have tried many of these experiments 
upon dogs, after having deprived them for some time of 
drink, that they might drink the more. The cellular 
texture in the neighbourhood of the stomach and intes- 
tines, that especially which, placed behind the mesentery, 
communicates with the pelvis where the bladder is situ- 
ated, having been attentively examined, did not appear 
to me to contain any fluid ; it was analogous to that of 
the other parts of the body. Besides, as we shall see 
hereafter, these phenomena can be explained in a very 
natural manner. 
The cellular texture is permeable, then, only to fat 
and lymph; and yet it appears that but little use is made 
in an ordinary state of this permeability by these two 
fluids, which remain in their cells, until absorption takes 
them up. We do not see them pass from one to another; 
they are stagnant, if we may so say. It is only in serous 
infiltrations, in effusions of pus, in one word, in a morbid 
state, that the cellular permeability becomes apparent. 
We can only consider, then, the cellular texture as the 
reservoir, in which are formed the serum and the fat. 
After death the cellular texture is every where penetrat- 
ed by fluids, which pass not only across the communi- 
cating openings of its cells, but also through the pores 
which it has, like all the solids; hence the infiltration of 
the integuments of the back, in dead bodies that have CELLULAR SYSTEM. 
117 
been laid upon it for a length of time; hence also the 
passage of the bile through the texture, which separates 
the gall bladder from the duodenum, and by which means 
this intestine is discoloured, &c. &c. But these pheno- 
mena have nothing in common with those that take place 
in the living body. 
II. Of the serum of the cellular membrane. 
The first of the two cellular fluids appears to be the 
same as that which is elsewhere furnished by the exha- 
lanls and taken up by the absorbents. The first deposit 
it in the organs, the second carry it from them. Thus 
when we expose to the air condensed by cold any part 
of the cellular texture of an animal recently killed and 
still preserving its heat, we see a vapour arise which re- 
sults from the solution of the serum in this air, a vapour 
perfectly analogous to a cloud that transpiration and res- 
piration produce in winter, or even to that which arises 
from any aqueous fluid, exposed hot, with a large surface 
to the action of fresh air. When the atmosphere is 
warm the solution takes place in the same way, but as 
the vapour is not condensed, there is no apparent cloud. 
The cellular serum varies in quantity in the different 
regions. Where there is po fat, as in the scrotum, the 
eye-lids, the prepuce, &c. it appears to be a little more 
abundant than elsewhere. We see also that these parts 
are much more disposed to different infiltrations. In this 
respect, the scrotum holds the first rank ; then come the 
eye-lids, afterwards the prepuce, &c. Observe upon this 
subject, that the cellular texture exterior to the mucous 
surfaces, the arteries, the veins, and excretories, a texture 
which by the absence of fat resembles the ordinary, dif- 
fers from it, however, in this, that serum is never effused 
in it. 
We cannot judge of the quantity of cellular serum by 
observations made upon the dead body, in which the 118 
CELLULAR SYSTEM. 
laxity of the parts permits a transudation of the fluids 
from all the vessels that pass through the cellular texture, 
and which then enter the cells. To estimate accurately 
the cellular moisture, I made an animal first emphysema- 
tous below the skin; 1 made a large incision into this; 
little blood only escaped, because the swelling separated 
the vessels from the course of the knife. By these 
means, the cellular texture being laid open, 1 have often 
been convinced that there was much less serum in this 
texture than we commonly suppose. I have not observ- 
ed, that during digestion, after sleep, and whilst much 
sweat is exhaled by the cutaneous organ, three circum- 
stances under which I have repeated these experiments, 
that the cellular serum is increased or diminished in a 
sensible manner. This fact coincides with what I have 
stated in my Treatise on the Membranes, upon the fluid 
that lubricates the serous surfaces, and the proportion of 
which is almost always nearly equal. 
We know that in leucophlegmasia, the quantity of cel- 
lular serum is much increased ; that it disappears in in- 
flammation, &,c. 
The nature of this fluid appears to be essentially albu- 
minous; experiments made upon that of leucophlegmasia 
show that there is albumen in it; but has not disease 
then altered its nature ? To be satisfied in this respect, 
I first made a dead animal emphysematous, for the pur- 
pose of distending the cells, and to make the alkohol, 
which I afterwards injected by a syringe, enter them 
more easily. Some minutes after, the skin having been 
removed, the subjacent texture presented here and there 
different whitish flakes. By immersing in diluted nitric 
acid the cellular portion of the scrotum of a sound body 
that is dead, or which is better, a portion taken directly 
from a living animal, we can observe the same thing. 
It appears, then, that in health as well as disease, the 
albumen is one of the essential principles of the fluid CELLULAR SYSTEM. 
119 
of the cellular texture. I have taken much of this tex- 
ture from the scrotum of many bodies, so as to have it 
separate from the fat, and I have made it boil in about 
the same time as nearly the same quantity of tendinous 
substance ; at the moment of ebullition, much whitish 
froth rises upon the water, but little appears in that 
which contains the tendons. 
Is the nature of the cellular fluid the same as that of 
the lymph that circulates in the absorbents? It cannot be 
doubted but that these vessels take off this fluid in the 
cells ; it is possible that it is mixed with other substances, 
those especially that come from nutrition, which alter its 
nature. Chemical analysis is defective upon this point. 
III. Of the cellular fat. 
The fat is the second of the fluids for which the cellu- 
lar texture serves as a reservoir. 
Natural proportions of the. fat. 
Very abundant under the skin, around the serous sur- 
faces, the organs of great motions, &c.; it is wanting, as 
we have said, upon the penis, the prepuce, the scrotum, 
&c. under the mucous surfaces, around the arteries, the 
veins, &c. Examined in the interior of the organized 
systems, the fat varies in quantity. There is none between 
the interstices of the arterial and venous coats. The 
lymphatic glands do not appear to contain any. The 
brain and spinal marrow are destitute of it. It, is always 
found in the intervals of the nervous fibres; it is not 
often very evident ; but in dissecting them, an unctuous 
substance escapes, which is constant, and which it un- 
doubtedly furnishes. For the most part, it is in consid- 
erable quantity in the muscles, especially those of animal 
life; very little of it is seen in those of organic. In 
the bones, where there is none, its place is supplied by 
medullary substance; the cartilages, the fibrous bodies, 120 
CELLULAR SYSTEM. 
the fibro-cartilagcs, are almost entirely destitute of it. 
The glandular system sometimes has it, as we see it in 
the parotids, around the pelvis of the kidnies; in other 
places, as in the liver, the prostate, &c. there is no trace 
of it. The serous and cutaneous systems are never fatty, 
although much fat surrounds them. It is the same of the 
mucous; the epidermis and the hair never have any of 
this fluid. 
From this we perceive that the interior of the organiz- 
ed systems contain in general but very little fat. The 
different apparatus have but a small proportion between 
their various parts. It is thus that between the coats of 
the stomach, the intestines, the bladder, &c. between the 
periosteum and the bone, between that and the cartilage, 
between the muscle and the tendon, &,c. this fluid is 
almost always wanting. 
It follows from this that it is prinripally in the inter- 
stices, which the different apparatus leave between them, 
that fat accumulates in cellular reservoirs. Now by ex- 
amining the different regions, in this point of view, we 
see, 1st. that upon the head, the cranium and face have 
an inverse arrangement; that it is very abundant in the 
second, and wanting in the first, especially in the inte- 
rior ; 2d. that the neck contains a considerable propor- 
tion ; 3d. that in the thorax we see very little around the 
lungs, but much about the heart; that upon the exterior 
of this cavity, the superior part has a considerable quan- 
tity around the breasts ; 4th. that in the abdomen, it par- 
ticularly abounds in the posterior part in the neighbour- 
hood of the kidnies, the mesentery, and omentum ; 5th. 
that in the pelvis, there is much of it near the bladder 
and rectum; 6th. that upon the extremities it is found, 
like the cellular texture, more abundant above and in the 
vicinity of the great articulations, &.c. 
We observe in infancy, that the quantity of fat is in 
proportion much more considerable under the skin, than CELLULAR SYSTExM. 
121 
any where else, especially that in the abdomen the cellu- 
lar viscera, the omentum in particular contains but very 
little at this age. I have established this fact in a great 
many instances. There are only some flakes of fat around 
the kidney, frequently these are scarcely visible. All 
the rest of the abdominal cavity is destitute of it. The 
pectoral cavity contains scarcely any more, and always 
much less in proportion than in afterlife. I have ob- 
served also that the intermuscular texture is almost every 
where deprived of it. We may say, then, that all this 
fluid is concentrated under the skin, at least while the 
foetus is in good health. Does this superabundance of 
sub-cutaneous fat perform any important office ? has it 
any connexion with the great size of the liver at that pe- 
riod ? I know not: it is a phenomenon that should fix 
the attention of physiologists, especially when it is com- 
pared with the absence of fat in almost all the parts 
where it is afterwards accumulated. 
Towards adult age, the abdominal fat is in much greater 
proportion than the sub-cutaneous. The exterior swell- 
ing is as rare towards the fortieth year, as it is common 
about the fourth and fifth, a period at which all the mus- 
cular forms are concealed by the superabundance of fat, 
and the body is remarkably rounded. Is there any con- 
nexion between the large quantity of abdominal fat at 
the adult period, and the frequency of diseases of which 
this region is then the seat 1 
However, the proportions of fat for the different ages 
are not always the same ; there are some exceptions. 
In old age almost all the fat is dissolved and disappears; 
the body is wrinkled, hardened, and becomes thin. 
Unnatural proportions of fat. 
Oftentimes the fat accumulates in very great quantity 
in the cellular texture. 1 will not cite examples of those 
enormous collections, of which different authors have 122 
CELLULAR SYSTEM. 
given a number of cases ; this would be superfluous. I 
shall only observe, that this state of great corpulency, 
far from being a sign of health, indicates almost always 
a weakness of the absorbents which are destined to take 
off the fat, and has, in this point of view, much greater 
analogy to serous infiltrations than we commonly think. 
Different facts establish this assertion. 1st. Every kind 
of unnatural corpulency is accompanied with a debility 
of the muscular power, with a state of lassitude and lan- 
guor of the individual who is the subject of it. 2d. In 
a man in whom strength and activity predominate, we 
do not see this fatty enlargement that hides the promi- 
nences of the muscles ; these are distinctly marked. It 
is necessary to distinguish carefully the size of the body 
which arises from cellular fat, from that which is the con- 
sequence of the proper development and nutrition of the 
organs. 3d. Oftentimes the causes which evidently 
weaken the powers of life, produce a considerable quan- 
tity of fat; such as inactivity, rest, great and long con- 
tinued hemorrhage, convalescence from certain acute dis- 
eases, in which the powers still languish, though fat 
abounds. 4th. A fatty state of the muscles is a state of 
evident weakness in them. 5th. 1 have been sometimes con- 
vinced, in examining atrophous limbs, that the small size 
which they retain is owing in part to the fat, which is in 
proportion almost equal to that of sound limbs, whilst all 
the other parts, the muscles in particular, are contracted 
and hardened. 6th. Castration, which takes from the 
vital powers a part of their activity, from nutrition a part 
of its energy, is very often marked by excessive corpu- 
lency. 7th. On the other hand, as a certain degree of de- 
velopment of the vital powers is necessary for generation, 
individuals who are too fat. in whom this degree is want- 
ing, are in general not fitted for this function. In woman, 
this fact is remarkable, it is not less so in man. In other 
animals we make the same observation. As fowls are CELLULAR SYSTEM. 
123 
fattened for the table, they cease to lay eggs. Most do- 
mestic animals are governed by the same law. We 
should say that there is a constant relation between the 
secretion of semen and the exhalation of fat, and that 
these two fluids are in an inverse ratio to each other. 
We may conclude from these facts, that if ‘he moderate 
exhalation of fat indicates strength, its superabundance 
is almost always a sign of weakness, and that there is in 
this point of view a kind of connexion between fatty and 
serous infiltrations, as I have mentioned before. It 
should be observed, however, that leucophlegmasia almost 
always arises from an organic disease of some of the 
viscera, particularly the heart, the lungs, the liver, the 
womb, and the spleen ; hence it is usually incurable, and 
death is the consequence of the organic disease. On the 
other hand, an organic disease rarely accompanies corpu- 
lency, which does not prevent a long life. If leuco- 
phlegmasia arose only from cellular weakness, I am per- 
suaded that it would not disturb the regularity of the 
functions. 
Great fatty collections are oftentimes an effect almost 
instantaneous of certain circumstances, for example, of 
atmospheric influence. It is thus that in twenty-four 
hours, a fog fattens thrushes, ortolan?,-red-throats, &c. so 
that they are unable to escape the sportsman. This phe- 
nomenon, which is very frequent in autumn, is never so 
striking in the human species. 
The diminution of the fat is as frequent as its increase, 
and it may be said that there are more cases of extreme 
emaciation than of remarkable corpulency. The causes 
which diminish this fluid are these : 1st. long abstinence ; 
the necessary fasting and sleep of dormant animals, furnish 
us with an example of this; so that in this point of view, 
fat is the nourishment which is reserved for the time 
when the ordinary kind is taken away; 2d. every or- 
ganic disease, continued for a long time, as phthisis, cancer 124 
CELLULAR SYSTEM. 
of the pylorus and womb, disorders of the liver, of the 
heart, &c.; those who are in the habit of examining 
bodies can judge by the external appearance, without 
knowing the previous disease, whether the organization 
of an essential part is changed. In general, in organic 
affections, there is not only emaciation, but also an alter- 
ation in the nutrition of the organs; they are more slen- 
der than usual. On the other hand, after an acute fever 
that has lasted only a few days, emaciation only is ob- 
served ; nutrition, a function that is deranged as it is 
exercised, that is to say, slowly, is not yet sensibly affected. 
There is in this respect a great difference between two 
bodies equally emaciated ; it is sufficient, in most cases, to 
dissect a limb of each, without seeing the internal viscera, 
to determine if death has been the gradual effect of an 
organic disease, or the sudden result of a bilious or putrid 
fever, &c. To the causes already pointed out, we must 
add, 3d. every considerable purulent collection, especially 
if it depends upon a chronic affection ; 4th. leucophlegma- 
sia, though we must not believe that fat and serum mutu- 
ally exclude each other, since we often observe much sub- 
cutaneous fat in dropsical subjects ; 5th. all melancholy 
affections of the mind which have an influence especially 
upon the internal life, and which affect the organs of it 
more particularly than those of external life; 6th. long- 
continued efforts of the mind, which in a particular man- 
ner affect the brain, consequently the first effect is upon 
animal life, though I have observed that an injury of the 
functions of this life has less effect upon corpulency than 
that of the functions of the other; 7th. all evacuations 
unnaturally increased, as those of the bile, the urine, the 
saliva, &,c.; too freqnfent emissions of semen, &c. ca- 
tarrhs, those especially that are seated on large surfaces, 
as the pulmonary, intestinal, &c.; 8th. long heat of sum- 
mer, compared with the cold of winter, which is in gen- 
eral favourable to an increase of fat; 9th. running, hard CELLULAR SYSTEM. 
125 
labour, fatigue of every kind ; 10th. long diseases, those 
especially where it is necessary to use only weak ali- 
ments, and not being able to continue even these for a 
longtime; 11th. long-continued watchfulness ; long sleep 
producing a contrary effect, that of increasing the fat; 
12th. the immoderate use of spirituous liquors, &,c. &c.; 
13th. the use of acrid and spicy aliments, of those which 
have opposite properties to the farinaceous, &c.&c. 
I do not cite a great number of the causes of emacia- 
tion ; after these it will be easily perceived what are 
omitted. I would only remark, that almost all may be 
referred to two principles, viz. 1st. a general weakness 
of the powers, a weakness that acts upon the cellular sys- 
tem, as upon all the others, and produces there this phe- 
nomenon ; 2d. a partial weakness of this system, a weak- 
ness arising from the affection of some other organ, 
whose action seems to increase at the expense of that of 
the cellular texture. 
Different states of the fat. 
The fat is almost always solid and coagulated in dead 
bodies, but in the living it approaches nearer a liquid state, 
at least in certain parts, as around the heart, the great 
vessels, &c. I nder the skin it has uniformly more con- 
sistence. In many experiments, where I have had occa- 
sion to open living animals with red and warm blood, I 
have never found it exactly flowing as it is when it is 
melted, though many authors have pretended that it is so, 
an opinion founded upon the belief that the vital heat 
would keep it melted. Undoubtedly a degree of heat 
equal to that of our bodies, acting upon fat out of the 
body, would make it much more fluid than it is in the 
living subject. Besides, we know that the temperature is 
nearly uniform, and that the degrees of the consistence 
ot tat vary remarkably. There is a great difference 126 
CELLULAR SYSTEM. 
between that of the omentum, which is among the most 
fluid of the economy, and that of the neighbourhood of 
the kidnies, the skin, which is much firmer. Many ani- 
mals with red and cold blood have liquid fat. 
In general, it appears that the nature and state of this 
fluid arc not the same in all the regions ; that the fat of 
the abdomen, thorax and brain differs from each other, 
though there is no precise rule concerning these differ- 
ences. 
In young animals the fat is white and very consistent 
after death. It is this consistence that gives to the exter- 
nal covering of the human foetus, a remarkable firmness 
and condensation, whilst in the adult the skin of a dead 
body is flaccid and loose, yields to the least communi- 
cated motion on account of the state of the sub-cutaneous 
fat. This fat in the foetus is formed into litlle globules 
more or less rounded, w’hich give the whole a gran- 
ulated appearance. Oftentimes it even forms consider- 
able masses ; for example there is almost always at this 
period, between the buccinator, the masseter and the 
integuments, a ball of fat, which is separate from the 
surrounding fat, and can be taken out whole. It con- 
tributes very much to the remarkable prominence the 
cheeks have at this period of life. 
Fat becomes yellow as we advance in years, and 
acquires a peculiar smell and taste. In comparing that of 
veal with that of beef, wre readily perceive the difference 
on our tables. In the dissecting room, this difference is 
not less remarkable between a subject of ten years and 
one of sixty'. 
Instead of fat, we often find around the heart of drop- 
sical and phthisical patients, and of all those who have 
died of a disease, in w hich there has been a constant and 
protracted weakness, a yellowish substance, transparent 
and fluid, having a gelatinous appearance, and which 
however, approaches near the character of albumen. CELLULAR SYSTEM. 
127 
This substance also occupies in similar cases other parts; 
but it is less frequent there. It appears to be gelatinous 
rather than oily. 
Exhalation of fat. 
Different hypotheses have been proposed concerning 
the manner in which fat is separated from the blood. 
Malphigi spoke of glands and excretory ducts, which no 
anatomist since his time has seen and which no one 
believes in at present. Haller supposed that the fat was 
completely formed in the arterial system, that it circulat- 
ed with the blood and floated on its surface on account of 
its specific levity. This circulating fat then, according to 
him, escaped through the pores of the arteries, and oozed 
from all parts into the neighbouring cellular texture. This 
opinion supposes two things; 1st. the existence of fat ready 
formed in the arterial system, an existence that is proved 
by no positive fact, of which I never could convince 
myself by the examination of red blood as it comes out of 
the vessels, for if it did exist there would be numerous 
little drops floating on its surface at the moment it was 
drawn. -In my experiments upon the colouring of the 
blood, I have frequently established this ; 1 have observed 
it also in examining the blood of maniacs upon whom ar- 
teriotomy has been performed at the Hotel Dieu. 2d. The 
opinion of Haller is founded upon a transudation truly 
mechanical, a transudation that easily takes place in dead 
bodies, but never in living. In fact, if we lay bare an 
artery of a living animal, separate it entirely from every 
thing else, and examine it ever so long, we shall discover 
no oozing of fat through its coats, though the blood cir- 
culates in it as usual. There is an infinity of arteries, 
spread in the cellular texture, through which fat never 
transudes, as we see in the scrotum, the eyelids, &c.; 
now in these places the arteries are organized as else- 
where, and they ought therefore to have the fat ready 128 
CELLULAR SYSTEM. 
formed in the blood that they circulate ; then, according 
to Haller, fat would be deposited there. Besides, vve shall 
see under the article upon exhalations, that this transu- 
dation through the pores of the arteries, whatever fluid is 
supposed to he transuded is evidently repugnant to the 
laws of the animal economy. 1 refer then to this article, 
to establish the fallacy of Haller’s opinion; under that 
article we shall see also, that the fat is separated by an 
exhalation analogous to that of all other exhaled fluids, 
that is to say, by the vessels of a particular order, which 
are intermediate between the extremities of the arteries 
and the cellular texture. Some authors have thought 
that they saw the vessels that carry the fat, and have 
designated them under the name of adipose ; but it 
appears, that like the other exhalants, they are invisible 
and can only be proved by a train of reasoning, which 
however, satisfactorily establishes their existence. We 
can apply to the exhalants of fat, what will be said upon 
the exhalant system in general. 
1 will not treat of the chemical nature of fat, of the acid 
it contains, of the particular alterations it undergoes 
under different circumstances, that for example, that it 
experiences when animal substances that contain it, such 
as the skin, the muscles, &c. are for a long time macer- 
ated in water. This would lead me into details foreign 
to this work. Besides, 1 could add nothing to what 
modern chemists have said upon this subject. 
I will terminate this article with an important re- 
mark; it is this, that in those parts which nature has 
deprived of fat, it would have injured their functions. 
The penis increased in size by it, would not have had 
a proper relation to the vagina. The eyelids loaded 
with fat could scarcely be raised. Accumulated in the 
sub-mucous texture, it would have contracted the cavity of 
the organs which the mucous surfaces line. Spread in 
that which surrounds the arteries, the veins and the CELLULAR SYSTEM. 
129 
excretories, it would have obstructed the caliber of these 
vessels; and here observe, that its uniform absence in the 
sub-arterial texture is a proof against the opinion of 
Haller upon its transudation. Accumulated in the cere- 
bral cavity, it would have compressed the brain on. 
account of the resistance of the bony parietes of the cra- 
nium, &c. which do not yield like those of the abdomen, 
when the gastric viscera are loaded with fat. In the 
thorax, the diaphragm can descend, and the lungs can 
without danger occupy less space when there is consid- 
erable fat exhaled in the mediastinum. This remark, 
applicable also to the serum, explains an important 
phenomenon in diseases, viz. that a very small quantity of 
fluid poured out upon the tunica arachnoides can disturb 
the functions of the brain, whilst a great effusion is unat- 
tended with danger in the abdomen or the thorax. 
ARTICLE FOURTH. 
ORGANIZATION OF THE CELLULAR SYSTEM. 
The cellular system, like almost all the others, is com- 
posed of a peculiar texture and of common parts. 
I. Of the texture peculiar to the organization of the cellular 
system. 
Much has been written upon the nature of this texture; 
Bordeu has given some vague ideas upon it, but no ex- 
periments. Fontana has made researches which lead but 
to few results, upon its intimate structure and upon the 
tortuous cylinders of which, according to him, it is an as- 
semblage. Let us throw aside all hypotheses that exami- 
nation does not support; let us follow nature in the phe- 
nomena of structure that she shows us, and not in those 130 
CELLULAR SYSTEM. 
she wishes to conceal. In thus considering the cellular 
texture, we see that it is very different from a species of 
glue, with which some have wished to compare it. It is 
an assemblage of many whitish filaments, crossing very 
often certain kinds of delicate layers, which form cells 
with these filaments. To see this organization well, a 
piece of the cellular portion of the scrotum should be 
taken, which has no fat, and whose texture is consequently 
not concealed by this fluid; this portion being stretched 
into a kind of membrane, is seen very distinctly. Then 
there may be plainly distinguished, 1st. a transparent 
net-work, arranged in layers, which makes the founda- 
tion, if we may so say, and the tenuity of which is such, 
that it has been aptly compared by a physiologist, to the 
soap bubbles that are thrown into the air with a pipe. 
It is impossible to distinguish, by the naked eye, any 
fibre in the texture of these layers ; every thing is there 
uniform. 2d. They are very evidently crossed by nu- 
merous filaments, which running in all directions, are 
interwoven in every way, all of which touch, when the 
cellular texture is pressed together, but when stretched 
out, there can be seen between them the layers of which 
I have just spoken. The more it is the larger 
consequently the membrane becomes, the interstices be- 
tween the filaments are greater, and the intermediate 
layers are also more apparent. 
What is the nature of these filaments? I presume that 
some are absorbents, others exhalants, and that many are 
formed in the places where the layers unite together for 
the formation of the cells. As the thickness arising from 
this union is greater, they are distinguished by more evi- 
dent lines upon the cellular texture stretched into a 
membrane. What induces me to believe this, is, that 
when, instead of examining the cellular texture upon a 
portion taken from the scrotum, and stretched as I have 
described, it is observed in an artificial emphysema, as CELLULAR SYSTEM. 
131 
in that of the slaughter-houses for example, then there is 
seen upon the covering of each cell, only the non-fila- 
mentous layers of which I have spoken, without any of 
those filaments that were seen crossing it in the other 
method. 
These layers have not the same thickness in all cases; 
quite dense when the cellular texture is contracted, they 
become, when it is distended with air or any other means, 
so fine and attenuated, that the mind cannot conceive that 
there is any thing organized in them. Their organiza- 
tion is real, however, though some have doubted it. 
What in fact is a texture that is nourished, inflames and 
suppurates, which is the seat of very distinct vital func- 
tions, and which evidently lives, if it is not an organic 
texture? All these vague ideas of concrete juices, of in- 
organic glue, of hardened juice, that have been applied 
to the cellular texture, have no solid foundation, and rest 
neither upon experiment or observation, and ought to be 
banished from a science in which imagination is nothing, 
and facts every thing. 
The cellular texture has essential differences of organi- 
zation ; everywhere where fat or serum is accumulated, 
there are real cells which have little sacs communicating 
with each other, which form reservoirs, the sides of 
which are composed of the transparent and non-filamen- 
tous layers of which we have spoken ; it is in these sacs 
that the serous and fatty depositions take place. On the 
other hand, in the sub-mucous texture, in that which 
forms the external membrane of arteries, veins, and ex- 
cretories, there are none of these sacs, no cells, properly 
speaking, and no layers to form them. When we care- 
fully raise this texture, and lift it from the surface upon 
which it is applied, and draw it a little so as to show its 
structure, we shall see very distinctly numerous filaments 
interwoven every way, forming a true net-work, meshes, 
if I may so express myself, but not sacs and cavities. 132 
CELLULAR SYSTEM. 
The air distends this net-work when it is driven forcibly 
into the neighbouring texture ; hut as soon as an open- 
ing is made near it, it escapes, and the texture sinks 
down ; when accumulated in the ordinary texture, the 
sub-cutaneous, intermuscular, &c. it remains in the cells, 
notwithstanding they have been in part opened, with- 
out doubt because the communicating openings are very 
small. This fact is evident in markets, where we see 
the cellular texture blown up, around the meats that are 
stripped of their skin. 
It appears that the filaments that are interwoven in 
every way, and which form about the vessels and under 
the mucous surfaces, a cellular net-work, are really of 
the same nature as those spread in different directions in 
the membranous layers which make the cells, only they 
are nearer together, and are by themselves. 
After what I have said, it is evident that there are two 
things in the common cellular texture; 1st. a number of 
fine, transparent layers, found everywhere where the 
texture is loose, capable of yielding suddenly to different 
distensions, and of retaining the fluids its cells contain, 
&c.: 2d. filaments intermixed w ith these layers wherever 
they are, and existing alone in certain places. These 
layers and cellular filaments have a remarkable tendency 
to absorb atmospheric moisture. We observe it in dis- 
secting rooms, where a subject dry and easy to dissect in 
the morning, is often much infiltrated by evening, if the 
weather has been damp ; now this infiltration takes 
place in the cellular system, which is a real hygrometer. 
Composition of the cellular texture. 
Chemists have placed this texture in the general class 
of white organs, among those which furnish a great 
quantity of gelatine. It has this in fact, and we obtain by 
a solution of tannin a remarkable precipitate from the 
water in which this texture has been boiled, without any CELLULAR SYSTEM. 
133 
foreign organs except the vessels that run through it, as, 
for example, that of the scrotum. I have made this ex- 
periment. But, however, different re-agents act very 
differently upon this texture, as they do upon the fibrous, 
cutaneous, cartilaginous textures, &c. 
Exposed to the action of the air, the cellular texture 
dries quickly, but without taking the yellowish colour of 
the fibrous texture; it remains white. When it is dried 
in considerable layers, its cells adhere together, and these 
layers being stretched a little to facilitate the drying, re- 
present a true serous membrane, so that it would be im- 
possible to distinguish it from one dried in the same way. 
Jn this state the cellular texture is pliable; it can be bent 
with great ease in every direction ; it has not the stiffness 
of dried fibrous texture ; when immersed again in water, 
it takes but imperfectly its former appearance; its cells 
are separated with difficulty. 
Exposed to putrefaction with other animal substances, 
it yields to it less readily than many of them, for exam- 
ple, than the glandular and muscular organs ; filled with 
the putrefactive juices it does not become pulpy until 
some time after these parts. This fact is particularly 
remarkable in the sub-mucous texture, in that which sur- 
rounds the vessels; the filaments that compose it, resist 
much longer than the other parts of the cellular system, 
the putrefactive process. 
The same may be said of maceration as of the pre- 
ceding phenomena. In looking at a tendon and a portion 
of cellular texture, who would say that the action of 
water would soften the first quicker than the second ? the 
one being soft and almost fluid, and the other compact. 
After remaining in water three months, of the tempera- 
ture of a cellar, the cellular texture of the arteries did 
not appear to me to have undergone any alteration. 
The sub-cutaneous, the sub-serous, the intermuscular 
textures, &c. are changed sooner, but not so soon as that 134 
CELLULAR SYSTEM. 
of some other organs. I have kept for six months, in a 
glass vessel, some nerves, which as we shall see, are not 
altered in water; the texture which separated the fibres 
of these, was as firm and distinct as at first. This resis- 
tance to the action of water is less, when the cellular 
texture is macerated with organs that soon yield and be- 
come pulpy, than when it is exposed alone. This resis- 
tance is the more remarkable, as this texture, being very 
fine, is accessible at many points to the contact of the 
fluid. If the texture of tendons, of cartilages, of apo- 
neuroses, of the skin, &c. was arranged in layers as fine 
and as much separated, I am satisfied that three or four 
days of maceration would be sufficient to reduce them to 
a mere pulp. 
As much may be said of ebullition; a few minutes 
would be sufficient to dissipate and melt into gelatine 
most of the white textures, if they were arranged in lay- 
ers as fine as the cellular system ; this, however, resists 
a long time; different layers are still seen between the 
fibres of the boiled muscles. The fat which remains in 
parcels among the fleshy fibres, after the boiling, would 
have been melted, if it had not been contained in cells 
which continue untouched; we can, moreover, be easily 
convinced of the existence of these layers in the parcels 
of fat. It is especially7 upon the texture exterior to the 
arteries, the excretories, &c. that the action of boiling 
water is longest in producing an effect. 
The cellular texture that is boiled exhibits phenomena 
analogous to other organs treated in the same way. 1st. 
At the instant of boiling, when an albuminous froth rises 
upon the water that contains it, it remains soft, and about 
the same it was at first. 2d. When this froth is formed, 
it becomes hard, is crisped and contracted in size. The 
hardening increases until it boils, which takes place al- 
most immediately. In this state the texture is firmer; it 
has become elastic ; if drawn in an opposite direction, it CELLULAR SYSTEM. 
135 
suddenly returns, which it would not do before. 3d. 
Ebullition being continued, it gradually softens and loses 
the hardness it had acquired ; then it can hardly be ex- 
tended at all; it may be much elongated without break- 
ing, in a natural state, the rupture of it is now the effect 
of the least effort. 4th. In fine, by the continued action 
of boiling water, it gradually melts. I have remarked, 
that it does not in any period of ebullition, assume the 
yellowish tinge, which is spread over the whole of the 
fibrous system when boiled. 
From the phenomena that cellular texture offers when 
exposed to the action of dry and moist air, of cold and 
boiling water, &c. I presume that it is less easily changed 
by the gastric juices than many others, the muscular tex- 
ture, for example ; besides, the following facts prove this. 
1st. The taste, almost always a certain index which na- 
ture has given us to judge of digestible aliments, is 
much less gratified with the cellular texture that is mixed 
with cooked meat, than with the meat itself. 2d. I have 
made this experiment upon myself; when my stomach 
contained a sufficient quantity of food, I excited vomiting 
nearly an hour after eating ; when it contained but little, 
I could not vomit without taking a large quantity of warm 
water; 1 then threw up this and with it the aliments the 
stomach contained. I have frequently ascertained by 
these means, especially by the last, that the cellular 
lumps which are found with the fleshy fibres of boiled 
meat, are much longer in being altered than the fibres 
these last have become pulpy before the 
others are acted upon. The fat, which generally fills 
these cellular lumps, may have an influence also in this 
phenomenon. 3d. I have made the same observation 
upon dogs that I have opened at different periods of di- 
gestion to determine the difference of the bile in the cys- 
tic and hepatic ducts, a difference of which I have al- 
ready given some account. 136 
CELLULAR SYSTEM. 
How can Hie cellular texture unite to the softness 
and delicacy that characterize it, a greater resistance to 
the different re-agents, than that of other textures much 
more firm ? 
We know that in those who are drowmed, a great quan- 
tity of gas disengaged from different organs, from those 
especially that contain much blood, as the muscles, the 
glands, &c. fills the cellular texture, renders it emphy- 
sematous and makes the body float. This does not so 
often take place in the open air, where putrefaction is 
sudden and whore there is a discolouration and disorga- 
nization of parts. The tendons, the aponeuroses, the 
cartilages, the bones, &c. have appeared to me in animals 
drowned for the purpose, not to assist in the produc- 
tion of this gas. The cellular texture itself has less part 
in it, I think, than the organs before pointed out. It 
would be easy to know the kind of gas that each or- 
ganized system furnishes, by macerating these systems 
separately in closed vessels, so arranged that their aeri- 
form products might be collected. If each has a pecu- 
liar mode of putrefaction and gangrene, &c. if in this 
state their appearance is different, it is presumable that 
the products that escape from them are also different. 
In dead bodies that are buried, and beyond the reach 
of the air, the emphysematous swelling often takes place, 
and it is sometimes so powerful, as I have observed in a 
church-yard, that it will raise the lid of the coffin, though 
it may be covered with half a foot of earth, which raises 
it then above the level of the earth that covers the other 
coffins. 
II. Parts common to the organization of the cellular system. 
Blood vessels. 
We must not judge of the vessels of the cellular tex- 
ture by injections. When they are fine and have suc- 
ceeded well, a thousand different threads interlaced in CELLULAR SYSTEM. 
137 
every way, destroy its whitish colour and change it into 
a vascular net-work. The appearance of a body thus 
injected is deceptive; it arises from this, that the exha- 
lants have admitted a fluid forced through the arteries, 
whilst their own sensibility would repulse the blood in an 
ordinary state. In dissecting the cellular texture upon a 
living animal, it is seen to be white as in the dead body, 
and that great trunks that do not belong to it, send off in 
passing through it different branches and ramifications 
that are evidently lost in it. In raising the skin from 
the subjacent organs, the sub-cutaneous texture is dis- 
tended, and we may clearly distinguish in it different 
little branches that end there ; this is remarkable in dogs. 
By first making the cellular texture emphysematous, the 
experiment succeeds better. We see, also, very well in 
this way, that the blood varies in the vessels; often after 
being exposed sometime to the air, there appears double 
the number of them there was when it was laid bare. 
There are always remarkable variations, if the place that 
is denuded is examined even for a short time ; it is the 
blood retained in the exhalants, and it seems thus to 
increase the number of little arteries. 
Exhalants. 
The existence of the exhalants is rendered evident, 
1st. by the preceding experiment, which is a natural 
manner of injecting them; 2d. by artificial injections, 
which shows there many more vessels than ordinary; 
3d. by transudations that sometimes take place in the 
cells, when these injections are driven with much force, 
transudations that really form an artificial exhalation; 
4th. by natural exhalation, which is continually going on, 
and which has for its materials the fat and the serum; 
5th. by accidental exhalations that sometimes take place, 
as when the blood is diffused in and colours serous infil- 
trations, &c. 138 
CELLULAR SYSTEM. 
Few systems in the living economy are furnished with 
a greater number of exhalants; I do not speak of those 
that contribute to its nutrition and that are consequently 
found there as in all other organs. The superabundance 
of these vessels is ow ing to the continual exhalation that 
is going on there. It is this superabundance w hich ren- 
ders, as we shall see, inflammation so much more frequent 
in a part where the cellular texture is in the greatest 
abundance; it is this that exposes it to that variety of 
alterations, in which its texture, loaded with the different 
substances it exhales, has a firm appearance, and offers at 
one time a fatty substance, at another a gelatinous one. 
sometimes a species of scirrhus, &c. &c. 
Absorbents. 
The absorbents correspond with the exhalants in the 
cellular system ; the eye cannot trace them, injections 
would not reach them. But their existence there is pro- 
ved, 1st. by the natural and constant absorption of fat 
and serum ; 2d. by the more manifest one that produces 
resolution of serous infiltrations in dropsies, sanguineous 
in ecchymosis, purulent in the different kinds of abscesses 
that arc removed; 3d. by the disappearance of mild 
fluids injected into these cells, an effect that must be 
owing to the agency of these vessels; 4th. by the reso- 
lution of natural and artificial emphysema, in which the 
air, or at least the principles that constitute it, have no 
other way of escaping. This is evident when the em- 
physema arises from a rupture of a bronchial cell, and 
when a very little opening is made in the animal, it is 
stopped after the air is driven by it into the sub-cutane- 
ous texture ; this 1 have convinced myself of. 5th. The 
drying up of external ulcers is owing to the cellular ab- 
sorbents. Oftentimes in phthisis the ulcers are suddenly 
emptied, and we find in the subject who dies immediately'-, 
only the place that was occupied by pus or sanies ; 1 CELLULAR SYSTEM. 
139 
have already known two patients to die in this way by a 
re-absorption almost instantaneous and exactly analogous 
to that of external ulcers. 6th. Where there is the most 
cellular texture, we meet with the greatest number of ab- 
sorbents, and the most of those bodies with a glandular 
appearance, in which these vessels ramify. Where the 
cellular texture is scarcely discoverable, as in the brain, 
we can with difficulty see the absorbent system, &c. 
We must consider, then, the cellular system as the 
principal origin of the absorbents, of those especially 
which serve to carry the lymph. These vessels and the 
exhalants appear to contribute particularly to the forma- 
tion of its structure. Many have thought that it was 
exclusively formed of them; but this is not founded 
either upon observation or dissection. We see a trans- 
parent filamentous texture, and nothing more. Each cell 
is a reservoir intermediate between the exhalants that 
terminate and the absorbents that arise there. They 
are in a small way what the serous sacs are in a large 
one. We do not see the orifice of either set of vessels. 
Nerves. 
We see many nerves running through the cellular tex- 
ture. But do these filaments stop there? Dissection 
affords no light upon the subject ; it arises perhaps from 
this, that these filaments being white like the texture, 
we cannot see them at their termination as well as we 
can the arterial branches, which are rendered apparent 
by their colour, when they contain red blood. 140 
CELLULAR SYSTEM. 
ARTICLE FIFTH. 
PROPERTIES OF THE dELLULAR SYSTEM. 
I. Properties of texture. 
The properties of texture are strongly characterized 
in the cellular system. 
Extensibility. 
Extensibility is proved in a variety of rases, as in 
oedema, in the accumulation of fat, and in different tu- 
mours, in which the cells are much spread and the 
membranes remarkably elongated. All the natural mo- 
tions suppose this extensibility ; the arm cannot be raised 
without the texture of the axilla acquiring an extent 
double, or even treble, what it has when the arm is 
down. The flexion and extension of the thigh, of the 
neck, and of almost all the parts, exhibit in different de- 
grees analogous phenomena. If we raise any organ 
from those to which it is contiguous, the intermediate 
texture is considerably elongated. 
The degrees of the extensibility of the cellular tex- 
ture vary. In the sub-cutaneous, the sub-serous, the in- 
termuscular, &lc. this property has much more extended 
limits than in the sub-mucous layer, in that exterior to 
the arteries, the veins, and the excretories. It exists, 
however, in this, as is proved by the dilatations of the 
gastric viscera, aneurisms, varices, &c. But these phe- 
nomena themselves prove the greater difficulty of exten- 
sion in this species of texture ; for example, the ordinary 
texture would be incapable of resisting the impulse of 
the blood after the rupture of the coats of the artery. 
There would be a sudden, enormous, and often fatal 
dilatation, if the arteries were only surrounded by this. CELLULAR SYSTEM. 
141 
It is the thickness of that which covers them, which 
makes the progress of these tumours slow and gradual. 
It is in fact an essential character of the extensibility 
of almost all the cellular system in which the layers and 
consequently the cells are united, to have the power 
always of being put suddenly in action and in an instan* 
taneous manner. We have an example of this kind of 
extension in emphysemas artificially produced, which 
make this texture go suddenly from a state of perfect 
contraction to the greatest extension of which it is capa- 
ble. The artificial injection of different fluids exhibits 
the same phenomenon. We observe it also as a conse- 
quence of fractures, and contusions of the limbs, in which 
we sometimes see enormous swellings appear in a manner 
almost as sudden. The cellular texture is evidently the 
seat of those swellings which take place in that texture 
which is sub-cutaneous, and not in that subjacent to the 
aponeuroses, because the extensibility of these mem- 
branes not being capable of being suddenly put into ac- 
tion, resists all dilatation that is not gradually made. 
Many other organs, as the tendons, the cartilages, the 
bones, &c. though possessing, like the cellular texture, ex- 
tensibility of texture, differ from it like the aponeuroses, 
in the impossibility of being suddenly distended. In 
general, the softness of the primitive structure appears 
to have great influence upon this modification of exten- 
sibility. 
The cellular texture, extended too far, becomes at first 
very thin, and then breaks. In a natural state, no mo- 
tion of the economy is capable of being carried so far as 
to occasion this; for example, 1 have remarked in regard 
to cellular texture taken from the axilla, that it is neces- 
sary to extend it at least three times as far as it is in the 
elevation of the arm, to produce this phenomenon. Be- 
sides, what opposes also this rupture, is a kind of loco- 
motion of which it is capable; so that if too violently 142 
CELLULAR SYSTEM. 
drawn, it displaces that which is contiguous to it, draws 
it towards itself, and thus becomes less stretched. We 
see this phenomenon in a remarkable manner in the 
swellings of the testicle, in large hydrocele. Then all 
the surrounding texture, that of the lower part of the 
abdomen, the top of the thighs, and the perinaeum, drawn 
by that which immediately covers the tumour, is thus 
brought also upon it. 
I have observed that the inflamed cellular texture loses 
in part this property, and that upon the dead body it 
breaks with great ease. This takes place also in differ- 
ent indurations of which it is the seat. For example, 
that surrounding a cancerous womb, being swelled, loses 
the capacity of being extended ; it is brittle, if I may 
be allowed to use the word; the least effort is sufficient 
to break it. This fact is uniform in all cancerous affec- 
tions, somewhat advanced, of the womb and in those of 
many other organs. 
Contractility. 
Contractility of texture always takes place in the cel- 
lular system when extension ceases. Thus in emaciation, 
in the resolution of dropsy and of tumours, the cells con- 
tract and lose a great part of the capacity they had ac- 
quired; in a wound which has affected the cellular tex- 
ture as well as the skin, the edges separate, and a space 
remains between them owing to the contraction of the 
cells. 
As we advance in life, this contractility takes place 
with less ease; youth is the period of its greatest energy; 
thus in consequence of great emaciation that takes place 
in old men, the skin is flaccid and wrinkled, because the 
subjacent cellular texture not having contracted, the cu- 
taneous covering remains at some distance from the ex- 
ternal organs and cannot lie close to them. In a young 
man, on the contrary, who has become emaciated, the CELLULAR SYSTEM. 
143 
skin is exactly applied to the organs, it preserves its ten- 
sion ; because the cells in contracting draw it with them ; 
these form the external prominences. It is necessary 
to observe these prominences; in the face, with the folds 
of the skin, they form what are called prominent features. 
II. Vital Properties. 
The animal properties are not among the attributes of 
the cellular texture in an ordinary state; we can with 
impunity cut it, draw it in different directions or distend 
it with gas. An animal that undergoes these experiments 
gives no indication of suffering. If he feels any pain, it 
is from the nervous filaments that pass through the tex- 
ture, and which may be accidentally irritated. In dis- 
ease however, the sensibility is raised to such a point, that 
it may become the seat of acute pain ; phlegmon is a 
proof of this. 
The organic properties are very distinct in the cellular 
texture ; fat and serum could not be absorbed there, if they 
did not make an impression that brings into action organic 
sensibility. I would observe concerning this property 
considered in the cellular system, that all substances have 
not an equal relation to it; among the animal fluids the 
blood, the lymph and milk do not raise it so high, when 
they are effused or injected there, as to prevent absorption, 
which takes place of them as well as of fat and serum. On 
the other hand this sensibility is so altered by the contact 
of urine, bile, saliva or other fluids destined to be thrown 
out, that inflammation is often the consequence, and pre- 
vents absorption. Among the foreign fluids injected 
water is absorbed. Wine and almost all other irritating 
fluids excite suppuration, and are thrown out with the pus 
that arises from them. We know that in the operation for 
hydrocele, abscesses in the scrotum are always the conse- 
quence of an accidental passage of the injection into the 
cellular texture. Experiments upon living animals agree 144 
CELLULAR SYSTEM. 
perfectly with this fact; every other irritating fluid, 
diluted acids, alkaline solutions, &c. produce the same 
phenomenon. 
Insensible organic contractility is clearly proved in the 
cellular texture, by the exhalation and absorption that 
take place there. 
It has to a certain extent sensible organic contractility. 
We know that cold alone is suflicent to contract the scro- 
tum in a remarkable manner ; that as it is irritated or not, 
this part has various degrees of contraction and relaxa- 
tion ; now it appears to contain under the skin only cellu- 
lar texture; the filaments of which, it is true, have a par- 
ticular appearance and seem to differ in their nature from 
the filaments of the other portions of this system. This 
contraction to be sure is not to be compared to that of the 
muscles, but it is certainly the first degree of it; it is of 
the same nature, or rather it is a medium between this 
and those oscillations that cannot be described, which we 
designate under the name of insensible organic con- 
tractility, and others call tone. 
Sympathies. 
The relations of the cellular with the other systems are 
very numerous and multiplied; but oftentimes it is not 
easy to perceive them clearly. In fact, as it is dissemi- 
nated in all the organs and contributes to the structure of 
all, it is frequently difficult to distinguish what belongs to 
it, from that which is an attribute of the parts where it is 
found. These relations however, become evident under 
various circumstances; in acute as well as chronic dis- 
eases, it is very susceptible of the influence of the affec- 
tions of the organs. I do not here mean the alterations 
arising from juxta-position and continuity, alterations so 
common as we have seen, but those produced in parts of 
the cellular texture that have not any known relation to 
the affected organ. CELLULAR SYSTEM. 
145 
In acute diseases which have their seat in a particular 
organ, as in the lungs, the stomach, the intestines, &,c. the 
cellular texture is often sympathetically affected; it be- 
comes inflamed, suppurates, &c. Most critical deposits 
arise from this real though unknown connexion between 
the affected organ and the cellular texture. Oftentimes 
it is the natural exhalation or absorption of this texture 
that is deranged in acute affections; hence the swelling, 
and dropsies that sometimes suddenly arise. I attended 
a man in the ward Saint Charles who, in consequence of 
great terror, had a sudden contraction of the epigastric re- 
gion ; a tinge of the jaundice, an indication of the affec- 
tion of the liver by the emotion of the mind, spread in a 
few hours after over his face. In the evening he had great 
cedema of the lower limbs, an oedema produced, without 
doubt, sympathetically by the influence of the liver upon 
the cellular texture. This influence of the principal or- 
gans upon this system becomes especially remarkable in 
chronic affections, in the alterations of texture they ex- 
perience. We know that most of the gradual diseases of 
the heart, the lungs, the spleen, the stomach, the liver, 
the womb, &c. have among their symptoms, in the latter 
stages, a dropsy more or less general, which arises from 
the debility created in the cellular texture. Medicine 
owes much to Corvisart, for being among the first to per- 
ceive that almost all infiltrations are symptomatic, that 
almost all consequently depend upon an influence produc- 
ed by the affected organ upon the cellular texture. That 
comes on gradually then, which took place suddenly in 
the patient I mentioned just now. 
We see in all acute diseases, that the skin very easily 
perceives the sympathetic influence of diseased organs, 
that it is many times alternately dry or moist, oftentimes 
in the same day. I am convinced that the cellular tex- 
ture experiences the same alterations as the skin, and that 
if we could see what is going on there, we should per- 146 
CELLULAR SYSTEM. 
ceive that its cells are more or less moist, or more or 
less dry, according to the kind of influence it receives; 
it is to this also that must be referred the different state 
of bodies that have died of acute diseases, which present 
innumerable varieties in their cellular serum. 
Most physicians consider in too general a manner a 
number of symptoms, which, to speak correctly, do not 
depend as they imagine, upon the disease, but wholly 
upon a sympathetic affection produced by the diseased 
organ upon the sound ones, which, according as they are 
affected, give rise to different phenomena truly foreign to 
the disease, that sometimes render it complicated but 
do not form an essential part of it ; they can take place 
or not, and the disease remains the same. 
Observe that organic sensibility and contractility are 
almost always in action in cellular sympathies, because 
these are the two vital forces essentially predominant in 
that system. Thus sensible organic contractility and an- 
imal contractility are particularly exercised in muscular 
sympathies, according as the system of organic muscles, 
or that of the muscles of animal life, receive sympathetic 
excitement. 
The cellular system not only receives the influence 
of other organs in its sympathies, but it exercises its 
own upon them. In phlegmon, which is the inflamma- 
tory state of this system, if the tumour is considerable, 
different alterations are oftentimes discoverable in the 
functions of the brain, the heart, the liver, the stomach, 
&,c. Sympathetic vomiting, which is called an overflow' 
of bile, delirium, ike. are phenomena that are seen w ith 
large phlegmonous swellings without belonging to the dis- 
ease itself. Art avails itself of the influence of the diseas- 
ed cellular system upon other organs, in the introduction 
of setons. Oftentimes in diseases of the eyes, a seton 
produces an effect that cannot be obtained from a blister; 
why ? because the relation that exists between the cel- CELLULAR SYSTEM. 
147 
lular texture and the eye, is more active than that which 
unites the latter to the integuments. 
Characters of the vital properties. 
After what has been said, we see that the vital activity 
is sufficiently evident in the cellular system. In this 
point of view, it is much superior to other organs that are 
white like it, and among which it has been ranked, such 
as the aponeuroses, the tendons, the cartilages, the liga- 
ments, &x. organs remarkable for the obscurity of their 
vital forces and the dullness of their functions. Thus the 
phenomena of inflammation go through their different 
periods much quicker in this system. Their progress is 
very rapid, compared to that of different tumours that 
appear in the systems of which I have just spoken. 
Suppuration takes place here with a rapidity of which 
we have an example in but few of the organs. Every 
one knows the fluid that comes from this suppuration. 
Its colour, its consistence, all its external qualities have 
become the type to which we refer the ideas that we 
form of pus ; so that that which does not resemble it, is 
considered to be pus of a bad kind, or as we say sanious. 
This opinion is incorrect. Certainly the pus that flows 
from a bone, a muscle, the skin in erisypelas, the mucous 
membranes in catarrh, is of a good kind so long as the 
inflammation is regularly going through its periods; it is 
however totally different from cellular pus. As this is 
most frequently observed, especially in surgery, we have 
formed a general idea of laudable, as of sanious pus. Cu- 
taneous, mucous, osseous pus, &c. have each their peculiar 
sanies, which differs among them according to the vital 
alterations of the organ, from which it is derived. So 
that the pus of each system differs from that of the 
others, in the same way as the alterations of which it is 
susceptible are different from their purulent alterations. 148 
CELLULAR SYSTEM. 
Has the cellular texture peculiar vital modifications in 
those organs to whose structure it contributes ? From 
what has been said above, it seems hardly probable. All 
that I have been saying, applies to the system considered 
in the interstices of the organs, separate from all com- 
bination with their structure. It is possible however that 
its vital activity is diminished in the cartilages, the ten- 
dons, &c. that it is increased a little in the skin, that its 
life, in general tends to an equilibrium with that of the 
parts in which it is found ; but these are conjectures that 
nothing positive confirms. 
That which ought not to escape us here, is the mani- 
fest difference of vitality that exists between the texture 
of layers and filaments almost every where spread, and 
the texture that is wholly filamentous, which is exterior 
to the mucous surfaces, to the blood-vessels, and excreto- 
ries, a difference from which arises the rareness of in- 
flammation and tumours in this last. It is often a real 
barrier that stops the affections of the first, a barrier that 
protects the organ it covers. Thus 1 have many times 
observed in opening bodies, that whilst the ordinary tex- 
ture, in which the arteries are embedded as in the axilla, 
is in a state of suppuration, and almost disorganized by 
the pus, that which forms the external covering of the 
vessels remains untouched ; it has not undergone the 
least alteration. I have seen the same phenomenon in 
the texture exterior to the urethra in deposits of pus at 
the loins. 
The cellular texture is distinguished from other organs 
by the faculty it has of throwing out a kind of vegeta- 
tion, of elongating and re-producing itself, of growing 
when it has been cut or divided in any manner. It is 
upon this faculty that depends the formation of cicatrices, 
tumours, cysts, &c. 
III. Properties of re-production. CELLULAR SYSTEM, 
149 
Influence of the cellular texture upon the formation of cica- 
trices. 
Cicatrices may be considered under two relations, 1st. 
in the external organs, in the sub-cutaneous texture and 
skin particularly; 2d. in the internal organs. Let us 
examine them at first in the external. 
Every wound that follows the ordinary periods, pre- 
sents between its formation and its cicatrization, the 
following phenomena; 1st. it inflames ; 2d. fleshy gran- 
ulations are formed upon its surface; 3d. it suppurates; 
4th. it sinks down; 5th. it is covered with a fine pelli- 
cle, red at first and afterwards becoming whitish. Let us 
trace these different periods. 
First period. 
Inflammation commences the instant the wound is 
made. This is the sudden result of the irritation caused 
by the instrument, the contact of the air, the dressings 
and surrounding bodies. Shut out until then from the 
coutact of the air, most of the parts concerned in the 
solution of continuity, enjoy only organic sensibility; 
but then these contributing to form the surface of the 
body, ought to enjoy animal sensibility, that which trans- 
mits to the brain the impressions that are received. 
Now the effect of inflammation upon organs endowed 
only with the first kind of sensibility, is to raise it so 
much, that it ascends to the same degree as the second, 
and can like it, transmit to the brain its impressions; so 
that by it the parts divided by a wound become capable 
of performing the functions of the integuments. This is 
the first advantage, without doubt, of this inflammatory 
period of cicatrization. 
Another advantage of this period is to dispose the 
parts to the development of fleshy granulations. In fact, 
inflammation always precedes this development; now 
the increase of life that it produces in the organs, appears 150 
CELLULAR SYSTEM. 
to be necessary to animate the parts that are to be re- 
produced ; by it the cellular texture, where the granula- 
tions are formed, is endowed with more sensibility and 
more insensible contractility; it raises it to a temperature 
above that of the neighbouring organs; it becomes the 
centre of a small circulating system independent of that 
of the heart. It is in the midst of this extension of the 
forces, that the fleshy granulations arise and increase, for 
the production of which the natural forces would have 
been insufficient. Hence the paleness and flaccidity of 
these granulations, when these different functions are 
weakened or cease. 
Second period. 
The production of fleshy granulations succeeds to in- 
flammation. It presents the following phenomena; small 
reddish bodies, like tubercles, arise, unequal and irregu- 
larly disposed upon the surface of the wound; they are 
not fleshy, as their name, given, no doubt, on account of 
their colour, would indicate ; they are little cellular 
vesicles, filled with a thick substance, like lard, which 
we are unacquainted with, and which it is important to 
analyze. This substance so fills the cells, that in blowing 
air into the texture subjacent to a wound, whether in a 
living or dead body, this fluid does not enter the granu- 
lations ; they are raised up entire, but no one of them is 
developed or distended as the cells which this substance 
does not fill; the granulations remain the same in the 
midst of the general bloating. I have often made these 
experiments upon animals that 1 have wounded for the 
purpose. 
In proportion as the granulations are developed upon 
an exposed cellular surface, we see them unite together, 
and form, by their union, a kind of provisional membrane, 
which absolutely prevents the contact of air upon the 
subjacent organs, while the true cicatrix, that which is to CELLULAR SYSTEM. 
151 
be permanent, is forming. This provisional membrane of 
cicatrices, this kind of epidermis destined to defend the 
parts during the work of cicatrization, differs from com- 
mon serous membranes in this, that they are smooth and 
every where uniform, whilst the granulations produce 
here an unequal and rough surface. This inequality of 
the granulations and their separation, appear to be oppos- 
ed to what I have said concerning the first state of cica- 
trices ; the following experiment leaves no doubt upon 
the subject. I made a large wound upon a dog, and let 
it go through its first periods ; the animal was then killed. 
I removed a portion of flesh upon which the granulations 
were developed; I distended it by a prominent body, 
placed on the side opposite to the granulations, so as to 
make the granulated surface convex, that had been con- 
cave ; the tubercles were effaced; the provisional pelli- 
cle, stretched out, became very evident; it might have 
been taken for an inflamed serous membrane. 
It follows hence, that when the granulations are united 
together, that the air is entirely excluded, and that what 
is commonly said of the contact of this fluid is inaccurate 
and contrary to the arrangements of nature, which knows 
how better than we can do by our dressings, to cover 
over a divided part, whilst the work of cicatrization is 
prepared and effected. 
These are the general phenomena that cutaneous cica- 
trices offer in the two first periods of their formation. 
The internal cicatrices show nearly the same thing. 
Now it is easy to prove that the cellular system here per- 
forms not only an important but an exclusive part, and 
that all these phenomena take place in its texture or its 
cells. The following observations prove in a satisfactory 
manner the cellular nature of the granulations and the 
provisional pellicle that arises from them. 1st. Where 
the cellular system is most abundant, as in the cheeks, 
granulations grow most easily and wounds are soonest 152 
CELLULAR SYSTEM. 
healed. 2d. The skin, stripped too much of the cellular 
texture, is not covered with ease with these productions, 
and adheres with difficulty to the neighbouring parts ; 
hence the precept so strongly inculcated in surgery, of 
saving this texture in dissecting out tumours, in the ex- 
tirpation of wens, cysts, &c. 3d. Maceration always 
reduces to this first base the surfaces of granulating 
wounds, when we expose a dead body that has one to 
this simple experiment. 4th. The nature of fleshy gra- 
nulations is the same every where, whatever be the organ 
that produces them, whether a muscle, a cartilage, the 
skin, a bone, a ligament, &c.; only they are more or less 
backward, according as the life of each organ is more or 
less active, more or less decided, and the vital forces 
found there marked in a greater or less degree; thus 
they appear at the end of four or five days upon the skin, 
and it is very much longer before they are visible upon 
the bones; but their structure, their external appearance, 
their nature, are always the same; then they are only 
the expansion, the enlargement of an organ, that is met 
with in all the others; now this organ common to all, 
this general base of every organized part, is the cellular 
texture. 
From the red colour of fleshy granulations, it has been 
thought that they were a vascular expansion ; but their 
development is unlike every production of the blood- 
vessels. On the one hand we have seen, that the cellular 
texture contains so many exhalants and absorbents, that 
it seems to be almost made up of them ; on the other 
hand, we shall see that in inflammation a passage is con- 
stantly given to red blood in this kind of vessels ; then, 
as the fleshy granulations are cellular, they consequently 
partake of the nature of this system; and when found in 
a real inflammatory state, we conceive that their redness 
is the same as that of an inflamed pleura, of the cellular 
texture that has become the seat of phlegmon, of erisy- CELLULAR SYSTEM. 
153 
pelatous skin, &c. ; a redness that does not imply an 
elongation of blood vessels, but only the passage of red 
blood, in those that usually carry white. This is so true, 
that when the inflammation is gone, the blood ceasing 
to enter these vessels, the membrane takes its natural 
colour ; so that the granulations, after the formation of 
the cicatrix that arises from their near approach to each 
other, whiten because the blood no longer enters them. 
Now if it had been a new production of vessels, they 
would continue and perform their functions. Moreover, 
how can we suppose a development of blood-vessels where 
they did not primarily exist, as in the tendons, the carti- 
lages, &c. which have, like other organs, fleshy granula- 
tions in their solutions of continuity ? 
Let us conclude from these circumstances, that the 
arterial system is not connected with the formation of 
fleshy granulations; that the cellular system is alone con- 
cerned in it, because that this alone is endowed with the 
faculty of increasing, extending, and reproducing itself. 
This is what takes place in the second period of the 
cicatrization of wounds ; the cellular texture, by the 
increase of power that it acquired in the first period, is 
raised into vesicles irregularly disposed, which exhale a 
white substance, that is not well understood, and unite at 
their superficies and form a provisional membrane. But 
how is this membrane changed into that of the cicatrix? 
Observe nature, and you will see that it brings on suppu- 
ration and a sinking down of the parts, before the arrival 
of this period. 
Third period. 
The period of suppuration does not take place in the 
cicatrization of the bones, in that of broken cartilages, of 
torn muscles and generally in the reunion of all divided 
organs without external wounds. We must then show 
what relation there is between their cicatrices and those 154 
CELLULAR SYSTEM. 
of the external organs ; for a common principle presides 
over all the operations of nature, though they may have a 
different appearance. 
When a bone is broken, the two first periods of its 
reunion are the same as those of the external organs; the 
ends inflame, and then are covered with cellular granula- 
tions. In the third period, these granulations, having 
first united together, become a kind of secretory or rather 
exhalant organ, which separates first the gelatine which 
encrusts it, and gives to the callus a cartilaginous nature, 
and then the phosphate of lime which completes the osse- 
ous arrangement. In the cicatrization of cartilages, gela- 
tine only is exhaled ; in that of the divided muscles, fibrin, 
&c.; in a w ord the cellular texture is the common base 
of all the cicatrices of the internal organs, then the fleshy 
granulations are the same for all; they resemble each other 
in each having the same base ; that which establishes the 
difference between them, is the substance that is separat- 
ed, and which remains in the cellular texture. This sub- 
stance is generally the same as that which serves for the 
nutrition of the organ, and which is by this function, con- 
stantly carried there and brought away. Now as each 
organ of the different systems has its peculiar nutritive 
substance, each has its peculiar mode of reunion ; we 
should understand the cicatrization of the different or- 
gans, as well as that of the bones, if the substances that 
nourish these organs were as well known as gelatine and 
phosphate of lime. The mode of development of the 
internal cicatrices is in general analogous to that of nutri- 
tion, or rather it is the same with this difference only, 
that the cellular texture rising into irregular granulations 
upon the divided surfaces, does not afford to the cicatrix 
a base formed upon the shape of the organ; hence the 
inequality of callus, &c. 
This then is what in general takes place in the third 
period of the cicatrization of the internal organs : phe- CELLULAR SYSTEM. 
155 
nomena very analogous are seen in that of the external. 
The membrane which covers the fleshy granulations thus 
becomes a kind of exhalant organ which separates from 
the blood a whitish fluid that is called pus. But there is 
this difference, that instead of remaining in the texture of 
the granulations, of penetrating and encrusting it, as the 
phosphate of lime and gelatine penetrate the bone, it is 
thrown out and has nothing to do with the reunion ; so 
that in internal cicatrization there is exhalation, then 
incrustation of the exhaled fluid, and in the external, 
there is exhalation and then excretion of this fluid. 
Besides, an internal wound which affects the cellular 
texture and suppurates, appears to me to resemble per- 
fectly serous surfaces, which are covered in consequence 
of their inflammation with a purulent exudation. The 
fine pellicle that covers the granulations is of the same 
nature as an inflamed pleura or peritoneum, that is, it is 
essentially cellular. The pus is in both cases almost of 
the same nature, and analogous to that of phlegmon, 
because it comes from similar organs, whilst if the skin 
alone is concerned, this fluid is of a very different nature, 
as we see in erisypelas. 
The exhalation of pus upon a cicatrizing surface and 
serous membranes, appears to me to have a great analogy 
with the whitish substance of some kinds of cysts. 
Fourth period. 
Suppuration gradually exhausts the whitish substance 
that fills the granulations; then their cells, which were at 
first swelled, insensibly diminish in size, they close by 
their contractility of texture ; by degrees they adhere to 
each other, and from their adherence arise the following 
phenomena. 1st. All the fleshy tubercles disappear and 
there is a uniform surface in their place. 2d. This sur- 
face is a very fine membrane, because the thickness of the 
granulations arose not from the cells, but the substance 156 
CELLULAR SYSTEM. 
they contained, and which being taken away, leaves them 
empty. 3d. This membrane has infinitely less width 
than the pellicle that first covered the granulations, be- 
cause the cells in contracting, draw the edges of the 
cicatrix from the circumference to the centre ; these 
approximate, and the breadth of the wound diminishes ; 
the same granulations that in the beginning occupied a 
space of half a foot diameter, as for example in the 
operation for cancer, are often contracted to an inch 
or two. 
When the adhesion is complete between all the cells 
that first form the fleshy granulations, the membrane of 
the cicatrix, the result of this adhesion, exists. Thus 
it is that all the flesh, the development of which astonishes 
us, and which amply repairs the loss of substance, is but 
a pellicle, reddish when the exhalants are full of blood, 
but afterwards white by the return of this blood into its 
vessels. 
From this mode of origin of external cicatrices, it is 
easy to conceive, 1st. why they adhere intimately to the 
places in which they are found, and have no laxity in 
the integuments ; 2d. why the skin approximates from all 
the neighbouring parts to cover the wound ; 3d. why it 
wrinkles in approximating ; 4th. why, where it yields the 
most, the cicatrix is the smallest, as in the scrotum, the 
axilla, &c.; and why on the contrary it is the largest, 
where it yields but little, as on the sternum, the cranium, 
the great trochanter, &c.; 5th. why the thickness of all 
cicatrices is uniformly in an inverse ratio to their width; 
in fact as there is only the same quantity of cellular gran- 
ulations to form them, it is necessary that they should 
lose in one way what they gain in another; hence those 
that are broad are much more easily torn ; 6th. why they 
have not a regular organization, do not partake of the 
functions of the cutaneous organ they replace, and why 
their texture is absolutely different from this organ. The CELLULAR SYSTEM. 
157 
cicatrization of wounds left to themselves, especially 
those with loss of substance, differs essentially from the 
union by the first intention, which is effected by the 
agglutination of the edges. In this last there is neither 
the second period, that of fleshy granulations, nor the 
third, that of suppuration, nor the fourth, that of sinking 
down. Union succeeds immediately to the first, that of 
inflammation. 
We see, from all that has been said, that the cellu- 
lar texture is the essential agent in the production of all 
cicatrices, that it forms their basis and their principle, 
that without it they could not take place, and that they 
depend especially upon the property it has of extending 
and increasing. 
Influence of the cellular texture in the formation of tumours. 
In the formation of cicatrices, the cellular texture grows 
but a few lines above the level of the place of division ; 
the cells it forms in its reproduction are generally small. 
It is not so when there is a departure from the ordinary 
laws of cicatrization, when any accidental cause alters the 
vital properties; then we see a very extensive growth, 
which often has more of this texture than the parts from 
which it arises. All those different excresences, known 
by the names of fungous flesh, fleshy protuberances, soft 
flesh, &c. are but the result of this increase of the cellular 
system, being greater than what it should be by the ordi- 
nary laws of cicatrization ; thus the cicatrices are not 
effected while these irregular productions continue; it is 
not until they are repressed that consolidation takes 
place. But it is especially in different tumours that we 
see this development, this remarkable growth of cellular 
texture. All the fungi, and productions that are developed 
exclusively in the mucous membranes, in the sinuses, the 
nasal cavities, the mouth and the womb particularly, 
and which differ essentially from those that have their 158 
CELLULAR SYSTEM. 
seat on the fibrous membranes, the dura-mater for exam- 
ple, though they are compounded under a common name, 
all the fungi, 1 say, arise from the cellular texture, they 
are of a peculiar substance deposited there, which as it is 
more or less abundantly separated, leaves its primitive 
base more or less exposed. 
Polypi, whether mucous or sarcomatous, tumours that 
are equally the attribute of the mucous system, have also 
the cellular texture for the primitive base of their organi- 
zation. All the different kinds of cancers exhibit it in a 
manner more or less evident, in the swelling of the parts 
which they occasion. It would be necessary to notice 
almost all tumours, to point out those that the cellular 
texture assists to form. 
We may then consider it as forming the general base, 
the nutritive parenchyma of almost all excrescences. It 
(shoots up, and grows first at the part where the tumour is 
to be developed ; then it is encrusted with different foreign 
substances, and their difference constitutes the difference 
of the tumours. These phenomena are precisely anal- 
ogous to those of ordinary nutrition. In fact, all the 
organs resemble each other in their nutritive base, the 
parenchyma of nutrition, which is vascular and cellular ; 
they differ in the nutritive substances deposited in this 
parenchyma. All tumours then are cellular, this is their 
common character. Their peculiar character is derived 
from the substances that the texture separates, according 
as the morbid alterations of which it is the seat, modify 
differently its vital forces and place it in relation with 
this or that substance ; thus as we have said, all the inter- 
nal cicatrices are similar in the first period, in that of 
fleshy granulations, and differ as the nutritive substance 
of the organ to which they belong, penetrates them. 
Thus we see, that nature is the same in her operations, 
that a uniform law presides over all, and the only differ- 
arises from the application of this law. Wherever CELLULAR SYSTEM, 
159 
there is natural nutrition or an accidental modification of 
this function, the cellular texture performs an essential 
part; now this important part which it has in cicatrization 
and the formation of tumours, arises from the singular 
property it possesses of extending itself, of dilating and 
growing. Examine the tumours that appear in the 
muscles, the tendons, the cartilages, &c. you will not see 
there an expansion of fleshy, or tendinous fibres, or of the 
cartilaginous substance, &x. the cellular texture alone 
goes from the organ and is spread in the tumour; thus 
the fibres of the bonnes, the muscles, the fibrous substances 
divided in solutions of continuity, are not raised above 
the level of the wound, as the cellular texture of the 
part is for the production of granulations. 
The tumours of which I have spoken, have nothing in 
common, as has been imagined, with the acute swellings 
that constitute phlegmon, nor with that engorgement that 
the limbs experience where there is a violent irritation, 
as a compound fracture or luxation, a whitlow, a punc- 
ture with a poisoned weapon, &c. an engorgement that 
is generally seen around the whole external parts, which 
are violently affected ; it sometimes comes on almost in- 
stantaneously, and is not really inflammatory, though 
there is tension, pain, &c. ; it deserves rather the name 
of inflation than engorgement. 
We must not confound these tumours with certain 
chronic swellings, in which, without increasing or grow- 
ing, the cellular texture is infiltrated, and different sub- 
stances enter it, that change its nature; such are those 
that take place in the diseases of the articulations; such 
is the callosity of fistulas, &c.; the fatty matter that is 
found in some tumours, &c. In all these cases there is 
neither growth or enlargement, as in a polypus, a fungus, 
&lc. ; it is a substance more solid than serum, that infil- 
trates the cellular texture, obliterates its layers, and pre- 
sents a homogeneous appearance. 160 
CELLULAR SYSTEM. 
There is after death a great difference between an 
acute and chronic tumour, between that produced by 
growth and that by infiltration. In fact, one remains 
the same, and preserves, until putrefaction, its size, its 
form, and its density, like all the organs. The other 
sinks away, as I have remarked, by the loss of the vital 
forces. This subsidence varies ; if the tumour is nothing 
but the cellular inflation of which I have spoken, and 
which is so common in external injuries, it entirely dis- 
appears ; if, besides this inflation, there is an accumula- 
tion of blood, as in carbuncle, phlegmon, &c. a portion 
of the tumour remains, though always much diminished 
in size. It is generally in this inflation, of the immedi- 
ate cause of which I am ignorant, that the subsidence 
especially takes place. Let us pass to a function of the 
cellular texture not less important, and which is very 
analogous to this. 
Influence of the cellular texture in the formation of cysts. 
A cyst is a membrane, in the form of a sac without an 
opening, which is accidentally developed, and which, 
containing fluids of a different nature, has been on this ac- 
count divided into many species. The cysts are formed 
from the cellular texture; they arise in its cells, grow in 
the midst of them, and have all its characteristics. 
To be convinced of the influence of the cellular sys- 
tem in the formation of cysts, it is sufficient to prove that 
between them and the serous membranes, there is the 
greatest analogy, and almost identity; for we shall see 
that these membranes are essentially cellular. The fol- 
lowing are some of the analogies of these two kinds of 
productions, the one of which is natural and the other 
accidental. 
1. Analogy of conformation. The cysts form all kinds 
of sacs without an opening, containing a fluid that is ex- 
haled from them, having a smooth, polished surface con- CELLULAR SYSTEM. 
161 
tiguous to this fluid, an uneven, loose one, continuous with 
the neighbouring cellular texture. 
2. Analogy of structure. Always formed of a single 
layer, like serous membranes, cysts have like them a cel- 
lular texture, as is proved by maceration and inflation. 
Thus they constantly arise in the midst of the cellular 
organ, usually where it is most abundant. Few blood- 
vessels enter them ; the exhalant system is conspicuous 
there. 
3. Analogy of the vital properties. There is no ani- 
mal sensibility in them in an ordinary state, but it is very 
evident in inflammation; organic sensibility is always re- 
markable in them, and tone, which is characterized by a 
slow and gradual contraction, in consequence of the arti- 
ficial or natural evacuation of the contained fluids, &,c.; 
these are the characters of cysts, they are also, as we 
have seen, those of serous membranes. 
4. Analogy of functions. Cysts are evidently secreto- 
ry or rather exhalant organs, which exhale the fluid they 
contain. Exhalation becomes very evident there, when 
after the evacuation of the fluids, the membranous sac 
has not been removed, or an artificial inflammation ex- 
cited in it. Absorption is proved, in the spontaneous 
cure of encysted dropsies, a cure which must depend on 
this function alone. 
5. Analogy of affections. Who does not know that 
between the dropsy of the tunica vaginalis and the en- 
cysted dropsy of the cord, there is the greatest analogy; 
that the curative means are the same, that in both cases 
the inflammation that is produced by the injection of a 
foreign fluid, wine, for example, is the same, and that 
the cure is effected by a similar mechanism ? Whoever 
has opened two bodies, each having one of these affec- 
tions, and examined the sacs in which the fluid is con- 
tained, must have perceived that their appearance is pre- 
cisely the same. Remove the fluid from the cyst of a 162 
CELLULAR SYSTEM. 
soft wen, and you will discover but little difference be- 
tween it, dropsical cysts, and serous membranes. 
The preceding considerations induce us to admit a 
perfect resemblance between cysts and serous membranes, 
of whose characters they partake, and into the system of 
which they essentially enter, and consequently into the 
cellular system. It is very probable that there is a rela- 
tion between them, and that when a cyst is formed and 
exhales copiously, the exhalation of the serous mem- 
branes is diminished ; this does not, however, rest upon 
direct proof. There is this essential question, how are 
these cysts developed ? How a membrane, which does 
not exist in a natural statp, can arise, grow, and even 
acquire a very considerable development under certain 
circumstances. This problem is usually resolved in the 
following manner; at first, it is said, a small quantity of 
fluid collects in a cell; this fluid increases and dilates in 
every direction, the parietes of the cell, which are attached 
to the neighbouring cells and thus increased in thickness. 
Gradually this fluid, serous in dropsy, white and thick in 
steatoma, &c. increases in quantity, presses in every di- 
rection the sac that contains it, enlarges, crowds against 
the neighbouring organs, and thus acquires the form under 
which we see it. Nothing at first sight appears more 
simple than this mechanical explanation ; nothing is less 
conformable to the process of nature. The following 
considerations will serve to prove this. 1st. The cysts 
are analogous in every point of view to serous mem- 
branes ; how then could they have a different origin from 
these membranes, which are never formed, as we shall 
see, by the compression of the cellular texture ? 2d. Does 
an origin thus mechanical, in which the vessels compress- 
ed against each other would inevitably be obliterated, as 
we see the skin become callous, accord with the exhaling 
and absorbing function of the cysls and with their pecu- 
liar kind of inflammation? 3d. Why, if the cells adher- CELLULAR SYSTEM. 
163 
ing to each other, form these unnatural sacs, is not the 
neighbouring cellular texture diminished and destroyed, 
even when they acquire great size? 4th. If, on the one 
hand, the cysts are formed by the compression of the 
cellular texture, and if it is true on the other, as we can- 
not doubt, that their fluid is exhaled by them, it is neces- 
sary to conclude then, that this fluid pre-exists in the 
organ that separates it from the blood: I would as soon 
assert that the saliva pre-existed in the parotid, &,c. 
The immediate consequence of the preceding reflec- 
tions, 1 think, is, that the common explanation of the 
formation of cysts, is directly opposite to the general 
course that nature pursues in her operations. How, 
then, do these sacs arise and grow ? these tumours that 
appear externally, or are developed within ; for there is 
no difference in these two sorts of unnatural productions, 
except in the form. Most tumours throw from their ex- 
ternal surface the fluid that is separated there. A cyst, 
on the contrary, exhales this fluid by its internal surface, 
and preserves it in its cavity. Suppose a fungous, sup- 
purating tumour, suddenly becomes a cavity, and suppu- 
ration is carried from the external surface to the walls of 
this cavity ; this will be a cyst. On the other hand, 
suppose a superficial cyst, the cavity of which is oblite- 
rated, and the fluid of which is exhaled upon the exter- 
nal surface ; this will be then a suppurating tumour. 
As the form, then, establishes the only difference be- 
tween tumours and cysts, why should not the formation 
of one be analogous to that of the other? Surely, no one 
ever thought of attributing to compression, the formation 
of external or internal tumours. We may conceive of 
the production of cysts in the following way ; they begin 
to be developed and grow in the midst of the cellular 
organ, by laws very analogous to those of the general 
increase of our organs, and which seem to be aberrations, 
and unnatural applications of these fundamental laws, of 164 
CELLULAR SYSTEM. 
which we are ignorant. When the cyst is once charac- 
terized, exhalation commences; at first scanty, it after- 
wards increases as the cyst grows. The increase of the 
e>halant organ, then, always precedes the accumulation 
of the exhaled fluid, so that other things being equal, the 
quantity of suppuration in a tumour is in a direct ratio to 
its size. 
ARTICLE SIXTH. 
DEVELOPMENT OF THE CELLULAR TEXTURE. 
I. Slate of the cellular system in the frst age. 
Jn the first periods after conception, the foetus is only 
a mucous mass, homogeneous in appearance, and in 
which the cellular texture seems almost exclusively to 
predominate. In fact, when the organs begin to be de- 
veloped in this mass, the spaces that are left between 
them are filled with a substance which, exactly similar 
to that which before formed the whole of the body, can 
be considered as the residue of it, or rather perhaps it 
exists in a distinct manner, because it has not been pene- 
trated with the peculiar nutritive substance, like that 
which forms the parent hyma of nutrition of the organs, 
which before this penetration resembled it precisely. 
This substance that lies between the organs, and which 
is the principle of the cellular texture, is the farther 
removed from a fluid state, as the period of labour ap- 
proaches. First it is a true mucus, then a kind of glue, 
then the cellular texture begins to appear. 
This primitive 6tate of the cellular organ, this appear- 
ance that it has at first, is owing to the great quantity of 
fluids that enter it at that period ; it does not denote an CELLULAR SYSTEM. 
165 
inorganic existence ; we can then compare it to the vitre- 
ous humour, which appears wholly fluid at first sight, 
because the transparency of its layers do not permit us 
to see them in the humour that enters its cells ; make a 
puncture so as to evacuate this humour, and they become 
evident. 
Thus the cellular texture, extremely fine and even 
transparent in the first periods of life, is then concealed 
by the humour that fills it, and becomes more sensible as 
this humour diminishes with age. This phenomenon 
sometimes takes place in after life, in different serous in- 
filtrations, those especially in which the infiltrated fluid 
has some viscidity. 
What is this humour that is so abundant in the cellular 
system, in the first months after conception ? Is it albumi- 
nous like that which afterwards lubricates it ? Probably 
it is; 1 should think, also, that it has much of the char- 
acter of gelatine, a character which predominates, we 
know, in the animal humours at this period ; I know of no 
experiment upon this point. Whatever the humour is, 
it is much more viscid and unctuous than it is afterwards; 
the touch is sufficient to convince us of this. It is its 
predominance, joined to the delicacy of the cellular lay- 
ers, that, in the first months, makes every attempt to 
render the foetus emphysematous, by blowing air under 
the skin, almost absolutely useless. 
At birth and some time after, the great quantity of 
sub-cutaneous fat makes artificial emphysema very diffi- 
cult ; it does not appear that the foetus ever has a natural 
one. The delicacy of the cellular layers and filaments 
is such at this period, that the imagination cannot repre- 
sent it; the texture of the hair is gross in comparison 
with it. I presume that the ball of fat, which I have said 
almost always exists in the cheek of the foetus, arises 
from a rupture of several layers, a rupture from which is 
produced a great cell, that is filled with fat. 166 
CELLULAR SYSTEM. 
Sometime before birth, at that period and in the subse- 
quent years, the cellular humour constantly diminishes ; 
the cells become dryer, consequently more apparent; the 
whole mass of the cellular system diminishes, because- as 
the organs increase, the interstices are contracted. This 
system however predominates for a long time over the 
others; hence the roundness of form that characterizes 
the infant, the want of prominence of its organs, that are 
almost concealed by it; hence in part the suppleness and 
multiplicity of its movements ; hence also the frequent 
diseases of which it is the seat at that age. 
The layers still preserve an extreme delicacy ; they are 
still easily broken. In producing emphysema, upon very 
lean children, I have observed that olten it forms in 
places very considerable dilatations, a kind of sacs in 
which the air accumulates in large quantity, and which 
arises from this rupture; whilst in the same experiment 
upon an adult, the air is propagated in an uniform man- 
ner and constantly infiltrates the cells without destroying 
them. By comparing in our slaughter-houses, the flesh 
of calves blown, and that of oxen in the same state, 1 have 
sometimes made an analogous observation. 
In infancy and in youth, the vital energy of the cellular 
texture is very conspicuous; at this age, the fleshy gran- 
ulations, essentially cellular as we have seen, arise more 
promptly and go through their periods more rapidly than 
at any other age; the union of wounds is easier; and all 
tumours, have in their development and their progress, a 
rapidity that particularly depends upon the high degree 
to which the vital forces of the cellular system are raised 
at this period. It is to the same cause, that must be 
referred the facility of absorption of serous fluid, which 
sometimes infiltrates accidentally the cells, as we see in 
the scrotum, the eye-lids, &c. ; the suddenness of the 
formation of cysts, &c.; then dropsies are much less fre- 
quent. When they do take place, why are the superior CELLULAR SYSTEM. 
167 
extremities almost as often affected as the inferior, whilst 
the leucophlegmasia of adults commences almost always 
in the last ? This is then as remarkable a phenomenon, 
as the singular tendency that there is in the legs of being 
infiltrated, compared with the arms. Does not this depend 
upon situation, which, forcing the lymph to ascend against 
its weight, gradually weakens the absorbents when it has 
continued for some time ? This explains, why varices 
are, as we know, more frequent in the inferior than supe- 
rior extremities. 
II. Stale of the cellular system in the after ages. 
In the adult, the cellular texture is condensed and 
becomes firmer; its layers have a more compact texture. 
It appears also to lessen in quantity, because as the organs 
increase in thickness, their interstices are contracted. If 
there is not a real diminution, there is at least one in 
comparison with the state of the organs. It is to this 
circumstance that must be attributed in part, their promi- 
nence under the integuments, the striking appearance of 
the form of the muscles. &c. It appears besides, that the 
quantity of cellular texture varies according to tempera- 
ments; that in those called phlegmatic or lymphatic, it 
predominates over the other systems, and in the bilious, 
which is characterized by a dryness and rigidity of fibre, 
it is in the smallest proportion. In women, it is in larger 
quantity than in men ; the roundness of their forms is in 
part the result of this. 
The motion of a part appears to have no effect in pro- 
ducing a more active nutrition of its cellular texture, as 
takes place in the muscles, the nerves, and sometimes 
even in the blood-vessels. 
In old age this texture is condensed and contracted ; it 
acquires consistence and hardness. The teeth tear it 
with difficulty in the boiled flesh of old animals; like it, 
it is tough and requires long boiling to soften it. Much 168 
CELLULAR SYSTEM. 
less fluid is exhaled there, hence a sort of dryness and 
rigidity, that render the motions of old age difficult. A 
kind of withering, that it experiences, contributes essen- 
tially to the general diminution that the body then under- 
goes. It loses its vital forces; hence its laxity, that pre- 
vents it from supporting the skin as usual. This becomes 
every where loose, dependent even in some places, in 
which it forms folds. The scrotum has no longer the 
power of contracting that characterized it and which it 
derived from the forces of the cellular system. This 
general relaxation, this sort of flaccidity is the constant 
attendant of old age, in individuals even in w hom excess 
of all kinds, or a primitive disposition, have rendered this 
age premature. I saw at the Medical Society a dwarf, 
sixteen years of age, hardly two feet high, who had 
already begun to growr old ; his sub-cutaneous texture 
had that laxity, that does not belong to his age. The 
premature decrepitude of the dwarf of the king of Poland, 
exhibited the same phenomenon. Two persons who 
lived a long time with him informed me, that at his death, 
there was externally this relaxation aud flaccidity of 
integuments, of which the subjacent cellular texture 
appears to be the seat. 
It is rare in old age to find osseous incrustations in the 
cellular texture. In the great number of old persons that 
I have had occasion to dissect, or to have dissected, I re- 
member to have seen but one, and that occupied the 
posterior part of the mesentery. I have seen some others 
in adults, especially in women, in whom they' are found 
frequently, in the cellular texture that separates the 
womb from the rectum ; I have preserved several speci- 
mens of these. NERVOUS SYSTEM OF ANIMAL LIFE. 
ALL anatomists have heretofore considered the ner- 
vous system in an uniform manner ; but if we reflect a 
little upon the forms, the distribution, the texture, the 
properties and the uses of the different branches that 
compose it, it is easy to see that they should be referred 
to two general systems, essentially distinct from each 
other, the one having the brain and its dependancies for 
its principal centre, and the other, having the ganglions. 
The first belongs especially to animal life; it is on the 
one hand the agent, that transmits to the brain the exter- 
nal impressions that are to produce sensations; and on 
the other it serves as a conductor of the volitions of this 
organ, which are executed by the voluntary muscles to 
which it goes. The second, almost every where dis- 
tributed to the organs of digestion, of circulation, of respi- 
ration, of the secretions, belongs more particularly to 
organic life, in which it performs a part much more 
obscure than that of the preceding one. Neither is 
strictly confined to the organs of either life. Thus the 
cerebral nerves send some branches to the glands, to the 
involuntary muscles, &c.; and the nervous system of the 
ganglions have ramifications in the voluntary muscles. It 
is from the general arrangement, without regard to par- 
ticular exceptions, that the division of the two nervous 
systems is founded, between which I shall not draw a par- 
allel here to show their difference, because the descrip- 
tion of each will be sufficient to do this. 170 
NERVOUS SYSTEM 
The nervous system of animal life is exactly sym- 
metrical. like all the organs of that life. The brain and 
spinal marrow, which are the double origin of this system, 
have this character in a remarkable degree. Nerves 
precisely similar go from them ; hence the name of pair, 
by which is designated the double, corresponding trunk, a 
name, that we should not be able to employ commonly in 
the system of ganglions. There are then really two ner- 
vous systems of animal life, the one right, the other left; 
the median line separates them. Their distinction is 
apparent not only from dissection, but from their diseases. 
At one time exactly one half of the body is deprived of 
motion, and the whole nervous system of that side remains 
passive, the other retaining its ordinary activity; at 
another, one side only has an unnatural energy and be- 
comes the seat of convulsions, while the other remains 
calm. In both cases, sometimes the phenomenon is gen- 
eral ; often it is limited to a greater or less number of 
lateral organs; but always there is an evident separation 
between the two nervous systems, the right and left. 
The kind of partial paralysis, of which I just spoke, and 
the principal character of which arises from the symmetry 
of the nervous system of animal life, is wholly different, 
as it regards this character, from that in which the lower 
parts of the body are deprived of motion in consequence 
of a fall upon the sacrum, or any other analogous cause. 
The relations of size of the nervous system with the 
brain are in man and most quadrupeds, in an inverse pro- 
portion, as has been observed by Soemmering. In man 
the brain is much more voluminous than in the others, 
who have nerves larger than his. It is easy to prove this 
assertion, in all the animals that we commonly employ 
for our experiments; in fact, small dogs are used, on 
account of the size of their nerves in very delicate experi- 
ments upon sensibility. This difference is a striking proof 
of the superiority of man, as it respects the intellectual OF ANIMAL LIFE. 
171 
phenomena, which are all referable to the encephalic 
mass. On the other hand, many animals are superior to 
him as it respects motions and the four senses of taste, 
of smell, of hearing and seeing. Observe however that 
he surpasses them all in the perfection of the fifth sense, 
viz. that of touch. Why ? Because this sense is entirely 
different from the others, is consequent to them, and cor- 
rects their errors. We touch, because we have seen, 
heard, tasted and smelt. This sense is voluntary; it sup- 
poses reflection in the animal that exercises it, the others 
do not. Light, sounds, &c. strike the respective organs 
without any effort of the animal; but he touches nothing 
without a preliminary act of the intellectual functions. It 
is not then astonishing, that the perfection of the organs 
of touch and the great development of the brain, should 
be in man, in the same proportion, and that in those ani- 
mals, in whom the brain is more contracted, the touch 
should be more obtuse and the organs less perfect. 
ARTICLE FIRST. 
EXTERNAL FORMS OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
I shall consider these forms, 1st. in the origin ; 2d. in 
the course ; 3d. in the termination of the cerebral nerves. 
I. Origin of the cerebral nerves. 
The word origin should only be understood in relation 
to anatomical arrangement. In fact, the nerves are 
formed at the same time as the brain; they are rather 
organs of communication with this viscus, than elonga- 
tions of it. If we take a view of the functions of one part 
of the nervous system, we shall see that the termination 
is at the brain, and the origin is upon the surface. Is it 172 
NERVOUS SYSTEM 
not said that the nerves go towards this or that part, that 
the arteries take this course, wind about, &c. ? These 
are only metaphorical expressions, the least reflection 
will determine their meaning. 
The nerves of animal life derive their origin from three 
principal portions of the encephalic mass; 1st. from the 
cerebrum ; 2d. from the Tuber Annulare or Pons Varoiii 
and its elongations ; 3d. from the spinal marrow ; the cer- 
ebellum gives origin to none. This circumstance, which, 
we ought not to lose sight of in the examination of the 
functions of each part of the brain, and which will per- 
haps hereafter elucidate these functions, is undoubtedly 
sufficient to make us appreciate the opinion of many phy- 
sicians of the last age, which placed in the cerebellum the 
source of involuntary motions, and attributed the volun- 
tary to the cerebrum. 
The cerebrum furnishes but two nerves, the olfactory 
and optic; these are remarkable, 1st. in this, that their 
adhesion is very strong at their origin with the brain, and 
that by raising the pia mater, we cannot remove them; 
2d. in this, that their softness is greater than that of most 
other nerves. 
The tuber annulare and its elongations, as well those 
that go to the cerebrum and the cerebellum, as that 
which begins the spinal marrow, furnish the motores com- 
munes of the muscles of the eye, the pathetic, the origin 
of which, though posterior, is evidently derived from the 
tuber annulare, the trigemini, the motores externi of the 
eye, the facial, the auditor}', the par vagum, the glosso- 
pharyngeal and the great hypo-glossal. All these nerves 
are distinguished by different characteristics. 1st. As the 
medullary substance, is every where exterior to the emi- 
nences from which they arise, all appear manifestly to be 
continuous with this substance. 2d. Almost all begin by 
many filaments separated from each other; sometimes, as 
in the trigemini and par vagum, these are very numerous* OF ANIMAL LIFE. 
173 
The others arise, some by one filament and others by two. 
3d. Except the auditory nerve, all have a greater con- 
sistence at their origin than these last. 4th. They ad- 
here but little to the corresponding cerebral portion, so 
that they are almost always raised in detaching the pia 
mater; thus it requires great precaution, to prevent 
breaking the nerves from the brain when it is taken out 
of the skull. The adhesion of the pathetic, the motores 
communes and the facial, is particularly weak. We 
should almost say, from a slight examination, that there 
was only contiguity. 
The spinal marrow gives origin to thirty or thirty-one 
pair of nerves, viz. eight cervical, twelve dorsal, five 
lumbar, five or six sacral, and to a nerve that enters the 
cranium and goes out of it under the name of spinal. The 
following are the characters of these nerves at their ori- 
gin. 1st* They are continuous, like the preceding, with 
the medullary substance. 2d. They all arise by two 
cords, one anterior, the other posterior. These cords 
derive their origin from many filaments, placed above 
each other, most usually separate and always distinct. 
3d. The adhesion is much stronger at the origin of these 
nerves than at that of the preceding, a circumstance that 
depends upon a cause that will be hereafter pointed out. 
4th. The consistence of the spinal nerves is also very 
evident in their canals. 
From what has been said, it is clear, that the nerves do 
not arise deep in the cerebral substance, at least in an 
apparent manner, but take their origin from its external 
surface. Many physiologists however, have admitted an 
origin more remote than can be proved by examination. 
They have believed that the nerves of one side arise from 
the opposite, and that each pair cross each other not only 
in the brain, but also in the spinal marrow. This opinion 
is founded upon a singular phenomenon, viz. this, that 
paralysis almost always takes place on that side which is 174 
NERVOUS SYSTEM 
opposite to the affected side of the brain, a phenomenon 
that is frequently noticed in diseases and proved also by 
experiments, as has been shown by Lorry. On the other 
hand, it is said that convulsions are seated in the side cor- 
responding with the injured side of the brain; but this 
fact is more uncertain than that of paralysis, which is 
incontestable. I do not believe that with our present 
knowledge we can explain this last, and the anatomical 
opinion pointed out above, is contradicted at the first 
sight. 
I will make but one observation upon this singular 
phenomenon, and that is, that it particularly concerns 
the nerves of motion, and hardly ever affects the nerves 
of sensation. In fact we know, that in wounds of the 
head, in consequence of apoplexy, &c. one eye, one ear, 
one side of the tongue, one nostril, do not become insen- 
sible, as the muscles of one side cease to move. We do 
not suddenly become paralytic on one side as it regards 
sensation, as we do as it respects motion in hemiplegia. 
Experiments cannot elucidate this, for it is impossible to 
perceive the alterations of sensibility as we do those of 
mobility. However, by compressing the brain of a dog, 
and thus rendering him paralytic on one side, and then 
shutting each eye separately and alternately, to see if he 
distinguished objects, and afterwards by presenting in 
turn to each nostril volatile ammonia, or other pungent 
substances, I have not seen, as it regarded the sensibility, 
an alteration corresponding with that which the mobility 
experienced. We often observe in man a discordance 
in the organs of sense. One ear hears better than the 
other, one eye sees further, &c.; hence false hearing, 
hence a species of strabismus, &c.; but the cause of 
these discordances appears to reside in the organ itself, 
and not to be connected with the brain. 
Moreover, it does not appear that each hemisphere 
always corresponds necessarily with the nerves of motion OF ANIMAL LIFE. 
175 
of the opposite side. Tn fact, we often see on the right 
side effusions or injuries of the cerebral substance, with- 
out any alterations of motion on the left, and vice versa. 
The following are the cerebral membranes that are 
found at the origin of the nerves; 1st. the dura mater 
forms for them a kind of canal in the fissure through 
which they go out, then it quits them entirely, and is part- 
ly lost in the cellular texture, and the remainder is re- 
flected upon the edges of the opening and continued with 
the periosteum. The optic nerve is the only exception 
to this; it is accompanied in its whole course by a fibrous 
canal, which goes even to the sclerotic coat, which in 
this way, communicates with the dura mater. 2d. The 
tunica arachnoides surrounds every nerve at its origin 
with a fold formed oftentimes in the shape of a tunnel, 
the broadest part of which is at the origin. By care- 
fully raising the brain, or by opening the dura mater of 
the spinal canal, we very easily discover this fold, which 
is continued to the osseous opening, through which the 
dura mater enters, it is then reflected upon the surface 
of this membrane corresponding with the brain, forming 
a sac between it and the nerve. Sometimes, as in the 
optic nerve and the motor externus, it penetrates the 
fibrous canal of the dura mater, and accompanies the 
nerve to the middle of the canal, which, consequently, is 
lined in part bv the tunica arachnoides, and partly by 
the cellular texture. 3d. The pia mater is used in a 
manner that is difficult to understand, and which has not 
as yet been well explained. I shall speak of its continuity 
upon the nerves, in treating of their peculiar membrane. 
The nerves go over a more or less considerable ex- 
tent before going out of the cranium or the spinal canal. 
1st. The two that arise from the cerebrum are much 
longer within than without. 2d. Among those of the 
tuber annulare and its dependancies, the pathetic nerves 
are the only ones that remain any length of time in the 176 
NERVOUS SYSTEM 
cranium before they go out of it, and that have a greater 
extent there than externally ; all the others go out almost 
immediately. 3d. The nerves of the spine have a much 
greater extent when examined lower down. Above, they 
become directly external; below, they are six inches long 
in the canal, and consequently pass many foramina be- 
fore they arrive at their own ; hence it happens, as has 
been observed by Jadelot, that if we avail ourselves of 
the spinous processes, on account of their prominence, to 
judge of the origin of the nerves in the application of 
the moxa, it is necessary, in the neck, in order to act 
upon a point corresponding with the origin of any nerve 
in particular, to take nearly the spinous process of the 
vertebra that corresponds numerically with the pair that 
we have in view, whilst in the loins it is much above this 
vertebra that the application should be made. 
The direction of nerves at their origin is also very 
variable. At the cerebrum and the tuber annulare, there 
is no general arrangement. But in the spinal nerves, this 
direction, almost perpendicular to the marrow above the 
cervical region, always becomes more and more oblique 
down to the end of the lumbar region. These three 
things, viz. the length in the canal, the size and oblique 
direction of the spinal nerves, successively increase from 
above downwards in a gradual manner, with some ex- 
ceptions as to size. 
Each pair of nerves, in going from the cerebrum, the 
tuber annulare or its dependancies, and the spinal mar- 
row, diverges in the two trunks which form the pair. 
The olfactories alone converge, and the spinal run nearly 
parallel. 
II. Course of the cerebral nerves. 
The nerves exhibit different arrangements at their 
exit from the osseous cavities that contain their origin. OF ANIMAL LIFE. 
177 
Communication of the cerebral nerves at their exit from their 
osseous cavities. 
1st. The two nerves of the cerebrum, go without com- 
municating with any other, to their respective destination. 
2H. Those of the tuber annulare and its dependancies 
begin to have communications, which are much more 
evident when examined inferiorly. Thus the par vagum 
and the great hypo-glossal nerves, send in going from 
their respective foramina, numerous filaments to the neigh- 
bouring organs, whilst above, the motores communes, the 
pathetici and even the trigemini shew this arrangement 
less evidently; the auditory nerve does not communicate 
with any other. 3d. The communications of the nerves of 
the spine are more, evident at their exit, especially in their 
anterior portion. The deep cervical plexus, the brachial, 
lumbar, and sciatic, arise from these communications, 
which are not so visible in the intercostal nerves. 
These kinds of plexuses have a particular arrange- 
ment. They are formed in the following manner; each 
nerve, at its exit from the foramen, sends a branch above 
and below, and also receives one; so that the cords 
that succeed those that go from the foramina, arise from 
two or three of these. These second cords, in dividing, 
send branches above and below, receive them and form 
third cords; so that in the brachial plexus, for example, 
when the nerves cease to communicate thus, and are di- 
vided into separate trunks, that each may go to its desti- 
nation, it would be impossible to say7 correctly from which 
pairs they arise. It would require a very tedious dissec- 
tion to ascertain precisely from what pairs come the 
median, the cubital, &c. 
It is this consideration that has induced me not to de- 
scribe the nerves of the spine as it is usually done, that is, 
as going from such or such pairs. I describe at first in 
each region the plexus that the nerves form there in going 
out of the spine ; thus, I expose before the cervical nerves, 178 
NERVOUS SYSTEM 
the deep cervical plexus, before the brachial the brachial 
plexus, and before the lumbar and sacral the plexuses of 
the same name. The general arrangement, the form, the 
relations of these plexuses being known, I pass to the 
description of the nerves that go from them before, be- 
hind, without, within, &c. without regard to the pairs of 
nerves that come through the foramina. This method 
has appeared to me, moreover, to be extremely conven- 
ient for students. Nothing, for example, is more com- 
plicated than the description of the cervical nerves, by 
referring them to the pairs that first furnished them. 
But understand well at first the deep plexus, arising from 
the anastomoses of these pairs at their exit; afterwards 
class the nerves, 1st. into internal, which go to the great 
sympathetic; 2d. into external, which are distributed 
upon the acromion and the triangular space, bounded in 
front by the sterno-mastoideus and behind by the trape- 
zius ; 3d. into anterior, which, winding upon the sterno- 
mastoideus, form there with the branches of the facial a 
kind of superficial plexus; 4th. into posterior, which go 
either to the occiput, or to the posterior muscles of the 
neck ; 5th. into those that go interiorly, as the diaphragm- 
atic, as those that communicate w ith the nervous branches 
of the hypo-glossal, &c. &,c. In this way, you will easily 
retain all the nervous distributions, because you will have 
one point to which your memory will refer them all, and 
not to as many centres as there are pairs. 
Internal communications of the nervous cords. 
It is not only at their exit that the spinal nerves thus 
communicate. The different cords of which each nerve 
is formed have precisely the same arrangement, as may 
be easily seen in the great trunks, as in the median, the 
cubital, the radial and especially the sciatic. By sepa- 
rating the different cords of these nerves, we see that 
they are not only in apposition longitudinally, but that OF ANIMAL LIFE. 
179 
they send numerous filaments to each other. These 
communications do not resemble those of the arteries, in 
which there is always continuity between the communi- 
cating branches. Here there is only contiguity, and each 
of the cords forming the nervous trunk is, as we shall 
see, composed of filaments; now it is these filaments that 
frequently go from the cord to which they belong to a 
neighbouring one; so that after a short distance, the 
cords that began the nerve are not composed of the same 
filaments as those that finish it ; the whole becomes 
mingled together in the course of the nerve. Thus the 
cords of the branches of the brachial plexus, at its origin, 
are not arranged like those of the branches that terminate 
it. For there is this difference between the very evident 
plexuses formed by the nerves themselves and those that 
are less evident formed during their course in their inte- 
rior even. viz. that in the first, it is the cords that go off 
and form the interlacing, and in the second it is the fila- 
ments. 1 once amused myself in tracing the filaments of 
the sciatic for a short distance; now those which com- 
posed above the external cords, were found for the most 
part below in the cords of the centre. 
This remark proves that there are not nervous cords 
destined to sensation and others to motion, and that if 
the same nerves do not serve the double use, the differ- 
ence is in the filaments, and not in the cords. 
In the interior of the vertebral canal, in which the 
nervous cords are much insulated, for the want of cellu- 
lar texture, the filaments that compose them do not thus 
communicate with each other; there is not, as without, a 
plexus in the interior of the nerve. This is remarked 
particularly at the extremity of the canal, where the 
nerves run a long course, as I have before said. 
The communication of the nerves at their exit from 
their osseous cavities is so general, that under this point 
of view it may be said that they form on every side a 180 
NERVOUS SYSTEM 
kind of organ every where continuous, an organ to which 
the optic, the olfactory, and the auditory nerves only are 
strangers. 
Besides, these kinds of communications, which are all 
made by juxta-position, do not appear to have much influ- 
ence upon the functions of the nerves. Each of their 
cords, though belonging in its course to many different 
trunks, can perform its functions in an insulated manner; 
so can each filament, though concurring in its course to 
form many cords of the same nerve. 
I would observe with regard to this, that it is necessa- 
ry to distinguish accurately these communications from 
anastomoses, in which two nervous filaments coming in 
an opposite direction, are confounded and identified with 
each other, which is seen between those of the facial, the 
sub-orbitary, the mental, &,c. 
Nervous trunks. 
After having thus communicated at their exit, the 
nerves separate from each other and go towards the differ- 
ent organs. They form at first considerable trunks, which 
pass through the great cellular interstices and go over a 
greater or less extent. The form of these trunks is 
sometimes flattened as in the sciatic ; but it is most com- 
monly rounded ; but the form does not affect nervous ac- 
tion, for the nerves that are naturally round, when flatten- 
ed by a tumour, perform their functions as usual. Jn 
general, whenever it does not interfere with her design, 
nature chooses the round form for the organs of animals. 
I would observe also, that this form requires a system 
generally diffused, and destined to fill up the spaces that 
necessarily exist between round organs; this system is 
the cellular. It would be infinitely less necessary, if the 
form of our organs was square, because there would be 
less space between them. OF ANIMAL LIFE. 
181 
The nervous trunks are of different length. Those of 
the extremities hold the first rank in this respect, be- 
cause the extremities being very distant from the origin 
of the nerves, these trunks must of course go over a 
certain extent before distributing their filaments. In 
the trunk and the head, on the other hand, as the organs 
are presented immediately to the nerves that enter them, 
the division into branches is immediate, and the trunks 
are very short. 
The nervous trunks are sometimes accompanied by a 
corresponding arterial and venous trunk, as the brachial, 
crural trunks, &,c.; at other times, as the sciatics, and 
those of the par vagum, they go separate. 
Of the nervous branches, &c. 
As the trunks advance, they furnish here and there 
different branches; these give out smaller ones, which 
send off those that are still smaller, from which arise the 
last divisions. All these different divisions take place at 
very different angles. The acute angle is the most com- 
mon. It is not a real origin, but merely a separation of 
many cords united, that forms the branches, of one or two 
of these for the smaller ones, of one cord only for the 
still smaller, and of separate filaments for the last divi- 
sions. Thus this separation is made more or less high, in 
different subjects. The place where it happens is never 
exactly determined. 
According to these divisions, the filaments which comr 
pose the cords of each nerve and these cords themselves, 
are of different lengths; the shortest separate first, then 
the middling ; in fine, the longest filaments of all go the 
whole extent of the nerve, and only terminate where it 
ends. The brachial and crural nerves exhibit this ar- 
rangement in a remarkable manner. 
The nervous branches are almost all accompanied by 
an artery and a vein,especially in the extremities; for in 182 
NERVOUS SYSTEM 
the trunk, there are exceptions to this rule ; in the neck, 
for example, the arteries often cross the nerves at an an- 
gle, instead of accompanying them in their course. In 
the head, many arterial branches are found thus separated 
from the nervous. This circumstance is sufficient to 
make us attach less importance than some authors have 
done, to this juxta-position of the nervous and sanguine- 
ous systems. Moreover, if this juxta-position was so 
essential, it would be seen with regard to the smaller 
branches ; but this never happens. 
III. Termination of the nerves. 
I call that the termination, where each filament ends 
and not that only where the whole trunk of the nerves 
terminates; so that the sciatic terminates at the thigh, 
at the leg and at the foot, and not merely at the extremity 
of this last. In fine, after what has been said already 
and from what will be said further, the union of filaments 
into cords and that of cords into trunks, is an arrange- 
ment disconnected with their functions, and each filament 
should be examined separately. The filaments of nerves 
have three different terminations. They are continued, 
1st. with other filaments of the same system; 2d. with the 
filaments of the system of the ganglions ; hence arise anas- 
tomoses. 3d. They are lost in the organs. 
Anastomoses with the same system. 
I have already observed, that true anastomoses should 
be distinguished, from the junction of a cord that passes to 
a nerve more or less remote from that to which it belongs, 
and which simply places itself by the side of its fila- 
ments, so that it contributes with them to the nervous 
cords. Thus there is no anastomosis in a plexus, in the 
union of the chord of the tympanum with the lingual 
nerve, &c. So that though the filaments of the different 
cords of a nerve pass frequently from one to the other, so OF ANIMAL LIFE. 
183 
as to give to the nerve a net-work-like texture, and not as 
anatomists say, a simple thread-like texture, still it can- 
not be said that the cords of the same nerve anastomose 
with eaeh other ; there is only juxta-position. On the 
other hand, the communication of the great hypo-glossal 
with the cervical pairs, forms a true anastomosis, because 
there is a continuity, and not merely contiguity of nervous 
filaments. 
If those physicians, who have considered the anasto- 
mosis as the exclusive causes of all sympathy, had reflect- 
ed how few they are in comparison with what they appear 
at first view, they would have been, by this simple reflec- 
tion, led to a different opinion. In fact, it is very evident, 
that though a filament is joined to a trunk, it has no more 
relation to the filaments of that trunk, than these have 
among themselves; that is to say, that there is nothing 
in common but the cellular covering. The arterial and 
venous anastomoses are infinitely more numerous than the 
nervous. I believe that they can perform a part in neu- 
ralgia, in some sympathies even, a part foreign to the 
simple communications of the filaments. 
We can generally refer anastomoses to three classes. 
1st. Two branches belonging to different nerves, go on 
together, as in the example cited above of the great hypo- 
glossal, and as also the branches of the facial with those 
of the sub-orbitary, the occipital with the frontal, &c. 
2d. The branches of the same nerve can unite together, 
as those of the three portions of the trigemini. 3d. 
Sometimes the two nerves of the same pair, or those of 
two different pairs, but coming from the two halves of the 
nervous system, unite at the median line; some examples 
of this may be seen in the superficial nerves of the neck, 
in those of the chin, &ic. This union does not take place 
upon the abdomen, where the median line, entirely apo- 
neurotic, has no nervous branch in its texture. It is per- 
haps by these anastomoses that take place at the median 184 
NERVOUS SYSTEM 
line, that we may explain, how certain motions can still 
continue in a part affected with paralysis. This sort of 
anastomosis is in general very rare. In the extremities 
it is evident, that they cannot exist ; in the trunk, they 
are hardly ever seen behind, and not frequently before. 
If every pair of nerves gave examples of them, it is 
clear that hemiplegia would rarely take place, because 
the sound side of the brain or spinal marrow would 
through them have an influence upon the nerves of the 
affected side. 
Anastomoses zvilh the system of organic life. 
This termination has a great analogy with the pre- 
ceding, since there are two nerves, which meeting at their 
extremity, are blended in such a manner, that we cannot 
tell where one begins, or the other ends. I shall treat of 
this in the following system. 
Termination in the organs 
The exposition of the following systems will show us 
the varieties that exist as it respects the nerves. 1st. In 
some there are many of them, as in the mucous, der- 
moid and muscul&r systems of animal and organic life. 
2d. In others we find fewer of them, as in the cellular, 
glandular systems, &c. 3d. Some require a more atten- 
tive examination than has heretofore been made of their 
nerves, which are little known, as the serous, the me- 
dullary, a portion of the fibrous, &c. 4th. In fine, 
many, as the cartilaginous, the fibro-cartilaginous, the 
pilous, the epidermoid, the tendons of the fibrous, &c. are 
evidently destitute of nerves. 
We arc ignorant of the situation of each nervous fila- 
ment at its termination ; is it deprived of its covering, 
and does the pulp only penetrate the interior of the 
fibi es ? In the optic nerve this last arrangement is evident. 
The covering of the nerve is continued only to the en- OF ANIMAL LIFE. 
185 
trance of the eye, and the pulp is expanded to form 
the retina. A similar expansion seems to take place in 
the olfactory and the auditory. But nothing is known 
concerning any of the others. 
ARTICLE SECOND. 
ORGANIZATION OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
Every nerve is formed, as I have said, of a greater or 
less number of cords lying in apposition to each other. 
These cords arise from filaments likewise in apposition 
and united together, like the cords by cellular texture. 
I have already mentioned how both are interlaced in the 
interior of the nerve, so as to form a kind of plexus, which 
differs from the true plexus only in this, that the branches 
applied to each other, do not allow us at fiist view to see 
their intermixing. 
The general character of the nervous cords varies con- 
siderably. 1st. Their size is not always the same. Those 
of the sciatic and the crural are smaller than those of the 
brachial nerves, except those of the median. 2d. Some 
nerves, as the par vagum, are formed of one cord only, 
divided by many furrows. Sometimes the filaments form 
around it a net-work, a very delicate kind of plexus. 3d. 
In the same nerve, there is sometimes united large and 
small cords; in many they are all equal, as in the sciatic. 
4th. The optic nerve, though furrowed in its whole 
extent, from the commissure to the eye, does not appear 
to have in its interior that interlacing, that the others 
evidently exhibit. 5th. In the posterior part of this 
nerve, and in the trunk of the olfactory, the cords are not 
distinct. 5th. Most of their nerves at their origin are 
I. Texture peculiar to this organization. 186 
NERVOUS SYSTEM 
separate in their filaments; the trigemini on the contrary, 
exhibit a common pulpous portion, in which all their’s 
seem to be implanted, &,c. 
It follows from all these considerations and many others 
for which we are indebted especially to Reil. that the 
internal arrangement of the nerves varies singularly, that 
each presents almost a different texture, that under this 
point of view they do not resemble the arteries and 
veins, which are every where the same, whatever be their 
size, their course, &c. These varieties however, do not af- 
fect the intimate structure, and our business is to describe 
this intimate structure even to the last fibres that we 
can separate. Reil appears to me to have thrown great 
light upon this subject. 1 have repeated exactly his ex- 
periments; they have given results very analogous to his. 
Some only have appeared to me so difficult, that 1 have 
not even undertaken them. 1 have added to his re- 
searches many new facts as will be easily seen by com- 
paring his work with this article, in which will only be 
found that which rests on accurate observation ; I have 
omitted all the theoretical ideas that Reil has added to 
the facts which he offers. 
We distinguish two things in every nervous filament, 
1st. an external membrane in form of a canal, in w hich is 
contained the medulla; 2d. the nervous medulla itself; 
I shall now treat of each separately. 
Of the nervous coat and its origin. 
This membrane forms for each nervous filament a true 
canal which contains in its interior the medulla ; as the 
veins and arteries contain the blood, with this difference, 
that this medulla is stagnant, while the blood circulates. 
The origin of the nervous coat is very evident at the 
spinal marrow. It is continued with the dense and com- 
pact membrane which covers its white substance, and 
which is called the pia mater, though it does not resem- OF ANIMAL LIFE. 
187 
ble the membrane of that name which surrounds the 
cerebral circumvolutions. To see this origin well, this 
spinal membrane should be cut longitudinally before or 
behind. The medulla then appears whitish, soft and 
easily raised up. If it is raised and scraped with a 
scalpel or any other instrument, the immediate covering 
of the spinal marrow is thus separated from either side, 
especially if precaution be taken to wash it. It might 
be had in the term of a sac, by cutting out a piece of the 
medulla of a certain extent and then pressing out the 
medullary substance at the two ends. In this double ex- 
periment, the nerves remain attached to the membrane 
separated from its medullary substance, because their 
nervous coat is continued w ith it. It is exactly as if a 
number of small arterial filaments went from the aorta ; 
the parietes of this artery w ould be to those of these fila- 
ments, what the pia mater of the spinal marrow' is to the 
coat of the nerves which go from it. Only the nerves are 
white, because their medulla fills them; whereas the ca- 
nal to which they belong is transparent, because it is de- 
prived of its own medulla. 1 do not pretend however, 
that there is a perfect identity bet ween these two mem- 
branes, since we do not exactly know the nature of 
either; 1 refer only to their anatomical arrangement. 
As to the origin of the nerves contained in the cra- 
nium, those coming from the tuber-annulare and its de- 
pendancies, that is to say, the elongations that it receives 
from the cerebrum and cerebellum, have an arrangement 
analogous to that of the nerves of the spine. However, 
the difference of thickness and density of the pia mater 
establishes differences. In fact the pia mater which 
covers these parts is different from that which serves as a 
canal to the spinal marrow; it is much softer, less adhe- 
rent, is torn with more ease, and appears to be analogous 
to that which covers the cortical substance of the brain. 
The coat of the nerves of the tuber annulare, which is 188 
NERVOUS SYSTEM 
manifestly continued from this portion of the pia mater, 
exhibits partly this character. At the place of their 
union, it is more soft than in the canal, hence the extreme 
facility with which, as 1 have observed, the origin of these 
nerves is broken. Moreover, the continuity with the pia 
mater is proved by the facility of raising the nerves by 
raising this membrane ; almost always both are attached 
together. 
As to the nerves of the cerebrum, the olfactory, loosely 
covered by the pia mater, does not appear to have a coat 
of its own. The optic is evidently destitute of it from 
its origin to its junction with that of the opposite side. 
Then it begins to be covered with it ; and canals are 
formed by it, filled with medullary substance, and which 
continue even to the retina. Besides, this nerve differs 
singularly from the others, 1st. because it has a kind of 
general nervous coat; 2d. because its medullary substance 
is more abundant and more easily obtained, its canals be- 
ing larger; 3d. because these canals, pressed against each 
other, give it the appearance in the interior of a continued 
body ; but by cutting it longitudinally, it is easy to see that 
the medullary substance is separated there by partitions. 
The auditory nerve has also a very peculiar texture. 
From what has been said, it is evident that the pia 
mater has greater analogy with the coat of the nerves, 
than any of the other membranes; it may be said to be 
almost the same in the spinal canal. Observe, in fine, 
that this membrane, which has never yet been well de- 
scribed, evidently presents three great modifications, ac- 
cording as it is examined ; 1st. upon the grey substance 
that surrounds the whole of the cerebrum and cerebellum, 
where it is reddish, extremely vascular, loose, slightly 
resisting, and very easily raised ; 2d. upon the white 
substance that covers anteriorly and posteriorly the tuber 
annulare and the four great elongations that it receives 
from the cerebrum and the cerebellum, where it is less OF ANIMAL LIFE. 
189 
red and where it begins to become more firm, more ad- 
herent, and less easily torn ; 3d. upon the whole spinal 
marrow and upon the corpora pyramidalia and olivaria. 
It is thickened and condensed at the furrow that separates 
these eminences from the tuber annulare, then, increas- 
ing in thickness below, becoming whitish, resisting, &c. 
it has an appearance entirely different from what it had 
in the cranium. It might be said to be a membrane 
wholly different. It has four times the thickness of the 
tunica arachnoides. 
In most of the subjects that I have examined it is much 
stretched, and compresses, if it may be so said, the medul- 
lary substance for which it serves as a canal; so that 
when a small opening is made in it the medullary sub- 
stance immediately comes out. But 1 presume that it is 
looser during life. Besides, this state of compression is 
much less sensible towards the superior part than towards 
the middle and inferior, on account of the difference of 
thickness. 1 would remark, that the density of the pia 
mater of the spine is necessary to prevent injuries of the 
medullary substance, which is very soft at one part, and 
which at another is smaller than the diameter of the 
canal; so that it can be shaken there; an arrangement 
wholly different from that of the brain, which completely 
fills the cranium. 
Arising in the manner we have pointed out, the coat of 
the nerves passes with them through the cavity of the 
cranium and that of the spine. It is very distinct in these 
cavities, because it is not surrounded there with cellular 
texture, but only with the arachnoides, which may be 
raised with great ease; instead of using the different 
preparations that Reil mentions for the purpose of sepa- 
rating the coat of the nerves from the cellular texture, it 
is infinitely more convenient to examine this membrane 
upon the last nerves of the spine, which are, as we have 
seen, remarkably long. 190 
NERVOUS SYSTEM 
Motion of certain substances upon the nervous coat; its resis- 
tance, <frc. 
Without the osseous cavities, the nervous coat embed- 
ded in the cellular substance, adheres to it strongly, but 
appears evidently to be of the same nature as in the inte- 
rior. We are ignorant what its nature is, w hether it is 
the same as that of the pia mater, of the medulla, of the 
tuber annulare and its dependancies. It appears to have 
great affinity with the cellular texture. It is transparent 
and consequently free from the colour of the nerves; 
hence why, when they have been deprived, by alkalies, 
of their pulp, they lose a great part of their white- 
ness. 
The coat of the nerves is one of the parts of the ani- 
mal economy which are hardened with the greatest ease, 
especially at the instant the nerves are immersed in an 
acid slightly concentrated, particularly the nitric and 
sulphuric. I have not observed in any other texture 
this phenomenon in so remarkable a manner ; the nerve 
is suddenly diminished in size and twisted in different 
directions; now we shall see that the medullary substance 
is in no way concerned in this phenomenon. The action 
of boiling water produces an analogous effect; by it the 
nerve is wrinkled, contracted and hardened ; then, after 
the ebullition has continued for a certain time, it gradu- 
ally becomes soft, and its whitish colour is changed to a 
sort of yellowish tint, very different from that of boiled 
tendon or aponeurosis. The action of the acids continu- 
ed for some time, produces an effect analogous to that of 
ebullition. To the sudden hardening like horn which 
the nerve undergoes, soon succeeds a softness so great 
that at the end of a short time it is easily moved under 
the finger, and afterwards becomes parti) dissolved. 
The alkalies do not produce the horny hardening in the 
nervous coat any more than in any other texture of the 
living economy; neither do they dissolve it. Hence, OF ANIMAL LIFE. 
191 
undoubtedly, why Reil, having macerated for some time 
a portion of nerve in soap-boilers lie, was able to sepa- 
rate accurately the nervous coat from its medullary sub- 
stance. 
The action of water upon the nervous coat produces 
a phenomenon that is exhibited by few others of the ani- 
mal textures. Far from softening it immediately and 
then reducing it to pulp, it seems in the beginning to in- 
crease its consistence. A nerve soaked in water becomes 
there harder and more resisting, and this state, at the 
ordinary temperature of cellars, continues for a month 
and a half, and even two months. It is only at the end 
of this time and frequently longer, that the texture of the 
nervous coat is gradually softened, and broken, and finally 
ends by being diffused like other macerated textures. I 
have not repeated this experiment in a very warm tem- 
perature, which has always succeeded in that of winter 
and spring. 
The coat of the nervous filaments has a very great re- 
sistance, because it is, in proportion to the medullary 
substance that it contains, infinitely thicker than the 
membranous canal of the spinal marrow. It is thus that 
the proportion between the thickness of the vascular 
parietes and the fluids they contain, is much less in the 
great trunks than in the small branches; the fluid con- 
siderably exceeds the solid in the first, there is at least 
an equality in the second. Thus a very small nerve 
would support a much greater weight than the spinal 
marrow. I believe that among the textures which are 
arranged in filaments or in elongated tubes, this and the 
arterial, next to the fibrous, afford the greatest resistance ; 
they surpass the venous, the muscular, the serous, &c. 
Medullary substance ; its origin. 
This substance occupies the interior of the nervous 
canal, in the same way as the substance of the spinal NERVOUS SYSTEM 
192 
marrow fills the canal formed by the pia mater. This 
medullary substance is whitish, as that of the brain and 
spinal marrowr; it gives the nerve its colour. It is in 
much greater proportion in the optic nerve than in any 
other ; it is found exclusively in that part of it posterior 
to the junction of the two, as wTell as in the olfactory. 
It is so abundant in the auditory that it seems to form a 
great part of it. In general, 1 think at the origin in the 
osseous cavities, it predominates over the nervous coat, 
but in the course of the nerve, the nervous coat is the 
greatest. Hence the greater degree of resistance of the 
nerves in the second, compared to what they have in the 
first. 
This substance appears to be continuous with the me- 
dulla of the brain, the tuber annulare and its dependan- 
cies, and the spinal marrow. I think, no one can deny 
this continuity with the origin of the optic and olfactory 
nerves, in which more of this medullary substance is found 
than in the other nerves. In the auditory, also, it is very 
apparent; in the spinal marrow, by scraping this white 
substance from the internal surface of the pia mater, so 
as to leave the nerves adhering to this membrane, we see 
evidently at the place where these nerves go off, that 
there is an elongation penetrating their nervous coat. 
Comparison between the medullary substance of the brain 
and the nerves. 
What is the nature of the medullary substance of the 
nerves? 1 have endeavoured to institute a comparison 
between it and the cerebral substance; there is consid- 
erable analogy under some points of view and some dif- 
ference under others. 
1st. Submitted to drying in the open air, in small slices 
to prevent putrefaction, the white substance of the brain 
becomes yellow, and acquires considerable consistence. 
The nerve dried becomes yellow also, hardens and con- OF ANIMAL LIFE. 
193 
tracts. These changes are undoubtedly owing in part to 
its coat. The proof of this is that if we dry the cover- 
ing that the pia mater furnishes to the spinal marrow, a 
covering that has great analogy to the nervous coat, the 
new qualities it acquires are very analogous to those of 
the dried nerves. But this does not prevent the medul- 
lary substance of the nerve from contributing also to the 
yellow colour by the evaporation of its watery part. I 
will make, in regard to this, a remark that I think inter- 
esting; it is this, that water has an influence upon the 
whiteness of a number of textures which become yellow 
or greyish by its subtraction, and are whitened again by 
its addition. Thus we have the power of making yellow, 
by drying, all the fibrous organs, the skin, &c. and of re- 
storing them afterwards to their primitive colour. Thus 
also the serous surfaces, the cellular texture, &c. that 
have become greyish from drying, regain their whiteness 
when immersed in water, if they have not been long 
dried. The epidermis of the sole of the foot and the 
palm of the hand turns from grey to white, when it has 
been immersed for some time in water. 
2d. The cerebral substance and that of the spinal me- 
dulla easily become putrid when submitted to the com- 
bined action of water and air ; they become of a greenish 
colour and have acid sufficient to redden blue paper. Of 
all animal substances, I think they exhibit this pheno- 
menon the soonest. The nervous medullary substance, 
on the contrary, resists putrefaction much longer. The 
nerves are among the slowest of all the parts of the ani- 
mal economy to become putrid. During life they are 
often found untouched in a gangrenous limb, in the mid- 
dle of an abscess, &c. In a dead body which is putrid, 
they preserve their whiteness and consistence, while the 
other parts are black and soft. I have observed that the 
water in which the nervous system has been macerated 
has but little odour, but that that in which the brain has 194 
NERVOUS SYSTEM 
been macerated is foetid. These phenomena clearly would 
not take place if the medullary substance of the nerve 
became as easily putrid as that of the brain. It is mani- 
fest, however, that it is especially to the nervous coat, 
that the nerves owe this sort of incorruptibility; for I 
have observed, that the optic nerve, in which the medul- 
lary substance predominates, and the olfactory and audi- 
tory, which are abundantly furnished with it, become 
putrid sooner than the others. I have remarked also 
uniformly, that whilst the white substance of the spinal 
marrow becomes putrid, its covering remains untouched. 
3d. The medullary substance of the nerves, as well as 
that of the brain and spinal marrow, does not seem to 
be susceptible of any kind of horny hardening. This 
is very evident when we immerse the two last in boiling 
water, in a concentrated acid, &.C. We may be con- 
vinced as to the first, by submitting to the same experi- 
ment the soft nerves that have their nervous coat pretty 
distinct. To this also must be referred the following 
phenomenon ; when the anterior part of the optic nerve 
is put into boiling water, the nervous coat becomes wrink- 
led, its canals shrink, and the medullary substance not 
contracting in proportion, is forced towards the extremi- 
ties, which become consequently enlarged. As this sub- 
stance is in less proportion in the other nerves, this phe- 
nomenon is less apparent in them ; it takes place, how- 
ever, and this explains the small round tubercle that is 
seen at each end of boiled nervous filaments; it is the 
medullary substance that produces these enlargements. 
This phenomenon is very evident in the spinal marrow, 
which, being immersed in boiling water, suffers the com- 
pressed substance to escape, either at the extremities, or 
at any openings that may be made in its covering. Thus 
in boiling a head, the dura mater detached from the cra- 
nium contracts powerfully in hardening like horn, com- 
presses the cerebral substance which does not contract OF ANIMAL LIFE. 
195 
like it, and sometimes breaks it, so that it escapes into 
the space that the boiling has produced between the dura 
mater and the cranium. 
4th. When the cerebral substance is agitated in water, 
it becomes suspended in it in the form of an emulsion, as 
has been observed by Fourcroy, then it is precipitated to 
the bottom of the vessel. A similar emulsion is made by 
the olfactory nerves, the posterior part of the optics, &c. 
When the anterior part of these, in which the nervous 
coat is very evident, has been soaked some time in water, 
and commonly even without this, a large quantity of 
whitish substance can be pressed out of them, which is 
evidently analogous to the medulla of the brain, and which 
colours the water that receives it. From the other nerves 
in which the medullary substance is much less abundant, 
it can often be forced out by pressure, from the cut ends 
of the filaments, especially if they have been previously 
macerated in an alkaline solution. 
5th. Boiling hardens the brain, and gives it a greyish 
and dingy appearance, very similar to what is seen in 
ataxic fevers. The same phenomenon takes place in the 
soft nerves. In the others, the nervous coat is in too 
great a proportion to the medullary substance to allow 
us to see what happens to this last. It is to this property 
of coagulating by heat, which the brain has, that must be 
referred the flaky precipitate that is obtained in a heated 
cerebral emulsion. 
6th. All the acids that are much concentrated harden 
the brain very evidently, the instant it is immersed in 
them. The sulphuric afterwards softens it, and finally 
reduces it to pulp, if it is not diluted. The nitric inake3 
it yellow only, in hardening it. The muriatic has the 
least action upon it. The effect of acids upon the soft 
nerves is very analogous to this. In those in which the 
coat is very distinct, the horny hardening of which this 
coat is the seat, conceals all the sudden phenomena rela- 196 
NERVOUS SYSTEM 
live to the medullary substance. When the coat is sof- 
tened and dissolved, this substance has appeared to me 
to be diminished in consistence and altered by the 
acids, whereas that of the brain keeps always the same 
degree of hardness, if the acid be not too much concen- 
trated. 
Wq all know that alkohol hardens the brain. This 
hardening, the effect of acids, of boiling, and of alkohol, 
is a phenomenon that the anatomist can avail himself of 
to give the parts he dissects a firmness, that will enable 
him to examine them better. It approximates this sub- 
stance to the albuminous fluids. I say that it approxi- 
mates it, for there are still great differences between 
them, of which, 1 think, we know but little. 
7th. The alkalies have an effect upon the cerebral sub- 
stance precisely opposite to that of the acids. They 
make it fluid, and even dissolve it completely after a short 
time. 1 have observed, with regard to this, that the 
grey substance is much quicker altered by them than 
the white, which is softened, disappears in part, but still 
leaves a considerable portion that is not dissolved. From 
whatever part we take these two substances to submit 
them to the action of the alkalies, the result is the same. 
The alkalies act also evidently upon the medullary sub- 
stance of the nerves. This action, as T have said, has 
been of great assistance to Reil in his experiments. 
8th. Thouret and Fourcroy have discovered, that the 
brain, after being buried, lessens considerably in size, and 
changes to a brittle substance, capable of softening under 
the finger, miscible in water, exhaling a disagreeable 
odour, having the properties of ammoniacal soap, and 
resembling very closely spermaceti in its nature. Do the 
nerves undergo a similar alteration in their medullary 
substance? We know nothing at present by which we 
can determine this question. OF ANIMAL LIFE. 
197 
9th. The muriate of soda, when sprinkled upon slices 
of the brain and the pulpy nerves, increases their consis- 
tence. 
10th. The digestive juices generally alter with ease 
the medullary substance of the brain. I think, however, 
that they would have a much more powerful action upon 
it in a natural than a boiled state ; for all the re-agents 
are in general more powerful in the first of these states. 
We know that most carnivorous animals esteem the cere- 
bral substance delicious food. Those that feed upon 
birds, the parietes of whose craniums are easily broken, 
almost always eat the brain first. The weasel, the pole- 
cat, &c. furnish examples of this. Man considers the 
brain as one of the most dainty parts of the animal. 
The nerves are much less easily digested ; but this de- 
pends wholly upon their coat, which does not yield so 
readily to boiling as the other parts. For example, the 
tendons, which are as hard or harder than the nerves in 
a natural state, become much softer by boiling. We can 
distinguish in boiled meat each of these parts. The first, 
in its gelatinous state, is more pleasant and digestible. 
11th. The cerebral medullary substance is very differ- 
ent in the brain, the tuber annulare and its elongations, 
and the spinalmarrow. If we examine it attentively, in 
all these we must perceive the difference in colour, con- 
sistence, hardness, humidity, and, without doubt also in 
its very nature, though our knowledge is not yet suffi- 
ciently advanced to decide with certainty upon this last 
point. Has the nervous medullary substance analogous 
differences ? I believe that it is similar in the same 
nerve, but that it varies in different nerves according to 
their uses. In fact, when the internal arrangement of 
the cords and the filaments which constitute the nerve, 
differs so much, when there are varieties in the ner- 
vous coat also, why should the medullary substance be 
every where of the same nature ? Certainly the colour 198 
NERVOUS SYSTEM 
and consistence of that of the olfactory are different 
from that which is forced out from the anterior part 
of the optic. That of the auditory does not resemble 
that of the trigemini, &c. We have seen that each of 
the organs of sense has its peculiar sensibility, which 
places it exclusively in relation with particular bodies in 
nature, that of the eye with light, that of the ear with 
sounds, &c. I think that these differences of sensibility 
depend upon the difference of organs; but I am per- 
suaded that the organization of the nerves has much in- 
fluence, and that the optic nerve would be unfit to trans- 
mit tastes, the auditory to propagate impressions made by 
light, &c. If we examine attentively, we shall see an 
essential difference of structure between the nerve of the 
eye, of the nostrils, the ear, and that of the taste, which 
approximates, in thickness, the nerves of motion. As 
to the nerves of touch, they do not require a peculiar 
texture; for I shall prove hereafter that a particular kind 
of animal sensibility is not necessary for this sense, but 
that this general property is sufficient for it, since its ac- 
curacy depends especially upon the mechanical form of 
the hand. As to the nerves that go to the voluntary mus- 
cles, as these muscles are every where analogous and per- 
form similar functions, I think their medullary substance 
is the same. But in the par vagum, whose destination is 
so different, why do not the varieties of internal organiza- 
tion coincide with that of the texture which we observe 
in dissecting this nerve? We may say the same of many 
nerves that go to parts whose sensibility presents an en- 
tirely different modification. 
This then is a comparison between the cerebral pulp 
and the medullary substance of the nerves, which may 
throw some light upon their difference and their analogy. 
I have not availed myself of all the details of the chem- 
ical experiments that have heretofore been made upon 
the brain ; I have only given the principal phenomena of OF ANIMAL LIFE. 
199 
the action of different re-agents, phenomena, all of which 
I have repeatedly proved. 
The medullary substance of the nerves is not arranged 
in filaments. It appears to be analogous to the white sub- 
stance of the spinal marrow which is a real jelly, stagnant 
in the canal of the pia mater, which serves as a reservoir 
for it. Besides, examination proves this assertion in the 
optic, auditory, olfactory nerves, &c. In general I think, 
that this substance, as well as the cerebral, would be 
ranked, if they were deprived of the vessels that run 
through them, rather among the fluids than the solids, 
or they would form a medium of connexion between the 
two. 
II. Parts common to the organization of the nervous system 
of animal life. 
Cellular texture. 
The nerves are entirely destitute of this texture in the 
interior of the cranium, and the spine ; but out of these 
they have a great quantity of it. A large external layer, 
first covers and then connects them with the neighbour- 
ing parts. This layer is looser than that which surrounds 
the arteries. Fat often accumulates in it; sometimes, 
though rarely it is the seat of dropsical effusions. 
From this common layer go off different elongations 
which communicate with the cellular texture of the neigh- 
bouring organs, and form a medium of union between 
the nerve and these organs. Within, there are other elon- 
gations that go between the nervous cords, and separate 
them from each other, and form for them kind of canals. 
When a nerve has been macerated some time in diluted 
nitric acid, the cords become separated from their sheath, 
which is to them what the layer of which we have spoken 
is to the whole nerve. These cellular canals often contain 
also fat in the great nerves, in the sciatic there is always 200 
NERVOUS SYSTEM 
some of it. Hence it is that when we dry these organs, 
there is almost always as I have observed, a fatty exhala- 
tion upon their surface; and that, when they are immersed 
in any alkaline solution, they have evidently an unctuous 
and truly saponaceous deposit. 
Finally new elongations going from the cellular canals 
that surround the cords, cover the nervous filaments with 
canals still smaller. Here, there is never any fat or 
serum, and the cellular texture has in part that peculiar 
nature which characterizes the sub-arterial, the sub- 
nervous texture, &c. ; perhaps even the nervous coat is 
DOthing but this texture considerably condensed. Be- 
sides, the cellular texture so connects the one to the 
other, the cords of the nerves, and the filaments of these 
cords, that no motion can take place there. 
Blood vessels. 
Each nerve receives its vessels from the surrounding 
trunks, which send to it branches which penetrate from 
all sides to the interior. The optic is an exception to this 
rule ; the membrane that surrounds it prevents the vessels 
from entering it laterally. An artery passes through it 
in the course of its axis and sends out different branches. 
In the other nerves, the arteries run first in the cellular 
texture between the cords, and are of a size there more 
or less considerable, according to the nervous trunks. 
Sometimes this size increases considerably. For exam- 
ple, in popliteal aneurism, the artery of the sciatic nerve 
has been seen with a caliber more than three times its 
natural size. 
The arteries running between the cords, send off a 
number of little branches that go into all the interstices 
of the filaments. In fine, from these arise the little capil- 
lary arteries which are spread upon the coat of the nerve, 
cross it and are continued with the exhalants of the me- 
dullary substance. We readily see this vascular arrange- OF ANIMAL LIFE. 
201 
ment in the spinal marrow. Numerous ramifications are 
spread first upon the dense and firm pia mater, which 
there takes the place of the hervous coat; they then pen- 
etrate the medullary substance, and are lost in continua- 
tion with the exhalants. 
The veins follow in the nerves a course analogous to 
the arteries ; however, in carefully dissecting many great 
nervous trunks, I have been convinced that their branches 
do not go out of the nerves at the place where the arte- 
ries enter. This arrangement is analogous to that of the 
brain, where the arteries enter below and the veins go 
out above. 
Many authors, particularly Reil, have overrated the 
quantity of blood that goes to the nerves, because, in or- 
der to ascertain it, they have made use of fine injections 
which have entered the capillary system, which does not 
commonly contain red blood. I am convinced by dissect- 
ing the nerves of living animals, the only means of having 
an accurate idea of what takes place in a natural state, 
how uncertain this method is here as every where else. 
The blood that goes to the nerves, like that which is 
sent to the brain, is a stimulant that supports their action. 
When this stimulant is increased the nervous excitability 
increases, as Reil was convinced by rubbing the nerves 
of a frog, so as to redden them by the quantity of blood 
that was brought there. Does this fluid, when carried in 
great quantity to the nervous system, sometimes interrupt 
its functions, as happens to the brain in sanguineous apo- 
plexy ? 1 have not had an opportunity yet of making 
this observation in a very decided manner in the great 
number of bodies that I have opened. Only the nerves 
are a little more reddish in some cases than others. Do 
these cases coincide with certain determinate diseases ? 
I have not any knowledge upon this point. As to the 
pretended compression of the origin of the nerves, by the 
blood that is carried to the brain and spinal marrow, who- 202 
NERVOUS SYSTEM 
ever has examined the relations of the nerves with the 
vessels of the base of the cranium, will see that such a 
compression is not probable. Besides, most of the holes 
through which the little arteries penetrate into the inte- 
rior even of this viscus, have a caliber greater than that 
of the arteries; so that how full soever they may be, they 
cannot press upon their parietes. I can only conceive of 
a compression at the origin of the nerves, from effusions 
at the base of the cranium. 
Exhalanls and absorbents. 
We cannot discover these vessels in the nerves; but 
nutrition supposes their existence there. It appears that 
this function is performed in the following manner ; the 
exhalants receive from the arteries, with which they are 
continuous, the medullary substance which they deposit 
in the canal of the nervous coat, which is, if I may so ex- 
press myself the reservoir of this substance, that is after- 
wards taken up by the absorbents. 
Many think that the nervous coat is the secretory organ 
of this medullary substance, which oozes out of its parietes, 
to lie in its cavity. I do not believe it, 1st. because the 
olfactory nerve would not theu be able to support itself, 
any more than the posterior portion of the optic. 2d. The 
cerebral membranes are not concerned with the secretion 
of the pulp of the brain, they only permit the vessels to 
pass, which enter this organ to deposit it there. 3d. There 
is the same arrangement at the spinal marrow, the pia ma- 
ter of which has so great an analogy with the nervous 
coat. The vessels cross this membrane, then losing 
themselves, as I have said, in the medullary substance 
renew it; so that if it was possible to remove 
this substance without touching the vessels, these would 
hang loose by their extremities in the canal of the pia 
mater. Thus, in some very soft fungi, the vessels cross 
here and there the substance that they deposit in their OF ANIMAL LIFE. 
203 
interstices, and would produce a vegetation like net-work, 
if we could remove this substance and leave them un- 
touched. 4th. In the optic nerve the vessels evidently 
are not confined to the nervous coat ; they penetrate also 
the canals it forms, and deposit there the medullary sub- 
stance. 
Every thing appears then to prove, that the nervous 
coat is no more the secretory organ of the nervous sub- 
stance, than the pia mater is of the cerebral substances 
or that of the spinal marrowr. It may have uses of which 
we are ignorant; but the principal certainly is that of a 
covering; it is the passive part of the nerve, the medulla 
being the part essentially active. 
From this way of describing the production of the ner- 
vous medullary substance, it is evident that it does not 
proceed from the brain, but that it is formed in each nerve 
by the means of the neighbouring vessels. Hence why 
the inferior portion of a cut nerve does not decay ; why a 
ligature that interrupts the cerebral communications, does 
not prevent the nervous nutrition; why in most paralyses 
in which the nervous system ceases to correspond with 
this organ, it is supported as usual. 
From these and other considerations, Reil considers 
the nerves as having an entirely insulated existence, as 
being bodies by themselves, communicating only on one 
side with the brain, on the other with the different parts. 
This assertion is true as it respects nutrition, but as it re- 
gards the functions it is in part false; for the nerves are 
evidently only conductors; it is from the brain that goes 
the impulse, and there too is the sensation. In animals with 
white blood, and even in those with red and cold blood, 
these functions concentrated in the brain, in man and the 
neighbouring species, are, it is true more generally spread 
throughout the nervous system, hence it is without doubt, 
that we can remove the brain, the heart and the lungs in 
reptiles without immediately destroying life; it is on this 204 
NERVOUS SYSTEM 
account, that I have remarked in my Researches upon 
Death, that we should never avail ourselves of experi- 
ments upon animals with red and cold blood, to draw con- 
clusions concerning those with red and warm blood. But 
in these and in man especially, it is undeniable, 1st. that 
the brain is the centre of animal life, which ceases when 
the action of this viscus is destroyed, as is proved by 
apoplexy, asphyxia, &c.; 2d. that it has also immediately 
dependant upon it organic life, though in an indirect way, 
that is by presiding over the mechanical functions of 
respiration, which by ceasing, stop the chemical, then the 
circulation, then the secretions, &c. so that the continu- 
ance of the two lives, and a serious injury of the brain, 
are two things wholly incompatible. Authors who have 
written upon life, the nervous system, &c. have usually 
considered them in too general a manner. The relations 
of the functions are absolutely different in animals with 
cold blood and in those with warm; that which is true for 
one, is not so for the other. 
Nerves. 
Does the nervous coat receive small nervous branches? 
Do these small branches penetrate the nerves, as the 
small arteries spread on the coats of the large ones ? 
Anatomical examination does not render this probable. 
ARTICLE THIRD. 
PROPERTIES OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
I. Properties of texture. 
Few systems exhibit these properties more obscurely 
than this. If we draw a nerve, in an opposite direction, 
in a living animal, it is extended with difficulty, makes OF ANIMAL LIFE. 
205 
great resistance, and acquires a length but little more 
than what is natural to it; this appears to depend par- 
ticularly on the nervous coat. The medullary substance 
would yield much more. We know how much that of 
the brain is stretched in the dropsy of the ventricles. If 
a great trunk is distended by a subjacent tumour, as in 
popliteal aneurism, by a swelling in the axilla, &c. it is 
flattened down like a ribbon ; its filaments are separated 
and lay at the side of each other, and it is consequently 
much widened. Thus distended, these filaments can yet 
sometimes transmit sensation and motion, at other times 
these two functions are annihilated there. 
In general, a sudden distension interrupts them much 
more certainly than that which comes on slowly. Hence 
why the luxation of the head of the humerus often occa- 
sions paralysis, whilst it rarely happens from very large 
chronic tumours in the axilla. Spontaneous luxations of 
the vertebrae, which always come on slowly, are rarely 
accompanied by paralysis, an accident which is always 
the result of those that happen from external violence. 
It is thus in thQ brain, osseous tumours, large fungi which 
increase slowly, disturb its functions but little, while the 
least depression of a bone of the cranium, that succeeds 
a fracture, entirely deranges them. In hydrocephalus, 
also, a great collection of serum has oftentimes but little 
effect upon sensation, which is nearly destroyed, when a 
little more of this fluid than common is exhaled in the 
ventricles, as happens in some kinds of apoplexy. 
When a large cavity, like the abdomen, is distended, 
the nerves that are there yield partly because their curves 
disappear, and partly because they are really elongated; 
there is also a greater separation of them. 
The contractility of texture is still less evident than 
the extensibility. A nerve cut transversely, does not 
retract at the two ends, which remain opposite to each 
other, like those of a tendon. In amputation, the end of 206 
NERVOUS SYSTEM 
the nerve remains longer than those of the muscles, the 
skin, &c. This is sometimes the cause of a painful pres- 
sure from some part of the dressing. 
These are less evident in the nerves, than would be 
thought at first, from the opinions of a great many phy- 
sicians, who have made these organs perform almost the 
whole part in diseases. 
II. Vital properties. 
Properties of animal life. 
The nerves must be considered, in regard to sensibility, 
in two points of view. 1st. We should examine that 
which is inherent in them. 2d. It is necessary to con- 
sider the part which they take in that of all the other 
organs. 
Animal sensibility inherent in the nerves. 
This property is, of all others, the most strongly mark- 
ed in the nerves. Exposed and irritated, they cause 
great pain. By tying, pricking, cauterizing, or exciting 
in any way a nervous filament, we uniformly obtain that 
result so well known in practical surgery, and by those 
who make experiments upon living animals. 
This property would seem at first to establish a very 
great difference between the medullary substance of the 
nerves and that of the brain, especially towards the con- 
vexity of this organ; for we can almost with impunity 
irritate this after having removed the cortical substance. 
It is only deep in the brain that the animal sensibility 
becomes strongly marked, and even there it is not so 
much so as in the nerves. Observe, however, that in the 
experiments upon the cerebral pulp you destroy the or- 
gan itself that perceives, that, without which it could not 
have animal sensibility, and whose derangement would 
consequently have an inevitable influence upon this pro- OF ANIMAL LIFE. 
207 
perty; whereas the seat of perception being untouched 
when we irritate a nerve, the pain is more sensibly felt. 
It is, in fact, principally in the medullary substance of 
each nervous filament, that animal sensibility resides. 
The nervous coat possesses a much less degree of it. 
Hence why simple contact, without pressure, occasions 
but little pain ; hence, also, why a nerve can almost with 
impunity be immersed in a purulent, ichorous fluid, or 
even in the sanies of cancer; hence why the contact of 
the air occasions but little pain when the nerves are 
merely laid bare, as I have had frequent occasion to see 
in animals; why, in a variety of cases, different tumours, 
in whose atmosphere the nerves are situated, have no 
influence upon them. The membrane of each filament 
is truly in every case a kind of covering that protects its 
medullary substance, in which the sensibility particularly 
resides. As to the cellular texture which enters into the 
composition of nerves, it has, as elsewhere, no connexion 
with this property. Hence why we can, as I have often 
done upon a living animal, separate from each other, 
with the point of a very delicate scalpel, the different 
filaments of a nerve of some size, of the sciatic, for ex- 
ample, when they have first been laid bare, without giv- 
ing the animal much pain. In these experiments, it is 
easy to be convinced of the kind of insensibility of the 
covering of each nervous filament. It is necessary to 
pierce it and arrive at the medullary substanee in order 
to produce pain. 
In experiments, the animal sensibility of the nerve 
seems to be gradually exhausted, and finally ceases. I 
convinced myself of this upon the eighth pair of nerves, 
in making my experiments upon the injection of black 
blood into the brain. At the moment the nerve is raised 
and drawn to detach it from the carotid with which it is 
connected, the animal cries out and is much agitated; but 
after the same thing is repeated two or three times, he 208 
NERVOUS SYSTEM 
bo longer gives any signs of pain. If we cease to excite 
the nerve for an hour or two, the sensibility returns with 
great energy, when it is drawn again. These experi- 
ments furnish a result very analogous to that of experi- 
ments relative to the animal contractility of muscles, 
experiments that are known to all physiologists. 
The animal sensibility of the nerves has a peculiar 
character which distinguishes it from that of all the other 
systems. It is this character which gives a peculiarity 
to the pain in these organs, which does not resemble that 
which has its seat in the skin, in the mucous surfaces, &c. 
What particularly fixed my attention upon the difference 
of pain of which each system is the seat, was the ques- 
tion of a man of great mind and coolness, whose thigh 
was amputated by Desault; he asked me, why the pain 
he felt when the skin was cut, was wholly different from 
that which he experienced when the flesh was cut through 
in which the nerves, scattered here and there, were di- 
vided by the knife, and why this last sensation differed 
entirely from that which was felt when the marrow was 
divided. This embarrassed me then, when I was wholly 
engrossed in surgery, and had studied physiology but 
little; I have seen since, however, that it is to be refer- 
red to that general principle of which I have already 
spoken, and which determines, that as each system has 
its peculiar kind of animal sensibility in a natural state, 
it has it also in a morbid state, that is to say, in pain. 
A very clear proof of this assertion, as it regards the 
nerves of animal life, is the peculiar kind of pain that is 
experienced in the tic douloureux, a kind that is unlike 
that of any other system. The sciatic disease, which 
has its seat in the nerve of the same name, has often been 
confounded with rheumatism, which affects the muscles 
or tendinous parts; but the difference of pain alone is 
sufficient to distinguish them. Mr. Chaussier has very 
judiciously taken for the first character of neuralgia, the OF ANIMAL LIFE. 
209 
nature of the pain. Every one knows the peculiar sensa- 
tion of numbness and afterwards of pricking, that is felt 
when a superficial nerve, as the cubital, &c. is compress- 
ed. No other organ in the economy gives the same sen- 
sation from the same cause. 
The animal sensibility of the nerves has another pecu- 
liar character, which consists in this, that the local irri- 
tation of a trunk often produces suffering in the whole 
branches. 1st. We know that when the cubital is com- 
pressed at the elbow, the pain extends along its whole 
course, and that it spreads over the wrhole external part 
of the leg, when the peroneal suffers. 2d. In the tic 
douloureux of the face, in the sciatic disease, and gener- 
ally in all that class of diseases of which Mr. Chaussier 
has given a sketch under the name of neuralgia, an 
analogous observation may be made. 3d. When we 
wound, without dividing, one of the branches of the sa- 
phena, the internal cutaneous or muscular cutaneous, in 
the operation of blood-letting, the subjacent part fre- 
quently becomes numb, then painful and swelled; the 
irritated point is a centre, whence go forth, along the 
whole course of the nerves, painful irradiations, the con- 
sequences of which oftentimes cannot wholly he stopped, 
except by dividing the irritated trunk. Thus, in tic dou- 
loureux, the division of the nerves has sometimes over- 
come the disease, though we shall succeed less frequently 
here by these means than in the preceding case, where 
the affection is local, while here it is usually extended 
along the whole course of the nerve. 4th. I have irri- 
tated, in a dog, the sciatic nerve with nitric acid; the 
whole limb was swelled and painful the next day. 1 have 
at this time another, the whole of whose fore limb is 
swelled, because I passed a pin, two days before, through 
one of the anterior nerves, taking care to entangle some 
of the nervous filaments. This precaution is essential, 
for I passed a pin through the cellular texture that sepa- 210 
NERVOUS SYSTEM 
rates the filaments of the sciatic, without producing any 
effect. I should observe, however, that these different 
experiments do not always succeed, and that I have irri- 
tated a nerve at one point sometimes without producing 
any effect. 5th. The ligature of nerves is rarely follow- 
ed by these accidents, because the communication with 
the brain is interrupted, by the very means that irritate, 
and because the medullary substance is flattened and its 
sensibility destroyed. However accidents have often 
happened from tying a nerve in the operation for aneu- 
rism, and though there is no real danger in making the 
ligature, all good practitioners advise that it should be 
avoided. 
These different considerations prove in a positive man- 
ner, the influence that a portion of an irritated nerve has 
upon the animal sensibility of all the subjacent ramifica- 
tions. Physicians do not give sufficient attention to this 
cause of pain, which is often very extensive without any 
apparent wound. An irritated nerve in a fracture of the 
ribs, in that of a limb, in a wound, in a tumour, &c. can 
produce at a distance a number of phenomena, the cause 
of which often escapes us, and which we should soon 
discover if we reflected upon the distribution of the 
branches going from the trunk of the nerve that is near 
the affected part. 
Why in these phenomena, is the animal sensibility of 
the nerve below the affected part always raised ? Why 
does this phenomenon never take place on the side of 
the brain, though it is in this direction that sensation is 
conveyed in a natural state? I know not. 
No other system, among those all of whose parts are 
united like the nervous system, presents the same pheno- 
menon. The arterial, the venous, the absorbent, never 
feel thus in their different ramifications, the affections of 
any one part of their trunk. The cellular is not affected 
at a distance by the diseases of one of its parts. In the OF ANIMAL LIFE. 
211 
mucous which is continuous, a part being irritated, often- 
times others also are affected, as when the stone in the 
bladder produces suffering in the glans penis; but there 
is always an intermediate portion more or less considera- 
ble, which remains without being painful ; this is a real 
sympathy ; whereas in the other, the whole nervous trunk 
suffers, from the affected part to the nervous extremities. 
Influence of the nerves upon the animal sensibility of all the 
organs. 
After having considered the animal sensibility in the 
nervous system itself, we must examine the part this sys- 
tem performs in this property described in relation to all 
the other organs, in which it is often the means of trans- 
mission between the organ that receives the sensation 
and the brain which perceives it. So that when any 
point of the nervous system sutlers, as in the preceding 
cases, the portion of nerve that is between this point and 
the brain, serves to conduct the impression. Thus in 
animal contractility, the nerves are always intermediate 
to the brain, which is the principle of the motion, and 
to the muscle that executes the motion. There is, how- 
ever, more difficulty in the first kind of transmission than 
in this, which, to be explained accurately, requires that 
we should distinguish two kinds of sensations perceived 
by the internal sensitive principle, 1st. the external; 2d. 
the internal. 
The external sensations are of two orders, 1st. the 
general; 2d. the particular. The general sensations are 
derived from the sense of feeling, as we shall see; they 
indicate the presence of the bodies that are in contact 
with the external organs; they give the general impres- 
sions of heat and cold, moisture and dryness, hardness 
and softness, &c.; they produce a painful sensation when 
the external organs are torn, pricked, or acted upon by 
chemical agents, &c. These sensations may originate 212 
NERVOUS SYSTEM 
upon the skin, the eye, the ear, the mouth, the nostrils, 
upon the beginning of all the mucous surfaces, &c.; all 
the bodies in nature may produce them, and all the ex- 
ternal organs may perceive them. 2d. The particular 
sensations are relative to certain determinate external 
bodies, or to particular emanations from surrounding 
bodies. Thus the eye exclusively perceives the light, 
the nose odours, the ear sounds, the tongue tastes, &,c. 
These particular sensations are to a certain degree inde- 
pendent of the general ones ; thus the eye may cease to 
see, the nose to smell, the ear to hear, the tongue to 
taste, and yet these different organs may preserve the 
faculty of perceiving the general attributes of heat and 
cold, moisture and dryness, &,c. and may be the seat of 
real pain. Every day we see patients affected with gutta 
serena suffering from the eye, those affected with deafness 
having pains in the ear, &c. I have seen a man that was 
deprived of the sense of smell from the use of mercury, 
and who still would suffer very much if the pituitary 
membrane was irritated, &c. It is necessary, then, to 
distinguish in the organs of sense, that which belongs to 
the general sense of feeling, from that which is dependant 
upon the particular kind of feeling that each has sepa- 
rately. 
If now we examine the part of the cerebral nerves in 
these two kinds of animal sensibility, it appears that they 
are equally essential to one and the other. 1st. This is 
without doubt as it regards the organs of sense ; the 
sight, the hearing, the smell, or the taste, could never 
continue after a serious injury of the optic, auditory, 
olfactory, gustatory nerves, &c. I do not speak of the 
touch, which does not require, like the other senses, a 
peculiar modification of animal sensibility, but only the 
general feeling, with a peculiar form in the organs that 
are provided with it, so as to mould themselves to the 
figure of external bodies. 2d. As to the general sensa- OF ANIMAL LIFE. 
213 
tions, whenever the cutaneous nerves cease entirely to 
act in any part of the skin, it becomes absolutely insensi- 
ble; it may be pinched, irritated, burnt, &c. without 
feeling it. The perfect paralyses of sensation exhibit in 
man this phenomenon, which can easily be produced in 
animals by cutting or tying all the nerves that go to a 
limb. When the general feeling is left in the pituitary 
membrane after the loss of smell, the olfactory nerve is 
alone paralyzed; if the nerves that enter by the spheno- 
palatine foramen, through the anterior and posterior open- 
ings of the nostrils, cease also to act, then the general 
feeling is likewise lost. It is the same with regard to the 
other organs of sense. 
I believe, then, that the nerves are actually necessary 
to the external sensations, whatever be their nature. 
Observe also, that all the organs with which external 
bodies can be in contact, as the dermoid system, all the 
origins of the mucous systems, and the organs of sense, 
are provided more or less abundantly with cerebral 
nerves; none of them receive the nerves of the gangli- 
ons. This external portion of the nervous system of 
animal life is very considerable; united to the portion 
that goes to the voluntary muscles, it forms almost the 
whole of this system, which has but very few appendices 
in the organs of internal life. 
As to the internal sensations, they have phenomena 
much more obscure than the preceding. The brain is 
undoubtedly the centre of these sensations, as well as 
those which take place without it ; in fact, if the action of 
this organ is suspended by wine, opium, or any other 
means, though acute pains may affect the internal organs, 
these pains are not perceived. Thus when the brain has 
received a concussion, though the impression of sounds, 
of light, of odours is made as usual upon the ear, the eye 
and the nostrils which are uninjured, yet there is neither 
hearing, seeing or smelling. But how do the impressions 214 
NERVOUS SYSTEM 
made upon the internal organs get to the brain ? Here 
are different phenomena, that it is impossible to conceive 
of well, by supposing that the nerves are charged with 
transmitting these impressions exactly like those which 
are experienced by the external organs. 
1st. There are organs that have the most acute sensi- 
bility upon the slightest touch, and which however receive 
very few apparent nerves; such is the medullary mem- 
brane of the long bones. 2d. Certain organs in which 
the cerebral nerves evidently enter, as the liver, the 
lungs, &,c. can be irritated in animals, without seeming to 
give them much pain. 3d. The muscles of animal life, 
in the structure of which so many nerves enter, in which 
also the branches of these perform so great a part as it 
relates to animal contractility, do not occasion much pain 
when their texture is cut without entangling the nervous 
filaments that penetrate them. 4th. The ligaments, that 
no nerve enters, are the seat of acute pain when they are 
distended, as my experiments have proved. It is the same 
as it respects the tendons, the aponeuroses, &,c. 5th. All 
the organs with the structure of which the nervous system 
has manifestly no connexion, transmit however to the 
brain the most painful impressions when they are inflam- 
ed, &c. &c. 
I could bring many other facts, which the opponents of 
Haller have carefully collected ; but these are such, that 
we cannot hesitate to admit, that the opinion of this cele- 
brated physiologist should not be entirely acceded to. 
All that we know upon the internal sensations is, that, 
1st. there is an organ in which the cause of sensation is 
seated ; 2d. that this organ transmits to the brain the par- 
ticular modifications that it experiences in its vital forces. 
But we are wholly ignorant of the medium of communi- 
cation of one with the other. Hence, why, in my division 
of the vital forces, I have avoided a systematic basis. The 
distinction of the two kinds of sensibility, of the three OF ANIMAL LIFE. 
215 
kinds of contractility, rests wholly upon the observation of 
facts. Such is the obscurity of the phenomena of life, that 
I doubt if we shall ever be able to establish divisions from 
a knowledge of the nature and essence of the vital forces. 
I observe that there is a great difference between ani- 
mal sensibility and contractility ; that in the first, the 
nerves are in certain cases the evident agents of commu- 
nication between the organs that receive the impression 
and the brain that perceives it, but that in other cases, 
we know not the kind of relation ; whilst in the second, 
it is always manifestly by the nerves that the brain com- 
municates with the muscles, and that the organs can 
never execute a voluntary motion without the influence 
of the cerebral nerves. 
Let us confine ourselves to this general view, which is 
from accurate observation ; let us abandon reasoning, 
where experiments are not the basis of it. Some modern 
authors have been less judicious; they have admitted a 
nervous atmosphere extending more or less remotely, and 
acting at a determinate distance; so that though an organ 
may not receive a nerve, it is sufficient that it should be 
in the atmosphere of a nervous cord to be the seat of 
sensations. This ingenious idea of Reil, should be placed 
at the side of a great number of those that Bordeu has 
scattered in his works, and which are rather proofs 
of an ingenious author, than an accurate and judicious 
mind, hostile to every opinion not founded on rigorous 
experiment. In fact, what is this atmosphere ? Is it an 
emanation that is constantly made at the exterior of 
the nerves? Is it a fluid that is independent of them, 
and that nature has placed around each nervous cord, 
as it has placed the air around the earth ? Is it a 
power that has been given to the nerves to act at a dis- 
tance without intermediate bodies ? Some galvanic ex- 
periments seem to prove something similar to this in the 
nerves; but these experiments have no relation to the 216 
NERVOUS SYSTEM 
transmission of animal sensibility. Moreover, when pain 
takes place in the middle of a very thick tendon, in the 
centre of a large articulation, as that of the knee for 
example, it would be necessary that the atmosphere of 
nervous activity should extend sometimes even an inch. 
Why is there not suffering produced, by the irritation of 
an insensible part that is at the side of a nerve, or even 
connected with it, whilst the pain is very acute in an 
inflamed part, though it is at a distance from every ner- 
vous cord ? Would the nerves then have also, a sphere 
of activity for motion ? But why should the contiguity of 
the nerve never be sufficient to produce it in the muscles? 
Why is it not the same of sensation ? 
Animal contractility. Influence of the nerves upon that of 
the other parts. 
The texture of the nerves is wholly destitute of this 
contractility. No kind of sensible motion is ever observ- 
ed in them; they perform however an essential part in 
this property, considered in relation to the muscles of ani- 
mal life. We shall see that they are the essential agents 
which transmit to them the principle of motion ; so that 
animal contractility always supposes the exercise of three 
successive actions, viz. that of the brain, the nerves and 
the muscles. 
The opinions of physiologists have been singularly 
divided upon the manner in which the nervous influ- 
ence is propagated. Some have admitted a kind of vibra- 
tion, others a fluid pervading the insensible canals of 
these organs. This last hypothesis is still in much credit. 
What has not been said upon the albuminous, electric, 
magnetic nature, &c. of this fluid? The article upon the 
nerves, in most physiological treatises, is almost wholly 
devoted to the examination of this question, but I shall 
say nothing upon it, for we do not know any thing 
that rests upon experiment. Moreover, are we not able Of animal life. 
217 
without knowing the mode of the nervous action, to 
study and analyze the phenomena of the nerves ? It is 
the common fault of all the ancient physiologists, to have 
washed to begin where they should one day end. Sci- 
ence was in its infancy when all the questions they dis- 
cussed turned upon the first causes of the vital phe- 
nomena. What is the result of it ? an immense deal of 
rubbish, and the necessity of finally coming to the accu- 
rate study of these phenomena by abandoning that of their 
causes, until we have observed enough to establish theo- 
ries. Thus mankind have disputed for ages, upon the 
nature of fire, of light, of heat, of cold, &c. until philoso- 
phers finally perceived that before reasoning it was neces- 
sary to have a foundation upon which their reasoning 
should rest, they then sought for these foundations and 
thus created experimental philosophy. Thus intermina- 
ble disputes have existed in the schools upon the nature 
of the soul, of judgment, &c. until metaphysicians have 
perceived the necessity of analyzing the operations of our 
intellectual faculties before they can know their essence. 
Each of the natural sciences has almost had two epochs ; 
1st. that of the last age, in which first causes were the only 
subject of discussion; an epoch useless to the sciences; 
2d. that in which they have begun to be composed of the 
study of the phenomena only that experience and observa- 
tion offer. Physiology has still one foot in the first epoch, 
whilst it has placed the other in the second. Physiolo- 
gists of the present day should advance it still further. 
Properties of organic life, considered in the nerves. 
They are in general very indistinctly marked in these 
organs. They want sensible organic contractility. The 
insensible and the organic sensibility are there only to 
that degree that is necessary to nutrition ; for these pro- 
perties have no other functions to support there. Thus 
observe, that almost all the diseases of the nervous system 218 
NERVOUS SYSTEM 
arc affections of the animal sensibility, and that but very 
few suppose a disorder in the organic. There is hardly 
ever an alteration in the nervous texture; no tumours, 
fungi, ulcerations, &c. as in the systems in which the or- 
ganic properties are predominant. Thus morbid anatomy 
finds but little to exercise itself upon in the nerves. 
The continual motion of a part sometimes increases a 
little the organic sensibility of the nerves that are found 
there, makes their nutrition more active and their size 
more apparent; but generally this phenomenon is infi- 
nitely less sensible in them than in the muscles. On the 
other hand though the nerves may have lost the faculty 
of transmitting sensation and motion, this last especially, 
they still preserve for a long time the same degree of 
organic sensibility, and their nutrition is the same as 
usual. I have many times examined comparatively the 
nerves of the sound side and those of the side affected 
with hemiplegia ; 1 have never found in them any differ- 
ence. It is only when the limb becomes atrophous, 
which never happens except at the end of a long time, 
that the nerve diminishes in size. 
I have often searched to see, if, when a part, in which 
there are nerves, has been a long time the seat of uninter- 
rupted painful sensations, the nutrition of these is altered, 
and consequently if their organic sensibility is affected. 
I have dissected the stomachic cords in cancers of the 
pylorus, the uterine nerves in those of the womb; I have 
not found any sensible difference, except in two subjects, 
in whom they were a little enlarged. Desault discovered 
also in a body affected with carcinoma of the fingers, the 
median nerve of uncommon size; but this phenomenon 
certainly is not as general, as the dilatation of the arteries 
in this kind of tumours. As to acute pains, like those 
of rheumatism, of different inflammations, &c. however 
severe they may be, they have no effect upon the nutri- 
tion of the nerves which transmit them. When the pain OF ANIMAL LIFE. 
219 
is seated even in the nervous texture itself, as in the 
tic douloreux, there is oftentimes no organic affection. 
At least Desault had occasion to open two patients that 
had had that disease, and the nerves were the same on 
each side. This, however, deserves further research, and 
it may be, that in many cases, the internal substance of 
the nervous cords is a little altered ; for I preserved the 
sciatic nerve of a patient, who had experienced very acute 
pain in its whole course, and this had at its superior part, 
a number of little varicose dilatations of veins that enter- 
ed it. 
Influence of the cerebral nerves upon the organic properties of 
other parts. 
Have the cerebral nerves any influence upon the or- 
ganic sensibility of other parts ? I think not, and this is 
the essential difference that distinguishes it from animal 
sensibility, which we can with difficulty conceive of, es- 
pecially in its natural state and in the external sensations, 
without the nervous influence intermediate between the 
brain and the part that receives the impression. To 
prove this assertion, let us examine the functions that de- 
pend upon organic sensibility. These are, 1st, the capil- 
lary circulation, 2d, secretion, 3d, exhalation, 4th, absorp- 
tion, 5th, nutrition. In all the phenomena of these func- 
tions, the fluids make an impression on the solids of which 
we have no consciousness, and in consequence of which 
the solids react. It is by the organic sensibility that the 
solid receives the impression, it is by the insensible con- 
tractility that it reacts ; now in none of these cases do 
the nerves appear to perform an essential part. 
1st. The capillary circulation exists in the cartilages, 
the tendons, the ligaments, &lc. in which the nerves ot 
animal life do not enter. Inflammation, which is oidy a 
derangement, an increase of this capillary circulation, 
takes place in these organs, as well as in those that are 220 
NERVOUS SYSTEM 
the most nervous ; what do I say ? where the nerves 
are the most numerous, this affection is not the most fre- 
quent; the muscles are an example of this. The tongue, 
whose surface alone has more than four or even five 
times the quantity of nerves of the mucous surface, is 
not so often inflamed as the rest of this system. The 
retina, which is entirely nervous, is rarely inflamed. 
Nothing is more rare as I have said, than the inflamma- 
tion of the nerves themselves ; the internal substance of 
the brain is hardly ever inflamed. On the other hand, 
examine the serous surfaces, the cellular texture, in which 
there are infinitely less nerves; the capillary circulation 
is constantly active there, and inflammation comes on. 
In the limbs of paralytic patients, in animals in whom 
the nerves are cut in order to render a part insensi- 
ble, does not the capillary circulation continue as usual, 
when the nervous action has ceased there ? Have you 
ever accelerated this circulation in a limb, or produced 
inflammation, by increasing convulsively by irritation the 
action of the nerves of this limb ? The phenomena of 
convulsions and those of paralysis, are wholly distinct and 
have no analogy with those of inflammation; this would 
not be so, however, if the cerebral nerves had any influ- 
ence upon thetp. In the first phenomena, it is the animal 
sensibility that is altered ; in the second it is the organic ; 
this is then independent of the cerebral nerves. 
2d. Exhalation is the second function over which this 
last property presides. I refer to the dermoid system to 
prove that the sweat is independent of the nerves. I 
would only observe here, that in the synovial, in which 
there is an evident exhalation, there are hardly any 
nerves ; that the serous surfaces and the cellular texture, 
so remarkable for this function, are, as I have said, 
almost destitute of them ; that whenever there are acci- 
dental exhalations, as in cysts, hydatids, &c. the nerves 
have evidently no influence, as the tumour is uniformly OF ANIMAL LIFE. 
221 
without them; that by acting in any manner upon the 
nervous system, as by irritating the nerves, the brain, or 
the spinal marrow, in order to excite this system, as by 
tying or cutting the first, and compressing the second, to 
annihilate or weaken its action, the cellular, serous, syno- 
vial, or cutaneous exhalations are never in any way affect- 
ed ; and that finally the diseases of the nervous system 
have no other influence upon this function, than what is 
derived from general sympathy. 
3d. As much may be said of absorption. It is during 
sleep that the skin oftentimes absorbs most easily; now 
there is at that time, an intermission in the action of the 
nervous system, as well as of that of the brain. This 
intermission, to which it is periodically subject, ought to 
produce one in the serous, synovial, medullary absorp- 
tions, &c.; but yet they go on constantly. It is the same 
of all the functions over which the organic sensibility pre- 
sides ; they are essentially uninterrupted, though the ner- 
vous and cerebral actions are essentially intermittent. 
4th. The same observation may be made concerning 
the secretions, notwithstanding what Bordeu may have 
said. For the rest, 1 refer upon this point to the glandu- 
lar system. 
5th. Nutrition takes place in parts that evidently re- 
ceive no nerves, as in the cartilages, the tendons, &c.; 
in paralyzed limbs also its alterations are always inde- 
pendent of those of the nervous system. Those people 
in whom this system is the most elevated, who are the 
most sensitive, are not those in whom nutrition is the 
most active. In no experiment, I believe, has any one 
been able to influence nutrition by acting upon the brain, 
the nerves, and the spinal marrow. Marasmus undoubt- 
edly succeeds all prolonged nervous diseases; but it 
is a phenomenon common to many diseases. In palsy, 
the long rest, as well as the deficiency in the action of 
the nerves, has an influence in producing atrophy; but it 222 
NERVOUS SYSTEM 
is a long time before this manifests itself. Who does not 
know that often at the end of two, three, or four years 
even, the diseased limb is exactly of the size of the well 
one ? Moreover, natural nutrition obeys the same laws 
as accidental nutrition, as that which takes place in the 
formation of fungous and sarcomatous tumours, and fleshy 
granulations. Now the cerebral nerves have evidently 
no connexion with all these productions ; they are never 
found in themj a phenomenon very different from that 
which is offered by the arterial system, which is almost 
always developed in a remarkable manner in these tu- 
mours. In fine, we shall see hereafter that the nerves do 
not increase in proportion with the parts to which they 
are distributed. 
From what has been said, it is evident that all the phe- 
nomena, over which preside what are commonly called 
the tonic forces, viz. organic sensibility and insensible 
contractility, are completely independent of nervous ac- 
tion ; and consequently that these properties would not, 
like those of animal life, require this action. Each kind 
of sensibility has its morbid phenomena over which it 
presides, Inflammations, suppurations, the formation of 
tumours, dropsies, sweating, hemorrhages, disorders of 
secretions, &c. &c. belong to the alterations of the or- 
ganic sensibility, whilst every thing like spasm, convul- 
sion, paralysis, trance, torpor, injury of the intellectual 
functions, &c. &c. every thing, in fact, which tends in 
diseases to destroy our relations with surrounding bodies, 
belongs to the alterations of animal sensibility or con- 
tractility, and implies a greater or less degree of disorder 
in the nervous system. 
In general, the diseases that affect the functions ot 
animal life are of a nature wholly different from those 
which destroy the harmony of organic life. They have 
not the same character, the same progress, and the same 
phenomena. Place on one side the injuries of the external OF ANIMAL LIFE. 
223 
senses, blindness, deafness, loss of taste, &c.; those of 
the internal senses, mania, epilepsy, apoplexy, catalepsy, 
&c.; those of the voluntary motions, &c.; on the other, 
fevers, hemorrhages, catarrhs, &c. and all the diseases 
that disturb digestion, circulation, respiration, secretion, 
exhalation, absorption, nutrition, &c. ; we shall then see 
what an immense difference there is between them. 
Physicians have used too vaguely the term nervous 
influence. If in medicine, as in physiology, we had ac- 
customed ourselves to use those expressions only to 
which was attached a precise and definite meaning, this 
would have been employed much less frequently. 
It appears that the nerves have some influence still 
unknown, in the production of animal heat. The follow- 
ing facts relate to this influence. 1st. In aneurism, the 
ligature of the nerve is often followed by a sensation of 
general torpor and coldness in the limb. 2d. Sometimes, 
in hemiplegia, the affected part is of a temperature below 
what is natural, though the pulse may be as strong in this 
side as the other. 3d. One of the characters of ataxic 
fevers, the principal seat of which is in the brain, is the 
remarkable irregularity in the temperature of the dif- 
ferent parts of the body. 4th. Animals, with a strongly 
marked nervous system, as quadrupeds and birds, are 
those of all others, in whom the degree of natural heat 
is the highest. 5th. I knew a person that had had the 
cubital nerve divided by a piece of glass above the pisi- 
form bone, and w hose little and ring fingers of that hand 
uniformly remained colder than the rest. 6th. Often in 
luxations, the compression of the nerves by the heads of 
the bones, produces an analogous effect, &c. &c. 
However, the heat is not always increased, when the 
nervous action is augmented, nor is it always lessened 
when this action diminishes ; there are as many cases in 
which the heat appears to be independent of the nervous 
system, as there are where it appears to be connected 224 
NERVOUS SYSTEM 
with it; so that we are still confined here to the collection 
of facts, without drawing general conclusions from them. 
* Sympathies. 
I divide what I have to say upon the sympathies of the 
nerves, as I did that which was said upon their vital 
forces ; that is to say, I shall examine first the relations 
that each nerve has with the other parts, then 1 shall 
speak of the general influence that the nervous system 
exercises upon the sympathies and of the part it takes 
in them. 
Sympathies peculiar to the nerves. 
There is no doubt as to the relations of the nervous with 
the other systems, of those which it has with the muscles 
and with the brain. In fact, these relations are natural ; 
for the one cannot be affected without the other’s feeling 
it. These three organs can in this respect be considered 
under one point of view. Thus too, the pulsation of 
the arteries is always connected with the action of the 
heart, &c. Every idea of sympathy excludes that of 
a natural connexion of functions. Barthez is mistaken 
upon this point. I speak only of the unnatural relations 
of the phenomena that take place between an organ and 
a portion of the nervous system which is not connected 
with it by the natural order of life ; now, thus consider- 
ed, the nervous sympathies are very numerous. 
1st. Two nerves of the same pair often sympathize 
with each other. We know in medicine the relation 
there is between the two optic nerves; the one being dis- 
ordered in its functions, the other frequently becomes so. 
This happens more rarely with regard to the ears, the 
nostrils, &c. though it sometimes takes place in them. 
Often in neuralgia (a word which I adopt very willingly 
and which is wanted in the science to express a class of 
diseases every genus of which has a distinct name) often I OF ANIMAL LIFE. 
225 
say in neuralgia a nerve being painful, the corresponding 
one becomes so sympathetically. I have an example of 
this at present ; it is a woman, who for two months has 
been afflicted with sciatica of the left limb. In changes 
of weather, a pain precisely similar spreads itself along 
the course of the nerve of the opposite side. I applied 
two blisters upon the thigh first affected ; the pain disap- 
peared in both sides at the same time at the end of twelve 
hours. Thus, in order to cure pains in both eyes, it is 
oftentimes sufficient to act only upon one, &c. 
2d. Sometimes two nerves of the same side sympa- 
thize without belonging to the same trunk. Thus an 
injury of the frontal nerve has been many times followed 
by a Sudden blindness in consequence of the affection of 
the optic nerve, &c. 
3d. In other cases it is the branches of a common 
trunk which influence each other reciprocally, as when a 
branch of the superficial temporal is wounded in the 
operation of arteriotomy, the whole face, which also re- 
ceives its nerves from the fifth pair, becomes painful, &c. 
4th. At other times, it is not among themselves that 
the nerves sympathize, but with other organs ; and then 
sometimes they influence, at others they are influenced. 
I say first they influence; thus a nerve being irritated 
in any way, a number of sympathetic phenomena take 
place in the system. Diseases frequently show these 
facts. It is thus in tic douloureux and analogous diseases, 
in which the nervous texture is particularly affected, 
sometimes the animal sensibility is raised in various re- 
mote parts, and hence the pains that are often experienc- 
ed in the head, in the internal viscera, pains that cease 
when the cause that supported them has disappeared. 
Sometimes it is the animal contractility ; hence the con- 
vulsions that occasionally take place in the muscles that 
receive branches from the affected nerve. In some cases 
it is the sensible organic contractility which is sympa- 226 
NERVOUS SYSTEM 
thetically excited by the nervous affections. Thus in the 
paroxysm of neuralgic pains there is often spasmodic vom- 
iting, the action of the heart is hurried, &c. We can by 
experiments produce the same phenomena. Thus by act- 
ing upon the nerves of the superior or inferior extremi- 
ties, by irritating them any way after they have been laid 
bare, I have frequently produced vomiting,or convulsions 
in muscles that were in no way connected with the 
nerves 1 irritated. 
In the second place, the nerves can be influenced by dis- 
eased organs; thus in many acute and chronic affections, 
sympathetic pains spread along the course of different 
nerves, particularly in the extremities. As the animal 
sensibility is the predominant property of the nerves, it is 
almost always that which is brought sympathetically into 
action. Physicians have not distinguished with sufficient 
accuracy in the pains of the extremities, that which be- 
longs to the nerves, from that which has its seat in the 
muscles, the aponeuroses, the tendons, &c. 
Influence of the nerves upon the sympathies of the other or- 
gans. 
Authors have been much divided upon the cause that 
supports sympathies. IIow can an organ which has no 
relation with another that is frequently very remote, in- 
fluence it so as to produce serious diseases there, merely 
because it is itself affected ? This singular phenomenon is 
often witnessed in a state of health ; but it is so wonder- 
fully increased in diseases, that if we could remove from 
them the symptoms that are not exclusively dependant 
upon the derangement of the function particularly affect- 
ed, we should find but little difficulty in their study or 
treatment. The moment an organ is affected, all the rest 
seem to feel simultaneously the disorder it experiences, 
and each seems to be agitated in its own way in order to ex- 
pel the morbific matter that has seized upon one of them. OF ANIMAL LIFE. 
227 
Most authors have believed that the nerves were the 
general means of communication that connected the or- 
gans with each other, and also their derangements. The 
anastomoses have appeared to them to be destined to this 
use; and with this opinion, some have thought that the 
brain was always mediately affected, but this others have 
rejected. The communication of parts by the means of 
blood vessels has also been thought to be a cause of sym- 
pathies. Others have admitted the continuity of the cel- 
lular texture ; some, that of the mucous membranes. I 
shall not undertake to refute in detail these different hy- 
potheses ; I would observe only, that as no one is applica- 
ble to all the cases of sympathy, it is because the aberra- 
tions of the vital forces have been described in too gener- 
al a manner ; it has been thought that a single principle 
presided over them, and this principle has been sought 
for. But in order to ascertain the cause that supports 
sympathies, they must be divided, as I have divided the 
vital properties; for as each of these properties sup- 
poses different phenomena, so the sympathies that put 
them in action, differ also. To make this distinction of 
the sympathies more evident, let us suppose a diseased 
organ, the stomach for example; it becomes then a cen- 
tre, whence go forth numerous sympathetic irradiations, 
which bring into action in the other parts, sometimes the 
animal sensibility, as when pains of the head come on; 
sometimes contractility of the same species, which is the 
case when worms in the stomach produce convulsions in 
children ; sometimes, sensible organic contractility, which, 
raised in the heart by certain pains in the stomach, occa- 
sions fever; oftentimes the insensible organic contractili- 
ty and the organic sensibility, as when the gastric affec- 
tions increase sympathetically the secretions that take 
place upon the tongue, and produce there a mucous 
coat. There are then sympathies of animal sensibili- 
ty and contractility, and of organic sensibility and con- 228 
NERVOUS SYSTEM 
tractility. This being premised, let us examine the cause 
of each. 
1st. When the animal sensibility is sympathetically 
raised in a part, this does not always depend on nervous 
communications; for oftentimes the organ in which is the 
material cause of pain does not receive any nerves, as the 
tendons, the cartilages, &c.; then it cannot communicate 
by them with that in which this pain is found. On the 
other hand we have seen above that it is still very uncer- 
tain if the nerves are the only agents that carry to the 
brain the internal sensations; we cannot say then that the 
affected organ acts at first upon the brain by their means, 
and that this reacts afterwards upon the part in which the 
pain is seated, by the nerves that go to it. Can we con- 
ceive that the cellular texture should be an agent for the 
communication of pain, which is insensible to it itself? 
Observe also that the parts that are the most abundantly 
supplied with this texture, as the scrotum, the mediasti- 
num, &lc. are not those that sympathize the most. The 
same is true of the blood vessels, which, by their nature, 
are not fitted to transmit animal sensibility, and which 
besides do not exist in all the organs. 
It appears that all sympathetic pains are nothing but an 
aberration of the internal sensitive principle, which refers 
to a part a sensation, the cause of which exists in another. 
Thus when the extremity of the stump gives the patient 
pain, who has just undergone amputation, the sensitive 
principle perceives the sensation correctly'', though it is 
deceived as to the place whence it comes; it refers it to 
the foot which no longer exists. It is the same when a 
stone irritating the bladder, produces pain at the glans 
penis. Thus all sympathy of animal sensibility is charac- 
terized by the integrity of the part in which we find the 
pain, and by the cessation of this sympathetic pain, when 
the cause that acts elsewhere has ceased. It is then prob- 
able, when a part suffers sympathetically, that that which OF ANIMAL LIFE. 
229 
is the seat of the material cause of the pain acts first upon 
the brain, either by the nerves, or by some means with 
which we are unacquainted, and that when the brain per- 
ceives the sensation, it is mistaken as to it, and refers it to 
a part from which it does not arise ; or it refers it at the 
same time to the part from which it arises, and to another 
where it does not; this happens frequently. The stone 
for example, produces suffering at the same lime in the 
bladder and at the end of the glans penis. 
These aberrations of animal sensibility then exist en- 
tirely in the brain; it is an irregularity, a derangement 
of perception ; this irregularity presents phenomena anal- 
ogous to the following ; we often refer to the skin a sen- 
sation of heat, as we shall see, though caloric is not disen- 
gaged there in a greater quantity than usual. We know 
that oftentimes the sensations of hunger and that of thirst 
are purely sympathetic, and that the cause which pro- 
duces them in a natural state does not then exist in the 
stomach or intestines. We know the illusions of vision, 
of hearing, of the smell even, &c. We have not studied 
sufficiently the irregularities of perception; those of the 
memory, the imagination, the judgment, &c. have been 
analysed. These, however, have been almost forgotten. 
They perform the greatest part in animal sensibility. 
2d. Animal contractility supposes constantly nervous 
action, when it is put in exercise sympathetically. In fact 
we shall see that this property cannot be exerted without 
the triple action of the brain, of the nerves that go to the 
muscles that move, and of the muscles themselves. When 
a muscle of animal life is brought into action by the irri- 
tation of any distant organ, by the distension of the liga- 
ments of the foot for example, this organ acts at first 
upon the brain, which then reacts by means of the nerves 
upon the voluntary muscles that are concerned in con- 
vulsions. The following is an experiment by which I 
satisfied myself of the cerebral and nervous influence in 230 
NERVOUS SYSTEM 
the sympathies that occupy us. I cut all the nerves 
of the inferior limb of one side, in different animals, and 
1 afterwards irritated in a thousand different ways, very 
irritable parts, as the retina, the pituitary membrane, the 
marrow' of the bones, &c. 1 produced in this way a num- 
ber of sympathetic phenomena, sometimes of organic con- 
tractility, as vomiting, involuntary evacuations of urine, 
fecal matter, &c. sometimes of animal contractility in the 
muscles whose nerves remained untouched. But the mus- 
cles whose nerves were cut, were never brought into ac- 
tion. I have very frequently repeated these experiments, 
which would have certainly produced results, if the ner- 
vous communications could, without the intervention of 
the brain, make the muscles of animal life contract. I 
w ould observe upon this subject, that sufficient regard has 
not been paid in experiments upon sensibility, to the sym- 
pathetic phenomena. I do not know even that these 
phenomena have been the object of any experiments 
upon animals, before those of which I have here given 
the first results, and which I propose to multiply under 
other points of view. There are then two things in all 
sympathy of animal contractility, viz. 1st, the action 
upon the brain of the organ that suffers, by means, of 
which as yet we know but little; 2d, reaction of the brain 
upon the voluntary muscles. In this last period of sym- 
pathy, the nerves of animal life are the agents constantly 
necessary. 
3d. The cerebral nerves and brain, have evidently no 
connexion with the sympathies that put in action sensible 
organic contractility or irritability. If they had, the af- 
fected organ would first act upon the brain, and this would 
react upon the involuntary muscle; thus, when tickling 
produces vomiting, there would be an action of the skin 
upon the brain, and of the brain upon the stomach. Now 
the brain never exerts any influence upon the involuntary 
muscles ; whatever be the irritation that the nerves ex- OF ANIMAL LIFE. 
231 
perience which go to them, the muscles remain unaffect' 
ed. Then although the brain may be sympathetically af- 
fected, it does not react upon the involuntary muscles ; 
the cerebral nerves then have no connexion with the sym- 
pathies of sensible organic contractility. The continuity 
of the membranes is not a more substantial cause, and 
this is the proof of it. We know that by irritating the 
uvula, the stomach heaves; now as the mucous surface 
of the one and the other is the same, we might attribute 
this sympathetic phenomenon to this circumstance. I 
have then made a wound in the side of the neck of a dog ; 
taken hold of the oesophagus and cut it transversely; the 
uvula has been afterwards irritated ; the dog, notwith- 
standing the interruption of continuity, made efforts to 
vomit as before. Let us acknowledge then that we do 
not know the cause of the sympathies of sensible organic 
contractility. 
4th. As much may be said of the sympathies of or- 
ganic sensibility and insensible contractility. We have 
proved that the nerves have no influence upon these 
two properties ; that by acting upon them we neither 
increase or diminish them in any manner, and that their 
diseases do not disturb the functions over which these 
properties preside. Then when they are sympathetically 
disordered, the nerves appear to have no connexion with 
these phenomena. Thus, 1st, every sympathetic exhala- 
tion, as the sweats of phthisical patients, certain serous 
infiltrations that take place almost instantaneously, &c.; 
2d, all secretions of the same kind, as those which appear 
in a number of diseases afford us examples of them, &c. 
3d, all analogous absorption, the three functions over 
which the preceding properties preside, are evidently un- 
connected with the nervous influence of animal life. I 
shall say the same of the cellular, vascular influences, &c. 
Certainly we have no data, by which we can explain 
how these means of communication produce sweat when 232 
NERVOUS SYSTEM 
the lungs are affected, and saliva in the mouth when the 
membrane of the palate is irritated, &c. 
From all that has been said it follows, 1st. that the 
sympathies of animal sensibility appear to be in the 
greatest number of cases an aberration of the principle 
that perceives in us, and which is deceived as to the 
place in which the causes of sensation act; 2d. that the 
sympathies of animal contractility require inevitably the 
intervention of the brain, but we know not how the part 
affected acts upon this viscus, though we know very well 
how this viscus sympathetically excited reacts upon the 
muscles to make them contract; 3d. that the causes of 
the two kinds of organic sympathies are absolutely un- 
known and that a thick veil hides the agents of communi- 
cation which connects, in this case, the organ from 
which the sympathetic influence goes to that which re- 
ceives it. 
It is this obscurity of the sympathetic causes, that has 
made me entirely neglect every kind of hypothetical 
opinion, in classing the sympathies in this work, in which 
1 examine them in each system of organs. I have had re- 
gard only to a natural division, to that indicated by the 
vital forces of which the sympathies are but an irregular 
exercise. Now by limiting ourselves to the most rigorous 
observation, it is evident that this division is the only one 
that is admissible ; and I believe that there is no other 
to be employed, until our knowledge shall be sufficiently 
extended to admit of their being classed by the causes 
that produce them, and not by the results they present. 
Besides l cannot recommend too strongly the necessity 
of distinguishing what belongs to them from that which 
arises from the natural connexion of functions. Observe 
what takes place in syncope,apoplexy and asphyxia; one 
organ is disordered; all the others soon cease to act. 
Sympathies have no part in these phenomena. Physi- 
cians have been much embarrassed by classing these OF ANIMAL LIFE. 
233 
affections, sometimes as if they belonged to the nerves, at 
others to the sanguineous system, &c. This is what 
takes place in each. 
1st. The heart first ceases to act in all syncopes, 
whether they arise from passions of the mind, disagreeable 
odours, &c. The circulation being stopt, the brain is no 
longer excited by the blood ; it ceases its action, and the 
whole of the animal life is interrupted. The organic life 
that the blood supports, is thus suddenly annihilated. 2d. 
Asphyxia commences in the lungs. Respiration is de- 
ranged ; it sends to the brain blood that cannot excite it; 
this ceases to correspond with the senses, to determine in- 
voluntary motions, &c. &c. 3d. It is in the brain that 
apoplexy has its first seat; thus animal life is immediately 
interrupted ; then, when it is very severe, the brain not 
being able longer to support the motions of the intercostal 
muscles, these motions are stopt; the mechanical, then 
the chemical action of the lungs ceases; circulation can- 
not go on, and organic life is interrupted. We see then, 
that in all the phenomena of these affections, the injury 
of one organ, produces, by a natural consequence, the sus- 
pension of the action of the others. 
This is wholly different in the sympathies. Thus the 
functions of the skin being suspended, sometimes the lungs, 
sometimes the stomach, and sometimes the intestines, feel 
it and are affected by it; these sympathetic phenom- 
ena may manifest themselves or may not; on the contra- 
ry, whether it be the cerebral, pulmonary or cardiac ac- 
tion, that is deranged, it is impossible but that the others 
should be consequently affected. 
III. Properties of reproduction. 
Are the nerves reproduced when they have been cut? 
The experiments of many distinguished anatomists evi- 
dently prove that they are. What is the manner of this 
reproduction? If we examine the results of these experi- 234 
NERVOUS SYSTEM 
ments it is easy to see that there is nothing peculiar in 
the nervous system, that it is a simple cicatrization analo- 
gous to the callus of bones, to the cicatrix of the skin, &c. 
When a nerve has been cut, its two ends inflame, the cel- 
lular texture that it contains sends forth granulations by 
the property of reproduction that it possesses. These 
granulations meeting, form adhesions that unite the two 
divided ends of the nerve. As the cellular texture, 
the means of union, grows from the cut extremity of the 
nervous coat, as well as from that which is between the 
cords, it partakes of the nature of the nervous coat, and 
becomes a parenchyma of nutrition, whose mode of organ- 
ic sensibility is analogous to that of the nerves, and whose 
vessels deposit there medullary substance, which gives a 
new appearance to the nervous cicatrix, and makes it re- 
semble very nearly the texture of the nerves themselves. 
However, as the granulations arising from the divided 
ends are not made in a regular manner, there is never at 
the place of union a thread-like arrangement as there is 
in the nerve itself. Thus the callus of a long bone, 
though analogous to this bone, is never regularly arranged 
like it in longitudinal fibres; thus a cutaneous cicatrix has 
always an irregularity in its organization, which arises 
from the irregular manner in which the parenchyma of 
cicatrization has been developed. 
The cicatrization of nerves is then analogous to that of 
bones. In the first period there is inflammation ; in the 
second, growth of the cellular texture which is to serve 
for the nutritive parenchyma; in the third, adhesion of 
those parts that have grown ; in the fourth, exhalation of 
themedullarv substance into the parenchyma. It is this 
medullary substance that makes this cicatrix differ from 
the osseous, in which phosphate of lime and gelatine 
are deposited, from the muscular, in which there is fibrin, 
&c. Sometimes there is an enlargement in the form of 
a ganglion, at the place of the reunion of the nerves; OF ANIMAL LIFE. 
235 
this depends upon the greater granulation of the cellular 
texture. Thus sometimes the callus is enlarged; at 
others, if the contact has been exact, we perceive but a 
slight difference; these are varieties that do not affect 
the nature of cicatrization. 
It follows from this, that the regeneration of the nerves, 
which has lately been the object of much research, and 
which Cruikshank, Monro, &c. have particularly de- 
monstrated, has nothing peculiar in it; that it is only a 
consequence of the general laws of cicatrization, and a 
proof of the constant uniformity of the operations of na- 
ture, though these operations present at first sight differ- 
ent results. A nerve, that is cut out in its whole course, 
is never reproduced like a nail, or the hair, which take 
a length, form, and appearance exactly the same as 
they had before they were removed. It is under the 
point of view that we have presented them, and not 
under this last, that the nervous reproductions should be 
described. 
ARTICLE FOURTH. 
DEVELOPMENT OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
T. State of this system in the Fcetvs. 
The nervous system of animal life is one of the first 
that is developed. If the heart is the first that has mo- 
tion, the brain is the first that has any considerable size. 
The disproportion of the head to the other parts is re- 
markable in the first periods after conception; its size is 
monstrous when compared with that of the subsequent 
ages. Now it is evident, that it is the brain that produ- 
ces this, and that the increase of the size of the bones 
and the membranes that surround it, is owing to it. 236 
NERVOUS SYSTEM 
We may say that by creating first the heart and the 
brain, and developing them much sooner than the other 
organs, nature wished first to establish the foundations of 
the organization of the two lives. For on the one hand, 
it is the brain which is the centre of animal life ; it is to 
this that all the sensations are referred ; it is from it 
that all the voluntary motions proceed. On the other 
hand, by sending the blood towards all the organs, the 
heart evidently presides over the circulation, the secre- 
tions, exhalations, nutrition, &c. which compose by their 
union organic life. When these two essential bases exist, 
nature begins to build, or rather develope around them 
the double organized edifice, which produces on the one 
part a communication between the animal and external 
bodies, and on the other nourishes it. 
Notwithstanding these early developments, the brain 
is not like the heart constantly active; its two great 
functions, relative to sensation and motion, are almost 
nothing. The intellectual functions also have but a very 
obscure action, if they have really commenced at all. The 
brain is then, if we may so say, in the expectation of ac- 
tion ; it has not acted; it requires the excitement of ex- 
ternal bodies. 1 do not say, however, that its inactivity 
is necessarily entire. It can undoubtedly perceive cer- 
tain internal motions that take place in the body, and es- 
pecially the pains that arise there; for if the organic dis- 
eases can produce the death of the foetus, why does it 
not suffer pain in these diseases ? Perhaps the brain is so 
much the more sensible to it, as it is not diverted by the 
external senses. The difference of the external and in- 
ternal sensations, is a question that deserves to be atten- 
tively considered. We have seen that the first are uni- 
formly transmitted by the nerves and that the mode of 
transmission of the second is uncertain. On the other 
hand the phenomena, the sensation, the impression, &c. 
are not the same in each ; so that an examination of their OF ANIMAL LIFE. 
237 
relations and their differences is essential. This exami- 
nation would have much influence upon the knowledge 
of the kind of animal life that the foetus can enjoy. 
Whatever it may be, there can be no doubt but that it is 
infinitely more contracted than after birth. 
The softness of the brain is very great in the foetus ;■ 
it is truly a kind of fluid, that the arteries, or rather the 
exhalants that arise from them deposit in their inter- 
stices. These arteries are then extremely numerous; as 
the brain has-a very evident reddish tinge. When it is 
cut in slices, numerous streaks of this colour are observ- 
ed in its substance. The two portions, the cortical and 
medullary, are infinitely Jess distinct than afterwards, 
because the second is much less white. The caustic 
alkali dissolves them at this period of life with great 
ease. The first effect before a complete solution, is to 
change the cerebral substance into a glutinous, transpa- 
rent and viscous matter, a little reddish however, and 
ropy, almost like the white of an egg. I discovered 
nothing similar to this in my experiments with the 
brain of an adult when treated with caustic alkali. The 
acids coagulate the cerebral substance of the foetus, it 
does not however attain by them a degree of hardness 
equal to what they produce in the subsequent periods 
df life. 
The extreme softness of the brain renders its dissec- 
tion very difficult in the foetus. 
The nerves of animal life have a development propor- 
tional to that of the brain. All of them are very large 
compared to the other parts ; thus the foetus and the young 
infant are the most proper for the study of the nervous 
system, as the less development of the other systems ren- 
ders this more apparent. Their medullary substance is, 
like the cerebral and that of the spinal marrow, very soft 
and even almost liquid under the finger; in this state we 
can see it in the anterior part of the optic, in which it is 238 
NERVOUS SYSTEM 
very evident though contained in the canals of the ner- 
vous coat, in the posterior part of the same nerve, and in 
the olfactory where it is found by itself, in the auditory in 
which it predominates, and finally at the origin of each 
pair, where its proportion to the nervous coat is very evi- 
dent. 
In all the other nerves it is much more difficult to ex- 
amine well this medullary substance, because the ner- 
vous coat that contains it, is as much or even more de- 
veloped in proportion to what it will be afterwards. 
Hence it is that the nerves are very hard and resisting 
in the foetus; and that they can support weights propor- 
tionably very great. Maceration in water, at a moderate 
temperature, increases this resistance as in the adult, 
and renders the nerve harder without increasing its size. 
We should say that this fluid acts at first upon the ner- 
vous coat, in an opposite manner to what it does upon 
the other animal substances; finally it softens it also, and 
renders it almost liquid. 
The blood vessels are proportionably much larger in 
the nerves of the foetus than in those of the adult. 
These nerves have in their whitish colour, a livid tinge 
that arises from the kind of blood that enters them ; it is 
the same phenomenon as that of the brain. 
The development of the cerebral nerves in the first age 
presents a phenomenon which essentially distinguishes 
it from the development of the arteries. These last al- 
ways follow the increase of the parts to which they go. 
Thus, the face proportionably less developed in the 
foetus, has less large arteries. It is the same of the vis- 
cera of the pelvis, whose very small arteries receive but 
little blood, which does not penetrate and dilate them 
until the umbilical are closed. On the contrary, the size 
of the cerebral, gastric arteries, &lc. is very considerable. 
The nerves are absolutely independent in their increase, 
of that of the parts to which they are distributed. The OF ANIMAL LIFE. 
239 
olfactory, whose organ is so contracted in the foetus, has 
the same proportion as the optic and the auditory, whose 
organs are already so much developed. It is the same of 
all the nerves of the voluntary muscles; their proportion 
of development is uniform, though the muscles vary in 
their size, according to the regions. If without regard to 
these regions, we examine in a general and comparative 
manner the nervous, cerebral and animal muscular sys- 
tems, we shall see that the first then predominates mani- 
festly over the second, while in the adult it is the mus- 
cles, which proportionably to what they were in the foe- 
tus, surpass the nerves that are sent to them. The par 
vagum which is distributed to organs whose increase is 
not in the same relation, presents nevertheless the same 
proportion of size as afterwards, in its different branches. 
This double opposite arrangement of the two systems 
the arterial and nervous cerebral, proves on the one part, 
the immediate relation of the first with the increase and 
nutrition, and on the other the small influence that the 
second exercises upon them. 
The nerves are, like the brain, principally inactive be- 
fore birth, though they have a great development. It is 
to this that must be attributed the constant absence of 
their affections at this period. 
The nerves are always found in the foetus, whereas the 
brain, and even the spinal marrow are sometimes want- 
ing; this is what constitutes acephalic subjects. I shall 
say elsewhere how the foetus can thus exist. I would 
only remark here that the heart, the liver and the other 
principal viscera of organic life, are on the contrary rare- 
ly deficient in the foetus. Why ? Because all the essen- 
tial organs of this life are necessary, for growth, vegeta- 
tion and nourishment, phenomena that can take place 
without the cerebral influence which is principally des- 
tined to preside over animal life, which is not particular- 
ly in exercise until birth. 240 
NERVOUS SYSTEM 
II. State of the nervous system during growth. 
At birth the animal nervous system experiences a re- 
markable revolution, in consequence of the red blood that 
penetrates it. Heretofore black blood only circulated in 
its vessels. The sudden difference that the circulation 
experiences, has a manifest influence upon its functions. 
In fact the least foreign substance, differing from red 
blood, which during life is forced towards the brain by 
the carotid, is sufficient to produce there a remarkable 
derangement, and oftentimes even death, as I have fre- 
quently convinced myself. Why ? because it is not only 
as a vehicle of nutritive matter, that the fluid sent by the 
arteries acts upon the brain, but also as an excitant, a 
stimulant. The change of excitement which the brain 
suddenly experiences at birth, inevitably increases its 
vital activity, gives it that which is new and renders it 
fit for the functions it has never before performed, those 
of receiving sensations. 
Asphyxia is real always when the lungs are not devel- 
oped after birth, when they do not receive air and conse- 
quently do not send red blood to the brain. Some mus- 
cular motions may undoubtedly be made; but animal 
life never begins in its perfection, until the organs that 
execute it are influenced by red blood. This blood is a 
general cause of internal excitement. This direct acts 
simultaneously with the sympathetic excitement that the 
brain experiences from the skin and mucous surfaces, 
which the external agents act upon immediately after 
the exit of the foetus from the womb. The lungs and the 
brain influence each other reciprocally at this period, 
the first by sending red blood to the second, and this by 
putting in action the diaphragm and the intercostals, 
which make the air, that is necessary for the produc- 
tion of this red blood penetrate the lungs; hence we see 
that other excitants act before that of this blood, since OF ANIMAL LIFE. 
241 
before its formation, the brain has already in it a princi- 
ple of motion. 
Besides, the brain and the whole nervous system are 
the more powerfully excited by the new principles that 
the blood has derived from the air, as, 1st. their vessels 
are in proportion larger and more numerous than after- 
wards; and, 2d. as all the cerebral arteries enter at that 
part of the base of the brain, where is found the. origin 
of the nerves, and which is without doubt the most sensi- 
tive part of the whole organ. 
There is certainly a rery great difference between as- 
phyxia that happens to an adult, and the state in which 
the foetus is found, since, if the first is prolonged, organic 
life ceases, while this life is in full activity in the foetus. 
Thus there is no resemblance in the composition of the 
black blood in the arteries in asphyxia and that in the 
arteries of the foetus. These two states, however, have 
a sort of analogy, especially under the relation of the 
remarkable diminution, of even the absence of animal 
life, which characterize both. Now in producing as- 
phyxia in an animal at will, by fixing a stop-cock upon 
the wind-pipe, I have always observed that this life is 
annihilated when the black blood penetrates the brain, 
and that when it is in part suspended, it suddenly revives 
and re-appears by opening the stop-cock, and permitting 
red blood to enter the brain, nerves, and all the parts. 
These experiments can, then, to a certain point, give us 
an idea of the part the red blood takes at birth, in the 
development of animal life; I say the part, for it is not, 
as we shall see, the only cause that puts it in action. 
For a long time after birth and during the whole of 
the growrth, the nervous system and the brain, which is 
the centre of it, predominate in their development over 
the other systems; this predominance is not uniform at 
all the periods; it diminishes at puberty, when the ner- 242 
NERVOUS SYSTEM 
vous system is in equilibrium with the others, and the 
genital organs succeed it in superiority. 
This predominance of the nervous system in the infant 
has an influence on the one hand on the sensations, on 
the other upon the voluntary motions. 
The first influence is very striking. Infancy is the age 
of sensations. As every thing is new to the infant, every 
thing attracts its eyes, ears, nostrils, &c. That which to 
us is an object of indifference, is to it a source of plea- 
sures. As a man receives great enjoyment from a show 
he never witnessed before, which is blunted by habit if 
often repeated. It was then necessary that the nervous 
cerebral system should be adapted, by its early develop- 
ment, to the great degree of action which it is then to 
have. In fact, all the organs that receive external im- 
pressions, the nerves that transmit them, and the brain 
that perceives them, are really in the infant when awake 
in permanent excitement, who in the midst of the same 
objects as the adult, fatigues these organs three times as 
much as he to whom a great part of these external objects 
is indifferent, because they have heretofore excited him. 
Thus observe that the periods of activity of animal life 
are much shorter in the infant who fatigues his organs in 
a few hours, in whom, consequently, the want of sleep 
returns oftener, and in whom this state of intermission of 
animal life is more profound. It is rare that infants, in 
the first months, can pass the whole day awake, especially 
if many objects engage them. We might prolong their 
wakefulness by removing them from light, sounds, Sic. 
The multiplicity and frequency of the sensations of 
the infant, lead necessarily to a number of motions 
which have not strength, because of the weakness of the 
muscles, but which are, like the sensations, extremely nu- 
merous. As the sight incessantly presents new objects 
to the infant, it wishes constantly to touch ; its little 
hands are in continual agitation, its whole body is also in OF ANIMAL LIFE. 
243 
constant motion. It is necessary that the nerves which 
serve to transmit the principle of these motions, should be 
adapted by their development, like those of the sensar 
tions, to their constant action. 
These two things, the great development of the ner- 
vous system and the frequency of its action in the infant, 
make the diseases of this system the predominant ones at 
that age. So great is the susceptibility of the brain in 
answering to sympathetic excitements, that if pains are 
at all severe in any part, they immediately produce con- 
vulsions, which are at least four times more frequent at 
this age than any of the following. I would observe upon 
this subject, that the different systems are more or less 
disposed in the different ages, to answer to sympathies, 
according as their predominance in the economy is more 
or less decided. The same morbific cause, fixed upon 
any organ, which produces convulsions in an infant 
by acting sympathetically upon the brain, would give to 
a young girl a suppression of the catamenia, by influenc- 
ing the womb, which then begins to predominate ; to a 
strong vigorous young man, a peripneumony ; to an adult, 
in whom the gastric viscera predominate, an affection of 
these viscera, &c. It is thus that the same passions that 
would give to this one a jaundice, engorgement of the 
liver, &c. would produce more particularly in an infant 
an epilepsy, which attacks the brain. 
The nervous functions are not only frequently deranged 
by sympathy in infancy, but it is particularly at this age 
that the greatest number of organic diseases is found in 
the brain, the spinal marrow, the nerves, or the organs 
that depend upon them. Cerebral fungi, hydrocephalus, 
spina bifida, &c. are a proof of this. The great quantity 
of blood that goes at that period to the nervous system 
has much influence upon this phenomenon ; now this 
quantity is brought there by the predominance of the 
vital forces. 244 
NERVOUS SYSTEM 
In proportion as the infant grows, its nervous system 
and the brain, which is the centre of it, lose by degrees 
the predominance that characterize them. Their dis- 
eases become less frequent. They are broughi finally to 
the level of the other systems. 
III. State of the nervous system after growth. 
At puberty, the empire of the brain, which is insensi- 
bly diminished, gives place to that of the genital organs, 
which have a sudden increase. The cerebral nerves ap- 
pear to me to have but little influence upon their de- 
velopment, as well as upon that of most of the other sys- 
tems. Observe, in fact, that all the phenomena of gene- 
ration are governed by the organic forces, which, as we 
have seen, are absolutely independent of the nerves. 
Thus the great excitement of the genital organs, from 
which arise satyriasis, nymphomania, &c. have no analo- 
gy with convulsions whose principle is in the brain ; 
as the destruction of the venereal appetite is wholly dis- 
connected with the phenomena of palsies. This is so 
true, that often during those that affect the lower half of 
the body by a fall on the sacrum, or by any other cause, 
the secretion of semen and venereal desires take place as 
usual. 
Beyond puberty, and towards the adult age, when the 
general equilibrium is more nearly established among 
the different systems, the nervous is not affected more 
than those of which we have had occasion to speak in 
treating of this system. 
At this period of life, the nervous cerebral system has 
but very few functions to perform. As to sensation, this, 
being almost blunted by habit, is the reason why external 
bodies make but little impression upon the organs of 
sense ; many of these, especially the eye and the ear, are 
IV. State of the nervous system in old age. OF ANIMAL LIFE. 
245 
often shut to sensations before general death. The 
nerves have then but little to transmit, and the brain but 
little to perceive. As to motion, there is but little in old 
age, because but little is felt; for feeling and motion are 
two things that generally follow the same proportion. 
The brain and the nerves are almost inactive in this res- 
pect. The first is not put in action by the intellectual 
functions; memory, imagination, judgment, attention, 
Slc. all are enfeebled, none are exerted with clearness. 
Changes of structure constantly accord with these 
changes of functions. In the foetus, the brain is almost 
fluid ; in old age, it is extremely firm. This organ has 
passed through a variety of gradations between the two 
extreme ages. We know that anatomists always select 
the brain of an old person in order to study this viscus, 
all the parts of which are broken with difficulty. I would 
observe upon this subject, that what is natural at this age, 
indicates in a young person a morbid alteration. In gen- 
eral, we have not yet sufficiently studied the comparative 
anatomy of the different ages, to make applications of it 
to the examination of dead bodies. 
The vessels diminish in the brain in proportion as its 
hardness increases. In this respect it has an inverse ar- 
rangement at the two extreme ages of life. Its colour 
becomes more dull in old age. It is rare that it is ossifi- 
ed ; there are, however, some examples of it. The phe- 
nomena, that the action of different re-agents presents, 
are very much slower in taking place than in the adult 
and especially in the infant.. The solution by alkalies is 
a remarkable proof of this. 
We cannot doubt but that this organic state of the 
brain in old age, has much influence upon the preceding 
phenomena; to this must be referred the less acuteness 
of pain at this age. A cancerous tumour of an old per- 
son, exactly analogous in its position, form, size and na- 
ture to that of an adult, produces much less suffering. 246 
NERVOUS SYSTEM 
Cancers of the womb, the stomach, the breast, &c. fur- 
nish examples of this. All the local causes of pain show 
also the same thing. In the numerous experiments I 
have made upon living animals, 1 have uniformly ob- 
served, that young ones, when the sensible parts are cut, 
give signs of the most acute pain; whilst old ones show 
infinitely less expression of it under similar circumstan- 
ces. I would make one other remark upon this subject; 
it is that the variety appears in dogs, in a certain degree 
to have an influence upon the acuteness of their sensa- 
tions. All the large varieties make but little noise, and 
are not much agitated, when their skin, their nerves, &c. 
are cut; whilst all the small ones, though they may be 
old, struggle, are agitated, and manifest upon the slight- 
est cause, the most acute sensibility. 
As to the influence of age upon pain, it is not astonish- 
ing that the animal sensibility having become very ob- 
scure in a natural state, should preserve the same charac- 
ter in disease. An old person suffers then much less than 
the adult, and especially than the infant, under the influ- 
ence of the same causes; it is a compensation for the 
diminution of their enjoyments. The infant finds in 
every thing that surrounds him, a cause of pleasure or of 
pain ; thus smiles and tears succeed each other a hun- 
dred times a day upon bis little face. An old person on 
the contrary is always calm; indifference is his natural 
state. 
The nerves experience the same changes as the brain; 
they harden gradually with age; however their propor- 
tion of hardness in the first and last ages is much less re- 
markable than that of this organ ; this arises from the 
nervous coat; for the effect upon the medullary substance 
appears to be the same. This medullary substance has 
appeared to me to be less abundant in the optic nerve of 
an old person ; however it is difficult to determine the 
quantity. The colour of the nerves becomes dull, like OF ANIMAL LIFE. 
247 
that of the brain. They receive fewer vessels. They 
are never ossified. 
Sometimes we say that the extremities of the nerves 
have become callous ; it is a vague expression, to which 
no meaning can be attached. When will medical lan- 
guage cease to refer to the empty and inaccurate hypo- 
theses that formerly constituted medicine? Most of these 
hypotheses have passed away, yet the names to which 
they gave birth remain. 
The nervous system and the brain frequently lose be- 
forehand, in old people, a part of their functions; hence 
hemiplegia is almost as frequent at that age, as convul- 
sions which are its opposite, are in infancy. It is neces- 
sary to distinguish the hemiplegias of old people from 
those of adults. They are of the same nature as the 
blindness, the deafness of old people; the difference is 
only in the injury of sensation or motion. NERVOUS SYSTEM OF ORGANIC LIFE. 
GENERAL REMARKS. 
NO anatomist has yet considered thd nervous system 
of the ganglions in the point of view in which I shall pre- 
sent it. This point of view consists in describing each 
ganglion as a distinct centre, independent of the others 
in its action, furnishing or receiving particular nerves as 
the brain furnishes or receives its own, having nothing in 
common, except by anastomoses, with the other analo- 
gous organs ; so that there is this remarkable difference 
between the nervous system of animal life, and that of 
organic life, viz. that the first has a single centre, and 
that it is to the brain that every kind of sensation comes, 
and that it is from it every kind of motion goes; whilst 
in the second, there are as many little separate centres, 
and consequently little secondary nervous systems, as 
there are ganglions. 
We know that all anatomists, even those who, without 
affixing to the expression any very definite meaning, have 
called the ganglions little brains, have taken them for 
dependancies, for enlargements of the nerves, in whose 
course they are found ; and as most of them are met with 
in the great sympathetic, they have presented them as a 
distinctive character of this nerve. But from the general 
idea I have just given of the ganglions, it is evident that 
this nerve has no real existence, and that the continu- 
ous thread that is observed from the neck to the pelvis, is 250 
NERVOUS SYSTEM 
nothing but a succession of nervous communications, a 
series of branches that the ganglions placed above each 
other, send reciprocally to each other, and not a nerve 
going from the brain or the spine. 
The first considerations that induced me to think that 
the great sympathetic is not a nerve like the others, but 
a series of anastomoses, were the following. 1st. These 
communications are often interrupted, without any in- 
convenience, in the organs to which the great sympa- 
thetic goes. There arc subjects, for example, in whom 
is found a very distinct interval between the pecto- 
ral and lumbar portions of this pretended nerve, which 
seems cut in this place, becaus-e the last pectoral ganglion 
and the first lumbar do not send branches to each other. 
1 have often seen also the sympathetic nerve cease, and 
afterwards appear again between two ganglions and from 
the same cause, whether in the loins, or in the sacral re- 
gion. 2d. Every one knows that the opthalmic ganglion, 
the spheno-palatine, &c. are constantly distinct, and that 
they do not communicate by their branches except with 
the cerebral nerves. It uniformly happens that there is be- 
tween them and those of the great sympathetic, what we 
sometimes see between these last, viz. a complete deficien- 
cy of communication. 3d. In birds, as has been observed 
by Cuvier, the superior cervical ganglion is also found 
constantly distinct; it never communicates with the in- 
ferior. The filament which in quadrupeds descends the 
length of the neck, is wanting in them. In many other 
animals we frequently find interruptions in this succes- 
sion of anastomoses of ganglions, which constitute what is 
called the great sympathetic. 4th. The communications 
of the ganglions are usually made by a single branch; 
but sometimes many go from one of these organs to the 
other, so that if the great sympathetic was a nerve like 
the others, it would present, in this respect, an arrange- 
ment wholly different from that of the cerebral nervous OF ORGANIC LIFE. 
251 
system. 5th. Whence does the great sympathetic arise? 
From the sixth pair? But all the nerves diminish as they 
go from the brain towards the organs ; but this presents 
then an arrangement entirely different; it increases as it 
sends off branches. Does it arise from the spinal marrow ? 
But then the branches with*which it furnishes a region 
would come from the branches that it receives from the 
spinal marrow in this region. Thus the great and small 
splanchnic would arise from certain intercostal pairs, 
now they are evidently much larger, the first especially, 
than the sum of the branches from which they would 
derive their origin. Observe then that all anatomists 
have been of a different opinion upon the origin of the 
great sympathetic. How could they agree upon a thing 
that has no real existence ? 
These different considerations render probable the opin- 
ion that I have entertained for some time, that the great 
sympathetic nerve does not really exist, that this cord is 
but a succession of communications between little ner- 
vous systems placed above each other, and that it is not 
essential that these communications should exist, as is 
seen constantly between the ophthalmic ganglion and 
the spheno-palatine, between that and the superior cer- 
vical, of which many animals furnish examples. Then I 
began to regard each ganglion as a separate centre of a 
little nervous system, wholly different from the cerebral, 
and distinct even from the little nervous systems of the 
other ganglions. By considering the functions of the 
nerves going from these centres, I became more and more 
convinced that they did not belong to the cerebral sys- 
tem, In fact, these nerves have properties very different 
from theirs, as we shall see; they do not serve for sensa- 
tions ; they have uniformly no connexion with voluntary 
locomotion; we see them only in the organs of internal 
life ; hence why they are found concentrated in the trunk, 
in the thorax and abdomen particularly; why they are 252 
NERVOUS SYSTEM 
not met with in the head, where almost all the organs be- 
long to animal life; why they are not seen in the ex- 
tremities, which are exclusively dependant upon this life. 
Distributed almost every where to the organs of the 
internal life, the ganglions and their nerves derive their 
character from it; and this is it. 1st. They are not 
symmetrical; thus the nerves of all the plexuses of the 
abdomen, those of the cardiacs, &c. have a remarkable 
irregularity. 2d. There are numberless varieties in the 
form of these plexuses and in that of the ganglions; it 
is thus that, sometimes lenticular, sometimes triangular, 
sometimes divided into many portions, that which is under 
the diaphragm is never seen twice alike. Hence the 
error of every name derived from the figure; a remark 
that is applicable generally to the organs of internal life. 
We might rather borrow the names of forms for animal 
life in which these forms are more invariable. On the 
other hand, the existence of many ganglions varies; 
sometimes there are three of them in the neck, at others 
but two. The arrangement of one side does not produce 
a similar one on the other. I have frequently remarked 
that the number of filaments arising from the superior 
cervical ganglion differs very much from those that take 
their origin from the opposite side. There are two analo- 
gous organs at each side ; but several attributes of struc- 
ture destroy the general character of symmetry ; it is 
like the lungs and the kidnies. We can, then, establish 
as a distinctive character between the two nervous sys- 
tems, the symmetry of one and the irregularity of the 
other; now, this character is one of those which distin- 
guish the two lives, as I have remarked before. 
From all this it is evident that a line of demarcation 
separates the nerves of the ganglions and those of the 
brain, and that the method is inaccurate which considers 
them as forming a single nerve, arising by some origin 
from this last. Their communications no more prove it OF ORGANIC LIFE. 
253 
to be a general nerve, than the branches which pass from 
each of the cervical, lumbar, or sacral pairs, to the two 
pairs that are superior or inferior to it. Notwithstanding 
these communications, we consider each pair in a sepa- 
rate manner, and not as one nerve by their union. So 
that each ganglion should be described separately, not- 
withstanding the branches it sends to others. 
The description of the system of the ganglions should 
be analogous to that of the cerebral nerves. For exam- 
ple, I describe first the lenticular ganglion, as was done 
for the brain ; then I examine its branches, among which 
is found the great splanchnic ; for it is very improper to 
say that this nerve gives origin to this ganglion. The 
same in the neck, in the head, &c. each ganglion is first 
described; then I treat of its branches, among which are 
found those of communication. There are, then, almost 
as many descriptions as there are separate ganglions. 
For example, we ought not to treat of the ophthalmic 
nerve with the common motor; to be convinced of this, 
it is sufficient to see how much the ciliary nerves differ 
from the others, which, belonging to animal life, are also 
contained in the orbit. 
From all that has been said, it is evident that there 
are two things to be examined in the nervous system of 
organic life, 1st. the ganglions; 2d. the nerves that go 
from them. 
ARTICLE FIRST. 
OF THE GANGLIONS. 
The ganglions are little reddish or greyish bodies, 
situated in different parts of the body, and forming so 
many centres, from which goes an infinite number of 
I. Situation, forms, relations, <^c. 254 
NERVOUS SYSTEM 
nervous ramifications. Their position most generally is 
along the vertebral column, where are seen succes- 
sively below each other, the superior and inferior cervi- 
cal, the intercostal, the lumbar, and the sacral. It is 
these especially whose communicating branches form the 
great sympathetic. But besides these ganglions, which 
are placed as it were in a row, we find many separate 
ones in different parts, as the ophthalmics, the spheno- 
palatines, the maxillaries in the head, as also the semi- 
lunars in the abdomen. In the thorax there are none 
thus separate; though sometimes we see a small one at 
the base of the heart. 
Besides the ganglions uniformly seen, there are often 
accidental ones, if we may so say; such are those that 
are sometimes found in the hypogastric plexus, in the 
solar even, at some distance from the semilunar, in the 
middle part of the neck, &c. On the other hand, some 
of those that are usually met with are oftentimes not 
found, as some of the lumbar, sacral, maxillary, &c.; so 
that it appears that there is really an essential difference 
between the ganglions under the relation of existence. 
The superior cervical, the semilunar, the ophthalmic, &c. 
are always found ; they appear to be essentially neces- 
sary to the action of the organs to which they furnish 
nerves. Most of the others may be wanting on the con- 
trary, and be supplied by those of the neighbouring 
ones, or by others formed not in the ordinary anatomical 
order. 
All the ganglions are generally in a deep situation. 
Destitute of a bony covering analogous to that of the 
brain, they are not less powerfully protected against the 
action of external bodies. It is this deep position, that 
prevents us from making experiments upon almost all of 
them, from making those at least which require that the 
animal should live a certain time after they have been 
made. It is this which will undoubtedly keep up for a OF ORGANIC LIFE. 
255 
length of time the obscurity that hangs over the functions 
of these organs. 
The form of the ganglions is extremely irregular. In 
general they are round ; but sometimes they are long, as 
the superior cervical; sometimes the ganglion is a species 
of triangular body, with obtuse and round ends, as the 
ophthalmic; sometimes the form is semilunar, like that 
which has this name, &c. Generally these forms are 
very variable, as I have said ; the most uniform is that of 
the superior cervical. 
Embedded in a quantity of cellular texture, all the 
ganglions are separated by it from the neighbouring or- 
gans. Almost all of them are so disposed, that they ex- 
perience but little motion from these organs, and cannot 
receive it from any of the vessels that enter them. 
Those situated along the vertebral column especially, 
present this phenomenon, very different from that which 
takes place at the brain, whose functions are essentially 
connected with the constant agitation that the blood im- 
parts to it, and very different from that which we observe 
in the plexuses of nerves coming from these same gan- 
glions. 
II. Organization. 
The ganglions have generally in the adult a reddish 
colour very different from that of the nerves ; sometimes 
they are greyish. When opened, they present a soft, 
spongy texture, resembling considerably at first view that 
of the pretended lymphatic glands. 
This texture has nothing in common with the cerebral 
substance, nor with that which occupies the canal of the 
nervous coat. These two last should rather be ranked in 
the class of fluids, as I have said ; their substance is a pulp, 
a real jelly. Thus thejr have not any of the properties of 
solids. They do not harden like horn ; the kind of har- 
dening, the result of the contact of alkohol, of the acids, 256 
NERVOUS SYSTEM 
and of caloric, is wholly different from the horny harden- 
ing. It is analogous to the hardening of the white of an 
egg. On the contrary, the texture of the ganglions har- 
dens like horn in an evident manner, a phenomenon 
which is characteristic of all the solids, except the epi- 
dermis, the nails, and the hair, which make a separate 
class. Treated by the acids, the ganglions, after wrink- 
ling, hardening like horn and hardening gradually, soften 
and become fluid. 
Boiling produces a phenomenon nearly analogous ; 1st. 
horny hardening and hardening at the instant the water 
boils; 2d. continuance of this state for half an hour; 3d. 
softening gradually brought on ; when this last is com- 
plete, the effect of the boiling is finished. In this state, 
the ganglions arc all different from the nerves submitted 
to the same experiment. I have observed also in veal, 
that they have a very different taste from that of the 
nerves, a method of research which should not be neg- 
lected in attempting to ascertain the difference of the 
nature of the organs. In fact, as we do not yet know 
the difference of the principles which enter into the 
composition of each, we should be satisfied with the dif- 
ference of the qualities. 
The alkalies act a little upon the ganglions, which 
they tend to dissolve, and which they do partly dissolve, 
if they are very caustic. But this solution is infinitely 
less prompt and less easy than that of the cerebral pulp 
by the same re-agents. The ganglions resist putrefaction 
as much and even more than the nerves; this forms also 
a very remarkable difference between them and the cere- 
bral substance. In general, we cannot establish any kind 
of analogy between them. 
The texture of the ganglions appears in nowise fibrous; 
there is absolutely no linear, filamentous appearance, &c. 
upon simple inspection. Homogeneous, if we may so 
say, in its nature, it presents every where an uniform OF ORGANIC LIFE. 
257 
aspect when cut in slices. However the celebrated 
Scarpa has considered the ganglions as resulting from a 
kind of expansion of the nerves, into an infinite number 
of extremely delicate fibres, which interlace with each 
other, and which become very distinct by maceration. 
I have not repeated all his experiments, which appear to 
me extremely difficult. I refer then to his work, and to 
the plates it contains. I would observe only that there 
is certainly something else in the ganglions, besides a 
simple division of the nerve into extremely fine threads. 
In fact, mere inspection is sufficient to establish between 
them the greatest difference. There is as evident a de- 
marcation between the ganglions and the nerves, as be- 
tween those of the brain and the brain itself. 1st. Dif- 
ference of colour, reddish or greyish tinge in some, white 
in others ; 2d. difference of consistence, of external quali- 
ties, &c.; 3d. difference of properties. If the nerves 
coming from the spinal marrow make only an expansion, 
in their passage, in the ganglions, by delicate filaments, 
there would then be only a difference of form and not of 
nature; the properties would be the same. Why then 
are they so different as I shall prove hereafter? Why, as 
a nerve goes from a ganglion, does it not communicate 
more voluntary motions? 4th. Why has not nature placed 
ganglions in the nerves of the extremities as in those of 
the other parts ? If there is only a division of the nerve 
into finer filaments, in the ganglion, why is there not a 
proportion between the filaments that enter on one side, 
and those that go out at the opposite ? In fact, those that 
enter into the superior cervical above, if they only ex- 
panded their filaments in this ganglion, and united after- 
wards to form those that go off below, would be equal in 
respect to size to those that go from it; all the ganglions 
would exhibit this constant relation between the nerves 
of one side and those of the opposite; now, it is sufficient 
to examine them to be convinced that an inverse arrange- 258 
NERVOUS SYSTEM 
ment exists. 6th. The ganglions ought always to be in 
proportion to the size of the nerves which form them by 
spreading their fibres. Why then are the intercostal 
ganglions so small, and the trunks that unite them, or 
rather that give origin to them and which go from them 
afterwards as we see in the usual manner, so large ? Why 
on the contrary, is the superior cervical ganglion so large, 
and its branches so small ? 7th. How can be explained 
the frequent interruptions between the ganglions in man, 
which are constant in many animals, if there is a continu- 
ity between the nervous filaments that enter the ganglions 
above, and those that go from them below ? 8th. How 
does it happen that the ganglions and their nerves do not 
follow an exact proportion as to development with the 
cerebral nerves, if these form them by expanding ? 9th. 
Why has not pain the same character in each species of 
nerves ? 
I have no opinion as to the nature or the functions of 
the ganglions, because I have no fact to support me; but 
there is certainly something more in their texture, than a 
mere expansion of nervous filaments. Scarpa admits a 
peculiar matter which separates these filaments; but 
this substance ought to predominate considerably, as the 
ganglion surpasses in size the nerves which are thought 
to give origin to it. Now I have never seen this sub- 
stance ; I do not know what it is; all is solid when the 
ganglion is cut. I think then by admitting, even to a 
certain extent, the internal arrangement that this author 
has observed in the ganglions, we cannot describe these 
organs in the point of view in which he has presented 
them. 
We know hut little of the alterations that diseases pro- 
duce in the texture of the ganglions. I have already 
many times examined in diseases of the heart, of the liver, 
of the stomach, the intestines, the ganglions that send 
nerves to these viscera; they have never appeared to OF ORGANIC LIFE. 
259 
me to have undergone any change. In cancers of the sto* 
mach in the very last stage, in which all the cellular tex- 
ture is engorged, and in which all the lymphatic glands 
are considerably swelled, I have always found the semi- 
lunar ganglion untouched, except however in one case 
where it was enlarged and its density a little increased. 
At another time I found this same ganglion of the size of 
a small nut, with a cartilaginous substance in its centre, 
resembling the stone of it, in the body of a man brought 
to the Hotel Dieu on account of periodical mania. Some 
authors have thought, and I suspect the same thing also, 
that the hysteric paroxysms, which begin by a contrac- 
tion at the epigastric region, and in which the patient 
feels a ball mount up even to the throat, arise from some 
affections of the semi-lunar ganglions, from the solar 
plexus and the communications which go from ganglion 
to ganglion, even to the neck. However two bodies that 
I have opened lately, exhibited no alteration, though dur- 
ing life the subjects had been frequently attacked with 
these paroxysms; but they may arise evidently from the 
ganglions and the epigastric plexuses, without their being 
altered in their structure, as a number of cerebral affec- 
tions leave after them no trace in the brain. This 
point deserves particular examination. 
It does not appear that the texture of the ganglions is 
surrounded by a peculiar membrane. The cellular tex- 
ture is only condensed in their neighbourhood; it then 
becomes very consistent, and much contracted around 
them. It there has the nature of the sub-mucous, the 
sub-arterial textures, &c.; it never contains fat. There 
is then truly around the ganglions, as around the arteries, 
under the mucous surfaces, &c. the two kinds of cellular 
texture of which we have spoken in treating of the or- 
ganization of this texture, and which differ so essentially 
from each other in their nature, and even in their prop- 
erties. It is the second kind, which is analogous to the 260 
NERVOUS SYSTEM 
sub-arterial texture, &c. which forms the peculiar mem- 
brane admitted by some authors. 
By examining attentively the interior of the ganglions, 
we see that there is but very little cellular texture there. 
I have found this texture constantly destitute of fat; thus 
the alkalies do not form a saponaceous deposit upon 
them, as upon the cerebral nerves when plunged in their 
solution. I have examined many ganglions in this way, 
on account of the opinion of Scarpa, who believes that 
these organs are penetrated with this fluid, at least in fat 
people. 
The ganglions receive many blood vessels. These 
penetrate them from all sides, run first in a kind of cellu- 
lar covering that surrounds them, then entering their tex- 
ture, ramify and are lost there in numerous anastomoses, 
and in continuation with the exhalants that carry nutri- 
tive matter. Fine injections show a great quantity of 
vessels in these little organs. Nutrition supposes exha- 
lants and absorbents there. 
111. Properties. 
It is difficult to analyze the properties of texture in the 
ganglions. As to vital properties, they cannot grow, live 
and be nourished without organic sensibility, and without 
insensible contractility of the same kind. Animal and 
sensible organic contractility do not exist there evidently. 
As to animal sensibility I have observed the following 
circumstance. As in opening the abdomen of an animal, 
of a dog, for example, he lives very well for some time, 
and remains even calm after the first moments of suffer- 
ing ; 1 have waited for this calm that succeeds the agita- 
tion arising from the incision of the abdominal parietes, 
then laid the semi-lunar ganglion bare, and irritated it 
powerfully; the animal is not agitated, whilst when I ex- 
cite a cerebral lumbar nerve, for comparison, he cries 
out, raises himself up and struggles. In general it ap- OF ORGANIC LIFE. 
261 
pears that the sensibility of the ganglions is infinitely less 
evident than that of many other organs. Certainly the 
skin, the mucous system, the medullary, the nervous of 
animal life, &c. surpass it in this respect. 
Our ignorance as to the diseases that have their seat 
in the ganglions, the distance of those organs from exter- 
nal excitement, prevent our having any data as to their 
sympathies. I think it very probable, however, that 
these sympathies take a real part in hysteria, in certain 
kinds of epilepsy, the paroxysms of which begin, like 
those of hysteria, by a painful sensation at the epigastric 
region, in that multitude of affections called nervous, and 
which the vulgar confound under the name of vapours. 
One of the most important objects of research in the neu- 
roses, is to determine those that have their particular seat 
in the nervous cerebral system and those which affect 
more particularly the system of the ganglions. Place on 
one side, palsy, hemiplegia, convulsions of infants, tetanus, 
catalepsy, apoplexy, the greatest part of epilepsies, all the 
numerous accidents that arise from engorgements, from 
compressions of the brain from wounds of the head, ner- 
vous affections of the sight, hearing, taste, smell, &c. and 
all the diseases the source of which is evidently in the 
head; on the other place hysteria, hypochondriasis, mel- 
ancholia and all that numerous class of affections in which 
the abdomen and the thorax, the first especially, seem to 
be the spot in which the evil is seated; you will see that 
there is an essential difference and that the symptoms 
have entirely a different character. 1 do not say that 
the last kind of nervous diseases affect exclusively the 
ganglions ; for too much obscurity hangs over these affec- 
tions to pronounce any thing positive as to their seat, or 
their nature. Undoubtedly even the secretory, circula- 
ting, pulmonary organs, &,c. can be then particularly af- 
fected in their peculiar texture and independently of the 
nerves they receive; but certainly it is an interesting sub- 262 
NERVOUS SYSTEM 
ject of research, and there is too great a difference in 
the phenomena of the two orders of affections, not to pre- 
sent differences in their primitive seat. It is difficult to 
conceive that the system of the ganglions has not a great 
part in the last order. 
That which induces me to think that the difference 
of the phenomena that the general order of neuroses 
presents us, arises particularly from the difference of the 
cerebral nerves and of those of the ganglions, is that their 
phenomena in a state of health are very different. Halle 
has observed very well that the pains that are expe- 
rienced in the parts in which the nerves coming from 
the ganglions are distributed, have a peculiar character, 
and that they do not resemble those that are felt in the 
parts where the cerebral nerves are sent. Thus the 
painful sensation that is experienced at the loins in affec- 
tions of the womb, by vinous injection made into the tu- 
nica vaginalis, &c. a sensation that appears to me to arise 
from the sympathetic influence exercised by the organ 
affected upon the lumbar ganglions, the pains of the intes- 
tines, the burnings at the epigastric region, &c. &,c. do 
not resemble pains of the external parts ; they are deep, 
and go to the heart, as we often say. We know that 
there are colics essentially nervous, which are certainly 
independent of every local affection of the serous, mu- 
cous, and muscular systems of the intestines. These 
colics are evidently seated in the nerves of the semi-lunar 
ganglions, which are spread along the whole course of 
the abdominal arteries. They are real neuralgias of the 
nervous system of organic life; now these neuralgias 
have absolutely nothing in common with the tic doulou- 
reux, sciatica, and other neuralgias of the nervous system 
of animal life. The symptoms, the progress, the dura- 
tion, &c. every thing is different in these two kinds of 
affections. OF ORGANIC LIFE. 
263 
What I have just said upon the injuries of sensation, 
applies also to those of motion. No kind of comparison 
can be made between the convulsions of the muscles that 
receive the nerves of animal life, and the spasmodic and 
irregular motions which arise in all the muscles that re- 
ceive nerves from the ganglions. Nothing resembles 
tetanus in the heart, the intestines, the bladder, &c. 
All these considerations establish striking differences 
between the cerebral nerves and those of the ganglions; 
differences upon which I can only present approxima- 
tions, as we have no data as to the functions of the last. 
IV. Development. 
The ganglions differ essentially from the brain in the 
early periods in their development, which is proportion- 
ably much less advanced than that of the brain. They 
are only on a level with all the other organs, whilst this 
is infinitely superior to them in this respect, as we have 
seen. By comparing the superior cervical, semilunar 
ganglions, &c. in the foetus, and in the adult, it is easy to 
make this remark. The ganglions receive also less ves- 
sels in proportion than the brain. They do not follow 
the proportion of increase of the organs to which they 
send nerves. Thus those that furnish the genital organs, 
which are nearly7, nothing during the first years of general 
nutrition, are as large in proportion as those which go to 
the liver, the stomach, the intestines, which are charac- 
terized by an early increase. These nerves follow in 
this respect the same law as the ganglions, though the 
most are found upon the arteries, which are more or less 
developed according to the organs they penetrate. 
The nervous system of organic life being less early in 
its development than that of animal life, should be sub- 
ject in infancy to fewer affections; and this is what is ob- 
served. Convulsions, and most of the neuroses of the 
second, are, as we have seen, a peculiar appendage upon 264 
NERVOUS SYSTEM 
infancy. On the other hand, the particular order of ner- 
vous affections of which we have spoken, and in which it 
appears that the first takes the principal part, is generally 
less frequent at this period. All nervous diseases, whose 
peculiar seat seems to be at the epigastric region, in which 
there is so great an abundance of nerves coming from the 
ganglions, appear to be foreign to this age. 
Another difference that distinguishes the ganglions 
from the brain as it respects development, is this, that in 
the foetus, they are not, like it, of extreme softness. Their 
hardness is little inferior to what they afterwards possess 
in adult age. 
In proportion as we advance from infancy, the organic 
nervous system begins to become predominant. It is 
towards the thirtieth or fortieth year that it appears at 
its maximum of action ; it diminishes as we approach old 
age; it decays in part at this epoch. The nerves be- 
come greyish; the ganglions are hard, resisting and 
smaller. The neuroses that appear to belong to them are 
infinitely more rare. Moreover, the obscurity that rests 
upon the functions of this system, does not allow me to 
point out definitely the alterations they experience in the 
different ages. 
V. Remarks upon the vertebral ganglions. 
In all that I have said thus far upon the ganglions, I 
have not noticed those which correspond with the fora- 
mina through which the nerves pass, and which some call 
simple ganglions. We know that at the instant each 
nerve goes from each of these foramina, it exhibits an 
evident enlargement, reddish, pulpy, analogous in its ap- 
pearance to most of the ganglions. I confess, that I 
know not how to class these organs. We cannot deny 
that they have the greatest analogy in structure to the 
others. They are approximated in another respect, 
which is this, that the nerves, in going from them, form OF ORGANIC LIFE. 
265 
almost immediately plexuses that we have designated 
under the names of cervical, brachial, lumbar, and sacral, 
in the same way as the solar, cardiac, mesenteric plex- 
uses, &c. are formed by the nerves of organic life, at the 
moment they go from their respective ganglions. How- 
ever, these last nerves are conductors of very different 
properties. Irritate in a living animal the superior cer- 
vical ganglion, the inferior even, which is more difficult, 
though it may be come at, the muscles to which they 
send nerves will remain unmoved; the same phenomenon 
takes place by exciting the nerves themselves. On the 
contrary, every irritation of a filament coming from the 
vertebral ganglions, produces immediately convulsions in 
the corresponding muscles. The sensibility is entirely 
different in the two species of nerves. Besides, there 
is no analogy between the manner in which the nerves 
go in all directions from the vertebral ganglions, and that 
in which the other ganglions furnish theirs. In the ex- 
pectation that further experiments may elucidate the sub- 
ject, let us content ourselves with pointing out what is 
the result of accurate observation. 
ARTICLE SECOND. 
OF THE NERVES OF ORGANIC LIFE. 
I. Origin. 
Each ganglion is, as we have seen, a centre from which 
go in different directions, various branches, the whole of 
which form a kind of little separate nervous system. 
The manner of the origin of these branches has but very 
little relation with that of the branches of the brain and 
of the spinal marrow. The following are some differences 
that distinguish it. 266 
NERVOUS SYSTEM 
1st. The adhesion is much stronger; the nerve breaks 
any where else rather than at its origin; the opposite of 
this takes place in the preceding system. 2d. It does not 
appear that the substance of the ganglion is continued 
in the nerve to form the medullary substance of it, since 
the organization of the one and the other is very differ- 
ent. Sometimes, however, the ganglion is continued for 
a short distance in the form of a cord. This happens es- 
pecially in the superior cervical, in the lumbar, the semi- 
lunar, &c. Then the form only is different; but it is 
easy at the first view to distinguish where the ganglion 
ends and the nerve begins. 3d. This beginning is made 
in a sudden manner; it is like a muscle implanted in a 
tendon. The best manner of seeing this arrangement to 
advantage is to cut longitudinally the superior cervical 
ganglion and the cord it sends to the inferior; the change 
of nature of the one and the other is then very apparent; 
or, if we consider the ganglion as a division of the numer- 
ous filaments of the nervous cords, we distinguish very 
well the sudden change that these filaments experience in 
passing from the cord to the nerve. 4th. The dense 
cellular covering that surrounds the ganglion is continued 
upon the nervous origin, and gives it an increase of con- 
sistence at that place. This must be carefully raised be- 
fore we come to the nerve. We see then each distinct 
filament arising from the ganglion. After it has gone 
from it, sometimes it remains separate ; this takes place 
at the semi-lunar, the lumbar, the opthalmic, whose elon- 
gations are of great delicacy. Sometimes many of these 
filaments unite together and form a cord as between the 
two cervical, as at the great and small splanchnic nerves, 
&, c. 
I have not been able by maceration, ebullition, or the 
action of the acids to destroy the adhesion of the nerve 
with the ganglion, as we destroy that of the muscle with 
the tendon, of this with the bone, &c. OF ORGANIC LIFE. 
267 
II. Course, Termination, Plexuses. 
The nerves after going from the ganglions, are distri- 
buted in many different ways which we shall now ex- 
amine. 
1st. There are always some which go immediately to 
communicate with the system of animal life. The oph- 
thalmic ganglion sends branches to the motores com- 
munes, and to the nasal nerve. The spheno-palatine 
communicates with the superior maxillary nerve; the 
superior cervical with all the nerves that surround it, viz. 
above with the motor externus, within with the great 
hypoglossal, the par vagum, the glosso-pharyngeal, the 
spinal, &c.; behind with the first cervical pairs. All 
the ganglions situated above each other along the verte- 
bral column, send communications through each pair of 
foramina that correspond with them. The par vagum 
communicates with the semi-lunar, &c. It is not then 
any separate ganglion of the nerves of animal life ; hence 
the common expression that designates each ganglion as 
arising from this or that pair, or being found in its course, 
is very inaccurate. Thus the opthalmic is by no means 
in the course of the common motor nerve. The one and 
the other send each a branch, which unites; or rather 
there is a branch of communication between the ganglion 
and the cerebral nerve. In general all these branches of 
communication with the system of animal life, are short, 
whitish, and of the same nature, or at least of the same 
appearance as the nerves of this last. They do not form 
any plexus in their course, rarely furnish branches, and 
appear to have no other use than that of establishing 
anastomoses between the two systems. 
2d. Each ganglion sends above and below-branches to 
the two ganglions that are contiguous to it. We have 
seen that the opthalmic and the spheno-palatine are ex- 
ceptions to this rule. Sometimes also, as I have said, 268 
NERVOUS SYSTEM 
there are interruptions in other regions. Notwithstand- 
ing this, these general communications make us regard 
the ganglions as being connected every where, and able to 
receive from each other the different affections of which 
they can be primitively the separate seat. These 
branches of communication are straight as in the preced- 
ing, sometimes very fine, as between the lumbar and sacral 
ganglions, at other times larger, as that which is between 
the two cervical, superior and inferior, in some cases very 
large, as the great splanchnic, which is a real trunk of 
communication between the intercostals and the semi- 
lunar. The nerves that we are now considering, the last 
especially, have like the preceding, an arrangement ex- 
actly analogous to the cerebral nerves; they are formed 
of whitish cords, which are the result of filaments. The 
eye discovers no difference between them. 
3d. Many filaments coming from ganglions, go to cer- 
tain cerebral muscles, as to the diaphragm, some of those 
of the neck, &c.; others go to neighbouring organs 
only. 
4th. The greatest number going from the ganglions in 
separate filaments, interlace in the form of a plexus with 
those of the contiguous ganglions, in the neighbourhood of, 
or upon the great vessels. The most remarkable plexus is 
the solar, composed by the innumerable branches that 
come from the semi-lunar; then we see the hypogastric, 
the cardiac, &c. The greater number of these plexuses 
are not exclusively formed by the nerves of organic life; 
those of the animal give some to them also, as the par 
vagum furnishes an example for the solar and the cardiac, 
as the sacral nerves afford another for the hypogastric, &c. 
However the nerves of organic life always predominate 
in these plexuses. There is only the pulmonary in which 
the par vagum particularly predominates, whilst the 
nerves coming from the inferior cervical ganglion are, if 
we may so say, but accessory. OF ORGANIC LIFE. 
269 
The primitive plexuses resulting from the interlacing 
of the organic nerves at their exit from the ganglions, 
form a mass of irregular nerves, buried in the cellular 
texture, accommodated to the forms of the neighbouring 
organs, and wholly different from those of animal life, as 
of the brachial, the lumbar, &,c. 
In fact, the filaments at every instant, not only place 
themselves as in the preceding ones, at the side of each 
other, at every change of position; but their extremities 
continue; they interlace with each other, change at every 
point the direction, form networks, and mix so together, 
that it is not possible to distinguish any thing except a 
thousand nerves, that we might say grew up under the 
cloth with which we wiped the place where the plexus 
was found. 
These organs are remarkable for their reddish or 
greyish colour, for their softness, for their indistinctness, 
&c.; it is often difficult to distinguish them from cellular 
texture. The best manner of making them evident is to 
let the subject macerate for a day or two open in the 
water; they whiten then sensibly, do not soften, and ap- 
pear even to increase in consistence, like the cerebral 
nerves in a similar case. Besides their delicacy is such, 
that it is impossible to submit them to any kind of re- 
agents. Only 1 have observed that they possess in an 
eminent degree the property of horny hardening, and 
that they do not yield in this respect to the cerebral. 
This delicacy depends upon this, that all the filaments are 
separate from each other, instead of being like the pre- 
ceding, collected into cords; it is this also that makes 
these nerves so numerous. If all the filaments of the 
brachial plexus were separated like those of the solar, 
they would present the same appearance and the same 
number in their interlacing. 
Do the primitive plexuses formed by the ganglions per- 
form a part in the nervous functions ? are they centres to 270 
NERVOUS SYSTEM 
which are referred important phenomena? What has not 
been said upon this subject, concerning the solar plexus ? 
But nothing, I believe, of all that has been advanced is 
founded upon accurate observation. 
The plexuses of organic life are soon separated into 
different divisions, which go to different parts, to those 
especially of this life. These divisions arise from an 
infinite number of little filaments which go constantly 
separate, though placed near each other, and which never 
unite into cords like the preceding. They accompany 
almost all the arteries; thus the renal, the hepatic, the 
splenic, the coronary stomachic, the mesenteries, the 
hypogastric, the carotid and its distributions, &c. are sur- 
rounded with filaments coming from ganglions. These 
filaments go in two ways. 1st. Some accompany the ar- 
tery without being connected with it; considerable cellu- 
lar texture separates them; they go in its course without 
intermixing in a sensible manner with it. 2d. The others 
form for it, if we may so say, a new coat, exterior to the 
others, which adhere to it intimately, and which interlace 
so together, that they might be taken for a network sur- 
rounding the artery. 
When the artery runs but a short course, these two 
orders of branches remain distinct from each other as far 
as the organ, as we see around the splenic, the hepatic, 
the renal, &c.; but if the course is longer, the external 
branches gradually get into the plexus, and are entirely 
lost there. This plexus can be followed upon the great 
trunks; it divides upon each branch, and can be still 
seen; but such is its tenuity upon the minute ramifica- 
tions that it disappears there entirely. The spermatic is 
one of the arteries upon which it can be traced the long- 
est. The arteries of the extremities appear to be desti- 
tute of it. In general it is upon those that go to the cen- 
tral organs of internal life, that this network is the most 
evident. When we deduct from the sum of the filaments OF ORGANIC LIFE. 
271 
coming from the ganglions, those by which they com- 
municate on one part with each other, and on the other 
with the nerves of animal life, we see that almost all the 
rest is finally destined to accompany the arteries. This 
arrangement is wholly different from that of the cerebral 
nerves, whose filaments are only in apposition with the 
vessels. These make almost an integrant part of them, 
the adhesion is so intimate; this certainly supposes a use 
of which we are ignorant, relative to the circulation, or 
to the other organic functions. As these vessels distri- 
bute every where the materials of these functions, of the 
secretions, exhalations, nutrition, &c. the organic nerves 
have no doubt some influence upon them. Neither ex- 
periment or observation have taught us any thing upon 
this point. 
The veins are not accompanied by so many organic 
nerves. It is the same as it respects the absorbent 
trunks, which go almost every where separate from this 
system. 
The constant union of the arteries with the organic 
plexuses, an union that presents an arrangement wholly 
different from that of the ganglions, has undoubtedly an 
influence upon the action of these plexuses, or rather 
upon that of the nerves that go from them, by the mo- 
tion the blood communicates to them. It should be re- 
marked upon this subject, that as nature has placed a 
crowd of arteries at the base of the brain to agitate it 
with an alternate motion, she has put also the most con- 
siderable plexus of the whole organic system upon one 
of the places to which the red blood communicates the 
strongest impulse, viz. upon the trunk of the cceliac. 
111. Structure, Properties, fyc. 
From what has been said above, it is evident that the 
nerves going from the ganglions are of two sorts as it res- 
pects organization; 1st. those that are identified with 272 
NERVOUS SYSTEM 
the cerebral system, by their white colour, by the possi- 
bility of dividing their trunks into distinct cords, and 
these into filaments, which appear to have nervous coats 
and medullary substance like the preceding; 2d. those 
which present only little separate filaments, greyish or 
reddish, soft, and which are seen in prodigious numbers 
in the plexuses. Have these a nervous coat and a me- 
dullary substance? It is impossible to determine it. 
The properties of texture are ascertained with diffi- 
culty in the organic nerves. As to vital properties, it is 
undoubted that the animal sensibility is not as much 
raised in these nerves as in those of animal life. 1 have 
often laid bare the plexuses in the abdomen ; then by let- 
ting the animal rest a moment, and by irritating them 
comparatively with the lumbar nerves, I have uniformly 
made this remark. We know that very frequently the 
ligature of the spermatic artery is not painful in sarco- 
cele, though the branches coming from the ganglions 
form for it a plexus like a network, which.can in no way 
be separated from it. If we draw out a portion of intes- 
tines by a small wound in the abdomen, the irritation of 
the sub-mucous layer at the side of the vessels, is hardly 
felt, though many nerves of ganglions are found at this 
place. I have had numerous occasions to act in different 
ways upon the carotid, to which the superior cervical 
ganglion furnishes branches from above ; now, as long as 
I did not touch the par vagum, the animal remained tran- 
quil. I am far, however, from believing in the absolute 
insensibility of the nerves of the ganglions ; but certainly 
under the circumstances that 1 have related, the cerebral 
nerves would have caused much more pain to the animal. 
I think that in a morbid state this sensibility is suscep- 
tible of being greatly raised. We certainly cannot deny 
but that the solar plexus takes a great part in the differ- 
ent sensations that are experienced at the epigastric re- 
gion; the very acute pains that often attend the forma- OF ORGANIC LIFE. 
273 
tion of aneurisms, are probably owing in part to the dis- 
tension of the nervous filaments that surround the artery. 
I have already said that it is probable that the organic 
nerves are much concerned in the different sensations 
that are produced by some peculiar neuroses. 
These nerves occasion evident sympathies in certain 
cases. It is to this that must be referred the different af- 
fections that Petit de Namur has produced in the organ 
of sight, by irritating their branches that are accessible. 
The development of the nerves of the ganglions follows 
nearly the same law's as that of those organs from which 
they emanate. 
Let us observe in finishing this system, that there is no 
one that ought to arrest the attention of physiologists 
more. All the others present a series of phenomena al- 
ready well known. Of this, we have hardly any know- 
ledge. It does not present as yet, if we may so say, but 
some of the negative attributes of the nervous system of 
animal life. Thus it is w ithout doubt that the organic 
nerves do not have the same part as the preceding in ani- 
mal sensibility ; that they are always foreign to contrac- 
tility of the same species ; that they have no direct influ- 
ence upon the sensible organic, since as we shall see, wre 
can cut or irritate them without destroying or hastening 
the motion of the muscles to which they go. But in 
knowing the parts they do not perform we are ignorant of 
those to which they are really destined. I have already 
observed that the difficulty of making experiments upon 
the ganglions and the plexuses, will much retard the pro- 
gress of science. We have scarcely any branches upon 
the exterior upon which we can act. 
Scarpa has collected the opinions of all who have pre- 
ceded him, together with his own, upon the uses of the 
ganglions. I refer to what he has said upon this subject. 
As the general point of view in which he has presented 
these organs, and that in which I offer them here, differ 274 
NERVOUS SYSTEM OF ORGANIC LIFE. 
essentially, the account that I have just given of the 
nerves of organic life has necessarily a general stamp 
wholly different from that of his work, a work, however, 
which, like all this author has published, confers the 
greatest honour upon the state of anatomy at the period 
in which we live. 
I will terminate this article by an important reflection. 
If the nerves were only divided to form the ganglions, if 
these presented in their interior only differences of 
forms, and a very minute division of their filaments, why 
should they be so Constantin animals? Many organs 
are wanting, vary, are presented under a thousand vari- 
ous forms in their different classes; on the contrary, the 
ganglions are constant. In those species even in which 
the cerebral system is imperfect, that of the ganglions is 
complete in its organization. Animal life diminishes and 
is contracted in an evident manner in most insects, in 
worms, &c. and generally in animals without verterbrae. 
The brain and the nerves become less evidently marked 
in proportion as this life is less perfect. The organic is, 
on the contrary, almost in its perfection in these animals. 
The ganglions and their nerves are also very evident. 
This remark has struck me in reading the researches of 
different authors upon the anatomy of the lower classes 
of animals ; now, if the ganglions were not the centres of 
certain important functions of which we are ignorant, 
would they be so invariable in the animal organization ? VASCULAR SYSTEM 
WITH RED BLOOD. 
ARTICLE FIRST. 
GENERAL REMARKS UrON THE CIRCULATION. 
ALL authors have considered the circulation in the 
same way, since the celebrated discovery of Harvey. 
They have divided this function into two ; one has been 
called the great circulation, the other, the small or pul- 
monary. The heart, being between the two, is their 
common centre. But in presenting in this point of view 
the course of the blood, it is difficult at first sight to per- 
ceive the general object of its course in our organs. The 
method in which I explain in my lectures this important 
phenomenon of the living economy, appears to me infi- 
nitely better calculated to give a great idea of it. 
I. Division of the circulation. 
I divide the circulation also into two ; one carries the 
blood from the lungs to all the parts; the other brings it 
from all parts to the lungs. The first is the circulation of 
red blood, the second that of black. 276 
VASCULAR SYSTEM 
Circulation of red blood. 
The circulation of the red blood commences in the 
capillary system of the lungs, where the blood acquires, 
by the mixture of the principles that it draws from the 
air,* the peculiar character that distinguishes it from the 
black blood. From this system it passes into the first 
divisions, then into the trunks of the pulmonary veins ; 
these pour it into the left auricle of the heart, which 
transmits it to the ventricle, and this drives it into the 
arterial system; this spreads it into the general capillary 
system, which may be truly considered as the termina- 
tion of its course. The red blood is then constantly car- 
ried from the capillary system of the lungs to the general 
capillary system. The cavities that contain it are all 
lined with a continuous membrane ; this membrane spread 
upon the pulmonary veins, upon the left cavities of the 
heart and upon the whole arterial system, may be consid- 
ered as a general and continuous canal, the exterior of 
which is strengthened in the pulmonary veins by a loose 
membrane, in the heart by a fleshy surface, which is 
delicate in the auricle, thick in the ventricle, and in the 
arterial system by a fibrous layer of a peculiar nature. 
In these varieties of the organs that are thus added to it 
without, this membrane remains every where nearly the 
same, as we shall see. 
Circulation of the black blood. 
The circulation of the black blood is performed in a 
manner the reverse of the preceding. It begins in the 
* It may be remarked, that this work was published at a time when 
the theory of the oxygenation of the blood was universally considered 
as explaining in a satisfactory manner the change that is effected in the 
colour of the blood by the lungs. The experiments of Allen, Pepys, 
and others, and the Treatises of Ellis, have proved to the satisfaction of 
most physiologists of the present day, that this change in the colour is 
not owing to the absorption of oxygen by the blood, but to the extrica- 
tion of carbon from it. Tr. WITH RED BLOOD. 
277 
general capillary system; it is in this system, that its 
blood takes the peculiar character that distinguishes it 
from the preceding; it is here that it is formed, by the 
subtraction probably of the principles of the air that it 
acquired by terminating its course in the lungs. From 
this general capillary system, it enters the veins which 
transmit it to the right cavities of the heart, which send 
it by the pulmonary artery, to the capillary system of the 
lungs. This system is its real termination, as it is the 
commencement of the circulation of the red blood. A 
general membrane, every where continued, lines the whole 
course of the black blood, and forms for it also a general 
and continuous canal, in which it is constantly carried 
from all parts to the interior of the lungs. At the exte- 
rior of this great canal, nature has placed a loose mem- 
brane in the veins, fleshy fibres in the heart, and a peculiar 
fibrous texture in the pulmonary artery ; but, like the 
preceding canal, it remains always nearly uniform, not- 
withstanding this difference of organs to which it is unit- 
ed externally. It is by the folds of this membrane in the 
veins that the valves are formed. It contributes to form 
all those of the right side of the heart, whose cavities it 
lines, as the preceding enters into the composition of the 
valves of the left side, which borrows from it the mem- 
brane that lines it. 
From the general idea that I have given of the two 
circulations,, it is evident that they are perfectly indepen- 
dent of each other, except at their origin and termination, 
where the red and black blood are alternately transform- 
ed into each other, and communicate for this purpose by 
the capillary vessels. In their whole course they are 
entirely separate. Though the two portions of the heart 
are united in one single organ, they may however be 
considered as uniformly independent in their action. 
Difference, of the two circulations 278 
VASCULAR SYSTEM 
There are truly two hearts, a right and a left. Both 
would be able perhaps to perform their functions as well 
if they were separate, as they now do united. When the 
foramen ovale remains open after birth, I have proved 
elsewhere that such is the arrangement of the two folds 
between which it is found, that the black blood cannot 
communicate with the red, and that the two hearts should 
equally be considered independent, at least as it respects 
the course of the blood. This entire separation of the 
two circulations is one of their most striking characters; 
it alone proves how much preferable the point of view in 
which I have presented the circulation, is to that which 
divides it into great and small, which are evidently con- 
founded and identified. 
From what has been 6aid, it appears that the origin and 
termination of each circulation take place in the two 
capillary systems, which are, if we may so say, the limits 
between which the two kinds of blood move. The lungs 
alone correspond in this respect, with all the parts. 
Their capillary system is in opposition to that of all the 
other organs, if we except the parts from which the blood 
of the vena porta goes. Each capillary system then is at 
the same time an origin and termination. The pulmo- 
nary is the origin of the circulation of the red blood, and 
the termination of that of the black. The general gives 
to the red blood its termination, and to the black blood 
its origin. Observe that this is a great character that 
distinguishes the two circulations. In fact, the blood not 
only takes an opposite course at the place where they 
finish and at that where they begin; but its nature 
changes also entirely, and in this respect the two capil- 
lary systems, pulmonary and general, present to us the 
most important phenomena of the living economy, viz. 
the first, the transformation of black blood into red, the 
second, that of red blood into black. WITH RED BLOOD. 
279 
There are evidently three things to be examined with 
regard to each of the circulations, 1st. the origin; 2d. 
the course; 3d. the termination of each kind of blood. 
In the origin and termination, there is on one hand the 
mechanical phenomena of circulation, on the other the 
phenomena of the transformation of the blond. In the 
course of this fluid there is only the mechanical pheno- 
mena of the circulation to be observed. 
By examining these phenomena in a general manner, 
we see, 1st. that the red blood going from the lungs, is 
formed into larger and less numerous columns, as it ap- 
proaches the cavities of the heart; that it is in the great- 
est masses in these cavities, and that from them to the 
capillary system, it is continually dividing into smaller 
columns; 2d. that the black blood going from the general 
capillary system, is formed into columns larger and less 
frequent, as it approaches the right cavities of the heart; 
that these cavities contain the greatest quantity of it, and 
that from them to the lungs, it is successively divided into 
smaller columns. 
The two kinds of blood circulate then on the two sides 
in branches that diminish asjhey go from the heart, and 
increase as they approach it. Represent to yourself for 
each of the two circulations two trees united at their 
trunks, sending their branches, one of them to the lungs, 
the other to all the parts. Each of the two parts of the 
heart is between these trunks,, which it serves to unite, 
so as to form a general canal of which we have spoken. 
Authors have commonly considered the arteries and 
veins as forming, each by their assemblage, a cone, the 
base of which is at all the parts, and the apex at the 
heart. This manner of describing them arises from this, 
that the sum of the branches is greater in diameter, than 
that of the trunks from which they arise ; now in adopt- 
General mechanical phenomena of the two circulations. 280 
VASCULAR SYSTEM 
ing this idea, it is evident that each half of the heart is at 
the summit of two cones, which would be united with- 
out it. The pulmonary veins represent one, and the 
aorta the other for the red blood; for the black blood, 
there is on one part the venae cavae and coronary veins, 
on the other, the pulmonary artery, which form the two 
cones. In each circulation, one of these cones is remark- 
able for its small size ; it is that of the lungs ; the other 
for its great extent; it is that of all the parts. 
Placed between these two cones, each part of the heart 
should be considered as an agent of impulse which has- 
tens the course of the blood, on one hand towards all the 
parts, on the other towards the lungs. In fact, if in each 
circulation these two cones communicate by their apex, 
it is evident that the parietes of the vessels that compose 
them would be insufficient to maintain the motion, from 
the base of one to the base of the other; that is to say 
from the general capillary system to that of the lungs, 
and reciprocally from that of the lungs to the general 
one. The course is manifestly too long, and the vital 
forces of the vascular parietes not sufficient to admit of 
this ; hence the necessity of the heart. 
This consequence leads to another, which is this. As 
the red blood has a greater extent to go over from the 
heart to the general capillary system, than the black 
blood has from the heart to the pulmonary capillary sys- 
tem, it is necessary that the portion of this organ belong- 
ing to the first kind of blood, should be endowed with a 
greater force than that destined to support the motion of 
the latter. Nature has effected this object by composing 
the ventricle with red blood of fibres much stronger than 
those of that of black blood. As to the auricles, as they 
only receive the blood and transmit it to the ventricles, 
their thickness is nearly uniform. 
From this wre see, 1st. that the part the heart performs 
in the two circulations, is absolutely relative to the me- WITH RED BLOOD. 
281 
chanical phenomena of the course of the blood, and that, 
if it has any influence upon the composition, it can only 
be by the internal motion it communicates to it; 2d. that 
if the course of the two circulations, of black blood and 
red, was of less extent, they might do without this inter- 
mediate agent of impulse. This is precisely what happens 
in the system of abdominal black blood, the two trees of 
which distributing their branches, one to the gastric 
viscera, the other to the liver, unite by their trunk in 
what is called the sinus of the vena porta, which occu- 
pies exactly the place of the heart in the great system of 
black blood and in that of red. 
It is then possible to conceive, 1st. how the heart may 
fail; of this we have many examples, in which the two 
great circulating systems resemble in a certain degree, 
the abdominal; 2d. how the blood can oscillate from one 
capillary system to the other, during a considerable time, 
though the heart, weak, enfeebled, and even in part dis- 
organized, can hardly any longer accelerate the course of 
this fluid ; 3d. how, this organ having entirely suspended 
its pulsation in syncope, asphyxia, &c. there is still an 
oscillation, a real progression of the blood from one capil- 
lary system to the other, so that if an artery or vein is 
then opened, it flows a little at the opening. Certainly 
this oscillation is very weak ; it cannot last a long time ; 
but we cannot deny that it exists without the influence of 
the heart, since the black blood is carried without the agent 
of impulse, from the intestines to the liver; hence it fol- 
lows that the cessation of the pulsation of the heart is not 
a proof of the want of motion in the blood, as some au- 
thors have thought. 4th. We know that in many ani- 
mals of the lower classes, there is no heart, though there 
are distinct vessels and circulating fluids. 
The importance of the part that the heart enjoys in 
the animal economy is only in relation to the general im- 
pulse that it communicates to all the organs and the con- VASCULAR SYSTEM 
282 
stant excitement in which it keeps them by this impulse. 
It does not send to them the materials of secretion, of 
exhalation and of nutrition ; it only in this respect trans- 
mits what it receives from the lungs. 
II. Refections upon the general uses of the circulation. 
This leads us to some reflections upon the general dif- 
ferences of the uses of the two circulations; differences 
which prove the necessity of presenting the single func- 
tion that results from them in the view in which I have 
placed it, and not in that in use in the treatises on phy- 
siology. The following are the differences. 
General uses of the circulation of the red blood. 
It is the circulation of the red blood that alone fur- 
nishes the matter of secretions, except that of the bile, 
a fluid which however deserves a further examination. 
It is from this circulation that the serous, cellular, cutane- 
ous, medullary exhalants, &c. draw the fluids that they 
transmit upon their respective surfaces. All the vessels 
that carry the matter of nutrition of the organs are also 
continuous with the arteries and consequently their fluids 
come from the red blood. In the organs even in which 
the black blood goes, as in the lungs and the liver, there 
are vessels with red blood evidently for the purposes of 
nutrition. It is the red blood that communicates to the 
organs of the whole body that general agitation which is 
necessary to their functions, an agitation so evident in the 
brain. The circulation of red blood is then the most 
important; it is that, whence are derived the great phe- 
nomena of the economy. 
The circulation of the black blood, on the contrary, 
having no connexion with any of the functions, seems 
only destined to repair, if we may so say, the losses the 
General uses of the circulation of black blood. WITH RED BLOOD. 
283 
blood has sustained in the preceding one. Observe in 
fact that a considerable part of the red blood is expended 
in the exhalations, secretions and nutrition. The prin- 
ciples it borrowed in the lungs and which gave it a ver- 
milion colour, have been left in the general capillary sys- 
tem. It is necessary that the black blood should receive 
what the other has lost; now a variety of substances 
enters the great canal that contains it. These substances 
are internal or external. 1st. The great trunks of the ab- 
sorbents constantly pour in the lymph of the cellular tex- 
ture and of the serous surfaces, the residue of the nutri- 
tion of all the organs, the super-abundant fat, synovia and 
marrow. All that which is to be thrown from within out, 
is first poured into the black blood. 2d. All that which 
enters in from without, is also received by it. The chyle, 
the product of digestion, is at first uniformly carried into 
the general canal, in which it circulates. In the second 
place, it is with it that are mixed the substances of the 
air, which pass through the lungs in the act of respiration. 
In fine, when cutaneous or mucons absorptions take place, 
the black blood is always the first that receives the pro- 
duct of them. 
It follows from this-, that the circulation of black blood 
is, if we may so say, a general reservoir in which is pour- 
ed in the first place all that is to go out of the body, and 
all that is to enter it. 
In this last respect, it performs an essential part in 
diseases; in fact it is undeniable, 1st. that deleterious 
substances may be introduced with the chyle into the 
economy, and produce ravages there more or less evi- 
dent in circulating with our fluids. For this, it is suffix 
cient that the organic sensibility of the chylous vessels 
should be changed ; then they admit what before they 
rejected, as the glands by changes in their organic sen- 
sibility, often secrete fluids that are usually foreign to 
them. 2d. We shall prove in the article upon the cuta- 284 
VASCULAR SYSTEM 
neous system, that it is oftentimes the seat of the absorp- 
tion of deleterious substances. 3d. We cannot doubt 
that besides the principles that colour the blood, there 
often passes through the lungs deleterious miasmata which 
produce diseases, as my experiments upon asphyxia have 
proved. The intestines, the lungs and the skin are then 
a triple gate open, in many cases, to different morbific 
causes; now these causes that enter thus into the econo- 
my are all received in the first place in the black blood ; 
it is not until afterwards that they pass into the red blood. 
An evident proof of this assertion is this, that we pro- 
duce phenomena exactly analogous to those which result 
from them, by pouring artificially into the black blood 
those substances that are introduced in a natural way. 
Thus when a purgative or emetic infusion is introduced 
into the veins, alvine evacuations or vomiting ensue, pre- 
cisely as when the substances of these infusions are intro- 
duced by friction upon the skin. The experiments of 
many physiologists leave no doubt upon this point. I am 
convinced that it is possible to give to animals artificial 
diseases, by making different substances infused into their 
veins circulate with the blood. I shall speak of these 
attempts in the article upon the glandular system. It is 
sufficient for me to mention them here, in order to prove 
that the black blood is a general reservoir in which many 
substances can enter, either naturally, or accidentally, 
and afterwards disturb the functions by passing into the 
whole circulating mass. The humoral pathology has un- 
doubtedly been exaggerated, but it has still real founda- 
tions, and in many cases we cannot deny, but that every 
thing arises from the disorders of the humours. 
Let us conclude from all that has hitherto been said, 
1st .that the essential part which the circulation of the 
black blood performs in the economy, is to introduce into 
this blood different new substances ; 2d. that that of the 
system of red blood is to expend on the contrary, the WITH RED BLOOD. 
285 
principles that constitute it. One is constantly increas- 
ing, the other diminishing ; to give is the attribute of one, 
to receive is that of the other. This sketch, which is 
perfectly true, and founded upon the most simple obser- 
vation, appears to me very proper to establish an evident 
demarcation between the two divisions that I have adopt- 
ed for the general circulation. 
Health supposes a perfect equilibrium between the 
losses the red blood experiences, and the acquisitions the 
black blood makes. Whenever this equilibrium is de- 
stroyed, there is disease. If the black blood receives 
more than the red blood expends, plethora follows. That 
which is called the poverty of the humours, is manifest 
when more substances go from the red blood than enter 
the black. 
These are I think sufficient characteristic attributes of 
the two great divisions of the general circulation, to jus- 
tify the point of view different from other authors, in 
which 1 present this important function of the animal 
economy. 
ARTICLE SECOND. 
SITUATION, FORMS, AND GENERAL ARRANGEMENT OF THE VAS- 
CULAR SYSTEM OF RED BLOOD. 
From the general idea that we have given of the two 
vascular systems, we should form the following of the 
position in the economy of that with red blood. 
1st. The capillary system of the lungs gives rise to 
many minute ramifications, which soon unite into small 
branches, then into larger ones, and finally into four great 
trunks, two for each lung. These trunks open into the left 
auricle towards its superior part. 2d. This, distinguished 286 
VASCULAR SYSTEM 
from the right by having fewer fleshy columns, by its 
smaller size, by the greater elongation of its appendix, 
which is narrower than that of the other, &c. communi- 
cates by an oval opening furnished with valves, with the 
left ventricle, the thickness of whose parietes, the arrange- 
ment of the fleshy columns, &c. distinguish it from the 
right. 3d. From this ventricle goes the aorta, the com- 
mon trunk whence arise all those that carry red blood to 
all the parts, where they terminate in the general capil- 
lary system. 
The first tree of the system of red blood, the trunk of 
the second and the heart that serves to unite them, are 
found then concentrated in the cavity of the thorax, 
whilst the branches of the second trunk are distributed 
among all the organs of the economy, and even to all 
its extremities. 
It is nearly between the superior third of the body and 
the inferior, that is found the agent of impulse of the red 
blood, or the heart. This position is important; it places 
under a more immediate influence of this viscus, the supe- 
rior parts, the head especially, all of whose organs, and 
particularly the brain, require inevitably a very active 
and habitual excitement from the blood, in order to keep 
their functions in permanent activity. Thus observe, 
that in the gangrene of old people, and the affections that 
arise from the blood not being driven with sufficient force 
to all the parts, it is the extremity of the foot that is first 
affected, and that of the head and the hands become much 
later the seat of mortification. In general, there are 
many differences between the phenomena that take place 
in the superior parts, and those that happen in the infe- 
rior. We shall see in the dermoid system, that the por- 
tion of the general capillary system which belongs to the 
first, is penetrated with blood with infinitely more ease, 
than the portion belonging to the inferior parts, as as- 
phyxia, apoplexy, submersion, different cutaneous erup* WITH RED BLOOD. 
287 
tions, injections even prove, which in young subjects 
blacken rather the face than the inferior parts; now this 
difference arises evidently from the relation of position 
of the superior and inferior parts with the heart. 
We have no general remarks to offer here upon the 
first tree and upon the agent of impulse of the circulation 
of red blood. In fact, the remarks belonging to the lungs 
and the heart will be given in the Descriptive Anatomy. 
It is then especially the second or arterial tree, whose 
distribution is now to occupy us. It is necessary in this 
article to examine the origin, course and termination of it. 
f. Origin of the Arteries. 
This article comprehends the origin of the aorta at the 
left ventricle, that of the trunks which arise from it, then 
that of the branches, the smaller ones and the minute 
ramifications that go from them. 
Origin of the Aorta. 
Most authors have described inaccurately the manner 
of the union of this great arterial trunk with the heart. 
This is the manner; the internal membrane of the 
heart with red blood, after having lined its ventricle, ap- 
proaches the opening of the aorta, is attached there, forms 
by its folds the three semi-lunar valves, and stretching 
afterwards into the artery, covers it in its whole extent. 
It is this internal membrane that forms the union of the 
artery with the heart. The peculiar or fibrous membrane 
is not identified with the fibres of the heart. Its extremity 
is cut into three semi-circular festoons, which correspond 
with the semi-lunar valves that they support. These fes- 
toons do not extend to the fleshy fibres; there is between 
them and these fibres a space of two or three lines that 
the internal membrane alone covers. Between them 
and consequently between the valves, we perceive three 
little empty triangular spaces, covered by the membrane 288 
VASCULAR SYSTEM 
also. To distinguish this structure clearly, the origin of 
the aorta must be dissected well from without, and strip- 
ped entirely of the fatty texture that surrounds it. Then 
by cutting this artery and the ventricle, and by examining 
when held up to the light the union of one with the other, 
after having first removed the valves, we distinguish very 
well by the transparency of the internal membrane and 
the opacity of the three festoons that commence the aorta, 
the arrangement that 1 have just pointed out. It follows 
from this, that if the artery is accurately dissected on its 
exterior, and we detach from below upwards the internal 
membrane that forms the great canal of the circulation of 
the red blood, the artery is entirely separated from the 
heart. This entire separation of the fibres of the aorta 
from those of the heart, would alone be a strong presump- 
tion that their nature is not the same if many other con- 
siderations did not prove it in the most evident manner. 
Origin of the trunks, branches, smaller branches, <^c. 
Arising thus from the left ventricle, the aorta divides 
almost immediately into two branches, one ascending goes 
to the neck, head and superior extremities; the other 
descending to the chest, abdomen and lower extremities. 
The first being very soon subdivided into four principal 
trunks, differs in this respect from the second, which forms 
for a long time one trunk only. The latter having to go 
over a much greater distance than the t>ther, preserves 
with more certainty by this arrangement the whole of the 
motion that is given to the blood by the heart; this does 
not prevent, however, owing to the less distance, the im- 
pulse from being more sensibly felt by the superior than 
the inferior organs, as I have said above. At the supe- 
rior part of the pelvis, the aorta divides into two second- 
ary trunks. Soon after, subdivisions begin under the 
name of branches, which are afterwards multiplied un- 
der that of ramifications, &c. WITH RED BLOOD. 
289 
Mathematical anatomists have exaggerated the number 
of the arterial sub-divisions. Many have thought there 
were a hundred to one artery; Haller reduced the num- 
ber to twenty, and even less. To ascertain what is really 
the case, it is necessary to take the arteries at their origin, 
and follow their course under a serous membrane, the 
peritoneum for example, where they are every where 
very apparent; it will be seen in this way, that the sub- 
divisions are not more numerous than is stated by Haller; 
I have frequently satisfied myself of this. Besides, the 
inspection of a living animal whose abdomen is opened, 
is almost the only means that can be employed without 
danger of mistake. Injections when too coarse do not 
fill all the branches; when too fine, they pass into the 
exbalant vessels, and communicate to the whole serous 
surface a colour that is not natural to it. It is almost 
impossible to ascertain by injections, the precise point of 
the natural circulation. To be convinced of this, inject 
a dog and open the abdomen of another of the same size ; 
you will see uniformly in one more or less vessels in- 
jected, than are seen in the other filled with blood. I 
frequently performed this experiment, at the time 1 was 
engaged in demonstrating the insufficiency of injections, 
either fine or coarse, to show the quantity of blood in any 
part. 
When they divide, the arteries form among themselves 
very different angles. Sometimes right angles, as at the 
middle intercostals; sometimes obtuse, which is more 
rare, as at the superior intercostals ; most commonly they 
are acute, particularly in the extremities. The origin of 
the spermatic artery is an instance of the extreme of this 
last kind of origin. 
We observe in general, that wherever there are two 
divisions, one is larger than the other. The largest fol- 
lows the original direction of the principal trunk, from 
which the other is more or less separated. In the inte- 290 
VASCULAR. SYSTEM 
iior of the artery, an eminence formed by the fold of the 
internal membrane, corresponds with the angle entering 
from without, and breaking the column of the blood, 
favours the change of its course. This eminence pre- 
sents an arrangement, that is very variable, which is 
owing to the angle of origin. 1st. If the angle is a right 
one, the eminence has a circular arrangement and is equal- 
ly evident in the whole circumference, 2d. If the angle is 
acute, as at the mesenteric, then this eminence is very evi- 
dent between the branch that arises and the continuation 
of the trunk ; it forms even a kind of semi-circular spur or 
projection, but between the trunk itself and the branch 
that arises from it, the union of which forms an obtuse an- 
gle, this eminence is less conspicuous. The more obtuse 
the angle is, and consequently the more opposed it is to 
acute, the less sensible is this second eminence; it has 
like the other a semi-circular form, and makes by its 
union with it a whole circle which is oblique; so that the 
portion of the circle formed by this second eminence is 
nearer the heart than that made by the other. 3d. If 
the angle of origin is obtuse, and consequently that form- 
ed by the branch with the continuation of the trunk is 
obtuse, things are then arranged in an inverse manner. 
There is at the mouth of the artery an oblique circle, the 
prominent half of which is nearest the heart. 
The origin of the arterial trunks is generally pretty 
uniform; but that of the branches is so variable, that 
hardly any two subjects have the same arrangement, in 
this respect. Take for example the hypogastric; .it 
would be impossible to form the least idea of its branches, 
if, neglecting the manner they separate from each other, 
you paid attention only to their course and distribution. 
These numberless varieties in the forms, are a remarka- 
ble character in organic life to which the arteries belong. 
This character must be placed at the side of the constant 
irregularity of the arteries. There is no symmetry in WITH RED BLOOD. 
291 
iheir general distribution, as in the distribution of the 
nerves of animal life. Those even of the extremities, 
that correspond, differ frequently in their mode of origin 
and the course of their branches. 
The branches, smaller branches, &c. arise at distances 
very near each other. There is hardly any, except the 
carotid, internal iliac, &c. that runs a considerable course 
without furnishing some. Thus experiments in which it 
is necessary to introduce tubes into arteries, to open 
them, &c. can scarcely be made except upon the first of 
these, they are prevented in others by divisions that arise 
from them and hinder us from raising the artery to any 
considerable extent. 
The origin of the arterial trunks, branches, smaller 
branches and ramifications, does not take place in a grad- 
ual and necessarily successive manner. Thus the smaller 
branches, and the ramifications even, arise equally from 
trunks and branches ; for example, the bronchial, thymic 
arteries, &c. go from the aorta, and yet they are not so 
large as most of the divisions of the tibial, which is itself 
a third division of the aorta. 
II. Course of the arteries. 
In their course the arteries present differences accord- 
ing as we examine, the trunks, the branches and smaller 
branches. 
Course of the trunks and branches. 
The trunks are the first divisions continuous with the 
two great portions of the aorta; such are above, the 
internal and external carotids, the subclavians, &c.; 
below, the iliacs, the hypogastrics, &c. Generally they 
are situated in broad interstices, that contain much cellu- 
lar texture, as in the groin, the axilla, the neck, the sides 
of the pelvis, &c. By dividing they form branches that 
are received into smaller and narrower interstices, and 292 
VASCULAR SYSTEM 
are consequently more exposed to the influence of the 
neighbouring organs. Both of them are covered almost 
every where by a thickness of parts that protects them 
from external injury. Besides this protection that the 
neighbouring parts and particularly the muscles afford 
them, they accelerate also the circulation of the blood, 
and reciprocally the motion of the arterial trunks gives 
to the neighbouring organs and even to the whole limb, 
a sensible motion, an agitation that supports its vital en- 
ergy. This agitation, which it is often difficult to per- 
ceive, sometimes becomes very evident upon mere inspec- 
tion. When the elbow is rested upon the table, and a 
body of considerable length held in the hand, its extremi- 
ty is seen to vaccillate, to rise and fall a little at each 
pulsation. If the legs are crost, being first bent upon the 
thighs, a spontaneous rising is noticed in that which is 
supported. To this we must refer also the cerebral mo- 
tion, that which is communicated to tumours that are sit- 
uated over a great art<*ry, &c. &c. 
The trunks and the branches are accompanied by 
veins, and surrounded in general with a large quantity of 
fat, a circumstance that has been considered favourable 
to the opinion of those who think that this fluid is exhaled 
b) the pores of the arteries. We have already said what 
should be thought of this opinion. 
The direction varies in the trunks and the branches. 
Usually straight in the trunks, as in the carotids, the in- 
ternal and abdominal iliacs, it renders the circulation less 
evident. When these trunks are exposed in a living ani- 
mal, we do not see any kind of locomotion there, as we 
do when the curves are great. There is however some 
exception to this rule as it respects the direction of the 
trunks ; the arch of the aorta is an example of it, so is the 
internal carotid, which has numerous curves, which are 
thought incorrectly, to be necessary to prevent the impe- 
tus of the blood from producing derangement in the deli- WITH RED BLOOD. 
293 
cate substance of the brain. More tortuous in the 
branches, this direction occasions the arterial locomotion 
that constitutes almost exclusively the pulse, according to 
many physicians. 
Course of the smaller branches, ramifications, fyc. 
Whilst the trunks occupy the large interstices that are 
left between several organs, and the branches the smaller 
ones that separate particular organs, the smaller branches 
are found in the interior of these same organs, without, 
however, entering into their intimate structure. Thus in 
the muscles, they are interposed between their fibres ; in 
the brain, in the circumvolutions ; in the glands, between 
the lobes that form them, &c. By them, an internal 
motion communicated to the whole organ, facilitates its 
functions by supporting its partial activity, as the motion 
of which I spoke above, supports the general activity of 
the part. Besides, the sudden cessation of life, when the 
blood ceases to agitate the brain, proves the immediate 
connexion between this internal motion and its energy. 
Thus we observe that life is much more active wherever 
the arteries are numerous, as in the muscles, the skin, the 
mucous surfaces, &c.; whilst on the contrary its phenom- 
ena are weaker and more obscure in the less vascular or- 
gans, as in the tendons, the cartilages, the bones and the 
other white parts. 
In the smaller branches, the windings are much more 
evident than in the branches. Injections make them 
very conspicuous, especially in the brain; but as they 
depend principally upon the cellular texture they disap- 
pear in part, if we separate from it the vessels of all the 
parts. Do these windings diminish the rapidity of the 
circulation, and does the straightness of the arteries in- 
crctse this rapidity as much as physiologists suppose ? 
I think they have exaggerated the effects of the direction 
of the arteries; the following are proofs of it. 1st. If in 294 
VASCULAR SYSTEM 
living animals we expose the hollow organs, as the sto- 
mach, intestines, &c. alternately in a state of fulness and 
in that of vacuity, I have observed that the circulation is 
almost equally rapid in both cases, though fulness renders 
almost straight the vessels of these organs, and that empti- 
ness, by forcing them to wrinkle, increases their curves. 
2d. I have opened the carotid artery of a dog, and having 
observed the force with which the blood is thrown out, I 
have also opened both sides of the thorax ; immediately 
the lungs are collapsed and consequently the windings of 
their vessels increased ; notwithstanding this no diminu- 
tion in the force with which the blood escapes from the 
artery, after having gone through the lungs is immediate- 
ly sensible. It is only gradually that the force is destroy- 
ed by the influence of causes, that it is not my object to ex- 
amine. 3d. If in another animal, an artery being open, we 
open also the wind pipe, and by a syringe affixed to the 
opening suddenly exhaust all the air the lungs contain, 
this organ is immediately reduced to a very small size; 
the vessels become much bent, and yet I have observed in 
this case that the blood goes from the open artery with 
as much force as before, for a considerable time. 4th. 
Finally, after having opened the abdomen of a living 
animal, I have alternately contracted and stretched the 
mesentery, whose numerous arteries had been first open- 
ed ; no difference is discoverable in the force with which 
the blood is thrown out, in either case. 
Let us conclude from these experiments, that the influ- 
ence of the direction of the arteries upon the course of 
the blood, is much less than is commonly thought, and 
that all the calculations of mathematical physicians 
upon the delay of the blood from this cause, rest upon 
unsubstantial foundations. There is no doubt that when 
the fore arm is strongly bent, the pulse is weakened, 
stops even, and it is essential when we feel the pulse that 
the arm should be extended; but this phenomenon does WITH RED BLOOD. 
295 
not depend upon the angle the artery forms; it arises 
from this, that the muscles that press it, contract its cali- 
ber and even obliterate it. This is so true, that the dif- 
ferent curves of the internal carotid are much more evi- 
dent than the single curve that the brachial then forms, 
and yet the circulation is performed there very well. 
Besides, open an intercostal artery which has but few 
curves, the force with which the blood will be thrown 
out is not stronger than it would be from the radial, &c. 
If the whole arterial system was empty and the blood 
going from the heart filled it successively, as this fluid 
would strike against the arterial curvatures, it would un- 
doubtedly experience some delay. It is on this account 
that in our injections a tortuous artery is slower in filling; 
as the spermatic for example often remains empty. But 
in a number of tubes full of fluid, it is wholly different; 
the impulse received at the beginning of them is sudden- 
ly propagated into all the cavities that form them, and 
not by a successive progression, as I shall say hereafter. 
The arterial curvatures are adapted to the different 
states in which the organs may be found. We see them 
very evident in those which are subject to an alternate 
dilatation and contraction, for example in the intestines, 
the lips, and the whole face. In the foetus, when the testi- 
cle is in the abdomen, the artery is very tortuous. When 
thi3 gland descends, the artery untwists and takes the 
straight course it has in the adult. In the motions of the 
womb, the bladder, the pharynx, the tongue, &c. these 
curvatures perform an important part in the preservation 
of these organs. In the fractures of the lower jaw, they 
prevent the rupture of the artery that traverses this bone, 
a rupture which the displacing of the bone would pro- 
duce without them. By them the arterial system is pre- 
served unhurt in the violent and oftentimes forced mo- 
tions that the limbs perform. 296 
VASCULAR SYSTEM 
The flexibility of the arteries would be insufficient for 
these motions; in fact, when an artery is extended longi- 
tudinally, its diameter is diminished. By accommodating 
themselves to the motions of our parts, the vessels would 
impede then the circulation, because there would be less 
space for the blood to move in. Hence why the arteries 
of all the parts subject to alternate dilatations and con- 
tractions, being uniformly tortuous, can without the aid 
of their extensibility, have very different degrees of ex- 
tent. I would remark upon this subject that the loco- 
motion of the arteries, observed by Veitbrecht, is far 
more evident at the time of the contraction of the hollow 
organs, or of the flexion of the limbs, than during the 
dilatation of the one or the extension of the others. I 
have invariably made this remark upon living animals. 
We can by emptying or distending the intestines, the sto- 
mach, the bladder, &c. make their arteries beat more or 
less strong, &c. &c. 
Anastomosis is the union of many branches, which 
mingle the columns of blood that each brings. There 
are two kinds of anastomoses; sometimes two equal 
trunks unite, sometimes a small trunk is joined to a large 
one. 
The first has three varieties. 1st. Two equal trunks 
sometimes unite at an acute angle, and form but one; it 
is thus that the ductus arteriosus and aorta are blended 
together in the foetus; that the two vertebrals produce 
the basilary trunks, &c. &c. 2d. Two trunks communi- 
cate at certain places by a transverse branch ; such are the 
two anterior cerebral, before they go between the hemi- 
spheres. 3d. Two trunks unite and form an arch; this 
is the case with the mesenteric ; then branches arise from 
the convexity of this arch. We see then that there are 
three kinds of anastomoses between equal branches; one 
Anastomoses of the arteries in their course. WITH RED BLOOD. 
297 
of these is that in which two columns of blood are united 
together and take a direction between the two first; 
another in which two columns follow their first direction, 
and only communicate with each other; finally in the 
last, two columns meet each other by their extremities, in 
an opposite direction, and the blood escapes afterwards 
by secondary vessels. 
The second kind of anastomoses is that of considerable 
branches with smaller ones; it is extremely frequent, 
especially in the extremities; it has no varieties. 
It is almost always in regions remote from the heart 
that anastomoses are met with. We find scarcely any in 
the trunks that arise from the aorta. They begin to be 
more frequent in the branches, as in the mesenteric, the 
cerebral, &c. The more the smaller branches are sub- 
divided, the more numerous are the anastomoses. In 
the last ramifications they are so numerous that they 
form an inextricable network. This arrangement is cal- 
culated to facilitate the circulation, which the anastomo- 
ses favour in places, w here the motion of the blood is lia- 
ble to experience obstacles. It is on this account that in 
the cavities in which the influence of the neighbouring 
parts upon the motion is less sensible, the anastomoses 
become more frequent, as in the brain, the abdomen, &c.; 
whilst they are more rare in the muscular interstices of 
the extremities, &c. It is not then a tree with distinct 
branches that forms the arterial system, but a tree all the 
parts of which communicate together, more frequently as 
they are the further removed from the origin. 
The principal object of the anastomoses, that of obvi- 
ating the obstacles the blood experiences in its course, is 
fulfilled in many cases. Thus, after the ligature of a 
wounded artery or one with an aneurism, after the spon- 
taneous obliteration of one of these vessels, we see the 
anastomoses between the fine branches, above and below 
this obliteration or this ligature, continue the circulation 298 
VASCULAR SYSTEM 
in the part. These collateral vessels then increase often 
in size ; but more frequently still, the course of the blood 
is supported almost entirely by the capillary vessels. 
Anastomoses suppose then the vitality of the arteries. 
It is because these vessels are not inert, but act them- 
selves upon the fluid they contain, that the circulat- 
ing phenomena are subject to so many variations; that 
oftentimes, and especially by the influence of the pas- 
sions, the spasm of their extremities, principally of the 
capillaries, obliges the blood to flow back, a reflux which 
is favoured by the anastomoses. This reflux is necessary 
also in inflammations, in the different engorgements of 
our organs, &c. How would the circulation be able to 
go on, if all the small branches went to their respective 
destinations, without communicating among themselves? 
Would not the least embarrassment occasion a trouble- 
some stagnation there ? 
I would remark upon this subject that the anastomoses 
furnish the first proof of a truth which we shall soon de- 
monstrate more in detail, viz. that in the great trunks, 
the blood is especially influenced by the heart, and that 
in the capillaries, it is exclusively by the vascular par- 
ietes. In fact it is because the vitality of the arteries 
is every thing for the motion of the last subdivisions, 
that the least alterations that they experience give rise 
to many engorgements that inevitably require anastomo- 
ses, which are extremely numerous at the end of the ar- 
terial tree. On the other hand, the vitality of the trunks 
having scarcely any influence upon the blood, it experi- 
ences but few obstacles in passing through them; there 
is less need then of anastomoses, which are in fact more 
rare there. 
If the least cause, the least irritation produced spasm 
of the trunks, as they produce that of their last divisions, 
it would be necessary that they should communicate as 
frequently together. A fleshy texture in the great arte- WITH RED BLOOD. 
299 
ries, and vital properties analogous to the involuntary 
muscles, would have required inevitably these numerous 
anastomoses, because a variety of causes influencing these 
kinds of muscles, they can at any moment increase unnat- 
urally their contraction, diminish their caliber and em- 
barrass the progress of the fluids that traverse them. 
Forms of the Arteries in their course. 
Many physicians of the present age have described 
each artery as forming a cone, the base of which is to- 
wards the heart, and the apex towards the extremities. 
If we examine a portion of it between the origin of two 
branches, whether after having injected it, or by cutting 
it perpendicularly when it is empty, or by measuring it 
when it is full of blood, we find it always cylindrical. 
Undoubtedly considered in its whole extent, it takes a 
conical form, the effect of its successive diminution by 
the branches it furnishes; but in this sense it is less a 
cone, than a series of cylinders successively joined to 
each other and always decreasing. 
Considered in its general arrangement, the arterial 
system represents on the contrary, as I have said, a cone 
absolutely inverted, that is to say, having its base at all 
the parts and its apex at the heart; so that the aorta has 
a diameter less considerable in proportion, than that of 
the sum of all the branches. We have a proof of this by 
comparing a trunk with two branches that succeed it; 
these surpass it in diameter, and the relation being al- 
ways the same in all the subdivisions, we conceive that 
the capacity of the arterial system goes uniformly in- 
creasing. 
This relation of the trunks and the branches has been 
exaggerated however by mathematical physiologists, who 
attributed to the last over the first a predominance much 
greater than really existed. A cause of error upon this 
point may arise from measuring the arteries at their ex- 300 
VASCULAR SYSTEM 
teriorafter having injected them; in fact, the caliber of 
the trunks is greater, in proportion to their parietes, than 
that of the branches separately examined ; that is to say, 
other things being equal, the aorta has parietes thinner 
in proportion to its cavity, than the cubital artery; hence, 
without doubt, why aneurisms are rare in the branches, 
and frequent in the trunks, especially when the diseases 
arise from a local cause; for if they are the effect of a 
general disease, oftentimes the little arteries, the radial 
particularly, are also affected; I have already seen two 
examples of it. This observation upon the proportions 
of the arterial parietes proves the impossibility of judg- 
ing of the relations of diameter between the two, at least 
by examining them in the interior. 
Besides, these relations are necessarily very variable, 
according as the vital forces which vary themselves so 
much, increase or contract the caliber of the small arte- 
ries; and in this point of view, this examination cannot 
have the importance that was attached to it by the an- 
cients, whose works are filled with calculations upon this 
point. 
III. Termination of the Arteries. 
After being divided, subdivided, and having the pecu- 
liarities we have just examined, the arteries terminate in 
the general capillary system. To point out where, this 
system begins, and where the arteries end, would be very 
difficult. We can prove that there the blood ceases to 
be entirely under the influence of the heart, and circu- 
lates by the influence of the insensible organic contrac- 
tility of the vascular parietes; but how can this line of 
demarcation be rendered evident to the eye ? 
Authors in treating of the termination of the arteries, 
have considered their continuity with the excretories, the 
exhalants, the veins, &c.; but it is evident that the gene- 
ral capillary system is between the arteries and these ves- WITH RED BLOOD. 
301 
sels. Thus I shall treat of their origin in speaking of this 
system, which is spread in all the organs, but has essen- 
tial differences according to the different systems, under 
the relation of its continuity with the arteries. In fact, 
1st. there are systems in which these vessels are distri- 
buted in great quantity, and in which consequently the 
general capillary system contains much blood; such are 
the glandular, the mucous, the cutaneous, the animal and 
organic muscular, &,c. 2d. Other systems receive but 
few arteries, as the osseous, the fibrous, the serous, &c. 
and consequently have but little blood in circulation in 
that portion of the general capillary system that belongs 
to them. 3d. Finally the pilous, epidermoid, cartilagi- 
nous systems, &c. destitute of arteries, contain only white 
fluids in the division of the general capillary system that 
has its seat in them. 
ARTICLE THIRD. 
ORGANIZATION OF THE VASCULAR SYSTEM WITH RED BLOOD. 
I. Textures peculiar to this organization. 
The red blood circulates, as I have said, in a mem- 
brane arranged in the shape of a great canal, variable in 
its form, extended from the pulmonary capillary system to 
the general one, and having every where the greatest 
analogy. At the exterior of this membrane, nature has 
added a fibrous coat for the arteries, fleshy fibres for the 
heart, and a peculiar membrane for the pulmonary veins. 
I shall speak here only of the arterial coat. The fibres 
of the heart and the membrane of the pulmonary veins 
will be examined, one in the organic muscular system, 
the other in the system with black blood. As to the in- 
ternal membrane of the arteries, which is also that of the 302 
VASCULAR SYSTEM 
whole system with red blood, we shall examine it in a 
general manner. 
This membrane is firm, compact, very apparent in the 
great arteries, less evident in the last divisions where it 
is insensibly lost. Its colour is usually every where the 
same. If the branches appear red in living animals, and 
the trunks yellowish, it arises only from the transparency 
of the one which allows the blood to be seen, and the 
opacity of the others. The colour of the arterial fibre is 
yellowish. However it assumes in certain cases a grey- 
ish appearance. I have often observed in arteries ex- 
posed to maceration, that it reddens in a very evident 
manner at the end of some days, or rather that it takes a 
rosy tinge, very analogous to that of the cartilages of the 
foetus and of the fibro-cartilages of the adult, submitted to 
the same experiment. This result is however less uniform 
in the arteries than in those two systems, in which it is 
never absent. Sometimes the internal membrane red- 
dens also, but never the external or cellular; on the con- 
trary, the longer this remains in water the whiter it be- 
comes. When the fibrous coat of the arteries has con- 
tinued some time with this redness, it gradually loses it, 
if maceration is continued. This phenomenon is often 
more evident in the branches than in the trunks. For 
example, the arteries at the base of the cranium become 
red very frequently in the dead body, by remaining in 
the fluids with which this part is moistened. We see, in 
opening the cranium, this redness which does not belong 
to the blood left in the arterial cavities, as we may be 
easily convinced. 
The thickness of the peculiar membrane of the arteries 
is very evident in the great trunks. It constantly dimin- 
ishes ; a circumstance that distinguishes it essentially from 
the internal membrane, which I have found almost as thick 
Peculiar Membrane of the Arteries. WITH RED BLOOD. 
303 
in the tibial artery as in the aorta. It has been thought 
that in certain arteries, as in the cerebral, the fibrous 
coat is entirely wanting. There is no doubt that in the 
vertebral and internal carotid it is thinner in proportion 
than in equal trunks situated in the muscular interstices; 
but by examining attentively these arteries, I have clearly 
distinguished circular fibres in them. Has the thinness 
of their parietes an influence upon the sanguineous effu- 
sions, which are, as we know, so frequent in the brain ? 
I cannot say. These effusions take place only in the ca- 
pillaries, the trunks are never the seats of them; now it is 
impossible to examine these capillaries. I have sought in 
vain to ascertain by injections the vessels torn in apoplexy. 
Besides, this hemorrhage does not resemble that of the 
serous membranes; it is not an oozing through the exha- 
lants of the ventricles ; for these cavities are very rarely 
the only seat of it. Almost always these effusions take 
place even in the cerebral substance, generally nearer the 
posterior than the anterior lobe. The cerebellum is rare- 
ly affected by it. When the tuber annulare becomes so, 
there are often small partial effusions there, separated by 
medullary partitions that remain uninjured. 
As to the arteries of the other parts of the body, their 
peculiar membrane presents generally a pretty uniform 
arrangement. It has appeared to me however, that in 
the interior of the viscera, of the liver, of the spleen, it is 
rather thinner than in the intermuscular spaces, and even 
than in the muscles. 
This membrane is composed of very distinct fibres, ad- 
hering to each other, easily separated however, arranged 
in layers, in such a manner that after having raised the 
cellular covering, we can without difficulty separate these 
different layers from each other; it is this that has made 
many authors believe that the great arteries were compos- 
ed of a great number of coats. The fibres that form these 
layers are circular or nearly so; the external ones appear 304 
VASCULAR SYSTEM 
to be attached to the compact cellular texture that is con- 
tiguous. In fact, by raising this, a number more or less 
considerable adheres to it always in an intimate manner. 
As to the internal membrane, it does not appear to fur- 
nish any attachment; we raise it easily, without bringing 
with it any arterial fibres. The manner of the adhesion 
of these fibres with the compact neighbouring texture, 
appears to me to have great analogy with the origin of 
the organic muscular fibres, which are attached in a great 
number of places, to the sub-mucous texture. 
When a branch arises from a trunk, the circular fibres 
of the last separate and form on each side a half ring, 
whence arises a complete one, which embraces the small 
rings formed by the circular fibres of the arising branch. 
These circular fibres go even to the eminence of the com- 
mon membrane, which is seen within the arterial cavity 
and of which I have spoken; so that the whole thickness 
of the peculiar membrane serves as a support to their ori- 
gin. But there is but little continuity between the two 
kinds of fibres. Those of the branch do not arise from 
those of the trunk; it is the internal membrane that 
serves to fix them together, as fibres of communication. 
Dissection shows easily these branches set at their origin 
in the ring which arises from the separation of the circu- 
lar fibres. We remark this at the origin of the intercos- 
tals and lumbars upon the aorta, &c. When two trunks 
of an equal size go off, as the iliacs, the last circular fibres 
of the primitive trunk which they formed, interlace inti- 
mately with the origin of each of the two circular layers, 
that arise at the fork that separates this origin. Thus 
the last rings of the aorta cannot be separated from the 
first of each iliac. 
There are no longitudinal fibres in the arteries. 
W'hat is the nature of the arterial fibre? Almost all 
anatomists have considered it the same with the muscu- 
lar. But if we examine them attentively, it is easy to WITH RED BLOOD. 
305 
be convinced of their differences. The want of red col- 
our does not establish these differences, since in man 
even, some parts really muscular, as the intestines, want 
this colour. But the muscular texture is soft, loose and 
very extensible; the arterial texture on the contrary is 
firm and solid, breaks before it yields. We can observe 
this, by tying an artery tight. The two internal coats 
are cut; the cellular alone is not, though the ligature is 
immediately applied to it; we observe, by opening the 
artery, a section corresponding with the thread, exactly 
similar to what a cutting instrument would have made. 
I have often repeated this experiment, pointed out by 
Desault, upon the dead body, and upon living animals; 
the result which is very uniform, explains the frequency 
of hemorrhages after the operation for aneurism. There 
is undoubtedly no texture so brittle, if I may use the word, 
as the arterial, none consequently less proper to be em- 
braced by ligatures. Why is it that this should be the 
only one in which it is necessary to apply them? This 
phenomenon alone would distinguish the arterial texture 
from the muscular. In fact, the preceding experiment, 
made upon a portion of intestine in which the fibres are 
arranged like the arterial, would produce a flattening, an 
approximation of these fibres, but would not cut them. 
Moreover compare the properties of texture of the arte- 
ries with those of the muscles; compare their vital prop- 
erties, by examining the articles in which I treat of these 
properties; compare their development, and especially 
the different morbid alterations to which the two are sub- 
ject, and you will see that there is not a single relation in 
which they have the least analogy. The aneurism of the 
heart and that of the arteries have nothing in common 
but the name. In one there is a rupture of the arterial 
fibres, a dilatation of the cellular coat; in the other an un- 
natural increase, a real development of muscular fibres 
which preserve their appearance and their properties. 306 
VASCULAR SYSTEM 
Notwithstanding the ease with which the arterial fibres 
are broken in cases of aneurism, they enjoy in a natural 
state a very considerable degree of resistance and force; 
another character that distinguishes them from the fleshy 
texture. The following are the proofs of this resistance, 
which takes place both transversely and longitudinally. 
1st. If we tie the carotid artery above, and drive a fluid 
afterwards into it, great force must be employed to break 
its texture. The same thing happens when we force in 
air instead of a liquid. Frequently the efforts of a man 
are insufficient to produce a rupture; thus the force of 
the heart can never cause it suddenly ; so that the forma- 
tion of aneurisms takes place only from the long continu- 
ed action upon the arterial parietes; I doubt whether 
these tumours can be formed, without a previous altera- 
tion of the arterial texture, by the force of the impulse of 
the blood alone against the weak parietes of the arteries. 
2d. the resistance of these parietes takes place longitudi- 
nally also. If we draw in a contrary direction, the two 
ends of an artery and of a muscle, we effect with more dif- 
ficulty the rupture of the first, when the dead body is the 
subject of this comparative experiment. But upon the 
living the effect is opposite; the vessel yields to a very 
strong action made upon it; it would be necessary that 
this action should be incomparably greater to divide the 
muscle. This difference arises evidently from the vital 
properties of the latter, w'hich in this case contracts vio- 
lently, whilst the artery can make no further resistance 
than from the nature of its texture. Besides, this longi- 
tudinal resistance to distension is less than the lateral re- 
sistance opposed to the injection; experiments prove it, 
and it arises without doubt from this, that no fibre, in the 
first case, is found directly opposed to the effort. 
This resistance of the arterial texture, so different from 
that of the venous, is a necessary consequence of the situ- 
ation of the heart at the origin of the arteries. In fact, WITH RED BLOOD. 
307 
this organ driving the blood with force into their tubes, 
should find there a force capable of resisting the greatest 
efforts of which it is susceptible, when its sensible organic 
contractility is raised to a high point. This is the great 
advantage of the arterial texture. What would become 
of the circulation and all the functions that depended 
upon it, if the least cause which increased the force of the 
blood could dilate the parietes of the arteries beyond the 
ordinary degree? It was necessary that their texture 
should render these parietes independent of the different 
degrees of motion of the fluid that circulates in them; 
whence it follows that a fleshy heart and resisting arte- 
ries are two things inevitably connected. If nature had 
doubled the energy of the heart, she would have doubled 
also the arterial resistance. On the other hand, they 
would have had but little resistance, if there had not been 
an agent of impulse at their origin ; this is precisely what 
happens in the hepatic portion of the vena porta, which 
by its distribution is analogous to the arteries. Why is 
the pulmonary artery thinner and less resisting than the 
aorta? Because the right ventricle being less fleshy, is 
not capable of so great efforts. 
From what has been said, it appears, that the external 
arterial membrane resembles the fibrous organs, which, 
as we shall see, are characterized by an extreme resist- 
ance. But if we observe on the other hand that this mem- 
brane can be broken, raised by layers and scales in dis- 
section, that it is elastic and even dry, if I may so say, 
whilst the fibrous organs are compact, form a solid body, 
resisting, but softer and more elastic, we shall be con- 
vinced that this external membrane is exclusively pecu- 
liar to the arteries ; that it has no relation with the other 
systems, but forms a distinct and separate texture in the 
economy. The structure with regular fibres, is the only 
circumstance that can, in my opinion, make us believe 
in the muscular nature of the arteries; but the ligaments VASCULAR SYSTEM 
308 
and tendons are fibrous also ; of what importance are the 
forms to the intimate nature ? Now, can we say that this 
nature is the same, when the physical properties, when 
the extensibility and contractility of texture, when the 
vital sensibility and contractility are different? 
Besides, the action of different re-agents upon the arte- 
rial texture, proves clearly how much it differs from the 
muscular. There are then general phenomena common 
to all the solids; but different peculiar phenomena that 
are distinctive. We may satisfy ourselves of this, by com- 
paring the following article with that which corresponds 
with it in the muscular system. 
Action of different agents upon the arterial texture. 
The action of the air by drying the arteries gives them 
a colour of a reddish yellow, very deep and even black- 
ish in the great trunks, more clear in the smaller ones. 
Thus dried, the arterial texture is almost as hard as the 
cartilages in the same state, extremely brittle, breaking in 
the great trunks with a crackling noise, that is not per- 
ceived in any other animal texture. It is especially in 
this preparation, that we see how much the cellular cov- 
ering of the arteries differs from their peculiar texture. 
This covering remains pliable; it is whitish when raised 
up separately. Immersed again in water, the arteries 
assume in part their natural arrangement. 
In drying, the arterial texture loses but very little of 
its thickness; this is a phenomenon that distinguishes it 
from most of the other textures. It arises from the small 
quantity of fluid that is contained between its layers, a 
circumstance that appears to be owing to the absence of 
the cellular texture. In opening the arterial layers, the 
kind of dryness they exhibit is remarkable, when compar- 
ed with the moisture in which the muscular fibres are 
immersed. WITH RED BLOOD. 
309 
Exposed wet among other organs to the action of the 
air, the arteries putrefy with great difficulty. Their tex- 
ture resembles in this respect that of the cartilages, the 
fibro-cartilages, &c.; it is like them for some time almost 
incorruptible; when it is left to putrefy by itself, it gives 
out an odour much less foetid than that of other textures; 
there appears to be less ammonia disengaged from it. 
The absence of foetor is also very remarkable in the wa- 
ter in which the arteries have been macerated, entirely 
separated from every neighbouring texture. By com- 
paring this water with that in which muscles have been 
macerated, the difference is striking. An evident proof 
of the resistance of the arteries to putrefaction and ma- 
ceration, is what is observed in the viscera, which have 
been a long time macerated or which are putrid, as in 
the liver, the spleen, the kidnies, &c. In both cases, in 
the first especially, these viscera are reduced to a kind of 
pulp; the arteries however have preserved their texture 
still hard, amid this general softening. By removing 
carefully the putrid substance, we can follow them even 
to their final ramifications. This method of seeing the 
arteries is easy, whether they are filled by injection, or 
left empty. In the living animal, these vessels are also 
infinitely less susceptible of putrefaction than the skin, 
the cellular texture, &c. An artery often passes through 
a mortified part without undergoing any alteration from 
it; this is frequently seen in gun-shot wounds. 
At the end of a period, very different according to the 
degree of temperature, the arterial texture yields finally 
to maceration and putrefaction. In the first case, it sof- 
tens gradually without changing colour, loses the adhe- 
sion of its fibres, and is ultimately* resolved into a pulp 
almost homogeneous and greyish. In the second case, it 
becomes greyish at first, then is reduced also to a pulp, 
and when all the fluid part is evaporated, there is left a 
kind of coal wholly different from that which remains 310 
VASCULAR SYSTEM 
after the putrefaction of the muscles. In general, it re- 
quires much longer time to soften the arterial texture by 
maceration than by putrefaction ; which shows the supe- 
riority of the action of the air over that of water, in the 
production of this phenomenon. 
Exposed to the contact of caloric, the arterial texture 
curls up, contracts and exhibits the horny hardening in 
the highest degree. If the action of water is added to 
that of caloric, which produces boiling, the following is 
the result of it. 1st. Very little froth rises before ebulli- 
tion, from the vessel that contains the arterial texture ; 
we might say that this texture and the muscular present 
in this respect, two opposite phenomena in the economy ; 
the small quantity of froth that arises from the first, is 
greyish. 2d. At the moment of ebullition, there is an 
evident horny hardening, less however than that of the 
nervous texture, more sensible in the direction of the 
diameters than in that of the axis ; a hardening accompa- 
nying this horny hardening, and a yellowish tinge of 
the liquor. 3d. This state continues for half an hour 
or more, ebullition constantly going on. 4th. Successive 
softening; but at the same time a greyish tinge succeed- 
ing to the yellow colour; want of adhesion among the 
fibres, increasing as the ebullition goes on, so that they 
break with great ease. 5th. However prolonged may 
be the ebullition, the arterial texture is never reduced, 
like the fibrous, the cartilaginous, &c. to a gelatinous and 
yellowish pulp. The fibres remain as they are, in the 
same relation, with the same size, &,c. The want of 
adhesion and the change of colour are almost the only 
phenomena they experience. 5th. The broth, produced 
by the boiling, is insipid and tasteless, a proof how few 
neutral salts the arterial texture contains. 
The action of the concentrated acids curls this texture, 
afterwards softens it, finally dissolves it in the form of a 
pulp,yellow ish by the nitric, and blackish by the sulphuric. WITH RED BLOOD. 
311 
Most of the others have a less sensible action than these 
two. When they are diluted, there is no horny harden- 
ing at the moment the artery is immersed in them; but 
its texture is gradually softened, and can be broken with 
the least effort, as after boiling. It is never reduced to 
a fluid state, how long soever it may continue in the 
acid. 
The alkalies, even the caustic, have but little action 
upon the arterial texture; immersed a long time in them, 
this texture remains almost untouched, loses but little by 
solution, cannot be broken as it can after being in the 
diluted acids, &c. 
Membrane common to the system with Red Blood. 
I call that the common membrane which lines the 
arteries, the left side of the heart and the pulmonary 
veins. It can be dissected with ease upon these two last 
organs. To separate it from the arteries, it is necessary 
to cut through by a very superficial circular section, the 
external fibrous layer, raise this layer by laminas from 
below upwards; we come then to the internal membrane, 
which adheres but little to the preceding, and can be 
detached from it in the form of a canal, of very 
great extent. It is distinct from it, 1st. by its extreme 
tenuity, and the transparency that results from it; 2d. 
by its white colour; for it appears yellow only by being 
applied to the preceding ; 3d. by the entire want of fibres. 
It is smooth and with a uniform texture like the serous 
membranes, which we may be convinced of by holding 
it up to the light. Besides, it differs essentially from 
these membranes by a kind of brittleness that character- 
izes it; it is broken and torn by the least effort. The 
whole resistance of the arteries resides in their fibrous 
coat. 
It appears that this membrane, though every where 
connected, has however some differences of structure in 312 
VASCULAR SYSTEM 
the different regions. 1st. It is evidently more delicate 
in the interior of the ventricle with red blood, than in 
the corresponding auricle and in the arteries. Qd. It 
yields in the heart and in the pulmonary veins, to dilata- 
tions much greater than those of which it is susceptible 
in the arteries, in which it would inevitably break, like 
the proper membrane, if the blood could produce as great 
differences of size in it, as it does in these organs. 3d. 
When we macerate the heart for some time, this internal 
membrane acquires in the auricle and upon the mitral 
valves, a very remarkable whiteness, and which is foreign 
to it in all the rest of its course. 4th. As to the action 
of the different agents, of the air, of water, of caloric, &c. 
it appears to me to be the same every where, and resem- 
bles precisely that upon the peculiar membrane. Only I 
have thought, that in the small arteries, the common 
membrane has the horny hardness more than this, which 
on this account wrinkles on the interior in different 
places, when a whole branch is immersed in boiling 
water; this does not take place in the great trunks. 
It is evident from this, that though the common mem- 
brane of red blood, is every where continuous, it is not 
uniform in its structure ; we shall have occasion to make 
an analogous observation for the different portions of the 
two general mucous surfaces. 
The internal surface of this membrane is moistened in 
the dead body, by an unctuous fluid, that is found in 
greater or less quantity. Does this fluid exist in the liv- 
ing? does it serve to defend the arterial coat from the 
impression of the blood ? It is difficult to determine. 
We know of no organ fitted to furnish it; it would arise 
from the exhalants, if its existence, as many authors have 
admitted, was real. It would be well to ascertain as to 
its existence, whether it was merely a transudation after 
death, analogous to that of the bile through the gall blad- 
der, or the consequence of a little serum remaining in the WITH RED BLOOD. 
313 
arteries after the expulsion of the blood. What makes 
me suspect so is, that these arteries being deprived of 
blood, contract intimate adhesions on their internal sur- 
face; which their fluid ought to prevent, as that of the 
mucous tubes does, which should they cease to transmit 
their respective substances, as the excrements for exam- 
ple, the secreted fluids, &c. would never be obliterated 
because of this fluid. 
It appears then that it is the membrane itself, and not 
a fluid that escapes from it, which serves to protect the 
artery; it can, in this point of view, be considered in re- 
lation to the blood, as a kind of epidermis. It is this, 
which by its folds contributes especially to form the 
aortic and mitral valves, and the different eminences at 
the origin of the branches, smaller branches, &.c. The 
external surface, feebly united to the other membrane as 
we have seen, has not an intermediate cellular one. 
Notwithstanding this slight adhesion, no means, boiling 
water, maceration, putrefaction, &c. can detach one of 
these membranes from the other, as takes place in the 
periosteum from the bone, which, are naturally much 
stronger united ; it requires always the aid of dissection. 
What is the nature of this common membrane? I am 
entirely ignorant; though with a different appearance it 
has the greatest analogy with the preceding coat, in its 
properties. We cannot class them in any system. They 
form a separate texture in the economy, a texture that 
has properties entirely distinct. 
When we dry the common membrane of the arteries 
by itself, it is infinitely more pliable than the other. It 
remains transparent, the other does not. As to the phe- 
nomena of the other re-agents, except the homy harden- 
ing, they are nearly the same. 
This membrane is remarkable, in all the organic sys- 
tems, for the singular tendency it has of being ossified in 
old age. I have been able to satisfy myself, that out of 314 
VASCULAR SYSTEM 
ten subjects, there are at least seven that have incrusta- 
tions after the sixtieth year. These incrustations, having 
no connexion with the peculiar fibrous membrane, begin 
uniformly on the external surface of this, the most exter- 
na! part of which they attack ; for there always remains 
over the incrustation a kind of pellicle that separates it 
from the blood, and which belongs to the membrane ; the 
earthy substance is never immediately in contact with 
this fluid. 
These incrustations do not follow any of the laws of 
ordinary ossification. The cartilaginous state rarely pre- 
cedes them. The saline substance is deposited immedi- 
ately upon the exterior of the common membrane by the 
exhalants. It is always in separate plates, more or less 
broad, that this exhalation is made ; rarely the whole of 
the artery forms a solid continuous tube; so that the 
membranous portions remaining between the plates can 
be considered as serving for articular connexions, and 
that the arteries, thus ossified, are composed of many 
pieces moveable upon each other, and being able to a 
certain extent to adapt themselves to the circulating 
motion. 
As long as these plates remain thin, the interior of the 
artery is as usual smooth and polished. But if many 
saline substances are deposited there, they then have a 
greater thickness and make a projection within. The 
fine pellicle that covers them and which is continued 
upon the artery, is broken; then they adhere only by 
their external surface to the peculiar membrane. Their 
circumference is unequal and rough. If there is a great 
number in the artery, the whole internal surface presents 
numerous asperities, produced by the rupture of this ex- 
tremely fine layer of the common membrane that covers 
the osseous plates. This arrangement is particularly 
remarkable at the origin and even in the course of the 
aorta. I have noticed it frequently in the dissecting WITH RED BLOOD. 
315 
rooms. Since I have practised medicine in the hospitals, 
I have already opened three or four subjects that have 
exhibited this arrangement, in which the heart was per- 
fectly untouched, but who died however with most of the 
symptoms that accompany diseases of that organ. The 
rupture of the fine pellicle when the osseous plates be- 
come large, arises from the remarkable brittleness that 
we have observed in the common membrane, of which it 
is an appendage. 1 have never seen these osseous platea 
entirely detached, and become loose in the artery. 
All the parts of the arterial system are subject to ossifi- 
cation. It appears as frequent in the branches as in the 
trunks. We know how common it is to find the radial 
ossified, in feeling the pulse of an old person. The rami- 
fications appear to be less frequently the seat of these in- 
crustations, which never take place in the capillary sys? 
tern ; a circumstance that would induce me to believe 
that the common membrane of the arteries does not ex- 
tend to this system, but that it changes gradually into a 
different texture. 
It is not only in the arteries that the common mem- 
brane of the system with red blood is penetrated with 
saline substance; this often happens to it in the heart, 
especially in the aortic and mitral valves. It is more 
rare upon the internal surface of the left ventricle and 
auricle and the pulmonary veins. I have had how- 
ever examples of these last. This general disposition to 
ossification in its whole course, proves that its nature is 
every where the same, and that notwithstanding the dif- 
ferences pointed out, I have had reason to consider it in 
an uniform manner, from the pulmonary capillary system 
to the general; for as I have already observed, an identity 
of diseases supposes an identity of nature. It is the fre- 
quency of ossifications of this membrane in the heart of 
old people, which renders extremely frequent the inter- 
mission of the pulse at that age. The ossification of the 316 
VASCULAR SYSTEM 
origin of the aorta has an influence also upon the circu- 
lation, as I have ascertained ; but that of the trunks, 
branches, &c. does not produce the least derangement. 
The ossification of the common membrane of the sys- 
tem with red blood differs essentially from those that 
happen in other parts, in this, that it is, if we may so say, 
a natural phenomenon, whereas the others are accidental 
and often preceded by inflammation and engorgement. 
Thus these ossifications do not follow the progress of age ; 
they happen in young people and in adults, as often as in 
old ones. Before old age, the ossifications of this mem- 
brane are observed also, but infinitely more rarely than 
at this age. The diseases of the heart which the ossifica- 
tion of the mitral valves accompanies and often alone 
constitutes, are a remarkable proof of this. A phenome- 
non has struck me many times upon this subject; such an 
ossification as an old man can live with very well, and 
which only makes his pulse intermittent, produces in the 
adult the most serious consequences. I have already 
opened many subjects, who had been affected with diffi- 
culty of breathing, frequent suffocation, cough, irregularity 
of the pulse, necessity of an erect position of the trunk, 
and in the later periods, infiltration, serous effusion in the 
thorax, spitting of blood, &,c. and in whom I have found 
only ossification of the mitral valves, less than we see 
every day in the bodies of old people in our dissecting 
rooms. I confess that even this natural disposition to 
ossification in the common membrane of the system with 
red blood, had made me think that they had exaggerated 
a little the cases in which this ossification becomes, in the 
adult and even in the old man, when it is very strongly 
marked, the cause of that series of phenomena, whose 
assemblage forms the asthma of most physicians. But 
the practice of the Hotel Dieu shows me every day, that 
these cases of ossifications, those of aneurisms and those 
of other organic affections of w hich the heart is the seat, WITH RED BLOOD. 
317 
form a class of chronic diseases almost as numerous as that 
of the chronic diseases of the lungs, to which generally 
were referred all the diseases of the chest, before the 
time of Corvisart. 
II. Parts common to the organization of the Vascular 
System with Bed Blood. 
Blood Vessels, 
The parietes of the arteries contain secondary arteries 
destined to their nutrition. These arteries come usually 
from neighbouring branches, sometimes from the artery 
itself, whose capillary divisions terminate in the texture 
of its parietes. The heart exhibits this arrangement. 
At its exit, the aorta sends off the coronaries which are 
spread upon the texture of this organ and upon the ori- 
gin of this artery itself. The bronchials furnish the pa- 
rietes of the pulmonary veins. In the arterial texture, in 
which it is especially necessary to examine the little arte- 
ries, they wind at first in the cellular texture exterior to 
the artery, they ramify there in a thousand ways, send 
some divisions to the neighbouring organs, but furnish a 
great number that penetrate the peculiar membrane, are 
interposed between its layers, leave filaments there and 
terminate before they arrive at the internal membrane. 
I have never seen, either by injections, or by opening in 
a living animal an artery in which I had first stopt the 
course of the blood above and below, as for example, the 
carotid, I have never seen, 1 say, the little arteries pene- 
trating even to this internal membrane. To distinguish 
well without injections, the vessels of the arteries, it is 
necessary to choose on one hand a great trunk like the 
aorta, and on the other to take this trunk in a young 
animal that has been kided for the purpose by asphyxia; 
all the little arteries then are perfectly injected with a 
very black blood. Examine the arteries of the foetus, 318 
VASCULAR SYSTEM 
especially if it has died by asphyxia at birth, you will 
be struck with the great abundance of blood vessels that 
its great arteries contain and which are sometimes as 
livid as in asphyxia. 
The veins accompany every where the little arteries 
in the parietes of the arterial trunks, they follow nearly 
the same distribution. I have not seen them become 
varicose in the parietes of aneurismatic arteries, in as 
evident a manner, as in the tumours of many other tex- 
tures of the animal economy. 
Cellular Texture. 
The arteries have around them two kinds of cellular 
texture ; one, which is very external, loose, fatty, full of 
serum, with distinct layers, unites them to the neighbour- 
ing parts, favours their motions, is in no way distinct 
from the rest of the cellular system ; the other, firm, com- 
pact, not fatty, filamentous and not lamellated, forms the 
first of their coats. We have spoken in treating of the 
cellular system, of this particular layer that covers the 
arteries, which authors commonly call the cellular coat, 
which the ancients called nervous, on account of its 
whiteness, and which, analogous in every respect to the 
sub-mucous, sub-excretory cellular texture, &c. differs 
essentially from the preceding, as it differs from that 
which is in the interior, around or in the interstices of 
the organs. 
These two kinds of cellular texture, the last especially, 
contribute to support the folds of the arteries; as when 
we have carefully dissected the peculiar coat, these folds 
entirely disappear. However when they are on one hand 
strongly' marked, and on the other, are not subject fre- 
quently to disappear in yielding to the elongation of the 
parts, as in the internal carotid in its canal, 1 have ob- 
served that the arterial fibres are accommodated to these 
folds; that the fibres are more numerous on the convex WITH RED BLOOD. 
319 
aide, than on the other, so that the thickness of the arte- 
ry is exactly uniform, which it would not be without 
this inequality; for being more pressed on the concave 
side, these fibres would make the art6ry thicker at that 
place. 
The cellular texture forms the first membrane of the 
arteries, and gives as we have seen insertions to the arte- 
rial fibres, but it does not extend into the interstices of 
these fibres; it is this that distinguishes essentially the 
layers of the arterial texture, from those of the muscular, 
venous textures, &c. 1 have never been able to discover 
the cellular texture there by any means that I could em- 
ploy. Maceration, of which Haller has said so much, 
does not show any thing like it. When at the end of a 
very long time, the arteries finally yield to it, they exhibit 
only a kind of pulp, in which there is no cellular appear- 
ance. 
In general, the resolution of the organs into cellular 
texture by maceration, exhibits a phenomenon much less 
extensive than is generally thought. It is the organic 
texture itself that forms the kind of pulp that is then ob- 
tained. As this texture varies in each system, the pulp 
of these systems, a long time macerated, varies equally; 
this undoubtedly would not happen, if, as Haller has ad- 
vanced, the cellular texture was the only base, to which 
all the organs are brought by maceration. But let us re- 
turn to the arteries. 
Not only their fibres are not formed of cellular texture; 
but as I have said, they do not contain it in their intersti- 
ces, a character in which it differs from all the other sys- 
tems. The most careful dissection does not show it. 
When we separate the fibres from each other, we see, 
either that they are merely in apposition, or that they are 
held by little elongations of the same nature as them- 
selves. I have said that this absence of the cellular tex- 
ture is observable between the proper and common mem- 320 
VASCULAR SYSTEM 
branes of the arteries, though Haller has pretended the 
contrary. 
I believe that this absence of cellular texture contributes 
much to the kind of brittleness that particularly distin- 
guishes the arterial texture, and which, as I have observed, 
renders it the least fit of all the animal textures, to sup- 
port ligatures without breaking. It is to this circum- 
stance also that must be referred the difficulty, the im- 
possibilitjr even of arterial dilatations, of the formation 
of cysts by the parieties of arteries. There are never, 
we know, true aneurisms; when these tumours increase 
at all, the two membranes of the artery break and the 
cellular coat alone is dilated. Hence the necessity of the 
peculiar structure which distinguishes the cellular tex- 
ture placed around the arteries, and gives it a resistance 
that it has not in most other parts. Authors are aston- 
ished at these ruptures which distinguish the dilatations 
of the arteries from those of all the other systems. If 
they had compared the texture of the arteries with that 
of the other systems they would have seen the reason of 
this difference. 
We easily understand, after what has been said, why 
there is never fat in the arterial texture; why it is never 
infiltrated in dropsies; why it does not develop hydatids 
and cysts in its layers, why the different tumours, for 
which the cellular texture serves as a base, as we have 
seen, do not appear in the arteries, &c. When an artery 
has been wounded, either longitudinally or transversely, 
we do not see fleshy granulations arise from the edges of 
the wound ; I do not know that surgeons have seen them in 
the operations for aneurisms. Never, in the numerous 
cases in which I have had occasion to cut the arteries, in 
animals, and then leave them free, after having interrupt- 
ed the course of the blood, have I observed any thing like 
it. If an arterial trunk is laid bare, the cellular coat often 
furnishes these granulations; but we never see them, if 
this coat is removed. WITH RED BLOOD. 
321 
Are there exhalants in the arteries ? Nutrition undoubt- 
edly supposes them ; but it is not probable, as I have said, 
that they open upon their internal surface. 
As to the absorbents, I thought for some time, that the 
absence of blood in the arteries, after death, arises from 
this, that their lymphatics preserving still the absorbent 
faculty for some time, take up the serum which is separated 
from the crassamentum. But lately experiments have 
undeceived me. I have enclosed blood, water, the fluid 
of dropsies, &c. between two ligatures made above and 
below on the common carotid, the body of which had 
been so managed on the exterior as not to break the ves- 
sels that come to it. At the expiration of a considerable 
time 1 have not discovered any diminution in the fluid. 
There had been then no absorption. I would observe 
that on account of the want of collateral branches, the 
carotid is alone proper for these experiments, and a vari- 
ety of other analogous ones. 
We know that the absorbents abound where there is 
cellular texture, and that they are wanting usually where 
there is none. It is probable then that the absence of 
this texture produces also the absence of these vessels. 
Exhalanls and Absorbents. 
Nerves. 
1st. The first tree of the system with red blood, re- 
ceives almost exclusively cerebral nerves. We know in 
fact, that the par vagum is spread upon all the pulmonary 
veins, as well as upon the neighbouring vessels of the 
lungs, which hardly receive any from the inferior cervi- 
cal ganglion. 2d. The middle portion of this system, that 
in which the heart is found, derives its nerves almost as 
much and even more, from the ganglions, than from the 
brain. 3d. The great tree with red blood, or the arterial, 
is almost exclusively embraced by the first class of nerves. 322 
VASCULAR SYSTEM 
We have said how these nerves go in this respect. 
The cerebral which accompany them, furnish hardly any 
filaments to the arteries. There is merely juxta5 posi- 
tion as we see it in the extremities, in the intercostal 
spaces, &c. 
I cannot repeat it too much, that the constant relation 
of the arteries with the nervous system of the ganglions, 
deserves the attention of physiologists, because it is too 
general not to belong to some great object of the functions 
of the economy, though the object may be unknown. 
ARTICLE FOURTH. 
PROPERTIES OP THE VASCULAR SYSTEM WITH RED BLOOD. 
What we have to say of these properties, will refer 
particularly to the arteries, as well as what we have said 
of the organization. In fact the fleshy parietes of the 
heart and the membranous ones of the pulmonary veins, 
possess properties that will be examined hereafter, and 
which differ from those of the arteries, on account of the 
the difference of texture. As to those of the common 
membrane they are nearly the same in the whole course 
of the red blood, the organization differing but very little. 
I shall consider the properties of the arteries only in 
the arterial texture and in the common membrane; for 
the cellular coat belonging to the system of that name, 
partakes of all its properties. 
I. Physical Properties. 
Elasticity, which is obscure iu most of the other animal 
textures that are characterized by a great degree of soft- 
ness is very remarkable in the arteries ; it is this that par- 
ticularly distinguishes them from the veins. This elasti- 
city keeps their parietes apart, though they may be empty. WITH RED BLOOD. 
323 
These tubes, with the cartilaginous, as the trachea, the 
meatus auditorius of the foetus, &c. which are equally en- 
dowed with elasticity, are the only ones that keep thus 
open of themselves. All the others have their parietes 
applied to each other, when the fluid that runs through 
them does not distend these parietes. 
It is to the elasticity of the arterial parietes that must 
be referred their recovering themselves when they have 
been flattened so as to obliterate their cavity, the sudden 
straightening of an arterial tube that has been bent, &c. 
This property takes also an evident part in that kind 
of locomotion the arteries have upon the entrance of the 
blood. In fact, lay bare a tortuous arterial trunk in a liv- 
ing animal, you see the whole of it rise at each pulsation, 
leave the place it occupied, and straighten itself, particu- 
larly at its curves. • At the moment the injection pene- 
trates a very thin small subject, we perceive also through 
the integuments, a locomotion of all the tortuous branches 
of the face. Now it is evident that if the arteries were 
not of a firm and elastic texture, they would not thus obey 
the motion that is impressed upon them; besides, ob- 
serve what takes place in the injection of the abdominal 
branches of the vena porta, which having no valves can 
be injected like arteries. Nothing similar to the locomo- 
tion of which I spoke is observed in driving the fluid into 
them. I have often made arterial blood circulate in the 
veins by the means of curved tubes, fitted to the vessels of 
a living animal, for example, by making the carotid and 
external jugular communicate; now, we observe clearly in 
the veins carrying the red blood, a kind of pulsation syn- 
chronous with the beating of the heart, and a distinct 
rustling noise, but not a real locomotion. 
The locomotion of the arteries supposes three things, 
1st, an agent of impulse, that communicates a motion 
more or less strong, to the blood contained in their inte- 
rior; 2d, a tortuous arrangement which allows the blood 324 
VASCULAR SYSTEM 
in striking their parietes to straighten them; 3d, the firm- 
ness and elasticity of these parietes which facilitate this 
straightening. On the other hand, the parietes must not 
be loo firm ; thus the cartilaginous texture would be im- 
proper for this locomotion. 
The elasticity of the arteries is as striking after death 
as during life ; it is essential to distinguish it from con- 
tractility of texture. There are many distinctive charac- 
ters, the following are the most striking ; 1st. The con- 
tractility of texture takes place only when there is a want 
of extension of the arterial parietes, that is to say, when 
these vessels cease to contain the blood which resists their 
contraction, or when they are cut and afterwards left to 
themselves. On the contrary, elasticity requires for its 
exercise, a previous compression and is manifested by the 
sudden return of the parts to their natural state. 2d. 
Contractility of texture has a permanent tendency to con- 
traction ; we may say that ail the parts that possess it 
are in a forced state ; so that as soon as this state ceases, 
contraction takes place. On the contrary, elasticity has 
not this constant tendency to exercise. 3d. Every elas- 
tic motion is brisk, sudden, as quick to stop as to begin. 
On the contrary, every motion of contractility of texture 
is insensible, slow, continues often many hours and even 
days, as we see it in the retraction of amputated muscles, 
&.c. 4th. Every organ in which there is contractility of 
texture, enjoys necessarily extensibility. On the con- 
trary, this last property is not necessarily connected with 
elasticity, as we observe it in the cartilages of animals, 
&c. 5th. Elasticity is purely a physical property. Con- 
tractility of texture, without being vital, is only inherent 
in the organs of animals. 
II. Properties of texture. Extensibility. 
The extensibility of the arteries may be considered. 
1st, transversely; 2d, longitudinally. WITH RED BLOOD. 
325 
The arteries have but little extensibility in the direction 
of their diameter. 1st. Whatever efforts are made to 
dilate them by injections of water, air, fat substances, 
&lc. their caliber is rendered but little larger than natural. 
2d. I have said that their texture is remarkable by a 
kind of brittleness, that when the blood distends them a 
little in aneurisms, this texture breaks instead of yielding, 
and that it is only the cellular coat, which, by the exten- 
sibility it has from the system from which it is derived, 
that is fitted to form the cyst that contains the blood. 
It is this that essentially distinguishes aneurismal from 
varicose tumours. 3d. If we tie superiorly the carotid 
artery of a dog, the blood pushed against the ligature that 
stops its course, reacts violently upon the parietes and 
yet the dilatation is hardly perceptible. We must not 
think however that the arteries do not yield at all. When 
the dilating cause acts slowly, it produces its effect to a 
certain determinate point, beyond which rupture takes 
place. The proof of this, is in the dilatatiou of the arch 
of the aorta, in that which true aneurisms present in their 
early stages, &c. 
Longitudinally, the arteries are more capable of stretch- 
ing, than they are transversely. We may be convinced 
of this, by drawing out these vessels, to place a ligature 
upon them in an amputated stump. By cutting upon a 
dead body a portion of artery, and drawing it in a con- 
trary direction, it is evidently elongated. It is necessary 
in these experiments, to pay attention to the develop- 
ment of the folds. In fact, I have said, that this devel- 
opment of the folds performs a principal part in the 
elongation of the arteries situated in the parts that are 
dilated. 
It is evident that in the extensibility in a transverse 
direction, it is the circular fibres of the peculiar membrane 
that especially resist; that on the contrary, in the exten- 
sibility in a longitudinal direction, it is the common mem- 326 
VASCULAR SYSTEM 
brane that opposes the resistance, since there are no lon- 
gitudinal fibres. It is not astonishing then that the first 
kind of extensibility should be less evident than the 
second. 
Contractility. 
It is necessary to consider it in a transverse and in a 
longitudinal direction. 
Considered in the first point of view, contractility is 
much more evident than extensibility. When the artery 
is no longer distended with blood, it contracts in a sensible 
manner. It is to this contraction, that the following phe- 
nomena must be referred ; 1st. the umbilical artery and 
the ductus arteriosus, become like ligaments after birth, 
by the adhesion of their parietes which are contracted. 
2d. If we make a ligature upon an artery, the whole por- 
tion comprised between this ligature and the first collat- 
eral branch, soon exhibits the same phenomenon, as is 
proved by the operation for aneurism. 3d. If we include 
a portion of the carotid between two ligatures, and after- 
wards empty it by a puncture, it suddenly loses half its 
caliber. 4th. In dogs in whom I have transfused blood 
in order to produce artificial plethora, I have observed 
the arteries to be almost double in diameter, to what they 
are in those of the same size, who had suffered great 
hemorrhage. Two animals of the same size, one killed 
by hemorrhage the other by asphyxia, exhibit the same 
difference. 5th. These experiments shew7 me satisfac- 
torily the cause of a large and small pulse, a cause admit- 
ted moreover by most physiologists. The artery is cer- 
tainly more or less large, according to the quantity of 
blood that fills it. There is a point of extension that it 
cannot pass ; but it contracts often for the want of blood, 
so as to be as it were, but a mere thread. 6th. Though 
you may have opened but few bodies, you have no doubt 
been astonished, that in those of the same size, the arte- WITH RED BLOOD. 
327 
ries have often very different diameters. This arises 
wholly from what takes place at the moment of death. If, 
from the want of blood, the arteries are for a long time 
contracted, they remain in this state, as happens to the 
heart in death by hemorrhage, &c. This is so true, that 
arteries of different diameters commonly become equal by 
injection, which brings them to an uniform degree of ex- 
tension that they cannot pass. 7th. In a longitudinal 
wound of arteries the ends of their cut fibrous circles sep- 
arating from each other, a space, which does not close, is 
left between them. 
Most authors have confounded contractility of texture 
of the arteries with irritability. I have no occasion here 
to show how much they are deceived. In none of the 
preceding cases, is it necessary that a stimulant should be 
applied upon the arterial texture; the only thing necessary 
is the absence of extension, a distinctive character of the 
contractility of texture. Moreover it is evident, that this 
property continues after death, though in a less degree 
than during life; whereas some hours after death, every 
kind of irritability disappears. I think that it is espe- 
cially in the arterial system, that may be seen the advan- 
tage of my division of the properties of our organs. Read 
all the authors upon this system, and you will see that no 
one is intelligible, because they have not assigned the 
limits of the vital properties and those of texture. 
Contractility of texture in the longitudinal direction, is 
in proportion less evident than in the transverse; it is 
however real. 1st. Thus when we cut an artery between 
two ligatures, the two ends retract immediately in an 
opposite direction. 2d. This retraction is evident in 
amputation ; that of the muscles and the skin however is 
greater, the artery often projects a little. 3d. An artery, 
cut transversely in a portion of its parietes, often presents 
at this place a broad opening, arising from the retraction 
of the eut parts, as happens in a longitudinal wound of 328 
VASCULAR SYSTEM 
which I spoke just now. 4th. When we draw an artery 
forcibly and suddenly let it go, its retraction is very evi- 
dent. In making this experiment upon an animal, the 
vessel buries itself in the flesh. Hence why, the spermatic 
artery and cord, drawn down by the weight of the testicle, 
often ascend into the abdomen after it is removed, if care 
is not taken to prevent them. 
It is this circumstance that has induced me to propose 
for the operation of sarcocele, a modification which con- 
sists, after having dissected around the cord after the first 
incision, 1st, in searching immediately for the vas defer- 
ens, which is easily found by its extreme hardness; 2d, in 
giving it to an assistant to hold ; 3d, in passing a bistoury 
between it and the blood vessels; 4th, in cutting the 
blood vessels first and leaving the vas deferens untouched ; 
5th, in afterwards tying the artery, which is easily dis- 
covered by the jet of blood; 6th, and then, when this is 
done in cutting also the vas deferens. It is evident, that 
by this section at two different times, we have the advan- 
tage of applying the ligature without fear of the retraction 
of the artery, since the vas deferens to which it adheres, 
and which is not cut, until it is tied, is sufficient to retain 
it. I have not performed the operation ; but it is evident 
that there is nothing to prevent the execution of this plan, 
since the parts are sound wrhere we cut. I have more- 
over always taught the student to manage in this way 
with ease. It is especially wrhen it is necessary to cut the 
cord very near the ring, because it is diseased in its course, 
that this method of operating appears to me to have great 
advantages. 
I think that the retraction of arteries that have been 
drawn, and their contraction afterwards, perform an im- 
portant part, in producing the absence of hemorrhage in 
most wounds by laceration, a singular phenomenon, that 
particularly distinguishes these wounds from those by 
cutting, even when a considerable vessel happens to be WITH RED BLOOD. 
329 
in their course. Many authors have given examples of 
this; we find some particularly in the works of Sabatier. 
III. Vital Properties. 
Properties' of Animal Life. Sensibility. 
Have the arteries animal sensibility? Upon this point, 
facts teach us what follows ; 1st. The ligature of an artery 
sometimes produces a painful sensation, more frequently 
it does not. It is especially in the spermatic that the pain 
is frequently felt, but this can be referred to the nerves. 
2d. I can without exaggeration say, that I have made ex- 
periments upon more than a hundred dogs, in whom I 
have forced various substances through the carotid to 
the brain, and have irritated this artery with the scalpel, 
acids, alkalies, &c. but that the animals have never given 
any marks of pain. Many authors have obtained similar 
results. 3d. I would observe also, that it is an additional 
proof of the kind of insensibility of the nerves of organic 
life, which as we have seen are distributed to the arteries. 
4th. This is what I have observed concerning the irrita- 
tion of the common membrane of the red blood ; the in- 
jection of a mild fluid at the temperature of the animal 
produces no effect; but an irritating fluid, as ink, a solu- 
tion of acid, wine, &c. creates severe pain equal to that 
arising from the irritation of the most sensible parts, if 
we may judge by the cries and agitation of the animal, 
the moment the fluid enters the carotid. 
Contractility. 
Animal contractility does not exist in the arteries. In 
fact this contractility could only depend upon a relation 
between these vessels and the brain, by the means of the 
nerves; now, 1st, any irritation produced upon this last 
viscus, occasioning convulsions in the organs under the 
influence of the will, has no effect upon the arteries. 2d. 330 
VASCULAR SYSTEM 
Opium, which in a certain dose, paralyzes, if we may so 
say, the same organs, leaves the arterial motion wholly 
unaffected. 3d. If we lay the spinal marrow bare, and 
irritate or compress it, the action of the arteries is neither 
increased or diminished, whilst the voluntary muscles be- 
come the seat of convulsions or paralysis. 4th. No effect 
is produced upon the arteries by different irritations, 
whether of the nerves of the cerebral system, which ac- 
company the vessels without giving them any apparent 
filaments, or of the nerves of the system of ganglions, 
which are distributed irregularly and in very great num- 
ber upon their external surface. 5th. To remove all 
doubt upon this subject, I selected galvanism, the most 
powerful kind of excitement. Without effect did I arm 
on the one hand the cerebral nerves, on the other, the 
arteries that are joined to them ; the contact of the two 
armed points does not produce in the arteries the motion 
it excites in the muscles in which the nerves are spread. 
The effect is the same in experiments upon the nerves of 
the ganglions. I armed on one hand the upper part of 
the mesenteric plexus, on the other, the arteries of the 
same name, first stripped of their serous and cellular coat; 
the contact was entirely without effect. The arterial sys- 
tem does not possess that faculty of motion which the ac- 
tion of the brain is capable of producing. All that has 
been written by different authors, by Cullen in particular, 
upon the nervous power, upon the action of the brain 
on the arterial system, is vague, illusory and contradict- 
ed by experiment. 
Properties of Organic Life. Sensible Organic Contractility. 
The sensible organic contractility is evidently wanting 
in the system of which we are treating, in whatever 
way we irritate an artery in a living animal, it remains 
uniformly immoveable. 1st. If we stimulate the external 
surface with a scalpel or any other instrument, it is easy WITH RED BLOOD. 
331 
to make this remark. 2d. The same observation is made 
when we excite the internal surface, an experiment that 
I have often made, because we know that the heart is 
more irritable internally than externally. 3d. An artery 
cut longitudinally in a living animal does not turn over 
at its edges like the intestines in similar circumstances. 
4th. An arterial tube, drawn out of the body, never gives 
like the intestines, the heart, &c. any mark of contrac- 
tility. 5th. If we raise the arterial plates, layer by layer, 
in a living animal or one recently killed, we see nothing 
of that trembling, that palpitation that the fibres of the 
organic muscles exhibit under like circumstances; on the 
contrary, we observe in them a kind of inertia very analo- 
gous to that of tendinous, aponeurotic fibres, &c. 6th. It is 
said, that by placing the finger in an artery, a contraction 
is felt. I have often made this experiment; the con- 
traction is infinitely less sensible than has been said ; be- 
sides it is produced evidently by the contractility of tex- 
ture. 7th. Laniure says, that a portion of blood being 
intercepted between two ligatures in an artery, the parie- 
tes of it continue to contract, though deprived of the in- 
fluence of the heart; this is not correct. It is so impor- 
tant that I have examined it myself; I have repeated this 
experiment at least ten times upon the carotid ; the fol- 
lowing has always been the result; the tube comprised 
between the two ligatures and filled with blood, is agitated 
by a real motion, but it is only that of the common loco- 
motion that it partakes with the whole artery, and which 
arises from the impetus of the blood against the ligature 
nearest the heart. To be convinced of this, it is only 
necessary to lay bare a considerable portion of this arte- 
ry ; we see evidently that the whole tube, whether the 
portion nearest the heart, or that comprised between the 
ligatures, or that which is beyond, is agitated by a com- 
mon motion. 8th. Instead of the blood I have intercepted 
different irritating fluids in a portion of an artery ; there is VASCULAR SYSTEM 
332 
the same inertia, the same want of contraction in the parie- 
tes; but the same motion derived from the general loco- 
motion. 9th. Many authors have produced a contraction 
on the part of the arteries by stimulating them with con- 
centrated acids. This is true, and 1 have also produced 
this effect; but it is not the result of contractility, but it 
is the horny hardening. Observe also that the arterial 
texture never returns to its primitive state after a con- 
traction like this; that the alkalies, that are as irritating 
as the acids when the vital forces are excited, have no 
effect here; it is the same phenomenon during life, as 
that which we have spoken of as taking place after 
death. 
There can be no doubt, I think, after this, that the ar- 
teries do not exercise during life any kind of contraction 
by themselves and under the vital influence. All that has 
been said upon this point, is the evident effect of the con- 
tractility of texture. Thus when we open an artery be- 
tween two ligatures, it empties itself of the blood it con- 
tains, or of the fluid that is accidentally pushed there; 
the same phenomenon takes place when we place only 
one ligature that intercepts the influence of the heart, <!cc. 
It is so true, that all these phenomena and other similar 
ones depend upon the properties of texture, that they 
take place in the dead body as long as an artery is not 
putrid. Fill any portion of the arterial system, after- 
wards open one ot its tubes, it empties itself immediately 
by contracting. The contraction produced by the defect 
of extension, is that which characterizes the contractility 
of texture. Irritability or sensible organic contractility, 
supposes on the contrary uniformly the application of a 
stimulus. 
Insensible Organic Contractility. 
Insensible organic contractility or tone very evidently 
exists in the arteries. In the great trunks and wherever WITH RED BLOOD. 
333 
the pulsation is sensible, its functions are limited exclu- 
sively to nutrition and exhalation, if this last takes place 
in the interior of arteries, which I do not believe. But 
w hen the influence of the heart upon the blood contained 
in these vessels ceases, wThich happens at the commence- 
ment of the capillary system, then the tone begins to 
have an influence not only upon the nutrition of the vas- 
cular parieties, but also upon the circulation that is going 
on there; it is even wholly by the tonic powers, as we 
shall see, that the circulation of the small vessels is car- 
ried on ; the heart has no influence there. 1 shall treat 
of this property under the general capillary system; here 
it performs but a very weak part. 
As to organic sensibility, it evidently exists in the arte- 
ries, since it cannot be separated from the preceding con- 
tractility ; like it, it is obscure in the great trunks, which 
have only what is necessary for their nutrition. 
From the small development of the organic forces of the 
arterial texture, it is evident that this texture would rare- 
ly be the seat of alfections, over which these properties 
particularly preside. This also is proved by observa- 
tion. 
1st. Acute diseases are rarely observed in the arteries. 
Among all the bodies that 1 have examined, I have found 
but very few in which there were traces of inflammation 
in the arterial texture. 1 would observe upon this sub- 
ject, that it is necessary to distinguish accurately the 
redness which is, as we have said, the effect of macera- 
tion, and which even appears spontaneously in the dead 
body some time after death, especially in the cerebral 
arteries; it is necessary, I say, to distinguish it from that 
which arises from inflammation. In one the arterial fibres 
are really red, in the other they appear so only by the 
injection of their vessels. Is the common membrane in- 
flamed in inflammatory fever? I am entirely ignorant. 
These simple fevers are so rare, especially in hospitals 334 
VASCULAR SYSTEM 
that we have hardly an opportunity of examining patients 
that have died of them. But by supposing that this in- 
flammation existed, the infrequency of these fevers con- 
sidered in their simple state, would prove even how little 
the arteries are disposed to inflame. 2d. The arteries 
are not often the seat of chronic affections. Except on 
the one hand aneurism, in which the arterial texture is 
hardly altered, but merely broken, and in which conse- 
quently its organic sensibility performs but a very small 
part; on the other, the osseous incrustations, most of the 
alterations that are so frequent in the other textures, are 
not observed in this. 
This texture must be ranked with the cartilaginous, 
the fibro-cartilaginous, the fibrous, the muscular even, 
&c. as it respects the infrequency of organic alterations. 
These textures exhibit a phenomenon opposed to that of 
the serous, mucous, glandular, dermoid systems, &x. 
which are especially characterized by the frequency of 
these alterations. Compare the organic properties, the 
sensibility and insensible contractility in the two classes of 
textures; you will see them very feeble in the first, in 
which in a natural state, they preside only over nutrition ; 
you will observe, on the contrary, that they are very 
evident in the second, because there they preside over 
nutrition, exhalation, absorption, secretion, &c. 
The difficulty with which the arterial texture inflames 
and participates in the different alterations of the neigh- 
bouring organs, preserves the integrity of the circulation 
in many cases. W hat would become of this function, if 
the arteries received as easily as the other textures, the 
influence of surrounding diseases ? Placed at every mo- 
ment by the side of inflamed, suppurating, swelled parts, 
&c. if they become changed by their neighbourhood, 
especially in the great trunks, a general derangement 
would soon be felt in the motion of the blood. Dissect 
the arteries in the organic affections of the stomach, the WITH RED BLOOD. 
335 
liver, the spleen, &c.; they are untouched, and only a 
little increased in size; whilst a general swelling seems 
to confound in a new mass all the neighbouring tex- 
tures. 
The clots in aneurism adhere sometimes so intimately 
to the common membrane, that we are obliged to remove 
them with an instrument. But this adhesion is entirely 
inorganic ; it is a kind of agglutination, that would imply 
the small degree of life of this common membrane, as 
the facility with which colours are fixed in the epidermis 
implies it in this last organ. 
Remarks upon the causes of the motion of the red blood. 
The red blood is moved in the heart by a mechanism 
which there is no difficulty in understanding. But an 
important question remains to be decided concerning its 
motion in the arteries; are these vessels active or passive 
in this motion ? When the physician examines the differ- 
ent states of the pulse, is it the state of the heart or that 
of the arterial system that he ascertains ? From the ab- 
sence of sensible organic contractility, as we have ob- 
served in this texture, it is evident that its part would be 
especially passive; that the motion of which it is the seat 
is communicated to it; that the heart is the great agent 
of the pulsation of the arteries ; that it is that which gives 
the impulse, which these vessels only obey, and that con- 
sequently in almost all cases the state of the pulse is the 
index of the state in which the vital forces of the heart 
are found, and not of the state of the arterial system, 
whose life is not more raised in the greatest and most fre- 
quent pulsatory motions, than in the feeblest and most 
infrequent. Thus in convulsions, the principle of which 
is a wound, an irritation of the brain, &c. the nerves, 
though conductors, are, if we may so say, passive. 
I will now examine in detail this important question, 
that so many physicians have considered differently. 336 
VASCULAR SYSTEM 
1st. The first reason that induces me to believe that 
the heart is almost every thing, and that the arteries are 
particularly passive on the score of vitality in the motion 
of the red blood, is the comparison of the vital forces of 
these two organs, the astonishing activity of the organic 
contractility of the heart, and the absence of this pro- 
perty in the arteries. In fact, to move of itself, it is 
necessary that an organ should have the principle of 
motion, that is to say, one of the two kinds of vital con- 
tractility in a sensible degree, the organic or the animal; 
for we do not know of other vital forces in the animal 
organs, and we cannot say that nature has created one 
especially destined for the arteries. Grimaud admitted 
that there was an active dilatation of the vessels, which 
opened of themselves, according to him, to receive the 
blood, and were not opened by its impulse. We shall 
see that this kind of motion is real, to a certain extent, 
both in the heart and in the organic muscles. But here 
it is wholly different; the heart dilates of itself when it 
is empty, as we see by drawing it out of a living ani- 
mal, and by emptying it afterwards of the fluid it con- 
tains, because it has in itself the cause of its dilatation. 
But in no case have 1 seen the arteries thus undergo an 
alternate motion when they are empty. They arc uni- 
formly found contracted upon themselves. 
2d. If the arteries produce the pulse by their vital 
contraction, there ought to be an irregularity in the pul- 
sations below an aneurismal tumour, since the arterial 
texture being altered, it loses in part its contractility, or 
least this property is changed. Now we observe pre- 
cisely the contrary. On the other hand, every organic 
disease of the heart inevitably affects the pulse. Is there 
an increase of the fleshy fibres, as in the aneurisms in 
which the left ventricle is so thick? it becomes strong; 
Influence of the heart in the motion of red blood. WITH RED BLOOD. 
337 
it is irregular, if obstructions exist at the mitral or aortic 
valves. If in old age, ossification exists only in the arteries, 
the circulation is unaffected ; if at the origin of the aorta 
or in the heart, it is irregular. An artery might become 
a bony canal, and the blood would circulate there as 
usual, with the difference only of pulsation. What 1 
have said of the chronic affections of the heart may be 
said of the acute ones. Syncope arrests its motion, it 
arrests also the pulse. Certain passions, as anger, fear, 
Sic. seem to be a stimulant to it; they hasten also the 
arterial motion. All kinds of inflammation of the peri- 
cardium affect the pulse. This membrane often adheres 
to the heart in consequence of inflammation, and at the 
same time the pleura of both sides adheres to it also; so 
that we might say then that the lungs and the heart made 
but one. I have seen four examples of this morbid state, 
in which the motions of the heart were much contract- 
ed ; in all the pulse was small, irregular, and intermit- 
tent. The more I open bodies, the more 1 am convinced 
that when the irregularity of the pulse is uniform for a 
considerable time, there are almost always organic affec- 
tions of the heart; from which there is reason to believe 
that the irregularities of the pulse that are acute, if I 
may use the term, arise from an alteration, not in the tex- 
ture, but in the vital forces of this organ, and that the 
arteries are almost entirely disconnected with it. We 
know how frequent these irregularities are in acute dis- 
eases. Since then every alteration of the heart essen- 
tially affects the pulse, and those of the arteries on the 
contrary, leave it unaffected, we should certainly con- 
clude from this, that the one is essentially active in this 
great phenomenon, and that the others, on the contrary, 
are almost passive. 
3d. There is no doubt that at the instant a ligature 
prevents an artery from receiving the influence of the 
heart, it ceases to beat. All the phenomena of aneu- 338 
VASCULAR SYSTEM 
risms, treated by compression or by ligature, establish this 
fact. If the contrary has sometimes been observed, it 
arises only from anastomoses, and then it is equally the 
heart that makes the artery beat above and below the 
ligature. It is absolutely false, as I have said, that an 
artery never beats between two ligatures. Often in aneu- 
rism the artery being compressed below the tumour, this 
beats much stronger than before. 
4th. Cut off the arm of a dead body, and make it plia- 
ble by leaving it for some time in a tepid bath. Fix 
afterwards to the brachial artery a small tube ; place the 
other extremity of this tube in the open carotid of a 
large living dog ; immediately the heart of the animal 
will drive blood into the arm. The artery will have a 
kind of pulsation, less, without doubt, than in a natural 
state, but sufficient to be perceived even through the in- 
teguments. 1 have often repeated this singular and curi- 
ous experiment, of which I shall have occasion to speak 
again. It was suggested to me by another, of which I 
ha\e given an account in my Treatise on the Membranes, 
and which consists in making the red blood circulate in 
the veins, without the motion of locomotion, it is true, 
hut with a rustling sensible to the finger, and with a 
velocity almost equal to that of the arteries. This last 
experiment alone would prove that the heart is almost 
the only agent of impulse of the blood circulating in the 
arteries; in fact, every throw of blood coming from the 
veins is uniform, because the capillary system pours with- 
out a jet this fluid into these vessels. On the other hand, 
every arterial throw is by jets, which are produced by 
the contraction of the heart. Now if you open a vein 
in which you have made red blood circulate by a curved 
tube, the throw of blood will be in jets, which will cor- 
respond to the contractions of the heart. With the dif- 
ference merely of locomotion, a vein presents during the 
circulation of the red blood, the same phenomena as an WITH RED BLOOD. 
339 
artery. Make, on the other hand, the reverse of this 
experiment, that is to say, fit a curved tube to a vein and 
an artery, so that the blood of the first may flow into the 
other; the artery will lose immediately its pulsatory 
motion, unless it be kept up in the collateral branches; 
this does not happen if we select great trunks, for exam- 
ple, the crural and corresponding vein. It is evident, 
that all these experiments, which I have frequently re- 
peated, would give a result entirely opposite, if the arte- 
ries took an active part in the circulation by their vital 
properties. 
5th. The force of the heart makes the blood circulate 
through inert tubes, fixed to the arteries, to a considera- 
ble extent. If we cut an inch of the carotid artery, and 
substitute a tube fixed to the two open ends of this artery, 
the. blood will go through this tube and the artery pul- 
sate as usual above. I cannot imagine in what way those 
have been deceived who have obtained different results. 
Cth. Take two dogs; fix the end of a tube to the ca- 
rotid of one, on the side of the heart, and the other end 
of the same tube to the crural or carotid of the other, on 
the side opposite to this organ; the heart of the first 
will uniformly make the arteries of the second pulsate, 
by sending blood to them. All my experiments upon 
death, experiments already published, have shown me 
this phenomenon. Besides, in aneurism the pulsation 
takes place below' the tumour; yet at that part, the two 
ends of the broken artery are separated; the cellular 
membrane alone serves to unite them, by forming the 
cyst. The blood passes then through an intermediate 
body that is not arterial. 
7th. Fix to an artery one end of a tube, which has at 
the other a sac made of skin, or gummed taffety, the 
blood will fill it immediately ; then at each contraction of 
the heart, it will have a sort of pulsation. It is thus 
that the aneurismal tumour pulsates, which is cellular. 340 
VASCULAR SYSTEM 
Whatever may be the organ that contributes to form the 
cyst, it would pulsate, provided it received, with the 
blood, the impulse of the heart. 
8th. I would ask, if the active dilatation of the arte- 
ries could be sufficient to raise the brain, impart a mo- 
tion to the leg that is crossed upon that of the opposite 
side, to overcome the weight of the tumours that are 
situated in their course, and raise them at each pulsation. 
It evidently requires a more powerful organ to produce 
these phenomena, and this organ is the heart. 
9th. How is it, that the pulsation of all the arteries is 
simultaneous, if a single centre does not preside over this 
pulsation ? The whole arterial system, struck suddenly 
with the same blow, is raised and pulsates at the same 
time. Is it not evident, that if the arteries contracted 
by themselves, the least derangement in one part, the 
least pressure, &,c. would produce a discordance in the 
motions ? 
10th. No animal has arterial pulsations, if it has not 
a heart, or a fleshy vessel, knotty, and divided by con- 
tractions, as in many insects; have the pulsations of this 
vessel, which is a substitute for the heart, been well ob- 
served ? It is thus that the system of the vena porta 
never has pulsations, though its hepatic part is arranged 
like the arteries. 
11th. The two ends of a cut artery pour out blood, 
but this is the effect of the anastomoses, and not of the 
re-action of the end opposite to the heart, as I thought 
myself for some time. It is for the same reason that an 
artery can pulsate sometimes below a ligature. 
12th. 1 have no doubt but that without the heart, the 
red blood would have in its great canal, a kind of mo- 
tion, a motion that would resemble that of the vena 
porta ; it would be entirely without pulsation. 
13th. Cases have been quoted, in which the motion of 
the arteries was said to take place as usual, though they WITH RED BLOOD. 
341 
contained no blood. I confess that I dd not know how 
we can be assured of this fact. But if it was real, it 
must be placed at the side of that of the soldier, who 
could stop the motion of his heart at will. What can we 
conclude from an insulated phenomenon, which is in 
contradiction to all those that nature daily presents ? It 
may not be useless, I think, to remark, that since healthy 
physiology has advanced, has been studied with method, 
a love of truth, and a desire only to collect facts, we have 
no longer been presented with those extraordinary cases 
in which nature seems to depart from the laws she has 
imposed upon herself. 
From all that has been said, it follows, I think, very 
evidently, that in the pulsation of the arteries, the heart 
is almost the only power that puts the fluid in motion ; 
that the vessels are then passive ; that they obey the mo- 
tion that is communicated to them, but that they have 
none of themselves dependant at least on their vitality. 
Thus nature has chosen for the arterial texture one of 
those of the economy, in which life is the least evident; 
as the heart is remarkable for its vital properties, the 
arteries are remarkable for the absence of them. They 
must be ranked with the cartilaginous, fibrous, fibro-car- 
tilaginous textures, &c. It is that they may not disturb 
the unity of impulse by their motions, that nature has 
thus formed the arteries. Suppose that they had the 
same vital forces as the intestines; what would become 
of life ? Any convulsive contraction a little too strong 
in the aorta or in the great trunks, by contracting 
their caliber too much, would arrest the circulation, and 
produce the most serious effects by agitating it in an op- 
posite direction to the heart. In the intestinal canal, 
this phenomenon only produces vomiting. It would pro- 
duce death suddenly in the arterial system. The more 
attentively we examine, the more we shall be convinced 
of the necessity of having but one agent of impulse for 342 
VASCULAR SYSTEM 
the arterial system, and of having this system inert, so 
that it cannot be able to arrest the course of the blood. 
I do not say that the arteries can never contract from 
the vital influence ; the skin which is not irritable, wrin- 
kles by cold. But the cases are very rare, in which the 
arteries contract. When they exist they cause an ine- 
quality of the pulse on the two sides; an inequality rarely 
noticed in diseases. 
Of the limits of the action of the Heart. 
The heart is then the essential cause of the pulse ; it is 
this which puts every thing in action in the arterial motion. 
Many authors have overrated its influence; they have 
thought that its impulse was sufficient to produce, not only 
the arterial motion, but also that of the general capillary 
system, and even that of the veins; so that the contrac- 
tion of the left ventricle alone is the cause, according to 
them, of the long course the blood runs from it to the 
right ventricle. But it is incontestably proved, as we 
shall see, that when this fluid has arrived in the general 
capillary system, it is absolutely beyond the influence of 
the heart, and that it moves only by that of the tonic 
forces of the small vessels, and therefore for a stronger 
reason, the left.ventricle has no influence in the venous 
system. It is in this respect that the authors, of whom 1 
have spoken, have erred, and not under that of the im- 
pulse that they have admitted in the arterial system on 
the part of the heart. 
We can, 1 think, establish nearly the limits of the influ- 
ence of the heart upon the blood, by fixing them where 
this fluid is transformed from red to black in the general 
capillary system. As it advances in the small vessels, the 
impulse received is undoubtedly weakened, and the small 
vessels supply it by their insensible organic contractility; 
but 1 believe that the motion received from the heart, is 
not entirely lost until at the place of the change into black WITH RED BLOOD. 
343 
blood; so that we can establish for a general principle, 
1st, that in the great trunks, in the branches and even in 
the smaller branches, the heart is almost every thing for 
the motion of the blood ; 2d, that in the ramifications, 
it is in part this organ and in part the vital action of 
the arteries, which contributes to this motion; 3d, that 
finally it is this vascular vital action alone in the general 
capillary system. 
The pulse exists in its fulness, only in the trunks, the 
branches, and the smaller branches. It is evidently weak- 
ened in the ramifications; it becomes nothing in the ca- 
pillary system. The arterial texture of the great trunks 
is provided, as we have seen, with insensible contractility. 
But the impulse received by the heart is on the one part 
so strong, and the column of blood so great, that the influ- 
ence of this kind of contractility is really nothing. Irrita- 
bility alone could have influence; but this does not exist 
in the arteries. On the contrary, in the small vessels, the 
shock on the one hand impressed by the heart is insensi- 
bly weakened ; on the other, the streams of blood being 
so fine, they have no occasion for any thing to pro- 
duce their motion, except a kind of oscillation, an insen- 
sible vibration of the vascular parietes. It is this that 
essentially distinguishes the two kinds of organic contrac- 
tility. The one is exerted only upon the fluids in mass, as 
upon the blood, the aliments, the urine, &c. The other 
causes the motion of the fluids when divided into small 
streams ; it presides over the capillary circulation, exha- 
lation and secretion. The influence of the first is very 
considerable wherever there is a great cavity, as the sto- 
mach, the bladder, the intestines; that of the other takes 
place only in the small vessels. As long as the blood is 
in a considerable mass, the heart must inevitably be the 
agent of impulse, the arteries cannot be, from their want 
of irritability. When it is in very small streams, then it 
moves by the insensible contractility of the vessels. This 344 
VASCULAR SYSTEM 
then is the part which this property performs in the system 
with red blood ; 1st, it exists in the trunks, the branches 
and the smaller branches ; but its effect is nothing where 
that of the heart is evident. 2d. That of the heart being 
weakened in the ramifications, its own contractility be- 
gins to have an influence. 3d. Finally7, the heart ceasing 
to agitate the blood in the general capillary system, the 
insensible’organic contractility or tone, is the sole cause 
of motion. 
Phenomena of the impulse of the Heart. 
What part then have the arteries in the pulse? The 
following is what takes place in this great phenomenon; 
the arteries are always full of blood, the impulse that the 
blood in them receives from the left ventricle, is felt at 
the instant in the whole system, and even to its extremi- 
ties. Imagine to yourself a syringe, the tube of which 
gives rise to an infinity of branches, which afterwards 
give origin successively to a number of smaller ones; if, 
when you push the piston of the syringe, its body and all 
the branches and smaller branches arising from it, are 
already full of fluid, it is evident that at the very instant 
in which the piston shall push the fluid in the body, it will 
go out on all sides through the open branches. Now sup- 
pose, that instead of a piston, you could make the parie- 
tes of the body of the syringe suddenly contract, the fluid 
at the instant of the contraction would spout out on all 
sides from these open branches. Another comparison 
will render this more evident; strike at one end of a long 
timber, the motion will be suddenly felt at the opposite 
one. 
We can from this form an idea of what takes place at 
the instant of the contraction of the left ventricle. Au- 
thors have spoken of a wave or undulation of blood, being 
propagated through the whole arterial system, and form- 
ed by the two ounces of blood that are poured into the WITH RED BLOOD. 
345 
arteries at each contraction. The arterial motion should 
be thus considered, if the arteries were empt) at the in- 
stant of contraction ; but in their state of fulness, the im- 
pulse is generally and suddenly felt, and with almost as 
much force at the extremities as at the origin of the arte- 
ries ; it is only in the ramifications that the motion be- 
comes a little weakened, Fill with water the arteries of 
a dead body, and fix a syringe full at the aorta; at the 
instant you push the piston, the water will spout out of 
the tihial or any other artery, if you loosen an opening 
that had been previously made in them. 
The idea that is commonly entertained of the progres- 
sive motion of the blood, is wholly incorrect. This fluid 
has been considered as flowing in the arteries almost like 
water in brooks. It is not so. At each contraction of 
the ventricle, it experiences suddenly a general motion 
that is felt at its extremities. Do you wish for another 
comparison? Suppose a syringe, to the tube of which is 
fitted a series of elastic pipes arising from each other; 
push the piston, you will see all these pipes swell simul- 
taneously, become straight, and the fluid flow at the same 
time to the extremities, if they are open. 
It is not the contraction of the arteries that drives the 
blood to their extremities. This is so true, that if you 
open one of these vessels at a distance from the heart, 
each jet that the blood will make in going out, will cor- 
respond to each contraction of the ventricle. Now if the 
arteries drove the blood to all the extremities, by con- 
tracting, their contraction and relaxation would alternate 
with those of the heart; but if it was so, each jet of the 
arterial throw should correspond to each relaxation of the 
ventricle; the contrary of this is the case as I have just 
said. 
From this we see how very inaccurate is the common 
opinion, which I believed myself for many years, viz. that 
the auricles contract at the same time with the arteries, 346 
VASCULAR SYSTEM 
and the veins at the same time with the ventricles. The 
circulation of red blood is thus explained; 1st, the pul- 
monary veins drive the blood into the left auricle. 2d. 
This by contracting forces it into the ventricle, which 
dilates to receive it. 3d. This last contracts afterwards, 
sends it to the aorta which dilates at the instant of con- 
traction ; 4th, then this contracts to drive it to all the 
parts. This last does not take place; you can never ob- 
serve it like the others, in a living animal. Examine as 
closely as possible, a great artery laid bare; it rises, but it 
does not dilate hardly at all in an ordinary state, nor does 
it contract. Contraction of the left ventricle ; general mo- 
tion of all the arterial blood; the entrance of this blood 
into the capillary system, are three things that take place 
at the same instant. It is like the blow on the timber, 
that is felt at one end, at the same time that it is received 
at the opposite. 
We can form a very accurate idea of the circulation by 
examining the mesenteric arteries through the perito- 
neum, after having opened the abdomen of an animal; at 
each pulsation you see them all simultaneously rise and 
pulsate at their extremity as well as at their origin. 
It is impossible to form an idea of the arterial motion, 
by considering the wave or undulation of blood as extend- 
ing itself at each contraction in the arteries, and arriving 
afterwards successively at the extremities. Read all the 
authors upon the circulation; you will see that there is 
no subject that is treated oftener or more at length, than 
that of the course of the arterial blood, and yet there is 
no one in which you are left in more doubt and obscurity. 
Why? because all go upon a false principle, and all the 
consequences are inaccurate, where the principle itself is 
not correct. 
It is not the wave of blood going from the ventricle, 
that is driven at each contraction into the capillary sys- 
tem; it is the portion of this fluid which is found nearest WITH RED BLOOD. 
347 
this system, as in the syringe, it is the portion that is in the 
tube that the piston forces out and not that with which it 
is in contact; whence it follows, that it is only at the end 
of some time that the blood arrives from the heart, at the 
general capillary system, that it remains during a number 
of contractions in the arteries, and that it is only succes- 
sively expelled ; which favours the mixture of the different 
principles that compose it. 
From this manner of considering the arterial motion, 
which is the only real and admissible one, it is evidently 
impossible that the curves can injure this motion, besides 
this is proved by many facts. 
I consider also as destitute of every kind of foundation 
all that has been said in the books of physiology, upon 
the causes of the delay occasioned in the course of the 
blood, 1st, by its passage from a narrower to a broader 
place, and by the conical form of the general arterial sys- 
tem ; 2d, by friction ; 3d, by the angles ; 4th, by the 
anastomoses which give an opposite shock, &c. &c. All 
this would be true if the arteries were empty at the time 
of contraction, because the blood would then have in 
them, truly a progressive motion. But in the general and 
instantaneous impulse that the w hole mass spread in the 
arterial system experiences, all these causes are evidently 
nothing. 1 return now to the trifling but very accurate 
comparison of the syringe. Suppose that a tube twisted 
in a thousand ways, with numerous angles, inequalities, 
internal projections, Sic. was fixed to it; if the tube and 
the body of the syringe are full at the instant we push the 
piston, the water will escape suddenly from the extremi- 
ty of this tube with as much force as if it was straight and 
short. It is so true that all the causes of delay, which 
would have some effect, if the arteries were empty at the 
instant the blood is driven into them, have none in their 
ordinary state, that many judicious observers, who even 
admitted the delay, have seen in their experiments that 348 
VASCULAR SYSTEM 
the motion was every where the same, in the smaller 
branches as in the trunks. Why did not this undeceive 
them ? We know that the pulse is the same in all parts of 
the arterial system ; how could it be if there was this de- 
lay? What has greatly retarded the progress of the phy- 
siology of the circulation, is the idea that is attached to 
the velocity of the course of the red blood. This velocity 
cannot be rightly estimated, because the motion is not 
successive, because, to speak correctly, the blood does not 
flow; it is suddenly driven by a general impulse, in which 
we cannot calculate any thing. 
Philosophers have calculated the motion of fluids, 
where their particles are successively displaced, as in the 
course of a river; but they have paid less attention to that 
brisk motion of the w hole or of the mass, if 1 may so say, 
that takes place in canals in which they are enclosed on 
all sides, and are acted upon at one extremity. 
Remarks upon the Pulse. 
Two things are already evidently proved, viz. 1st, that 
the heart is the peculiar agent of the arterial motion, and 
that the arteries are almost passive in this motion; 2d, 
that it consists in a general impulse suddenly experienced 
by the whole mass of red blood, felt at the same time at 
the extremities and in the trunks, and not in a successive 
progression of a wave or undulation that goes from the 
left ventricle. It remains for me to examine how the 
heart produces the pulse by this brisk and instantaneous 
motion. There is still much to he elucidated upon this 
point; but we cannot deny that the locomotion of the arte- 
rial system does much in this phenomenon. At the instant 
the mass of blood is driven thus from the heart towards 
the extremities, by a motion of the whole, if we may so 
say, it tends inevitably to straighten the arteries,especial- 
ly when they are tortuous. This straightening necessarily 
produces a locomotion, which causes the pulsation of the 
artery. WITH RED BLOOD. 
349 
As to the dilatation, it is hardly any thing in an ordi- 
nary state ; however if you press a little upon an artery, 
the blood makes an effort to dilate it and this effort in- 
creases the sensation of the pulse ; Jadelot thought that it 
alone constituted it. On the other hand, if much blood 
enters the arterial system at the instant of the contraction 
of the heart; if a resistance exists in the general capillary 
system, the arteries can be also dilated, but it is not their 
return upon themselves or contraction that drives the 
blood into the capillaries; this return is subsequent. In 
fact, at the instant of contraction, the blood enters on 
the one part into the arteries in going from the ventricle, 
and goes on the other to enter the capillary system ; these 
two phenomena take place at the same time, since they 
arise from the same impulse. Then when there is a con- 
traction in the artery, a motion which is only the con- 
tractility of texture put into action, this contraction does 
not drive the blood ; but it cakes place, Decause the blood 
has been driven into the capillary system at the instant 
of the contraction; it is because the artery ceases to be 
distended, that it returns upon itself or contracts, and not 
because it is actually distended. Hence how the arterial 
contraction can alternate with that of the left ventricle; 
but it is not in the sense that authors have understood it. 
There are then two periods in the motion of the red 
blood; 1st, contraction of tnc ventricle ; slight dilatation 
of the arterial system by the blood that enters it; general 
locomotion ; passage into the capillary system of a por- 
tion of this red blood ; all these phenomena happen at 
the same time ; it is the period when the pulse is felt; it 
is that of the diastole. 2d. In the next period, the ven- 
tricle is relaxed to fill itself anew; less full of blood, the 
arteries contract a little upon themselves ; all take the 
place they had lost during the locomotion ; this is the 
period of the systole, a period purely passive, while some 
have thought it a very active one for the arteries. 350 
VASCULAR SYSTEM 
As but little blood is driven at each pulsation out of 
the ventricle, which does not wholly empty itself; and 
as, on the other hand, at the same time it enters the 
arteries it goes out from the side opposite to the heart, 
the arterial dilatation and, consequently, contraction, are 
almost nothing; thus, they cannot be perceived. Be- 
sides, if the contraction really took place, it would hardly 
be apparent; for when it is the contractility of texture 
that is in action, it produces a slow insensible motion, a 
real tightening; whereas contraction, the effect of irri- 
tability is abrupt, instantaneous, and produces a motion 
that the eye always distinguishes. 
I cannot insist too much upon this fact, which is cer- 
tain, viz. that if there is a slight contraction in the arte- 
ries at the instant the pulse ceases to beat, it is not that 
they have contracted to drive the blood, but merely that 
they contract upon themselves, because the blood that 
has gone into the capillaries prevents their being suffi- 
ciently dilated ; it is contractility for the want of exten- 
sion. Hence why the throws of arterial blood going 
from an open artery, correspond with the dilatation of 
these vessels, and the weakening of the throw with their 
contraction, which would be entirely the reverse, accord- 
ing to the common opinion. 
The dilatation and contraction of the arteries being 
almost nothing in the ordinary state, it appears that the 
peculiar cause of the pulse is. as Weitbreck has observed, 
in the locomotion of the arteries, a locomotion that is 
general and instantaneous in the whole system, and not 
consecutive, as this author has understood it. I shall not 
relate here the proofs of this locomotion ; they can be 
found every where. 1 would observe only, that it is so 
manifest in living animals, that when we have often ex- 
amined the circulation by their means, it is impossible to 
doubt its reality. WITH RED BLOOD. 
351 
Different causes can make the pulse vary ; these causes 
are, 1st, relative to the heart, almost the only agent of 
impulse ; thus its sensible organic contractility, increased, 
diminished, altered sympathetically or in any other way, 
can make it with the same stimulus contract quicker, slow- 
er, or more irregularly than common ; thus the diseases 
of its organization inevitably alter its motion. 2d. The 
blood charged with different natural or morbific substan- 
ces is a stimulant more or less capable of putting in play 
the motion of the heart. 3d. The general capillary sys- 
tem, according as it receives a greater or less quantity 
of blood, or refuses admission to that which the arteries, 
send there, &c. produces necessarily numerous varieties 
in the pulse. There are but few causes relative to the 
arteries themselves. 
If now we consider the great number of causes that 
can be referred to these three principal heads, we shall 
cease to wonder at the prodigious variety that the pulse 
exhibits in health, and especially in diseases. Besides, 
I shall not examine here in its whole extent the ques- 
tion concerning the pulse; it is sufficient to have an- 
nounced the principles; I shall hereafter develop the 
consequences, which are, as we know, of the greatest 
importance to the physician. We see by the different 
views that I have presented, that almost all authors 
have described in an inaccurate manner the motion of 
the blood, and what loose ideas they have had of it. 
Experiments have only served to confuse them; it is a 
work that requires to be entirely done again, either with 
the materials that many respectable authors have already 
amassed, especially Haller, Spallanzani, Weitbreck, La- 
mure, Jadelot, &c. or with new facts. I have only pre- 
sented the first bases of this work. 
We have seen how favourable the firm and elastic 
structure of the arterial texture is to the locomotion of 
the arteries, and the influence the curves of these vessels 352 
VASCULAR SYSTEM 
have upon it. I will add that the loose union that they form 
with the neighbouring parts, and their uniform position 
in the cellular texture, singularly favour this locomotion. 
If the red blood flowed in the veins, we should feel 
under the finger a kind of rustling, instead of the motion 
of the pulse ; this is what happens in varicose aneurism. 
There would be no locomotion if the arterial parietes 
were made of the dermoid, mucous, serous textures, &c. 
there would be different phenomena with the common 
impulse. 
There are then two things in the pulse; 1st, impulse of 
the blood, sudden and general motion of its mass by the 
contraction of the heart; 2d, locomotion of the arteries, 
an effect produced by this fluid upon the arterial parietes 
which transmit it. The first is the most essential; as to 
the second, it would vary, if the arterial texture that pro- 
duced it ceased to be the same; it depends upon this 
texture, and is not essential to the circulation. 
When an artery is cut at the end of its trunk, the loco- 
motion is much less sensible in this trunk, because less 
resistance is offered there to the course of the blood. 
If an artery is opened laterally, it forms two currents 
of blood in an opposite direction, which are driven to- 
wards the opening, and which unite in one throw. One 
of these currents is direct, the other arises from anasto- 
moses. It is the same as when an artery is cut, and the 
blood flows at both ends. 
If an artery is wholly divided, more blood flows from 
it in a given time, than passed through it before in the 
same lime to go to the capillary system, which resisted 
more. We cannot then judge of the velocity of the 
blood by the throw from the open arteries. 
Sympathies. 
We have seen that the arteries are rarely the seat of 
diseases either acute or chronic, on account of the ob- WITH RED BLOOD. 
353 
gcurity of their vital properties. They can exert then 
but a very slight influence upon the other organs ; thus, 
except some sympathetic pains that are experienced in 
aneurism, this influence of the arterial texture upon the 
other systems is merely nothing. In two or three cases 
I have seen convulsive motions produced by the injection 
of a very irritating fluid in the arteries. It is easy to 
distinguish these sympathetic motions, from those that 
pain produces in an animal who is struggling to disengage 
himself; they are violent tremors or stiffness, like tetanus. 
It may be imagined that these experiments should not be 
made in the carotids, because the brain, irritated by the 
injected fluids, would produce convulsions arising from 
the stimulant that would be then directly applied to it, 
and not from a sympathetic relation. Besides, death 
would be the immediate consequence of the experiment, 
if it was made upon the carotid. 
On the other hand, as the arteries have not sensible 
organic contractility, hardly any animal sensibility, and 
but little tone, the other organs can with difficulty de- 
velop in them sympathies by their influence; for, in 
order that a vital property should be brought sympathetic- 
ally into action in a part, it is necessary that it should 
exist there, and even be conspicuous. Thus the innu- 
merable variations of the pulse, which are the product 
of sympathies, have all essentially their seat in the heart; 
the arteries are not connected with them. Now the 
sympathies make the heart contract or arrest its motion, 
as stimulants or sedatives directly applied to it, that is to 
say, by acting on its sensible organic contractility. When 
an aneurism is broken in a fit of anger, or in the act of 
coition, a case of which I have seen with Desault, it is 
the motion of the blood, which is suddenly increased, 
that is the cause of it; it is not the arterial texture that 
has been affected by the passion. Besides, upon what 
can the sympathies act in the arteries ? It could not be 354 
VASCULAR SYSTEM 
either upon the elasticity or the contractility of texture, 
the only properties, however, capable of contracting these 
vessels. Observe, also, that the sympathies put in action 
only the vital properties, because they are themselves a 
phenomenon purely vital. The physical properties and 
the properties of texture cannot be exercised under their 
influence ; this is an important observation. 
Besides, as the arteries are every where spread in the 
organs, and as they form, if we may so say, a part with 
them, it would be difficult to distinguish what belongs to 
them, especially as it respects sensibility, from what is 
peculiar to these organs. 
ARTICLE FIFTH. 
DEVELOPMENT OF THE VASCULAR SYSTEM WITH RED BLOOD. 
I. Stale of this system in the Foetus. 
The foetus differs essentially from the infant that has 
breathed, in this, that its two great vascular systems in 
reality form but one, since the foramen ovale on the one 
hand, and the ductus arteriosus on the other, form a di- 
rect communication between the two. This communica- 
tion is much more evident at the period nearest concep- 
tion ; these openings contract towards the period of birth. 
1st. The foramen ovale is formed, in the first months, by 
two productions in the form of a crescent, whose concave 
surfaces are opposite, and leave between them an oval 
space, which is constantly contracting, because these two 
productions constantly approximate and have a tendency 
to cross each other, which in fact takes place after birth. 
2d. The ductus arteriosus contracts as the pulmonary 
artery dilates. WITH RED BLOOD. 
355 
While these two openings are free, which is constantly 
the case in the foetus, the two systems evidently make 
but one, as I have said; whence it clearly follows that 
the blood that circulates there must be entirely of the 
same nature, that there cannot he two kinds in the foetus, 
as there always is in the adult. This is, in fact, a re- 
markable difference between the two ages. 1st. I have 
many times dissected small Guinea pigs in the womb of 
the mother; their vessels have uniformly contained the 
same fluid, which is blackish, like the venous blood of 
the adult. This experiment is easy. The abdomen of 
the mother being divided, we successively open each of 
the separate sacs that the womb has for each foetus. 
When one of these sacs is laid open, we cut the mem- 
branes, then the abdomen of the small animal, leaving the 
umbilical vessels untouched. The transparency of the 
parts easily allows us to see the uniformity of the colour 
of the blood of the vena cava and the aorta. The same 
remark applies to the superior parts. The carotid and 
jugular pour out the same blood when they are opened. 
2d. I have three times made the same observation upon 
the foetus of a dog. 3d. We know that the blood of the 
umbilical arteries is always black; all accoucheurs have 
remarked this. 4th. The change of the black blood to 
red arises from the contact of air in the lungs; the foetus 
not breathing, cannot then have this kind of blood. 5th. 
I have dissected many foetuses that have died in the 
womb of the mother; the blood of the veins and the 
arteries has appeared to me to be uniformly the same. 
It is true that this is not a very conclusive proof, since 
the mere standing of the red blood in the vessels, for a 
considerable length of time, is sufficient to make it black, 
as Hunter has observed. 
The preceding facts are sufficient to establish incon- 
testibly the uniformity of the blood in the two systems of 
the foetus; an uniformity that exists at least in external 356 
VASCULAR SYSTEM 
appearance, if it is not real in its intimate composition. 
It is for the chemists to elucidate this point. 
How is it, that the instant the black blood enters the 
system of red blood in the adult, alarming consequences 
follow, soon asphyxia, then death, take place, whilst in 
the foetus, the black blood circulates with impunity in the 
arteries? It is a difficult question to resolve, and yet 
these two contradictory facts are equally true. The 
difference of the nature of the blood of the foetus might 
perhaps serve to remove this difficulty, if we better un- 
derstood this difference. In fact, though the colour as- 
similates this blood with that of the veins of the adult, 
yet it does not appear to be the same ; it has an unctuous 
feel, unlike the other. It is never found in the dead 
body coagulated like it, but always fluid, like the blood of 
those who have died of asphyxia. Fourcroy discovered 
no fibrin in it; he observed that it did not take the ver- 
milion colour by the contact of the air; that it contained 
no phosphoric salts, &c. It is then very probable that if 
the black blood is fatal in the arteries of the adult, whilst 
it circulates with impunity in those of the foetus, that it 
arises from the difference of the nature of the one and 
the other. Besides, observe that there is a very great 
difference in the functions of the foetus and the adult. 
The first scarcely has animal life; it wants many func- 
tions of organic. The relation of the organs with each 
other, is of a nature wholly different from what it will 
be after birth. No kind of analogy ever can be estab- 
lished between the foetus and the infant in this respect. 
Thus we have observed that the experiments upon life 
and death give a result wholly different in animals with 
red and warm blood, and in those with red and cold, 
which approximate nearly the organization of the foetus 
in some respects. We cannot then establish any kind of 
parallel in respect to the injury of the respiratory phe- 
nomena, between the foetus and the infant, an injury, the WITH RED BLOOD. 
357 
causes of which I have sought in my experiments, since 
the organization relative to these phenomena differ so 
essentially in the one and the other. 
Although, as I have said, the blood of the two vascular 
systems is confounded in the foetus, yet there is, especially 
in the first periods, a kind of separation in the general 
mass of blood, a separation that was first accurately ob- 
served by Sabatier, and which is the result of the arrange- 
ment of the foramen ovale and the ductus arteriosus. 
This separation divides the mass of blood into two. The 
following is the manner in which the circulation of the 
blood is performed in this respect. 
1st. All the blood that the trunk of the inferior vena 
cava receives, either from the capillary system of the 
inferior extremities, or from that of the abdomen, or from 
the placenta by the umbilical vein, instead of stopping 
in the right auricle, as in the adult, passes entire into the 
left through the foramen ovale, the superior edge of 
which is so arranged, that nothing can mix with the blood 
of the superior vena cava ; so that when we examine at- 
tentively, we see that it is really with the left auricle that 
the inferior vena cava is continued. Hence why this 
auricle is in proportion as much dilated as the right; for 
it would be very contracted, if it had only to receive the 
blood of the pulmonary veins, the quantity of which is 
merely nothing in the first periods of life. From this 
auricle the blood passes to the left ventricle, which trans- 
mits it to the aorta, where it meets the carotids and sub- 
clavians, which, by numerous ramifications, carry it to the 
capillary system of the head and the superior extremities. 
2d. After having remained in this system, the blood 
returns by the different branches of the superior vena 
cava to the right auricle, where the superior edge of the 
foramen ovale prevents it from communicating with the 
other blood ; from this auricle it passes to the ventricle, 
which transmits it to the pulmonary artery, which sends 358 
VASCULAR SYSTEM 
a small part of it that returns to the left auricle by the 
veins of the same name, but transmits almost the whole 
of it by the ductus arteriosus to the descending aorta, 
below the origin of the carotids and the subclavians, 
which carry the other blood. This is carried by the 
branches and ramifications of the aorta to the capillary 
system of the abdomen and inferior extremities; the re- 
mainder is afterwards carried by the umbilical artery and 
lost in the placenta. 
It follows from what we have just said, that notwith- 
standing the continuity of the two great sanguineous sys- 
tems in the foetus, there is in the first months after con- 
ception, a kind of separation of the blood they contain; 
that there is even if we may so say, two systems wholly 
different from those which will afterwards exist in a sepa- 
rate manner in the adult. 
The first of these systems has, 1st, for origin all the 
capillaries of the abdomen, of the inferior extremities, and 
even those of the placenta; 2d, for common trunks, below 
the inferior vena cava, above the quadruple branch called 
the aorta; 3d, for agent of impulse the left side of the 
heart; 4th, for termination all the capillaries of the head 
and the superior parts. The second commences in these 
last capillaries, and is composed, 1st, for its trunks, of the 
superior vena cava and the descending aorta; 2d, for its 
agent of impulse, of the right side of the heart; 3d, for 
its termination, of the capillaries of the inferior parts. 
The blood is then evidently divided in the first months 
after conception into two circulations, rvhich cross, if it 
may he so said, in the form of the figure 8, as has been 
remarked by Sabatier; it is carried in each, from one as- 
semblage of capillaries to another of the same vessels. 
Only instead of moving between the pulmonary capillary 
system and the general one, as in the adult, it moves be- 
tween the superior and inferior part of this last system; 
ivc may then say in this point of view that the inferior WITH RED BLOOD. 
359 
and superior parts of the body are in opposition in the 
foetus, as the lungs in the adult are in opposition to the 
rest of the body. 
This complete opposition on the part of the circulation, 
between the upper and lower part of the body, in the first 
months of the foetus, is probably the origin of the differ- 
ence that takes place afterwards between these parts. 
All physicians have observed this difference in diseases. 
If the median line frequently separates the affections of 
the right side from those of the left, the diaphragm seems 
often to be the boundary of many diseases. Who does 
not know, that scorbutic affections appear particularly 
below, that serous infiltrations are most frequent there, 
and that ulcers are infinitely more common in the inferior 
extremities, and that on the other hand, most cutaneous 
eruptions take place in the superior parts, &c.? Bordeu, 
who has said much of the division of the body into supe- 
rior and inferior parts, considered one pulse as the pre- 
cursor of evacuations from above, and another as that of 
those from below, he has however without doubt exag- 
gerated this opposition of the two parts of the body ; still 
it really exists, and I think that it is very probable, that 
the manner of the circulation of the foetus is the primary 
source of it. 
After the first months, things begin to change. The 
quantity of blood passing by the pulmonary artery was at 
first scarcely any thing, because the dilatation of the duc- 
tus arteriosus was so great, that it turned almost the whole 
of it into the descending aorta. This canal gradually 
contracting, the pulmonary arteries dilate, and then more 
blood goes through the lungs, and is brought by the pul- 
monary veins to the left auricle, which transmits it to the 
left ventricle, which sends it to the arch of the aorta; 
then the mechanism of the circulation described above 
begins to change, and approximate that of the infant, as 
we shall see. 360 
VASCULAR SYSTEM 
Still this first mechanism predominates for a long time 
over the second; hence it happens that during the great- 
est part of the time that the infant is in the womb of the 
mother, it is the left ventricle that sends the blood to the 
superior parts, whilst the inferior receive theirs by the 
impulse of the right. Now as the parietes of the first are 
evidently thicker than those of the second, and the heart 
is further from the inferior than the superior parts, these 
last receive a stronger impulse than the others. This 
perhaps is a new source of the difference of the two halves 
of the body; hence nutrition is more active in that above, 
hence the degree of vital energy that it preserves a long 
time after birth, and which makes it susceptible, the head 
especially, of many more affections than the lower half. 
As the period of birth approaches, the pulmonary arte- 
ry sends more blood to the lungs, and less passes through 
the ductus arteriosus. For, as I have said, it is only in a 
gradual manner that the whole of this fluid, contained in 
the body, comes finally at birth to go through the lungs. 
Though before it undergoes no alteration there, it does 
not circulate the less, which is undoubtedly to habituate 
it to the passage that it is constantly to take after birth. 
The quantity of blood then is in a direct ratio to the age 
in the pulmonary artery, and in an inverse one in the duc- 
tus arteriosus. 
This arrangement evidently requires a corresponding 
one in the foramen ovale; in fact, if in proportion as the 
ductus arteriosus contracted, this was not diminished also, 
all the blood would finally accumulate in the superior 
parts. For instead of passing from them to the inferior, 
the whole of it would return to them by the left auricle 
and the ventricle of the same side. In proportion as the 
ductus arteriosus is contracted, the foramen ovale being 
lessened also, the blood of the inferior vena cava, the 
whole of which cannot pass through there, begins to mix 
with that of the superior, enters the right auricle, then the WITH RED BLOOD. 
361 
right ventricle, afterwards returns by the lungs to the left 
auricle and ventricle and the aorta. What is the conse- 
quence of this ? that this artery begins to receive from 
the left ventricle a much greater quantity of blood than 
can pass into the carotids and subclavians; a portion of 
it then goes into the descending trunk and is distributed 
to the inferior parts. 
From what has been said, it appears, that the two por- 
tions of the blood of the foetus are almost wholly separate 
in the first months; all that comes from the inferior vena 
C3va goes into the ascending aorta ; all from the superior 
passes into the descending, the lungs receiving scarcely 
any except by the bronchial arteries for their nutrition. 
But as the period of birth approaches, these two portions 
of blood begin to mix, and the circulation then has an ar- 
rangement between that of the adult and that of the first 
months. At birth even, the foramen ovale and the duc- 
tus arteriosus are much contracted, the circulation goe9 
on in the mother’s womb almost in the same way as it does 
after birth ; the w hole difference is that the fluid is of the 
same nature, because respiration has not taken place. 
The sudden change of the circulation at birth, arises par- 
ticularly from the introduction of red blood into the econ- 
omy. As to the mechanical phenomena, they are gradual- 
ly produced by the gradual contraction of the two openings 
of communication. The blood gradually ceases to move 
from the inferior to the superior capillaries; it then goes 
from both of these to those of the lungs and reciprocally. 
In considering the circulating phenomena, we err in 
supposing that their change is sudden at birth. It is suffi- 
cient to examine the foramen ovale and the ductus arte- 
riosus at different periods of pregnancy', to see that they 
contract successively, and that consequently these pheno- 
mena are successive, so that if the foetus should remain in 
the womb a long time beyond its period, and the contrac- 
tion should continue in the foramen ovale and the ductus 362 
VASCULAR SYSTEM 
arteriosus, the blood would circulate as in the adult, from 
the pulmonary to the general capillary system exclusively, 
and reciprocally. The only difference would be in the 
uniformity of its colour, because it would pass through the 
first system, without coming in contact with the air. 
I do not say that the entrance of the air does not sud- 
denly bring to the lungs the remainder of the blood which 
passed by the ductus arteriosus; but this kind of sudden 
turn takes place only in a part of the blood of the pulmo- 
nary artery; a part already passed through the lungs be- 
fore birth, though the air cells were empty. 
In general, there is a constant relation between the 
quantity of blood that the right ventricle sends to the 
lungs, and that which the left sends to the inferior parts. 
The more the first increases, the more abundant is the 
second; this last evidently exceeds that which goes to 
the superior parts. These three things, 1st, the quantity 
of the blood of the inferior vena cava which mixes with 
that of the superior, and passes with it into the right au- 
ricle; 2d, that which from the right ventricle goes through 
the lungs and returns to the left auricle; 3d, that which 
from the left ventricle goes to the descending aorta, con- 
stantly increase as the period of accouchment approaches. 
The descending aorta does not undergo by these varia- 
tions any change in its caliber; in fact, it is the same 
thing to it, whether it receives the blood of the ductus ar- 
teriosus, below the origin of the carotids and subclavians, 
or whether this fluid comes directly to it from the left 
ventricle, through its arch; its parietes constantly increase 
in a uniform manner; all depends upon the successive 
contraction of the ductus arteriosus and the foramen ovale. 
The whole vascular system is generally remarkable in 
the foetus for its great development. The arteries are in 
proportion larger, w hich corresponds with the size of the 
heart, which is much developed at this age; it is nearly 
the same as the nerves in relation to the brain. WITH RED BLOOD. 
363 
The development of the arteries however is not like 
that of the nerves, nearly uniform every where. These 
vessels follow in general the same order as the parts to 
which they are distributed. Thus in the superior parts, 
the cerebral arteries are much more evident than the fa- 
cial; among these, the ophthalmic is more so than the 
nasal, the palatine, &c. In the thorax, the thymic arte- 
ries are much larger in proportion than afterwards. In 
the abdomen, all the gastric viscera being very consider- 
able, their arteries are already very large ; the supra-renal 
are much larger in proportion than in the adult. In the 
pelvis on the contrary, the arterial system is very con- 
tracted, because the viscera are small, as they receive 
but little nourishment. In the inferior extremities, the 
arteries are a little more contracted in proportion than in 
the superior, especially in the earlier periods, for towards 
birth, the proportion is nearer equal. 
The arterial texture is infinitely more pliable in the 
foetus than in the adult; it will yield more easily to ex- 
tension ; ligatures applied upon the arteries break it less 
easily. Aneurisms are extremely rare in infants. 
Many little arteries w ind upon the parietes of the great 
ones in the foetus ; they are often livid, to see them dis- 
tinctly, it is necessary, as I have said, to examine them at 
this age. Does this abundance of vessels dispose the ar- 
teries in the first age to inflammations, which are so rare 
afterwards? I have never observed this alteration. 
In the first periods of the foetus, the layers and arterial 
fibres are indistinct; we should say that the coat of the 
artery is homogeneous. But it has however much more 
consistence than most of the surrounding textures ; this 
consistence corresponds with that of the heart. Destined 
to distribute every where the nutritive matter, the arteries 
ought necessarily to precede the other organs in their nu- 
trition. This early growth, always concomitant with that 
of the heart, would alone prove that the arteries are made 364 
VASCULAR SYSTEM 
to develop themselves, and that the heart does not hot- 
low them out, as Haller has said, in the interior of our 
organs by the force of its impulse. Besides this mechan- 
ical manner of considering their formation is evidently 
contrary to the known laws of the animal economy. 
II. Stale of the Vascular System with Red Blood during 
growth. 
At the moment of birth, two great revolutions take 
place in the system with red blood ; 1st, a mechanical 
one, if it may be so said, in the phenomena of the course 
of the blood ; 2d, a chemical one, in the nature of this 
fluid. The mechanical revolution depends upon the en- 
tire cessation of the passage of the blood through the 
foramen ovale, the ductus arteriosus, the umbilical arte- 
ries and veins. The chemical revolution depends upon 
the formation of red blood. I will now examine this last. 
The foetus finds at birth that all surrounding objects are 
the causes of great excitement; the cutaneous surface, all 
the origins of the mucous, are strongly stimulated. The 
sensations they experience are even painful, because the 
difference is very great between the waters of the amnios 
and the bodies with which the foetus comes in contact at 
birth, and every abrupt change in the sensations is pain- 
ful. Habit soon familiarizes this sensation; but it is not 
less real at birth, and it may be said that this moment is 
as painful for the infant as the mother. Now, as every 
lively sensation is generally accompanied with great mo- 
tions a general agitation succeeds the impression that the 
foetus perceives from without; all the muscles move, the 
intercostals and the diaphragm like the others. The air 
which already filled the mouth and wind-pipe, then enters 
the lungs, and there colours the blood red, then it is alter-? 
nately expired and inspired until death. The first inspi- 
ration then is, in this point of view, a phenomenon analo- 
gous to all the motions that the change of external ex- WITH RED BLOOD. 
365 
citement suddenly produces at birth in the voluntary 
muscles of the foetus. 
The respiratory motion is, however, too important, 
since it commences a new kind of relation between the 
organs, to depend exclusively upon this cause. I presume 
that an unknown principle, a kind of instinct, induces 
the foetus at the moment of birth, to contract the inter- 
costal and diaphragm. This instinct, which 1 do not 
understand, and of which I cannot give the least idea, 
is the same that makes the infant the moment it comes 
from its mother’s womb, contract its lips, as if to nurse. 
We certainly cannot say that this motion is an effect of 
the very acute external impressions that it feels; these 
impressions produce agitations, irregular motions, as if to 
get rid of these impressions, and not a uniform motion 
evidently directed towards a determinate object. If we 
examine all animals separately at the instant of their 
birth, we shall see that every one performs particular 
motions, directed by its instinct. The small quadrupeds 
seek the breast of their mother; the gallinaceous animals 
the grain that is to nourish them; the small carnivorous 
birds immediately open their bills, as if to receive the 
prey the mother is afterwards to bring to them in the 
nest, &c. 
In general, it is essential to distinguish accurately the 
motions, which, at the instant of birth, arise from new 
excitements that the body of the foetus receives, from 
those which are the result of a kind of instinct, of a 
cause of which we are ignorant. I believe that the res- 
piratory motion belongs at the same time to the two 
causes, and more especially perhaps to the last. 
I pass now to the mechanical revolutions of the course 
of the blood. At the instant the lungs change to red the 
black blood that enters them by the pulmonary arteries, 
they receive ail that which before passed through the 
ductus arteriosus,; this ceases to transmit any to the 366 
VASCULAR SYSTEM 
aorta, though, however, it often remains still more or less 
dilated ; for at birth it is hardly ever entirely obliterated ; 
this contraction varies singularly at this period. Why 
does the blood then cease to flow there? As the aliments 
do not enter the ductus choledochus, the lacteal or pan- 
creatic ducts, though they pass their orifices ; so undoubt- 
edly this takes place, because the kind of sensibility of the 
ductus arteriosus repels the new venous blood of the foetus, 
which comes no longer from the placenta, because that 
which the lungs have reddened will not mix with it. We 
cannot certainly give any mechanical reason for its not 
passing ; it really does not, and it evidently depends upon 
the vital laws. Besides, the motion of which the lungs 
become the seat, the dilatation, and especially the new 
excitement that the external air produces there, by ren- 
dering considerably more active the capillary circulation, 
facilitate that of the two pulmonary trunks, and give the 
blood a tendency to pass there rather than through the 
ductus arteriosus; it is in this way that the langs attract, 
as I have said, the blood from the pulmonary artery. 
Does not the great irritation, of which certain tumours 
are the seat, draw there more of this fluid ? Is it not on 
this account that the arteries of these tumours dilate and 
acquire a double or even treble caliber? What takes 
place in these tumours in a gradual manner, happens 
suddenly to the blood that still passes by the ductus arte- 
riosus at birth, and which was very much diminished, as 
I have said, by the successive contraction of this canal. 
For the same reason that all the blood of the pulmo- 
nary artery goes through the lungs, the foramen ovale 
is closed; in fact, this foramen is so arranged at birth, 
that its valves approximate so as to cross, as it were; so 
that when they are pressed against each other, the com- 
munication of the auricles is really closed. Now the 
fed blood entering the left auricle by the pulmonary 
veins, pushes the valve of the foramen ovale correspond- WITH RED BLOOD. 
367 
ing to this auricle, against the other, and consequently 
opposes the blood of the vena cava inferior that endea- 
vours to enter there. This blood flows back to the right 
auricle. Now when this contracts to drive the blood 
into the ventricle, far from forcing it through the foramen 
ovale, it necessarily brings the two valves against each 
other, and obliterates it. By examining with care the 
state of the heart of the foetus, it is evident that when 
the blood enters the left auricle by the pulmonary veins, 
the right by the venae ca.vae and the valves are crossed, 
it is impossible that the blood can pass them either in 
contraction or dilatation. 
Though the foramen ovale may be open at birth, still 
the black blood ceases to pass through it; I say further, 
oftentimes this foramen remains open during the whole 
of life. Many authors have related examples of this. 
I have seen a great number, though this assertion may 
appear extravagant at first. It is impossible from the 
arrangement of its two valves, for the blood to pass 
through it. When the two auricles contract at the same 
time, the blood which is forced by them from without 
within, brings the valves together, and thus itself creates 
an obstacle to its passage. In the greatest number of 
cases, the adhesion of the two valves crossed, is extremely 
weak ; they are rather in contact than united; so that 
by forcing between them the handle of a scalpel, they 
are easily separated and hardly any traces of rupture are 
found. If they were arranged so that the blood could 
insinuate itself between them, it would soon separate 
them and re-establish the communication. Authors need 
no longer attempt to explain, how life is supported when 
the foramen ovale is open; it is the same as if it tvas 
closed, no more blood passes through it. 
The obliteration of the foramen ovale, and the cessa- 
tion of the passage of the blood through its opening, are, 
as we see, phenomena to a certain degree mechanical. 368 
VASCULAR SYSTEM 
The vital laws perform also, without doubt, their part 
on this occasion. Who knows if the sensibility of the 
left auricle, stimulated and modified anew by the red 
blood, does not repel the black which tries to enter it 
by the foramen ovale? We see every day in the econo- 
my, fluids passing at the side of openings, without enter- 
ing them, though they may be wide, for the sole reason 
that their sensibility is not in relation with these fluids. 
Why does the trachea convulsively reject all fluids and 
solids? why does the air alone enter it ? Why does not 
the blood enter the thoracic duct, which is often furnish- 
ed with a valve, as I have observed, incapable of oppos- 
ing its passage, and sometimes even has none ? Why 
does the urethra repel the urine in coition ? It is a fault 
of all authors that they seek only for mechanical causes 
in all the phenomena of the circulation. Without doubt 
the course of the blood is a mechanical phenomenon; 
but the laws that govern this course are vital; it is the 
same as a bone that is moved by muscular contraction ; 
the effect is the mechanism of the lever; the cause is 
vital. 
The blood no longer passing through the ductus arte- 
riosus, this closes immediately by its contractility of tex- 
ture; it becomes a kind of ligament, which fixes to a 
certain degree the aorta and pulmonary artery in their 
respective position. As to the obliteration of the foramen 
ovale, it does not arise from this contractility ; this ob- 
literation is not made by a contraction, but by a real ag- 
glutination of the two valves, between which it is obliquely 
situated at birth. This agglutination appears to be the 
effect of a pressure that is made in an opposite direction, 
upon the partition between the auricles, by the blood that 
each contains. In fact their fibres are so arranged that 
they contract from without within ; now by contracting 
thus, they press from each side the blood against the 
partition, and consequently the two valves against each WITH RFD BLOOD. 
369 
other. Now this agglutination sometimes does not take 
place, whilst the contractility is always exerted when the 
parts in which it exists cease to be distended ; the ductus 
arteriosus is uniformly obliterated. 
At the same time that the ductus arteriosus and fora- 
men ovale cease to transmit blood at birth, this fluid is 
stopt in the umbilical artery and vein. Why does the 
blood cease to flow in this artery, though its diameter 
continues very large at birth? The principal cause ap- 
pears to me to be the nature of the red blood, which is 
no longer in relation with the sensibility of this artery. 
A proof of this is, that if some time after the foetus has 
breathed, respiration is stopt, and the black blood con- 
sequently returns, the umbilical arteries begin to pulsate, 
and if the ligature is loosened, they pour out considerable 
blood. Baudelocque has frequently observed this. 
In general, when respiration is well established, the 
blood no longer flows by the umbilical artery, the liga- 
ture of the cord is then useless. On the other hand, 
when this function is badly performed, there is reason to 
fear hemorrhage of this artery. I confess, however, 
that there may be other causes for this interruption of 
the passage of the red blood. These four things, 1st, 
the cessation of the entrance of the blood into the um- 
bilical vein; 2d, interruption of the passage of that of 
the inferior vena cava by the foramen ovale ; 3d, of that 
of the pulmonary artery by the ductus arteriosus ; 4th, of 
that of the descending aorta by the umbilical artery ; 
these four things, I say, the three last especially, ap- 
pear to depend upon a cause that we do not yet under- 
stand. The change of the relation of the organic sensi- 
bility with the nature of the blood, is perhaps only acces- 
sory, since, as I have observed, it is less this property 
than the action of the heart itself, which is the cause of 
the circulation in the trunks. This subject deserves the 
most attentive examination of physiologists. 370 
VASCULAR SYSTEM 
Respiration being once well established, the lungs are 
in opposition to the whole body ; it sends blood to all 
the parts, and they all send it to the lungs. The bounda- 
ry is then rigourously established between the system 
with black blood and that with red, and things then go 
on as we have before described. 
After birth the vascular system with red blood pre- 
dominates for some time by its greater development and 
its more numerous branches. In fact the red blood enters 
more parts then than it does afterwards. It is sufficient 
to dissect living animals of different ages, to be convinced 
of the greater quantity of blood in young animals, that 
the system contains, of which we are treating; so that, 
as I have said elsewhere, the two opposite ages of life 
exhibit an inverse arrangement as it respects the fluids 
and solids. The first are much more abundant towards 
the period of conception. The second always predomi- 
nate more towards the last age. 
The predominance of the system with red blood re- 
mains evident to the end of the period of growth. We 
see the necessity of this predominance to distribute to all 
the parts the materials of their nutrition and growth ; in 
fact, in the adult the arteries contain only what is des- 
tined to the first, In the infant, they contain moreover 
what is destined to the second. Hence the caliber of 
the arteries is proportionably larger than afterwards, in 
order to contain more fluid. Injections demonstrate this; 
and on this account small subjects are not less favourable 
for the study of the arteries, than of that of the nerves. 
These vessels are more prominent in them; only the sur- 
rounding parts being less developed, we cannot see the 
connexions so well. 
In proportion as the infant advances in age, the equi- 
librium is gradually established in the system with red 
blood. In the head, the facial arteries are more evident, 
and come gradually in their development to the level of WITH RED BLOOD. 
371 
the cerebral. In the thorax, the thymus diminishing as 
the lungs increase, their nutritive arteries follow an in- 
verse order ; the bronchials dilate and the thymic con- 
tract. In the abdomen less blood goes to the capsular 
arteries; but most of the others receive as much of it. 
The pelvis and the inferior extremities have more of it, 
and their development is proportionably evident. 
III. State of the Vascular System with Red Blood after growth. 
It is about the period of puberty that the increase in 
height ceases; the increase in thickness continues always. 
The genital parts, hitherto without influence, seem to be 
then a centre of more active vitality than most of the 
other organs. The portion of the system with red blood 
that belongs to them, then becomes greater. The first 
effect that results from it is the secretion of semen, and 
a general impulse of the individual towards new tastes 
and desires, towards those relative to the propagation of 
the species. 
Another phenomenon is soon the consequence of this. 
As the lungs are connected in an intimate, though un- 
known manner, with the genital parts, they acquire also a 
predominance with them. Their vital energy is increas- 
ed, and then begins the period of the affections of this 
viscus; then, the cause that would in the adult produce 
a gastric affection, brings on a pulmonary one. 
It is truly only at this period, that the predominance 
of the superior parts, of the head especially, ceases en- 
tirely. Thus whilst in infancy the nose is frequently 
the seat of hemorrhage, in youth it takes place partic- 
ularly from the lungs. We may consider the increase 
of the energy of the lungs, which happens shortly after 
puberty, as the termination of the predominance of the 
superior parts. The cutaneous eruptions of the cranium, 
tinea capitis, &c. cease to be as frequent. Convulsions, 
and all the diseases that arise from the extreme suscep- VASCULAR SYSTEM 
372 
tibility of the brain, become also more rare, and seem to 
give place to a great number of acute pulmonary affections. 
It is towards this period, that is, some time after the 
end of the increase in height, that the diseases that are 
considered as the product of an arterial plethora, begin 
especially to manifest themselves; this may be said to be 
their age, and it arises from the following cause ; as the 
blood contains before puberty, not only the materials of 
nulrition, but also those of growth, and whilst this con- 
tinued the whole is expended in the system with red 
blood. But when the parts cease to increase in length, 
if this system still continues to receive the materials of 
growth, a true arterial plethora takes place. About the 
end of growth generally, some affections appear that indi- 
cate a predominance of the blood; as this is however un- 
der the influence of temperament, of the mode of life 
hitherto led, of the season and a thousand other causes, 
which, making the phenomena of the animal economy 
vary, rarely permit us to establish exclusive general prin- 
ciples. Thus all that is said upon the disposition to dif- 
ferent diseases, in the different ages, &c. is subject to 
many exceptions. 
The predominance of the lungs is gradually lost; the 
equilibrium is established among all the organs, which, 
hitherto had each performed a part more or less conspi- 
cuous in the phenomena relative to the different ages. 
As the system with red blood is uniformly, in every part, 
in proportion to its growth, to which it especially contri- 
butes, the equilibrium is in that way established between 
the different parts at twenty-six or thirty years of age ; all 
the arteries have a proportional size, analogous to what 
they will always have afterwards. Whilst until then, 
some predominated, according to the predominance of 
the growth of the organs to which they are sent. 
Towards the fortieth year, the gastric viscera seem to 
acquire a more decided vital activity; but this activity WITH RED BLOOD. 
373 
has no influence upon the size of the arteries that are dis- 
tributed to these viscera. 
Though the growth in height may end about the six- 
teenth or seventeenth year, that in thickness uniformly 
continues; so that the internal viscera still grow, and 
their arteries consequently enlarge, until the last growth 
ceases. This phenomenon has constantly struck me, in 
comparing arteries injected in subjects from sixteen to 
twenty years, with those in subjects beyond thirty-six or 
forty. In the last they are uniformly larger. It is this 
difference that first gave me the idea of distinguishing 
growth, into that in height, and that in thickness. For 
the development of the arteries is the constant index of 
the state of the growth of the organs. The period of the 
cessation of growth in thickness h then remarkable, 1st, 
by the cessation of the increase of the caliber of the arte- 
ries ; 2d, by the general equilibrium that is established in 
their development. 
As the arteries grow in the years that succeed the end 
of the growth of the body, they increase in compactness 
and thickness. Their fibres become more evident; their 
elasticity increases; their pliability is lessened; hence 
why the age of the adult is that of aneurisms. Observe 
that the density of the arteries follows, in its augmenta- 
tion, the same proportion as the flesh}’ fibres of the heart; 
so that as this is more able to send the blood with force, 
these are more able to resist it. 
IV. State of the Vascvlar System with Red Blood during 
old age. 
In the last years, the system with red blood is remark- 
able for the following phenomena. 
The number of the arterial ramifications is much dimin- 
ished. As the heart loses its energy, it sends less blood, 
and with less force. The general vibration that it pro- 
duces in the whole arterial tree, is less felt at the extremi- 374 
VASCULAR SYSTEM 
ties of this tree. The small vessels that form these ex- 
tremities gradually contract, are obliterated and become 
so many little ligaments. Hence why, when the perios- 
teum is separated from the bone, the dura mater from the 
internal surface of the cranium, only a few drops of blood 
escape; why the skin, having hardened like horn, no 
longer exhibits the rosy tint of the preceding ages, espe- 
cially of youth; why the section of a bone does not fur- 
nish hardly any blood, whilst it was so abundant in the 
foetus; why the mucous surfaces look pale, the muscles 
have a dull colour, &c. All anatomists know that injec- 
tions succeed less in proportion, as the subjects are more 
advanced in years; that in extreme old age the trunks 
alone are filled ; that the fluids never enter the ramifica- 
tions ; that it is the reverse in young subjects; that even 
coarse injections oftentimes so fill the ramifications, as to 
render dissection difficult. I have dissected many old 
living animals; and the small quantity of blood their 
vessels contain compared with those of young animals 
is very remarkable. The general proposition that I 
have established, viz. that the solids are constantly ac- 
quiring the predominance, is perfectly true. This oblit- 
eration of the small vessels is remarkable even upon the 
parietes of the great vessels ; we see it in the dead body; 
I have observed it in the living. 
The less quantity of red blood that is found proportion- 
ably in old age, is referable especially to the state of nu- 
trition, which is merely nothing when compared with that 
of infancy. Observe also, that united with the weakness 
of the motion that animates the blood, it is a cause of the 
small degree of excitement which the parts have in old 
age. In fact the use of the circulation is not only to car- 
ry to the different parts the materials of the secretions, 
of exhalations, nutrition, &c. we shall see that it keeps 
them also in a state of constant excitement by the shock 
it gives them at its entrance, a shock, the principle of WITH RED BLOOD. 
375 
which is evidently in the heart. Now this shock is in a 
ratio compounded, 1st, of the quantity of the fluid; 2d, of 
the force with which it is sent. In both respects, the ex- 
citement constantly diminishes, as age advances. Observe 
also that all the functions of the infant, both organic and 
animal, are characterized by a vivacity and impetuosity 
that form a remarkable contrast with the slowness and 
want of energy of those of old people. 
The arterial texture always becomes more and more 
condensed as age advances. The layers that form the 
fibres of the peculiar membrane become drier, if I may 
be allowed the expression. 
I have said that the internal membrane is very often 
the seat of a kind of peculiar ossification, which has hard- 
ly any influence upon the circulation, except when it is 
seated at the origin of the aorta. 
The caliber of the arteries does not dilate in old age. 
There is scarcely any except the arch of the aorta, which 
constantly undergoes an enlargement more or less con- 
siderable, which is always without rupture of the fibres, 
consequently supposes an extensibility of these fibres, and 
undoubtedly depends upon the habitual and direct im- 
pulse that the blood exerts against the concave side of this 
curvature. I have often examined to see if there was a 
similar dilatation at those places in the arteries where 
the curves are very evident, in the internal carotid, for 
example, at the place where it passes through the carotid 
foramen; I have not discovered any. 
In the last periods, the pulse is remarkable for its ex- 
treme slowness; a phenomenon opposite to that of infan- 
cy, in which the blood moves with great quickness. 
These two opposite facts are, after what we have said, 
foreign to the arteries. They indicate only the state of 
the forces of the heart, which is the agent of the general 
impulse of the red blood. 376 
VASCULAR SYSTEM 
It is the same of the pulse in the last periods of life. 
It is not a real pulsation of the arteries; it is a kind of 
undulation, of weak oscillatory motion, and the more ob- 
scure, as life is more feeble. Now 1 am convinced that 
the heart alone is the agent of this undulation ; I am con- 
vinced of it by the following very simple experiment. I 
have laid bare in many dogs, on one hand the carotid, on 
the other the heart by a section of one side of the thorax, 
made in such a manner that the other can still perform 
respiration. By placing the finger upon the artery, I ob- 
served that as long as the heart beat by a sudden impulse, 
that the pulse was kept up as usual, that it was even ac- 
celerated, because the contact of the air increased the 
quickness of the contractions of the heart; but at the end 
of a little lime, this organ began to be weakened in its 
motions, then it contracted by a kind of general tremor 
of its fibres. In proportion as the weakness of the mo- 
tions of the heart increased, the pulse was successively 
weakened. Then when the tremor extended to all its 
fibres, the pulsation of the artery changed to a kind of 
undulation, of feeble oscillation, the precursor of the ces- 
sation of all motion. 
I shall observe, under the system of the muscles of or- 
ganic life, that the heart has many kinds of contraction. 
The principal are, 1st, that which it ordinarily has, in 
which there is a contraction and a dilatation that succeed 
suddenly and regularly; 2d, that in which these two mo- 
tions, retaining their natural character, are irregularly 
connected; 3d, those in which the fibres only oscillate, 
and by which the cardiac cavities a little contracted, com- 
municate to the blood a less sudden shock, a general tre- 
mor, an undulation, &,c. Nowr with each kind of motion 
of the heart, there is a peculiar pulse that corresponds. 
It is easy to be convinced of this upon living animals. 
I am astonished that authors who have disputed so 
much upon the cause of this phenomenon, have not WITH RED BLOOD. 
377 
thought of having recourse to experiment to elucidate 
the question. There are undoubtedly many modifications 
in the pulse, whose coincidence with the motions of the 
heart could not be perceived ; but that of the slow and 
frpquent pulse, the strong and weak, the intermittent, un- 
dulatory, &c. can be immediately discovered, by laying 
the heart bare and placing the finger at the same time 
upon the artery. We see then uniformly, during the 
moments that precede death, that whatever may be the 
modification of the arterial pulsation, there is always an 
analogous modification in the motions of the heart; this 
certainly would not be the case, if the pulse depended 
especially upon the vital contraction of the arteries. I 
have had occasion to make these experiments many times, 
either directly for this object, or with others in view; I 
have seen the motion of the heart always correspond with 
that of the arteries. In general the theory of the pulse 
requires as l have said, new researches; but I have facts 
enough upon this point to be convinced that the varieties 
it undergoes in the different ages, as under other circum- 
stances, depend almost exclusively upon the heart, which 
produces in particular this kind of undulation, of oscilla- 
tory motion which is between the pulsation of the natural 
state and the complete cessation of this pulsation. 
V. Accidental development of the System with Red Blood. 
I shall speak under the organic muscles, of the acci- 
dental development of the left portion of the heart. As 
to the arteries, new ones are never formed ; but often- 
times, those that do exist acquire a remarkable size; this 
depends on two causes, 1st, on an obstruction to the course 
of the blood ; 2d, on the growth of any tumour. 
1st. The dilatation of the arteries by an obstruction to 
the circulation, is evident in the ligature of aneurismatic 
arteries, in the spontaneous cure of aneurisms, a phenom- 
enon of which within a few years a great number of ex- VASCULAR SYSTEM WITH RED BLOOD. 
378 
amples has been published, &c. Then, sometimes the 
great collaterals increase in size, sometimes their caliber 
remains the same, and it is by the ramifications that the 
communications are made. As the branches dilate, their 
thickness increases in proportion with their breadth; at 
least I have twice observed this fact, which is analogous 
to that which the left ventricle presents when it becomes 
aneurismatic. 
2d. All tumours do not produce a dilatation of the arte- 
ries; w'e see this dilatation in cancers, in those of the 
breast, of the womb, &c. in osteo-sarcosis or spina ven- 
tosa, in the different fungi, &c. In general, most tumours 
that give great pain to the patients exhibit this phenome- 
non. We should say even that pain in a part is suffi- 
cient to attract there habitually more blood, and dilate 
the arteries ; we know" that in the operation for lithotomy, 
when the patients have previously suffered much, hemor- 
rhage is often more to be feared. 
After long and copious secretions or exhalations, I have 
not observed that the arteries were more dilated in the 
glands or around the exhalant organs. How large soever 
the cysts may be, their parietes never contain arteries 
proportioned to those that are developed in cancerous tu- 
mours. The cerebral in hydrocephalus, the mediastinal, 
intercostals, &c. in hydro-thorax, the mesenteric, the lum- 
bar, the stomachic,vthe epigastric, &c. in ascites, the sper- 
matic in hydrocele, the renal in diabetes, the branches 
that go to the parotids after a long salivation, retain their 
ordinary size, and under some circumstances they become 
even smaller. 
When the arteries dilate in tumours, do their parietes 
thicken in proportion, as in the preceding case? I have 
no data, from which 1 could determine this point. VASCULAR SYSTEM 
WITH BLACK BLOOD. 
THE red blood circulates in a single system, the 
branches of which every where communicate. The black 
blood on the contrary is contained in two separate sys- 
tems, which have nothing in common but the form, and 
which are, 1st, the general system; 2d, the abdominal. 
We shall now examine the first, and afterwards the second. 
The general vascular system with black blood arises 
as we shall see, from the whole of the great capillary sys- 
tem, is collected towards the heart in great trunks, and 
terminates in the pulmonary capillaries. As the portion 
of the heart that belongs to it will be examined hereafter, 
and the pulmonary artery, by its peculiar membrane, has 
great analogy with the peculiar membrane of the other ar- 
teries, we shall now particularly examine the veins; but 
we shall describe in a general manner, the common mem- 
brane that is spread upon the whole system with black 
blood. 
ARTICLE FIRST. 
SITUATION, FORMS, DIVISION AND GENERAL ARRANGEMENT OF 
THE VASCULAR SYSTEM WITH BLACK BLOOD. 
We shall now examine the veins as we have the arte- 
ries, in their origin, course and termination. Only we 
shall do it inversely, to accommodate our ideas to the 
course in which the blood flows in their channels. 380 
VASCULAR SYSTEM 
I. Origin of the Veins. 
This origin is in the general capillary system. I shall 
point out in this system, how the veins are continued with 
the arteries. 1 would only remark here that these vessels 
never arise from any organ that the arteries do not enter, 
as the tendons, the cartilages, the hair, &c.; which evi- 
dently proves that the blood is not formed in the general 
capillary system ; it leaves there the principles that made 
it red, it perhaps acquires there new ones; it is modified 
in fact, but never created. 
It is not as easy to distinguish accurately the veins at 
their exit from this system, as it is the last arteries at their 
entrance into it, because the valves prevent injections 
from penetrating so far. It is in subjects that have died 
of asphyxia, apoplexy, &c. that the venous ramifications 
can be best observed. We see then that they are soon 
divided into two orders; one accompanies the last arte- 
ries, the other is distinct from them. 
In the greatest number of organs, venous branches go 
out at the same place that the arteries enter. There are 
however some exceptions to this rule. In the brain, for 
example, the arteries enter below, the veins go out above. 
In the liver, the first enter below, the others go off behind, 
&c. This circumstance is, in general, indifferent to the 
circulation, which goes on the same whatever may be the 
relation of the arteries with the veins. In those places 
where the small veins go out at the same time that the 
small arteries enter, sometimes more or less of cellular 
texture serves to unite the small vessels that are in appo- 
sition, sometimes there is a space between them, as in the 
muscles, the nerves, &c. 
Besides the venous origins corresponding with the ar- 
terial terminations, there is an order of veins which is 
separated from the arteries at the exit from the capillary 
system. This order is particularly remarkable at the ex- WITH BLACK BLOOD. 
381 
terior of the body. We see that all the organs that are 
found there furnish, 1st, veins that go to the interior to 
accompany the arteries; 2d, others that go to the exterior 
to become sub-cutaneous, and to form trunks of which we 
shall soon speak. In many internal organs, the same ve- 
nous division is observed. 
It follows from this general arrangement, that many 
more veins go from the capillary system than there are 
arteries that enter it. This is the principle of the dis- 
proportion of the capacity existing between the system 
with red blood, and that with black, a disproportion of 
which we shall soon speak. 
The veins at their origin frequently communicate 
among themselves. We see many little spaces that arise 
from their interlacing, in the places where they can be 
seen, as under the serous surfaces, &c. 
II. Course of the Veins. 
At their exit from the general capillary system, as we 
have just said, the veins are differently arranged. 1st. In 
the extremities and external organs of the trunk, they 
form two sets, the one interior, which accompanies the 
arteries ; the other exterior, which is sub-cutaneous. 2d. 
In the internal organs we frequently make a similar ob- 
servation ; thus there are superficial veins of the kidney, 
and deep ones, that accompany the arteries ; but oftentimes 
all the veins unite themselves to those that follow the 
artery. 
The cutaneous portion of the veins is very remarkable 
in the extremities, where there are considerable branches, 
viz. the saphena in the lower, the cephalic, basilic, and 
their numerous divisions in the superior. In the trunk 
and the head, we do not see any great sub-cutaneous 
branches, except the external jugular in the neck; but 
there is a number of smaller branches proportioned to 
the minuter ones that are distributed there. 382 
VASCULAR SYSTEM 
The external parts, then, are remarkable by the pre- 
dominance of the trunks with black blood over those 
with red. Oftentimes these trunks can be traced through 
the integuments, upon which they show themselves much 
more than those that are whiter and more delicate ; they 
have, besides, no connexion with the tinge that colours 
them, which arises from the blood contained in the gene- 
ral capillary system. 
In the interior of the body, the veins almost every 
where accompany the arteries ; they follow the same dis- 
tribution ; so that they are not commonly described, be- 
cause the course of the arteries is sufficient to repiesent 
theirs. Usually a common cellular space receives both 
the. trunks of the two sorts of vessels and those of the 
nerves. Sometimes, however, the veins are separate, as 
the azygos, for example, which has no corresponding ar- 
terial trunk, and which on this account requires in des- 
criptive anatomy, like the superficial ones of the trunk 
and the extremities, a particular examination and an ac- 
curate dissection to obtain an idea of it. 
The deep-sealed veins have a caliber much more con- 
siderable than that of the arteries ; most usually they 
are more numerous, as in the extremities, where each 
artery is almost always accompanied by two veins. 
III. Proportion of the capacity of the two systems with Black 
and Red Blood. 
After the observation I have just made upon the origin 
and course of the veins, it is evident that their sum total 
has a capacity much greater than that of the arteries. 
This assertion it is easy to prove in detail, wherever there 
is an artery and vein united, as in the kidneys, the spleen, 
the extremities, &c. ; where the arteries are separate 
from the veins, as in the brain, the liver, &c. it is not 
less sensible. Finally, there is, as I have just said, a WITH BLACK BLOOD. 
383 
division of sub-cutaneous veins, which is evidently one 
more than the arteries have. 
Many physiologists have endeavoured to calculate the 
relation of capacity between the two systems with black 
and red blood; but this relation varies too much ever to 
be the subject of any calculation. Is it upon the dead 
body that the attempt is made ? But the veins will be 
more or less dilated according to the kind of death; in 
apoplexy, asphyxia, drowning, &c. they have a diameter 
almost double that which they exhibit when the subject 
has died of hemorrhage, because the first kind of death 
accumulates much blood in the veins, and the second de- 
prives them of it. We can give a greater or less capacity 
to the veins of an animal, according to the manner in 
which we kill him, as we can enlarge or contract the 
right cavities of the heart by similar means. You can 
never find the veins exactly equal in any two subjects, 
though there may be a great resemblance as to size, age, 
&c. Is it upon a living animal that the attempt is made? 
But, besides its being very difficult, you will not then 
have a result uniformly applicable, because the veins vary 
in diameter as they are more or less full. Examine these 
vessels in subjects in whom you can see them by the 
transparency of the integuments; sometimes they are 
more, sometimes less apparent; their size sometimes ap- 
pears double, at others, hardly distinguishable. Certainly 
after drinking copiously, by which the black blood has 
received a great augmentation of its fluid, the vessels are 
more dilated than in an opposite state. The veins are 
remarkably contracted after death from hunger. I have 
often observed the same phenomenon in dropsies, phthisis, 
marasmus, &,c. Always when the mass of blood is di- 
minished, the veins contract by their contractility of tex- 
ture. The arteries are infinitely less subject to variations 
of diameter, on account of their firm and compact tex- 
ture, though, however, they show much of it. 384 
VASCULAR SYSTEM 
Let us reject, then, every kind of calculation upon the 
proportions of capacity of organized canals. We can 
only calculate what is fixed and invariable; but that 
which varies at every instant can only be the object of 
general assertion. Besides, of what importance are the 
rigorous proportions that some physicians have endea- 
voured to establish between our parts ? They are nothing 
in the explanation of the phenomena of health and dis- 
ease. Let us, then, be content with this general asser- 
tion, that the venous capacity surpasses the arterial. It 
may be said, that in a given time there is more blood in 
one than the other. 
The same observation applies to the two sides of the 
heart, one of which belongs to the same system with the 
veins, and the other to the one with the arteries. The 
right has commonly a greater capacity than the left, not 
precisely under the relation of the fleshy texture, but 
under that of the fluid that distends it; this is so true, 
that if in an animal whose thorax is opened, the blood is 
made to accumulate in the left side by ligatures, and the 
right is emptied by puncturing it, the last will be less in 
size than the first. Always when we find it larger than 
the other in the dead body, except in diseases of the 
heart, it is because it contained mere blood at the mo- 
ment of death; in fact, as this fluid ordinarily stops first 
in the lungs, it flows back to this side of the heart, which 
is almost always the largest. 
This is the great difference between inert cavities and 
those that possess life, viz. that these last can change 
their capacity every moment, whilst the others remain 
always the same. In the living animal, the right side 
of the heart has almost always a greater capacity than 
the left, because the quantity of blood it contains is 
greater. 
There are, then, two things generally true, viz. 1st, 
that the great tree that terminates the system with red WITH BLACK BLOOD. 
385 
blood is in general of less capacity than the great tree 
that commences the system with black blood ; 2d, that 
the same observation is applicable to the two sides of the 
heart, which correspond with these two trees. 
As to the tree that terminates the system with black 
blood, compared with that which commences the system 
with red blood, the same thing does not hold true. The 
pulmonary artery and the veins of the same name exhibit 
a disproportion of capacity, less it is true, than in the 
other parts, a disproportion which is real, however, and 
which, notwithstanding what many authors have said, is 
in favour of the veins. How does this happen? it would 
seem that since the one is continuous with the veins and 
propels the same fluids, it ought to have the same propor- 
tion of diameter; and that since the others are continuous 
with the arteries, that they also should be in proportion 
to them. This arises from the difference of the velocity 
of the blood; in fact, this fluid circulates quicker in the 
pulmonary artery than in the veins of the same name, 
since it has the impulse of the heart, which these last 
want; then, in a given time, as great a quantity of blood 
passes through it, though the diameter of this artery is 
smaller; what do I say? if it was equal, the circulation 
could not go on. In the same wray, if the aorta equalled 
in capacity the two venae cav® and the coronaries united, 
and the blood had. the same velocity there, the circulation 
would cease. 
The four pulmonary veins united are a little larger 
than the aorta, which, however, transmits all the blood 
received from them. Why? Because the impulse that 
the left ventric le communicates, makes, in a given time, 
more blood pass by the aorta than by the four pulmonary 
veins. These two things, 1st, the velocity of the fluid ; 
2d, the capacity of the cavitifes in which it circulates, are 
then in an inverse order in the two opposite trees that 
form each vascular system. In that with red blood, there 386 
VASCULAR SYSTEM 
is less velocity and greater capacity from the pulmonary 
capillary system to the agent of impulse; and from this 
agent to the general capillary system, there is, on the con- 
trary, greater velocity and less capacity. In the vascular 
system with black blood, there is less velocity and greater 
capacity from the general capillary system to the agent 
of impulse; and from this agent to the pulmonary capil- 
lary system, there is more velocity and less capacity. 
Without this double opposite arrangement, it is evident 
that the circulation could not take place. 
There is, however, a remark to be made upon this 
subject; it is, that the capacity of the four pulmonary 
veins united, is not so much larger than the aorta as that 
of the venae cavae and the coronary is than the pulmonary 
artery ; and this is the reason of it ; as the pulmonary 
veins run a very short course, the impulse, on the one 
hand, that the red blood has received from the pulmonary 
capillary system, is preserved there more; on the other 
hand, this fluid is there free from numerous causes of 
delay that the blood experiences in the venae cavae and 
coronaries ; then the velocity is greater there, and the ca- 
pacity should be therefore less. If the lungs were situated 
in the pelvis, the pulmonary veins would certainly have 
a greater capacity, because having a greater extent to go 
over, the velocity of the blood would be more retarded. 
We can easily understand now the cause of many ar- 
rangements that have engaged the attention of anato- 
mists; viz. 1st, why the sum of the arteries coming from 
the aorta has less capacity than that of the veins going 
to the right auricle ; 2d, why the four pulmonary veins 
surpass also in diameter the artery of the same name ; 
3d, why these four veins are not exactly in proportion 
with the aorta, which is really a continuation of them j 
4th, why the venae cavae and coronaries are so dispro- 
portioned to the pulmonary artery, which is, as it were, 
their continuation. WITH BLACK BLOOD. 
387 
If there was no agent of impulse in the two systems with 
red and black blood, their capacity would be every where 
nearly the same, because the velocity of the fluid would 
be every where nearly the same. This is precisely what 
happens in the system with black abdominal blood, in 
which the hepatic portion of the vena porta is nearly as 
large as the intestinal one, because there is no heart be- 
tween the two. 
The velocity is less in the general veins and in the 
pulmonary, because they have not at their extremity an 
agent of impulse; we see there only a capillary system. 
The opposite reason explains the velocity of the course 
of the blood in the general arteries and in the pulmona- 
ry. We have seen in the preceding system, that the 
presence of an agent of impulse at the origin of the two 
great arteries, requires there a considerable resistance of 
this texture, whilst the absence of this agent requires but 
little resistance in the veins. 
We see, then, clearly, why these three things, 1st, 
weakness of the parietes ; 2d, slowness of the motion ; 3d, 
great capacity, are the attributes of the veins with black 
and red blood ; w’hy these three opposite things, 1st, 
strength of the parietes; 2d, velocity in the motion; 3d, 
less capacity, characterize the arteries of both sanguife* 
y 
rous systems. 
We see also frerm this why, though the red and black 
blood form in their whole course a continued column, 
though the common membrane over which they pass 
may be in the whole extent of each system nearly the 
same, the organs exterior to this membrane are, however, 
very different. 
The inverse ratio of the velocity of the motion with 
the capacity of the vessels, appears to me so evident, 
that we might be able to judge nearly by the inspection 
of the vessel of the velocity of the blood that runs 
through it, if many causes did not, as I have said, make 388 
VASCULAR SYSTEM 
the vascular parietes vary at the moment of death. 
We know that all the causes that lessen in the veins the 
velocity of the blood, increase their capacity; it is thus 
that we make them prominent by ligatures; that preg- 
nancy enlarges those of the inferior extremities, that 
long-continued standing produces the same effect, &c. 
It is to the same reason that must be referred the ex- 
planation of the following phenomenon ; viz. that the re- 
lation of the arteries and the veins is not every where 
the same; thus the renal, bronchial, thymic veins, &,c. 
are in general smaller in proportion to their arteries, than 
the veins of the spermatic cord in proportion to the ar- 
tery of the same name, than the hypogastric veins in 
proportion to the corresponding artery. The blood has 
less difficulty in circulating in the first than in the second, 
where it rises against its weight; hence why the veins of 
the inferior parts, especially at a certain age, surpass 
their arteries more in diameter, than those of the superior 
parts exceed theirs. 
Rarnijicalions, Small Branches, Branches, Angles of 
Union, fyc. 
The veins present in their course, as it respects 
branches, smaller branches and ramifications, an arrange- 
ment analogous to that of the arteries, except that it 
takes place inversely. The ramifications are nearest the 
origin; they soon unite into smaller branches, these into 
branches, and these last into trunks. 
The ramifications and most of the small branches are 
found in the interior of the organs. The first make an 
integral part of these organs, and are between their 
fibres, &lc. ; the second lie in their great interstices; in 
the glands between the lobes, in the brain, between the 
circumvolutions, in the muscles between the fasciculi, &c. 
In going out of the organs, the small venous branches 
run into, the branches, which take, as we have seen, two WITH BLACK BLOOD. 
389 
positions, one sub-cutaneous, the other deep. The sub- 
cutaneous branches go in the extremities between the 
aponeurosis and the skin, in the trunk between this and 
the cellular layer that covers the muscles. The deep 
branches lie in the interstices that the organs have be- 
tween each other, accompanying almost every where the 
arteries. The cerebral branches have a peculiar ar- 
rangement ; they are placed in the interstices of the 
dura mater, and form with them what are called sin- 
uses. 
The venous branches differ from the arterial in this, 
that they are infinitely less tortuous ; this is remarkable 
under the skin and in the interstices of the organs. This 
is a reason that would prevent locomotion, supposing that 
there was an agent of impulse at the origin of the veins, 
and that their parietes were not so loose. Hence a series 
of arterial lubes is really longer than a corresponding 
series of venous tubes; this facilitates the motion of the 
black blood, which has a less extent to go over, and which 
besides would find causes of delay in the curvatures, 
greater than the red blood, because this is driven by a 
strong agent of impulse, and the other is not. 
The venous branches unite to form a certain number 
of trunks that are connected with those that are imme- 
diately discharged into the right auricle; these trunks are 
the internal jugulars, the iliacs, the azygos, the subcla- 
vians, &c. They are still less tortuous than the branches; 
they have, like the arterial trunks, deep positions, far 
from external agents, from which many organs defend 
them, as a hemorrhage from them would be followed with 
serious consequences. 
The trunks, branches, smaller branches and ramifica- 
tions do not always arise necessarily from each other, in 
the manner we have just pointed out. The branches 
are often united to the trunks, the ramifications to the 
branches, &,c. &,c.; as it is with regard to the arteries. 390 
VASCULAR SYSTEM 
The angles of union vary; sometimes they are right 
angles, as in the lumbar, renal veins, &c.; sometimes they 
are obtuse, as in some of the intercostals ; most common- 
ly they are acute. 
The arrangement of the smaller branches and the 
branches is as variable at least in the veins as in the arte- 
ries ; they partake, in this respect, of the lieneral charac- 
ter of irregularity that the organs of internal life exhibit. 
It is necessary only to attend to the general position and 
distribution of the branches, smaller branches, &,c. Their 
union with the trunks and among themselves, is different 
in almost every subject. 
Forms of the Feins. 
The same observation may be made upon the forms of 
the veins as upon those of the arteries. 
1st. A trunk, branch, &,c. are cylindrical, when ex- 
amined in a space where they receive no branch. In the 
dead body they appear flat, which arises from the col- 
lapse of the parietes, and this is owing to the absence of 
blood. But by distending them with air, water, &c. they 
take their primitive form. In the living body they appear 
round. 
*• 2d. Examined in a considerable extent, a venous branch 
appears conical, so that the base of the cone is towards 
the heart and the apex towards the general capillary sys- 
tem. This form arises from the smaller branches, that 
are successively united to this branch, and increase its 
capacity as it approaches the heart. 
3d. Considered as a whole, the venous system repre- 
sents three trunks; one corresponds with the vena cava 
superior, another with the vena cava inferior, and the third 
with the coronary vein ; these three trunks have their 
apex at the auricle and their base at the general capillary 
system. Anatomists thus represent the whole of the 
veins, because the sum of their divisions, like the arteries, WITH BLACK BLOOD. 
391 
has a greater capacity than the trunks from which these 
divisions arise. 
There is however an observation to be made upon this 
subject, and that is, that the relation between the trunks 
and their divisions is not as exact in the veins as in the 
arteries; thus the sum of certain divisions considerably 
surpasses their trunks, whilst this relation is infinitely less 
in other cases. But all this arises still from the extreme 
variation of the venous parietes, according to the quantity 
of blood they contain ; thus in dead bodies, sometimes 
the branches are much dilated by this fluid, and the trunks 
remain the same; sometimes an opposite phenomenon is 
observed. 1st. This last takes place especially when the 
lungs are obstructed; then in fact the blood flows back 
to the right cavities of the heart, then into the great cor- 
responding venous trunks; these are then almost equal in 
capacity to the divisions they furnish, sometimes they even 
surpass them. 2d. When in the living subject, a limb has 
been situated for a long time perpendicularly, when 
standing has been long continued, for example, then the 
branches are more dilated than the trunks. Now as these 
causes of dilatation vary ad infinitum, the dilatations 
themselves are very variable. 
From these varieties in the dilatation of the venous 
branches and trunks separately, it is evident that the re- 
lation existing between them is extremely variable, that 
it is affected by the manner of the death, by the diseases 
that have preceded it, by the habits of the subject, &c. 
Let us disregard then, upon this point, as upon every 
other, all calculations, even if they have a solid basis, if 
they do not lead to a useful result. 
Injections are also a deceptive means of estimating this 
relation ; in fact, they dilate the trunks much more than the 
branches, and especially than the smaller branches. The 
internal jugular injected, for example, becomes of an enor- 
mous size when compared with the sinus that empties into 392 
VASCULAR SYSTEM 
it. The two venae cavae, the azygos, the subclavians, &c. 
dilate a little less than the jugular; but their size how- 
ever is remarkable when they are injected, in comparison 
with that of their branches injected. 
Anastomoses. 
The veins communicate in general more frequently than 
the arteries. 1st. In the ramifications there is a real net 
work, the anastomoses are so numerous. 2d. In the smaller 
branches, they are not so frequent. 3d. In the branches, 
they are still less numerous; but still we find many of 
them, and it is this that particularly distinguishes these 
branches from the arterial, which are almost always sepa- 
rate from each other. 
The communications between the branches of the veins 
unite immediately in an evident manner the cutaneous to 
the deep division; thus there is a communication between 
the cerebral sinuses and the temporal, occipital veins, &c.; 
between the external and internal jugular by one and even 
two considerable branches; between the basilic, cephalic, 
and their numerous divisions spread upon the fore arm, 
on the one hand; on the other, the brachial, the radial 
and cubital, by different branches that penetrate deep into 
the muscles; between the saphena and crural, tibial, pe- 
roneal, by analogous branches. 
Though separated, the two great venous divisions can 
then evidently supply the functions of each other by mix- 
ing their blood. Hence why, 1st, by agitating the mus- 
cles of the fore arm, we increase the throw of blood in 
venesection, though the muscles do not furnish many 
branches to the open vein, which then receives the blood 
from veins, from which it is forced out by the muscles; 
2d, why in external pressure that obstructs or even en- 
tirely stops the motion of the superficial venous blood, 
the circulation continues as usual; why, for example, if a 
ligature is left for a long time applied to the arm, the su- WITH BLACK BLOOD. 
393 
perficial veins at first swelled, gradually become empty, 
by pouring their blood into the deep ones ; why, notwith- 
standing tight bandages in fractures and luxations, the 
venous blood returns as usual to the heart, though it passes 
in less quantity by the superficial veins. 3d. If a strong 
band is applied high up on the leg, and the saphena vein 
is injected below, it does not fill above the band, but the 
injection goes into the crural. In the same manner the 
internal jugular may be filled by the temporal, &c. 
The anastomoses between the superficial and deep veins 
are more necessary in man than in any other animal, on 
account of his clothing, by which the neck, the ham, the 
arms, &c. are subjected to compressions that would be dan- 
gerous without these anastomoses. We can say that upon 
them alone is founded the possibility of a variety of 
modes in clothing. That they show in fact that these 
modes are less dangerous than some physicians have 
thought; that the danger of apoplexy from a tight cravat, 
of varices from tight garters, &c. is much less than they 
have said. 
When a single trunk is compressed, the blood passes 
easily into the neighbouring ones; but if the compression 
is made upon all the trunks of a limb, a certain time is 
requisite for this fluid to dilate the anastomoses. It expe- 
riences, before this dilatation takes place completely, a 
kind of stoppage in the capillary system, a stoppage that 
explains the momentary redness of the fore-arm in women, 
when the arm is covered with too tight a sleeve, that of 
the hand or the foot when the bandages of the fore-arm 
or the leg are too tight. 
The mode of the venous anastomoses is very analogous 
to that of the arteries. Sometimes the smaller branches 
anastomose with the trunks, sometimes the trunks com- 
municate among themselves. 
In the last mode, 1st, there is merely a branch of com- 
munication, and this is the most common case; we see 394 
VASCULAR SYSTEM 
this between the jugulars, between the deep and superfi- 
cial veins of the thigh, the arm, &,c. 2d. Two branches 
unite by their extremities and form an arch, the mesen- 
teries afford an example of this. 3d. Sometimes instead 
of a trunk, there is an interlacing of the smaller branches 
that form a real venous plexus; such as that which sur- 
rounds the cord of the spermatic vessels. 
In general, where there are the most obstacles to the 
blood, there the anastomoses are the most numerous. 
Hence why the veins that surround the spermatic cord 
communicate so frequently together, why the smaller 
branches of the hypogastric vein which are spread in the 
bottom of the pelvis, form there a plexus so extended, that 
it is a real net work iti w hich the course of no one branch 
can be traced, so numerous are the communications. 
Notwithstanding this, these two portions of the venous 
system are the frequent seat of varices; they are even 
found more frequently dilated in the dead body on account 
of the difficulty the blood experiences there in rising 
against its own weight. 
This leads us to a general reflection upon the venous 
system in relation to the anastomoses, and that is respect- 
ing the necessity there is for the communications being 
more numerous in this than in the arterial system. In 
fact, if we compare the course of the black blood wdth 
that of the red, wc shall see that there are many more 
causes to modify that of the first. 
The black blood evidently obeys its weight in certain 
cases. 1st. If we remain standing a short time the veins 
swell, especially after diseases in which the forces have 
been diminished ; this swelling soon disappears if the 
leg is inclined ; it increases if it remains perpendicular. 
2d. There are many cases, in w hich the forces being very 
weak, the circulation cannot go on in perfection, except 
the legs are in a horizontal or inclined position. The in- 
fluence of position upon many tumours and ulcers of the WITH BLACK BLOOD. 
395 
legs is undoubted. 3d. We know that the first effect of 
the attitude with the head reversed, is a giddiness pro- 
duced by the difficulty the blood experiences in rising 
against its weight. 4th. The valves are particularly des- 
tined to counteract the effect of gravity. 
Every violent motion communicated to the black blood, 
and independent of gravity, can also disturb the course of 
this fluid; it is thus that when we move violently in a cir- 
cular direction, the venous cerebral blood receives, if we 
may so say, a centrifugal motion, which, turning it from 
its natural direction, and preventing it from going entirely 
to the heart, produces a stoppage of it, and hence the diz- 
ziness that is experienced. 
It is not only gravity and every other external cause of 
motion, which influence at every moment the motion of 
the blood in the veins, but there are also external and in- 
ternal pressures, and a variety of other mechanical causes. 
On the contrary, that of the arteries is independent of 
most of the causes, of weight especially, and of the inter- 
nal motion. Why? because the rapidity of the motion is 
so great which the heart gives to the red blood, that the 
influence of gravity and every other analogous cause is 
necessarily nothing. Let us take a comparison; the 
greater the force with which a projectile is thrown into 
the air, the less influence the weight has in making it de- 
viate ; in the case of the blood its influence is still less. 
If the blood was driven in empty vessels, gravity would 
have some effect in the arteries; but in the sudden shock 
impressed upon the whole fluid that fills them, a shock, 
the effect of which is felt at the extremities at the same 
time as at the origin, it is evident that its effect is nothing. 
For an opposite reason, we can understand why it is so 
powerful in the veins, in which there is no agent of im- 
pulse, in which the parietes and capillary system alone 
produce the motions, where the motion is consequently 
slow, &c. 396 
VASCULAR SYSTEM 
From these considerations, it is easy to see the reason 
of the very different arrangement that the arteries and 
veins exhibit in their branches, as it respects anastomo- 
ses, which are as rare on one side as they are frequent on 
the other. 
IV. Termination of the Veins. 
The veins terminate by two principal trunks, the supe- 
rior and inferior venae cavae. There is also another, viz. 
the coronary vein, which empties separately into the right 
auricle; but as this trunk only brings back the blood that 
■went to the heart, we shall pay but little attention to it in 
our general remarks, and but little to those small venous 
branches that empty separately from it into the same au- 
ricle. 
Some authors have thought, that the two venae cavae 
were continuous and formed but one vessel; but it is easy 
to see how different their direction is. It i3 particularly 
in the foetus, that their separation can be well perceived, 
since one corresponds with the right auricle, and the 
other with the left. There is behind the right auricle a 
kind of continuity of the membrane between the one and 
the other; it is the membrane of the black blood that is 
common to them, and which passes from the inferior to the 
superior; but in this respect there is no more continuity 
between them, than between the right side of the heart 
and the pulmonary artery, between the left and the aorta, 
&c. 
By considering the whole of the trunks and the branches 
as a cone, we can say that there are two great venous 
cones distinct from each other; one for all the parts 
which are above the diaphragm, the other for all those 
that are below it. 
The superior vena cava does not answer, then, entirely 
to the union of the arteries that form the aorta of the 
same name, which is only destined to the neck, head, and WITH BLACK BLOOD. 
397 
superior extremities, whilst the other belongs moreover 
to the chest by the vena azygos. For a contrary reason, 
the descending aorta has a destination much more ex- 
tended than the inferior vena cava. 
The limit between the two cones of the ascending and 
descending venae cavae, is placed at the diaphragm. It 
is especially in this respect that we can say that this mus- 
cle divides the body into two parts. Has not this ar- 
rangement some influence upon the difference that is ob- 
served in certain diseases between the superior and infe- 
rior parts ? Should not this cause be connected with those 
pointed out under the article upon the foetus? As yet 
there is nothing certain with regard to this, but I think it 
not improbable. 
Though forming each a distinct cone, the two venae 
cavae communicate, however, especially in the neighbour- 
hood of their common limit, that is to say, in the neigh- 
bourhood of the diaphragm ; the azygos is the great means 
of communication. We know, in fact, that its trunk opens 
into the right renal, into the vena cava itself, or into 
some of the lumbar veins, and that the semi-azygos that 
arises from it, goes also to the left renal or to the lumbar 
of the same side. This anastomosis is very important; 
physicians have not paid sufficient attention to it. It 
proves that when an obstacle is situated in the trunk of 
the inferior vena cava, a great part of the blood of this 
trunk can flow into the superior. Much has been said 
of the compression of this trunk by the enlargements of 
the liver, in the production of dropsies. But, 1st, it is 
ascertained by the numerous examinations of dead bodies 
in modern times, that the production of these diseases 
belongs to every kind of organic affection; that the 
lungs, the heart, the womb, the spleen, &c. can likewise 
occasion them in the latter periods of the alteration of 
their texture; and that, in this respect, they are but a 
symptom in the greatest number of cases, and a symptom 398 
VASCULAR SYSTEM 
wholly disconnected with any sort of compression. 2d. 
By supposing that the liver could exert upon the vena 
cava an analogous compression, in the place where this 
vein crosses its posterior part, it is evident that the anas- 
tomoses of which l have just spoken, would prevent the 
effect of this compression, at least in great measure. 
By supposing that an obstacle was encountered in the 
vena cava superior, the same anastomoses would undoubt- 
edly answer the same end; but as the azygos is inserted 
very near the auricle, as the course of the trunk of the 
vena cava superior is consequently very short, it is evi- 
dent that it is especially to counteract the obstacles the 
inferior may experience, that these anastomoses have 
been established. 
When the blood of this vein passes thus into the supe- 
rior, it goes through certain branches in a direction oppo- 
site to that which is natural to them. For example, 
suppose that the anastomosis takes place in the renal, 
which most often happens ; then the blood of the trunk 
of the vena cava enters by one extremity of this vein ; 
that from the kidney comes by the opposite extremity, 
and both pass into the azygos. A similar motion evi- 
dently supposes the absence of valves in the renal, from 
the vena cava to the insertion of the azygos. Now the 
renal veins never in fact have these folds; the capsular, 
the adipose of the kidney, all the lumbar, are also desti- 
tute of them, as Haller has seen, and I have ascertained 
it to be uniformly so. This absence of valves at the 
places of the anastomoses of the azygos, is a remarkable 
phenomenon ; it proves very well the use that I attribute 
to the communication of the two venae cavae by means of 
this. WITH BLACK BLOOD. 
399 
ARTICLE SECOND. 
ORGANIZATION OF THE VASCULAR SYSTEM WITH BLACK BLOOD. 
I. Texture 'peculiar to this organization. 
This organization is nearly the same for the whole 
system, in the common membrane that forms the great 
canal in which the black blood is contained; but it dif- 
fers in the textures that are connected exteriorly with 
this membrane. In the heart the texture is fleshy; it is 
analogous to the texture of the divisions of the aorta, in 
the pulmonary artery; it has a peculiar character in the 
veins; it is this that will now particularly engage our 
attention. 
In order to see this membrane, it is necessary to re- 
move, 1st, the loose cellular texture that unites the veins 
to the neighbouring parts; 2d, the cellular layer of a pe- 
culiar nature that immediately covers them, and of which 
we have spoken in the article upon the cellular system. 
Then we distinguish in the great trunks, longitudinal 
fibres all parallel to each other, forming a very fine layer, 
often difficult to be seen at first view, but always having 
a real existence. When the veins are much dilated, 
these fibres being more separated, are less evident than in 
a state of contraction. These longitudinal fibres are 
seen more clearly in the trunk of the inferior vena cava 
than in that of the superior. In general it may be said, 
that they are also more marked in all the divisions of 
the first than in those of the second ; dissection has con- 
vinced me of this. Undoubtedly this arises from the 
greater facility that the blood experiences in circulating 
in the second than in the first of these veins, in which it 
Membrane peculiar to the veins. 400 
VASCULAR SYSTEM 
mounts against its own weight; this is moreover a proof 
that man was designed to go erect. 
I have uniformly made another remark, it is, that in the 
superficial veins these fibres are much more evident than 
in the deep-seated ones ; the internal saphena is a remark- 
able example of this. It suffices to open it in its course, 
to see very distinctly its fibres through the common mem- 
brane, especially if it is a little contracted. By cutting 
the crural vein to compare it with this, it is easy to per- 
ceive the difference, which arises without doubt from this 
circumstance, that the neighbouring parts assist the cir- 
culation in the deep veins, whilst there is less of this as- 
sistance given to the superficial ones. 
The branches have fibres in proportion greater than 
the trunks; hence the proportional excess of the thick- 
ness of their parietes, their greater resistance to the blood, 
their less frequent dilatation, &c. 
At the place where any branch arises from a trunk, we 
observe that the fibres change their direction and go upon 
the branch, a circumstance that distinguishes them from 
arterial branches, whose fibres are not a continuation of 
those of the trunk. 
Venous fibres oftentimes approach each other, are 
united, and give a greater thickness to the vein ; this is 
frequently observed at the origin of the saphena. I have 
also seen this arrangement in the hypogastric vein ; 
Boyer has likewise noticed it. 
In general, the venous fibre, except in these places, is 
remarkable for its delicacy, for the little thickness that it 
consequently gives to the membrane that it forms. The 
peculiar membrane of the arteries infinitely exceeds that 
of the veins in this respect ; it is this delicacy that fa- 
vours to a great degree venous extensibility. Observe 
that the structure of each kind of vessels is adapted to 
their peculiar circulation. If the blood circulated in the 
veins with parietes like those of the arteries, its motion WITH BLACK BLOOD. 
401 
would be continually disturbed. A thousand causes re- 
tard the venous blond ; when its motion is languid, the 
capacity of the vessels is increased ; now, the arterial tex- 
tures not allowing of this dilatation, it is evident that the 
circulation would be interrupted. If then the agent of 
impulse, placed at the commencement of the arteries, 
requires a firm and unyielding texture, the slow motion 
of the blood in the veins, the frequent causes that retard 
its progress, demand a texture of an opposite character. 
What is the nature of the venous fibre? Its appear- 
ance, its want of elasticity and brittleness, its great exten- 
sibility of texture, its softness, its colour, its direction, 
distinguish it completely from the arterial fibre. Is it 
muscular? it does not appear to be irritable, and it does 
not look like the muscular fibres. I believe that it is of 
a peculiar nature, essentially different from that of all the 
other textures, having its peculiar properties, life and 
organization; I do not think it capable of much motion. 
We have, however, but few data upon this point. 
The venous fibre, though infinitely more extensible than 
the arterial, is also more resisting; it will support without 
breaking, very considerable weight. The experiments 
of Wintringam have proved this. In the superficial and 
inferior veins especially, this is very remarkable. 
There is a great difference in individuals as it respects 
the venous fibres. In some they are very apparent; in 
others, they are hardly distinguishable upon the great 
trunks; but then ttiey are always very evident in the 
branches, particularly in the superficial ones. 
There are places in the venous apparatus where we 
cannot discover either external fibres, or external cellular 
texture; this is the case with the cerebral sinuses, which 
have the following arrangement. The jugular vein at its 
sinus, loses its peculiar texture, and keeps only the com- 
mon membrane, which, entering the lateral sinus, lines 
it, and extends below into the inferior longitudinal sinus, VASCULAR SYSTEM 
402 
and above into the superior; in a word, into all the 
sinuses of the dura mater. Hence every sinus supposes, 
1st, a separation of the layers of the dura mater; 2d, the 
common membrane of the black blood lining this sepa- 
ration. It is not then upon the dura mater that the blood 
circulates; it is upon the same membrane that it flows 
elsewhere; it is easy to establish this fact in the superior 
longitudinal sinus. This sinus is triangular when consid- 
ered in relation to the separation of the layers of the 
dura mater; but in opening it, we see clearly, that the 
common membrane, by passing over its angles, makes it 
round; this is very evident. It is easy, also, in many 
other sinuses, to separate in certain places this membrane 
from the dura mater; but in the greatest number the ad- 
hesion is close, like the union of the arachnoides with the 
internal surface of the dura mater. This common mem- 
brane of the black blood is spread over the folds of the 
superior longitudinal sinus ; it forms a singular net-work, 
which I shall describe in the cavernous sinuses. 
From this general outline, it is evident that the coats 
of the dura mater supply in the sinuses the place of the 
venous fibres and their external dense cellular texture; 
the common membrane is always the same; but the tex- 
ture that is added to it externally is different. At the 
place where each cerebral vein opens into a sinus, the 
common membrane of that sinus connects itself with it 
in its passage and lines it to its extremities. I know of 
no author who has thus considered the cerebral sinuses, 
as having the common membrane of the black blood ex- 
tended into all the separations of the dura mater. How 
little soever we examine the internal surface of a sinus, 
it is easy to see that this surface differs as much from the 
texture of the dura mater, as it resembles the internal 
surface of the veins. 
The cerebral veins, of which the sinuses are the ter- 
minations, are analogous to the arteries of that part in WITH BLACK BLOOD. 
403 
the extreme tenuity of their parietes, a tenuity that ap- 
pears to be owing to the absence of the cellular coat, and 
which is so great, that you might believe that there was 
only a common membrane. 
There are no circular fibres in the veins. 
Common Membrane of the Black Blood. 
This membrane generally extended from the general 
capillary system to the pulmonary, is every where nearly 
of the same nature. It differs essentially from that of 
the red blood in a great number of respects. 
1st. It admits of much greater distension ; consequently 
it is less brittle. Tie a vein, and it will not break, unless 
the constriction be excessive; it is almost as pliable as 
the cellular coat. This pliability renders it much easier 
of dissection than the common membrane of the arteries. 
2d. It appears to be much more delicate; we have a 
proof of this in the valves, which at first view are hardly 
visible from their extreme tenuity, when they are lying 
against the external surface of the vein. 3d. This com- 
mon membrane is never ossified in old age, like that of 
the arteries; its organization seems to resist the deposi- 
tion of phosphate of lime. When it does take place, it 
is an unnatural state ; whereas the ossification of the 
common membrane of the red blood is almost a natural 
state in old age, as I have before observed. This differ- 
ence between the two common membranes of the black 
and red blood, gives a distinctive character to the dis- 
eases of the heart. We never see ossification in the tri- 
cuspid valves, or in the semilunar valves of the pulmo- 
nary artery, whilst they are so frequent on the left side ; 
this is the uniform result of observations made at the 
Charity; in the bodies of old people dissection has 
always showm me the same thing. So the pulmonary 
artery, though analogous to the aorta by its peculiar 
membrane, is never the seat of these ossifications, because VASCULAR SYSTEM 
404 
the common membrane differs essentially from its own. 
This single phenomenon, so striking in both these mem- 
branes, would incontestibly prove their organic differ- 
ences, while it establishes the necessity of considering 
them in a general manner, whether, in the black blood, 
they line the veins, the pulmonary artery, and the right 
side of the heart, or in the red blood, they are spread 
upon the arteries, the left side of the heart, and the pul- 
monary veins. 
Of the Valves of the Veins. 
The common membrane of the black blood has nume- 
rous folds that are called valves. These folds are want- 
ing in the pulmonary artery, except at its origin, where 
we find the semilunar valves ; in the heart, the tricuspid 
valves are in part formed by this membrane; but the 
venous valves are wholly made by it; it is with them that 
we are particularly concerned. 
The form of these valves is parabolical ; their convex 
edge is attached, and most remote from the heart; their 
straight edge is loose, and nearest that organ. There is 
between them and the vein a space analogous to that of 
the semilunar valves of the aorta and the pulmonary ar- 
tery. They have not, like these valves, a granulation 
upon their loose edge. On a level with the attached 
edge, the venous texture is firmer; there is a kind of 
hardening, w'hieh makes a prominent line of the same 
curved form as that edge. This hardening supports the 
valves, like the one corresponding to it in the semilunar 
valves. It appears to he of the same nature as the ve- 
nous texture, the direction of whose fibres are changed 
to form it. When the common membrane arrives at 
this prominent line, it is folded to form the valve ; so 
that it seems to be made.of two layers, which are sepa- 
rated with difficulty, from its extreme tenuity. WITH BLACK BLOOD. 
405 
The venous valves exist in the inferior vena cava, as in 
the superior. In the first, the divisions of the hypogas- 
tric, of the crural, tibia), internal and external saphena 
veins, &c. are full of them. The second presents many 
of them in the external jugular, in the azygos, in the facial 
veins, in the veins of the arms, &c. Many veins have no 
valves, as we see in the trunk of the inferior vena cava, 
in the emulgents, in the cerebral sinuses, &c. 
The size of the valves is always in proportion to that 
of the trunks in which they are found ; very distinct in 
the azygos, less so in the saphena, and still less so in the 
plantar veins. If we compare them with the caliber of 
the trunk they occupy, we shall see that sometimes they 
can entirely obliterate its cavity, and that at others they 
are too narrow to produce this effect. All authors have 
noticed this arrangement; they have thought that it de- 
pended upon primitive organization ; but I am convinced 
that it arises wholly from the state of dilatation or con- 
traction of the veins. In the first state, the valvps being 
drawn and not dilating in proportion, become smaller 
compared to the caliber of the veins, whose cavity they 
cannot entirely obliterate when they fall down. In the 
second state, as they do not contract in proportion to the 
vessel, they become more lax and are capable of closing it 
completely. All that has been written by authors upon 
the size of the valves, depends then wholly upon the state 
of the veins at the moment of death. This is so true that 
they appear large if the animal dies of hemorrhage, and 
small if he dies of asphyxia. I have twice proved this 
fact. 
From what has just been said, it is evident that the 
reflux of black blood takes place much easier and ex- 
tends much further when the vein is dilated ; and that 
consequently the first pulsation, the effect of this reflux, 
does not extend as far as the second, nor this as far as the 
third and so on. It is this that happens in the cases that 406 
VASCULAR SYSTEM 
we have spoken of before. The reflux never extends to 
the capillary system, especially in parts at a distance from 
the heart, because there being many valves and each 
checking in a degree the blood, it soon stops by losing all 
the motion received from the heart. 
The existence of valves is generally constant, but their 
situation and number are very variable. Sometimes they 
are very near each other, at others at a greater distance* 
in this respect there is a great variety. Generally in the 
small trunks they are nearer, and at a greater distance in 
the large ones. 
They are rarely arranged three by three, most often in 
pairs, and sometimes they are insulated ; this is the case 
especially in the small vessels, in those of the foot, of the 
hand, &c. We find in the works of Haller very minute 
descriptions of the general arrangement, form and posi- 
tion of the vascular folds of which we are treating. 
These folds perform, as we shall see, an important part 
in the venous circulation; by them we are enabled in 
most operations, to dispense with tying the venous trunks, 
if they are not very considerable. In fact, without them, 
the blood poured by the collateral branches into the open 
vessel, would easily escape by a retrograde motion, and 
then we might fear the effusion of all that, which passes 
in the whole course of this vessel, whilst now none can 
escape except what flows between the opening and the 
first or second valve. 
The valves constitute an essential difference between 
the veins and the arteries. Let me observe, that the w ant 
of them in these last vessels is a proof in addition to what 
has been already named, of the absence of vital contrac- 
tility in their texture. In fact if they contracted like the 
heart to drive the blood, this fluid, tending as much to 
return towards the heart by the effect of this contraction, 
as to go to the extremities, there would be at intervals in 
the arterial tubes, valves to counteract this first motion: WITH BLACK BLOOD. 
407 
now we only see them at the origin of the aorta; why? 
because it is only necessary in the arteries to resist the 
effect of the contractility of texture, which, exerting itself 
without a jerk, by a mere contraction, can return but very 
little blood to the heart. A single obstacle at the begin- 
ning of the arterial system, is sufficient then to prevent 
the derangement of the circulation, which might be the 
effect of the reflux caused during the systole by the con- 
tractility of texture of the arteries, a reflux which only 
takes place in certain cases; for ordinarily the return of 
the arteries upon themselves, is produced as I have said, 
by their containing less blood, which has been driven 
through them during the diastole. In order that this re- 
flux might take place, it would be necessary that the effect 
of the contractility of texture should in the systole ex- 
ceed what the arteries have lost of blood in the diastole. 
Action of re-agents upon the Venous Texture. 
This texture exposed to drying, becomes yellowish, re- 
mains pliable and can be bent in any direction ; so that 
the dried venous bands, might in this respect, be applied 
to uses, to which the arterial could not in the same state. 
This texture becomes putrid also more easily than the 
arterial, but less so than the others, particularly the mus- 
cular. To ascertain this, I have exposed at the same time, 
venous trunks and portions of intestines of fine muscular 
layers, to the contact of a moist air. 
It resists maceration less than the arterial texture, but 
more than the others; water in which it has been mace- 
rated by itself is much less fetid than that in which an 
equal portion of muscular texture has been placed. 
The horny hardening of the venous fibres is very evi- 
dent when they are plunged into boiling water or the con- 
centrated acids. They contract then more than half, at 
the same time they become more evident; in this way 
they can be studied better; I have used it often; their 408 
VASCULAR SYSTEM 
contraction thickens the parietes of the vein. When they 
are hardened in this way, if they remain in boiling water 
or the acids, they become soft very soon in the second, 
more slowly in the first. Boiling acts upon them quicker 
than upon the arterial fibres; they can also be reduced 
by long ebullition to a pulpy state, to which we can never 
bring the arteries. 
The caustic alkali seems to have a very remarkable ac- 
tion upon the veins. After remaining a short time in a 
solution of this alkali, they become diaphanous, diminish 
in size, do not entirely dissolve, it is true and become 
liquid, as in the acids, but evidently lose their elementary 
principles, give a remarkable precipitate, and always 
render the liquor less strong, by the new combinations 
which it forms. 
II. Parts common to the organization of the Vascular Sys- 
tem with Black Blood. 
Blood Vessels. 
The veins have in their texture little arteries and veins, 
which take very much the same course as in the arteries. 
They ramify at first in the cellular membrane, send small 
branches to the neighbouring parts, then penetrating the 
venous fibres, wind there in a thousand different direc- 
tions and finally terminate about the common membrane, 
which when injected has appeared to me to receive more 
than in the arteries. 
Cellular Texture. 
The veins, like the arteries, have around them two 
kinds of cellular texture; one which is exterior and of 
the same kind as that which is found in the interstices of 
all the organs; it contains fat and serum, and serves only 
to connect the veins with the adjacent organs; the other 
dense and compact, forms for them a proper coat. No WITH BLACK BLOOD. 
409 
author has yet distinguished the cellular system of this 
particular texture from that which is generally spread 
over the organs, though it differs from it so essentially in 
its filamentary texture, in its dryness, its uniform want of 
fat and serum, its remarkable power of resistance, &c. 
When we raise it, by tearing it with the fingers from the 
veins, it appears as if it was formed of an infinite number 
of little filaments interwoven with each other. 
After having formed this external covering to the veins, 
this cellular texture of a peculiar nature analogous to the 
sub-arterial, sub-mucous, &c. passes between the longitu- 
dinal venous fibres, separates them, forms for them a kind 
of sheath, and terminates in the common membrane, which 
appears to contain it in its texture, and which owes per- 
haps in part to this circumstance, the great extensibility 
that it possesses. 
1 would observe that the presence of the cellular tex- 
ture in the venous parietes is a distinctive and striking 
character that distinguishes them from those of the arte- 
ries, with which their texture has in other respects no kind 
of analogy. 
Exhalants and Absorbents. 
It appears that there is no exhalation upon the internal 
surface of the veins. This surface is always moist in the 
dead body, though the vessels are empty ; but I attribute 
this phenomenon, as in the arteries, to a transudation that 
has taken place after death. If there was in fact a fluid 
exhaled, it would prevent the adhesions of the venous 
parietes, when during life the blood ceases to flow through 
them. Now every vein that is empty is obliterated into 
a sort of ligament, like the arteries in similar cases. 
There is no more absorption upon the internal surface 
of the veins, than exhalation. To satisfy myself of this 
fact, I have tried upon the external and internal jugular 
veins, the same experiment before noticed, as having been 410 
VASCULAR SYSTEM 
made upon the carotid artery; 1 obtained the same result 
and drew from it the same conclusion. I have been in- 
duced to make these experiments, from the opinion of 
many distinguished anatomists, who thought that the ab- 
sorbents arose immediately from the veins and the arte- 
ries. It is possible that this is the case in the smaller 
branches, in the capillary system especially, as 1 shall say 
in the absorbent system ; but I do not believe that any 
thing similar can be demonstrated in the trunks. 
It appears then that the exhalants and absorbents of the 
venous parietes, like those of the arterial, are confined to 
the nutritive functions, and that they are consequently 
few. This remark is applicable not only to the veins, but 
to the whole of the vascular system with black blood. 
Nerves. 
1st. The veins differ essentially from the arteries by the 
few nerves of the ganglions that accompany them. Whilst 
these nerves form for most of the arteries a kind of cover- 
ing, they are scarcely spread at all upon the veins. By 
laying bare the venae cavae, jugulars and azygos, it is easy 
to observe this. 2d. The side of the heart with black 
blood, receives as many nerves as that with red; this 
proves that they have no influence upon the contraction, 
as it is evidently weaker on the right side than the left; 
whereas if it was produced by the nerves it would be equal, 
as there is an equal distribution of them. 3d. The pul- 
monary artery has but very few nerves. I know not as 
yet the relation that exists between it and the pulmonary 
veins in this respect. 
It appears from this general survey, that the system with 
red blood has many more nerves than that with black. 
In fact beiny nearly equal at the heart, and the difference 
being very sensible in this particular between the aortic 
arteries and the veins that go to the right auricle, although 
the pulmonary artery may have a few more than thecor- WITH BLACK BLOOD. 
411 
responding veins, which I think very probable, yet the 
short course of these vessels would not prevent the dispro- 
portion from being very apparent. 
ARTICLE THIRD. 
PROPERTIES OF THE VASCULAR SYSTEM WITH BLACK BLOOD. 
The veins are in general but little elastic, soft, and 
loose; they partake of the character of many of the ani- 
mal textures, and are essentially distinguished in this re- 
spect from the arteries, which as we have seen are very 
elastic. We shall now treat of the vital properties and 
the properties of texture in these vessels. 
I. Properties of Texture. Extensibility. 
The veins have in regard to this property, an arrange- 
ment entirely opposite to that of the arteries, which are 
very extensible longitudinally, but very little so trans- 
versely. 
The veins stretch but little in the first direction. When 
drawn out of a stump after amputation upon the dead 
body, they lengthen but little in proportion to what they 
dilate in varices, though here they experience an actual 
increase of size. Perhaps however this depends less upon 
the deficiency of extensibility of texture, than upon the 
circumstance that the folds arc less evident than in the 
arteries, and of course the development is less. What- 
ever may be the cause, the fact is certain and uniform. 
Few organs, on the other hand, exhibit a greater de- 
gree of extensibility transversely, than the veins. In the 
dead body, they can be enormously dilated, by injections 
of air, water, fatty substances, &.c. In the living, we 
know the varicose dilatations, which arise in the great 
trunks, from the obstacles to the course of the blood in 412 
VASCULAR SYSTEM 
the lungs. While the arteries do not appear very often 
more than to double their diameter without breaking 
their common and peculiar membrane, the veins treble, 
quadruple, and even quintuple their diameter without this 
rupture’s taking place. 
We have however numerous examples of this accident. 
Haller has related many in his great work. We see these 
ruptures take place during pregnancy in the veins of the 
lower extremities; there are examples of them also in the 
external veins of the head in violent headaches. We have 
seen the venae cavae, the jugulars, the subclavians sudden- 
ly break and produce death. Every one knows of the 
hemorrhages that arise from the rupture of the hemor- 
rhoidal veins, &c. 1 think that the extreme tenuity of the 
parietes of the cerebral veins exposes them to being fre- 
quently torn by blows upon the head, wounds upon that 
part, &e. When there is an effusion in the tunica arach- 
noides, it can certainly come from no other source than 
the venous trunks, which being surrounded by a fold of 
the arachnoides, pass through this cavity to go to the ce- 
rebral sinuses. Now we know that this case is very com- 
mon, and that it even takes place at the same time with 
that, in which the dura mater being detached from the 
cranium, is found separated by an effusion. Is not apo- 
plexy a sudden rupture of the venous extremities? I have 
already observed that we have no data upon this point. 
All these cases are very different from arterial aneurism; 
they often take place when the dilatation is infinitely less 
than in many instances where the veins remain whole. 
Very commonly this does not happen. The whole of the 
vein, with the cellular tunic containing it, bursts. The arte- 
rial rupture in true aneurisms, is on the contrary uniform ; 
when the dilatation is carried to a certain point it always 
happens. The two arterial coats break easily, the cellular 
remains whole. I do not believe that there is a solitary 
instance of a great aneurism, without rupture. Why? WITH BLACK BLOOD. 
413 
because the arterial extensibility can only yield to a cer- 
tain point. The ruptures take place then from a want of 
this property; they are disconnected with this cause in 
the veins. We do not know yet how they are produced. 
In a great number of cases certainly, there is an affection 
of the venous texture ; this is undoubtedly the case in he- 
morrhoids, &,c. Let us be content to point out the differ- 
ences between arterial and venous ruptures, and wait till 
further observation shall discover to us all their causes. 
If we bear in mind, that the arterial fibres are very nu- 
merous and all circular, that the venous, on the contrary, 
are on the one hand longitudinal where they exist, and on 
the other that they are very thinly scattered on their ves- 
sels, we shall then see why the first resist much longer a 
distension in the direction of their diameter than of their 
axis, and why the opposite phenomenon is observed in the 
second, though much less decided. 
Contractility. 
This corresponds with the extensibility. Slight in the 
longitudinal direction, much greater in the transverse. 
1st. It produces the contraction upon themselves, of the 
parictes of the umbilical vein, of any trunk that is tied, 
&ic. 2d. It produces in a trunk that is pricked, the sud- 
den evacuation of the blood contained between the two 
ligatures by the return of the parietes upon themselves. 
3d. It manifests a decided influence on the flow of blood 
in venesection. 4th. The numberless varieties of caliber 
that the veins exhibit after death, according to the quan- 
tity of blood they contain, are the result of their exten- 
sibility and contractility of texture. 5th. During life, 
the superficial veins appear very various ; dilated in 
summer, contracted in winter, expanded in the warm 
bath, as we see the saphenas, especially in pediluvium, 
lessened in the cold bath, prominent by a long continued 
perpendicular position, flattened by a horizontal one, &c. VASCULAR SYSTEM 
414 
they present to him who observes them, at different times, 
numerous varieties. 1 very much doubt whether those 
who have calculated so much the capacity of the vessels, 
the velocity of the blood, &.c. would have undertaken 
their labours, if they had opened many bodies, or made 
many experiments upon living animals ; now all the va- 
rieties depend upon the extensibility and contractility of 
texture. 
II. Vital Properties. 
Properties of Animal Life. 
Have the veins sensibility ? The following is the result 
of my experiments upon the subject. 1st. Irritated ex- 
ternally by any mechanical instrument, pam is not pro- 
duced, as Haller has seen ; 2d, a ligature put upon theta 
gives no pain, whether it is done upon living animals, or 
in certain surgical operations, in great amputations, for 
example, in which it is recommended to tie the vein as 
well as the artery. 3d. Irritated internally, they exhibit 
the, same phenomenon. I have many times pushed a stilet 
very far into one of these vessels, without making the 
animal cry out. I would observe also, that this is a good 
method of examining the sensibility of the heart, without 
producing in the chest a disturbance,that would increase, 
diminish, or alter this property in any manner, by the 
general derangement that it would occasion in the econo- 
my. I force then a long stilet into the right external 
jugular vein, opened as it is in the operation for bleeding. 
This stilet goes to the heart, without any accident, by 
straightening out the venous angles. The animal often- 
times gives no sign of pain ; sometimes, however, he 
does ; the motion of the pulse is always accelerated. 
We might easily reach in a man, without accident, with 
a stilet, the right side of the heart, by introducing it into 
the right external jugular vein. Why, in certain as- WITH BLACK BLOOD. 
415 
phyxias, in syncopes which resist all other stimulants, &c. 
might we not employ this method to re-animate the action 
of the heart? 4th. When we inject a foreign fluid into 
the veins, however irritating it may be, the animals rarely 
show any sign of pain. Urine, bile, wine, the narcotics, 
&c. are transfused with impunity in this respect. 5th. 
On the contrary, when a bubble of air enters them, the 
animal cries out, is agitated, and struggles before dying; 
is this owing to the contact of the fluid upon the common 
membrane ? I believe not; for usually there is an interval 
between the cries and the injection of the air. It is pos- 
sible that the pain happens at the instant when the air 
strikes the brain, after having passed through the lungs, 
a passage which is constant, as I have observed else- 
where. 
There is evidently no animal contractility in the veins. 
The same experiments that demonstrate its absence in 
the arteries, prove it also as it respects the veins. I 
have made them at the same time upon both kinds of 
vessels. 1 refer, then, upon this subject to the preceding 
system. 
Properties of Organic Life. Sensible Contractility. 
This property does not appear to be an attribute of the 
veins. Haller, by irritating them in different ways, per- 
ceived no sensible motion in them. I have usually made 
the same observation, whether I employed internal or 
external irritation. 
It has appeared to me, however, in two or three cases, 
that a manifest contraction took place. As the venous 
fibres are only longitudinal, and as they are very few, it 
i3 evident that in admitting that they are muscular, it 
wrould be very difficult to observe the effect of irritants 
applied to them, though it might be real. The question 
is not, then, fully settled, though I incline much more to 
fhe belief that there is no venous irritability. As the 416 
VASCULAR SYSTEM 
venae cavae have evident fleshy fibres at their origin, it is 
evident that they possess at that place the contractility 
of which we are treating. 
A proof of the great obscurity of the sensible organic 
contractility in the veins, is, that it is never increased in 
disease. All the organs, in which this property exists, 
are remarkable for its frequent increase, which constitutes 
in the heart the quickness and the force of the pulse, in 
the stomach vomiting, in the intestines diarrhoea, in the 
bladder incontinence of urine, especially in children, 
&c. Now the veins never exhibit a derangement, which, 
corresponding to these, would make us believe in the ex- 
istence of a power of which this derangement is the ex- 
cess, if I may so say. 
Observe, that this observation is also applicable to the 
arteries; never in a determinate portion of the arterial 
system, do we see this local disturbance, this insulated de- 
rangement, which certain portions of the intestinal canal 
sometimes exhibit. The irregularity of the motion of 
the blood is always general, because it arises from a sin- 
gle cause, viz. the irregular impulse of the heart. 
Observe, that this way of discovering the presence or 
absence of this or that vital force in a part, by the affec- 
tions which increase that force there, deserves an impor- 
tant consideration in the examination of these forces. 
Authors have not employed this method of discovering 
them, of pronouncing consequently upon their presence 
or absence in the organs. 
Of the Venous Pulse. 
The pulsation that the veins have under certain cir- 
cumstances, must not be taken for an effect of the venous 
irritability. It is an effect of the reflux of the blood, 
which not being able to go through the lungs, stagnates 
in the pulmonary arteries and in the right side of the 
heart ; so that when this contracts, as the blood finds an WITH BLACK BLOOD. 
417 
obstacle in the ordinary course, it flows back whence it 
came, as when the aliments are unable to pass down, 
they take the other direction. This reflux takes place, 
to a certain distance, notwithstanding the valves ; it is 
often very evident in the jugular vein, when animals, sub- 
mitted to experiments, breathe laboriously; then it is 
discontinued ; it takes place three or four times, then 
ceases, and returns irregularly ; it is observed also in 
the last moments of life, when the lungs are embar- 
rassed. 
The vein is then sensibly dilated; then it contracts. 
But if you apply the finger above, you do not experience 
a sensation analogous to that of the pulse; you will per- 
ceive only a wave of blood which flows back. 7"he rea- 
son of it is plain; 1st, there is no locomotion; 2d, as the 
venous parietes are loose, they could not strike the finger 
sufficiently strong, if there was a similar change of place. 
Observe, that it is less the blood than the artery itself 
which by its firm texture gives the sensation of the pulse ; 
if it could straighten itself when empty, as it does when 
it is full, it would produce nearly the same sensation ; 
this is a remark that should be added to what I have said 
upon the pulse in the preceding system. 
The contraction of the veins in the motion of the re- 
flux, of which we are treating, is only the contractility of 
texture. When the heart ceases to propel the blood in 
its cavity, it contracts, after having been dilated; it is 
nearly the same in the dead body, in which we fix a 
syringe in the veins; when they are very full of water, if 
we draw back the piston a little, immediately the fluid 
returning, the vein contracts; it is as when it contracts 
from a puncture that evacuates the blood; this does not 
imply any irritability. 
I believe that sometimes this reflux may depend upon 
an irregular motion of the heart, which contracts in an 418 
VASCULAR SYSTEM 
opposite direction to the ordinary one, though there is no 
obstacle in the lungs. What induces me to think so, is, 
that frequently in experiments, at the moment the ani- 
mal begins to suffer much, the reflux takes place before 
the lungs have had time to be disturbed. A very re- 
markable thing in experiments is the quickness with 
which pain disturbs the motion of the heart, accelerates 
it, renders it irregular, &c. We can always at will hasten 
respiration, by making the animal suffer ; now the accele- 
ration of the pulse is always prior to that of respiration, 
which appears to be determined by it. I am persuaded 
that if the diseases of the heart were as frequent on the 
right side as the left, they would often produce this 
reflux and this pulsation of the veins. 
The limits of the reflux of the venous blood vary. 
Haller has observed it as far as the iliacs. In general, it 
rarely goes beyond the great trunks, on account of the 
valves. I have demonstrated in my Researches upon 
Death, that the colour of those who die of asphyxia, of 
those who are drowned, &x. does not depend on this, be- 
cause it cannot evidently extend to the capillary system, 
which receives the black blood that colours it, from the 
arteries that then circulate that kind of blood. 
The reflux of the black blood in the veins, produced 
in the preceding cases, either by an obstruction in the 
lungs, or by a sudden derangement in the action of the 
heart, takes place in a natural state, though in an infi- 
nitely less degree. In fact, when the right auricle con-' 
tracts, all the blood does not pass into the corresponding 
ventricle; the veins being open, a portion flows back 
into them. It is difficult to determine the extent of this 
natural reflux, of which all authors have spoken. When 
the thorax is opened, we observe it distinctly ; we might 
then ascertain its extent; but in this case, respiration not 
being performed as usual, it is evident that we cannot 
judge by it of what ordinarily takes place. WITH BLACK BLOOD. 
419 
Insensible Contractility. 
This property, which, like the preceding, is insepara- 
ble from the organic sensibility, exists in the veins as in 
the other parts; it presides only over nutrition; it ap- 
pears more evident than in the arteries ; at least the dis- 
eases which particularly increase it are more frequent in 
the veins. The texture of these vessels is often inflam- 
ed. 1st. Bell relates cases of it, the effect of external 
violence. 2d. Every one is acquainted with the inflam- 
mation of the hemorrhoids. 3d. The cicatrization of 
venous wounds after bleeding is a product of inflamma- 
tion. Without doubt this cicatrization is promoted by 
the want of impulse, to which the arteries are subjected ; 
but certainly these last would not in like circumstances 
heal so fast, if they did at all. When an artery has been 
tied, it is necessary that its parietes, inflamed by the ac- 
tion of the thread, most often cut by it, and brought into 
contact, should form adhesions, that the cure may be 
complete, and the ligature come off without danger. 
Now, nothing is more difficult and slower than their ad- 
hesion, from the difficulty with which the arterial texture 
inflames. Hence the frequency of hemorrhage after the 
operation for aneurism and other great operations. The 
blood often bursts out at the end of twenty, thirty, or 
forty days ; the surgeon should always be upon his guard 
when he has tied these great trunks, from the want of 
disposition in the arterial texture to inflame. Frequently 
when the artery is obliterated, it is not by inflammation. 
Whilst the ligature stops the blood, the portion of artery 
comprised between it and the first collateral branch, 
closes gradually by the contractility of texture, and forms 
a kind of ligament, which arrests the blood after the 
thread has fallen off. I do not know but that these cases 
are more numerous than those of inflammation. Now 
the veins alwaj's adhere soon when they are tied ; their 420 
VASCULAR SYSTEM 
wounds cicatrize immediately. In great wounds it is 
almost always useless to tie them at the first moment, on 
account cf the valves, as I have said above, and after- 
wards, because the cut ends contract, and soon inflame 
and adhere. If there are venous hemorrhages, it is at 
the time of the injury, and not as long after as in the 
arteries. 
Every thing proves, then, that the vital activity is 
much greater in the venous than in the arterial system, 
in respect to the tonic powers. The absence of the cel- 
lular texture in the second and its presence in the first, 
may have an influence upon this phenomenon. 
Observations on the motion of the Black Blood in the Veins. 
From what has just been said, it appears, that the blood 
is beyond the influence of the heart when it arrives in 
the veins. It is evident, then, that the veins can have no 
pulse. 1st. This phenomenon depends upon a single im- 
pulse, suddenly received by the contraction of the left 
ventricle; now, the blood is poured from all parts by the 
capillary system into the veins, this agent of impulse is 
wanting; the cause of the pulse does not exist in the 
veins. 2d. Jhe necessary conditions for its production in 
the texture of the vessels in which it takes place, are 
elasticity and resistance, which are also wanting in the 
veins. They are only susceptible, then, either of a pul- 
sation which occasions the reflux of the blood in the de- 
rangement of the lungs, or in the irregular motions of the 
heart, or of an undulation of which they are the seat, 
when arterial blood accidentally circulates in them; now, 
in either, the heart is the principle of motion, and it could 
not exist without it. 
This is what takes place in the venous motion. The 
capillary system, by its insensible contractility, pours con- 
tinually into the venous system a certain quantity of 
blood. This fluid, added to what is already there, corn- WITH BLACK BLOOD. 
421 
municates a general motion to it. Now, as the whole 
venous system is constantly full, it is necessary that while 
the fluid enters at one side it should go out at the other; 
if not, the venous parietes would dilate ; but, as they have 
a resistance by which they can act to a certain point 
upon the blood, this fluid not being able to dilate the 
veins, flows towards the heart. 
The impulse given by the insensible contraction of the 
capillary system, is too weak, however, to extend instan- 
taneously from one extremity of the veins to the other, 
especially where the blood rises against its weight. As 
this fluid enters these vessels, the weight of that which 
is before it not being overcome, it would produce a gene- 
ral dilatation, and the blcod would not reach the heart; 
but the valves counteract this, by supporting at short dis- 
tances the column of blood. Weakness of the venous 
parietes and the existence of valves are necessarily con- 
nected. If the veins were as strong as the arteries, una- 
ble to dilate when the blood enters them, they would ne- 
cessarily transmit the surplus to the heart, if they were 
destitute of valves; but on the other hand, their circu- 
lation would be every instant embarrassed. 
It appears that it is not only the insensible contraction 
of the capillary system which propels the blood in the 
veins; but that the ramifications of these vessels have a 
kind of absorbent power, by w'hich they draw blood into 
this system. Now the insensible motion produced by this 
power tends evidently from the ramifications towards the 
trunks, as in the lymphatics ; then, when, on the one hand, 
the blood is propelled in the veins, and, on the other, as it 
were, attracted by them, it is evident that the primitive 
source of motion that it obeys, is in the capillary system. 
This impulse communicated to the blood, exceeds but 
very little the resistance which this fluid experiences in 
its motion; so that the least resistance deranges this mo- 
tion. Hence* as we have seen, the necessity of anaslo- 422 
VASCULAR SYSTEM 
moses. Hence also the necessity of other assistance to 
aid this motion, such as, 1st, the muscular action, the in- 
fluence of which we cannot doubt, when we see the flow 
of blood in venesection accelerated by the motion of the 
muscles of the fore-arm, the palpitations of the heart, 
produced by the blood that flows there after a rapid cir- 
culation ; when we observe that varices are as rare in the 
veins situated among the muscles, as they are common in 
the sub-cutaneous ones, &c.; 2d, the pulsation of those 
arteries which are in many places joined to the veins, and 
which communicate to them a kind of motion; 3d, the 
motion of certain parts, like that of the brain, which con- 
tinually rising and falling, accelerates the circulation of 
the blood of the sinuses in an evident manner; so also the 
constant locomotion of the gastric viscera, propels it in 
the veins of the abdomen, and that of the pectoral visce- 
ra, in those of the thorax. It is so true that the veins de- 
rive assistance to their circulation from external motions, 
that if a limb is a long time immoveably fixed when frac- 
tured, these vessels often dilate. 4tn. External frictions, 
if they are not so violent as to embarrass the venous cir- 
culation, evidently facilitate it; this is one of the advan- 
tages of dry frictions. 5th. A slight compress, not suffi- 
cient to check the venous blood, often promotes its circu- 
lation, when the external organs are weakened. We 
know, since the time of Theden and Desault, the ad- 
vantage of tight bandages, for varicose ulcers, even for 
varices, &c. 
Since the principle of the motion of the venous blood 
is generally spread throughout the whole general capil- 
lary system, instead of being concentrated, like that of the 
arteries, in a single organ, it is evident, that this motion 
cannot be uniform, that it must vary according to the state 
of the capillary system in the different parts; that it can 
be more rapid in some veins, and slower in others. This 
is in fact what we see, especially externally where the WITH BLACK BLOOD. 
423 
veins are more or less swelled, according as the blood cir- 
culates there more or less rapidly. In the arteries on the 
contrary, the motion is every where the same; it is a gen- 
eral and sudden shock, an impulse, which, every where 
felt at the same time, is necessarily every where uniform; 
so you never see some arteries more full, others more 
empty, as it happens in the veins. 
There are numerous researches to be made on the mo- 
tion of the blood in the veins. Notwithstanding all that 
authors have written upon this question, there is an ob- 
scurity in it in which we perceive but few rays of light. 
These difficulties arise from this, that we do not know pre- 
cisely what is the kind and form of motion communicated 
to the blood in the capillary system, what is the influence 
of the vascular parietes upon this fluid, &c. &e. Our 
knowledge upon this point is reduced to certain views 
which I have just presented, and which are particularly 
relative to the parallel between the motion of the blood 
in the veins and the arteries. I believe that this parallel 
carried further at some future day, will throw much light 
upon the venous circulation ; in fact, as the first motion is 
much more easily understood than the second, we must 
proceed from what is known to what is unknown, and 
place in opposition what wre are acquainted with in one, 
with that which we seek to know in the other. This is 
the summary of this parallel, though imperfect; 1st, Gen- 
eral pulsation in the arteries, absence of this general pul- 
sation in the veins. 2d. Rapidity of the course of the 
blood in the arteries ; slowness of the same course in the 
veins. 3d. Greater capacity and thinner parietes in the 
veins; less capacity and greater thickness in the parietes 
of the arteries. 4th. Necessity for accessory assistance 
for the venous circulation ; the inutility of this assistance 
for the arterial circulation. 5th. The blood flowing per 
saltern, from the second, the uniform flow from the first. 
6th. The susceptibility of the blood in the to be in- 424 
VASCULAR SYSTEM 
fluenced by its gravity and other accessory causes; there 
is some of this influence in the arterial motion. The fol- 
lowing arc the phenomena, which, from what we have 
just said, evidently depend upon the existence of an agent 
of impulse at the origin of the arteries, and of the absence 
of this agent at that of the veins. 
1st. Constant uniformity of the motion in the arteries; 
variety of motion in every part of the venous system; 
2d, dilatation and contraction generally the same in all 
the arteries of dead bodies; extreme variety in this re- 
spect in the veins of the different parts; these are the 
other phenomena which arise from the unity of impulse 
in the first, and from the varieties of the principle of the 
motion of the blood in the second, &c. 
Some authors have insisted much, in explaining the 
causes of the difference of the arterial and venous motion, 
upon this, that in the arteries the blood is propelled in de- 
creasing vessels, to the capillary system that resists; in 
the veins on the contrary it flows in vessels always in- 
creasing till it arrives at the right auricle, which offers 
no resistance. But the black abdominal blood is also car- 
ried without the agent of impulse, in a series of decreas- 
ing tubes to the capillary system of the liver, and yet the 
motion is analogous to that of the veins. 
Sympathies of the Veins. 
The sympathies of the veins are very obscure, like those 
of the arteries. As the textures of these two kinds of ves- 
sels are rarely affected, as inflammation and the different 
kinds of tumours do not frequently exist in them, and as 
they are hardly ever the seat of pain, we know but little 
of the influence they exert upon the other textures. How- 
ever when we transfuse substances into the vessels, we 
have often seen acrid and irritating ones upon being intro- 
duced into the veins, produce sudden convulsions in dif- 
ferent muscles. WITH BLACK BLOOD. 
425 
As to the influence that the other organs when affected, 
exert upon the veins, we know also but very little. As 
they are every where disseminated, like the arteries and 
the nerves, it is difficult often to know if it is the vein 
itself or the organ that it forms, which is the seat of the 
sympathetic phenomenon. 
ARTICLE FOURTH. 
DEVELOPMENT OF THE VASCULAR SYSTEM WITH BLACK BLOOD. 
I. State of this System in the Foetus. 
The veins have in the foetus an arrangement inverse of 
that of the arteries ; they are in proportion much less de- 
veloped. It is not in the great trunks, as in the venae 
cavae, subclavians, iliacs, &c. that we should compare 
these vessels, because the reflux of the blood at the mo- 
ment of death often dilates these trunks, so as to make 
us believe that they are much larger than they really are 
in a natural state. It is in the branches and the ramifi- 
cations that we should make the comparison; now it is 
easy to see there, that the veins nearly equal the arteries, 
but are not superior to them, as is uniformly the case in 
the adult. 
However, the side of the heart with black blood, and the 
pulmonary artery which make a part of the system with the 
veins, are proportionably larger than these. This arises 
not only from their receiving and transmitting the blood 
of these vessels, but also that of the umbilical vein. It is 
to this last circumstance that must be attributed also an 
anatomical fact always existing in the foetus, viz. that the 
very short trunk of the vena cava, which is extended from 
the liver to the heart, is found in proportion much greater 426 
VASCULAR SYSTEM 
than the trunk of the superior vena cava, which is not the 
case in after life. 
The less development of the venous system, compared 
with that of the arteries, appears to arise in the foetus 
from this, that much substance being employed for nutri- 
tion which is very rapid in the early periods, less returns 
by the veins. This phenomenon however is not peculiar 
to the black blood. We shall see that the excretories trans- 
mit less fluids by the glands, and that the exhalants pour 
out less upon their respective surfaces. Much blood enters 
the general capillary system of the foetus; hence why the 
arteries are very large. There remains in the organs, 
much of the substances that it contains, to nourish them; 
but little goes out of the general capillary system for 
secretions, and exhalations; little returns by the veins. 
The more the foetus advances in age, the more of this 
blood is carried in the veins. In the early periods, almost 
all remains in the organs to form them. Towards the 
period of birth, these things approximate to what they 
will be in the adult. 
In this general phenomenon of the venous system in the 
foetus, the proportions are always preserved between the 
veins of the different parts, according to the increase of 
them. It is thus that most of the superior parts, the brain 
in particular, being in the foetus the seat of a more active 
nutrition than the inferior, the veins there are also more 
developed. 
We can hardly distinguish fibres at this age in the 
venous parietes, though they no doubt exist. I have only 
remarked, that they then contain much fewer small vessels 
in proportion than the arteries, whose trunks are covered 
with them, as it is easy to see upon the aorta. 
Though les3 dilated than afterwards, the veins appear 
to be as strongly organized ; their parietes are very re- 
sisting; they dilate less easily; this continues during the 
whole of youth. It is to this that 1 attribute the absence WITH BLACK BLOOD. 
427 
of varices at that age. As on the one hand less blood 
circulates in the veins, and on the other they appear to 
be in proportion more resisting, it is evident that they 
must yield less. 
II. State of this System during growth and afterwards. 
A remarkable revolution takes place at birth, as we 
have seen, in the system of black blood. The right auri- 
cle and ventricle receive the whole of the blood, of which 
a part until then went immediately to the right side by the 
foramen ovale. This difference has not much influence 
upon the size of the right auricle and ventricle; differ- 
ences only in their form take place, which I shall point out 
in the Descriptive Anatomy. 
During the first years of life, the veins have a real infe- 
riority as it respects the arteries. This inferiority con- 
tinues during the whole time of growth ; of this you may 
be satisfied by examining the external veins; they are 
never as evident, or as much developed in children as 
in an adult. Compare the arm of a man with that of a 
child, and the difference will be perceptible. 
The proportion of the cerebral veins over the others, is 
gradually lost as we advance in age, because the brain 
does not continue to predominate so much in its nutrition. 
At the period of puberty, and towards the end of growth 
in height, the veins partake of this general plethora, which 
seems to manifest itself, and which is, as we have seen, 
the source of many diseases. 
When the growth in length and thickness is completed, 
the veins begin to have a larger diameter; they become 
more prominent externally; it appears that more blood 
constantly passes through them. Make the muscles of 
an adult man contract strongly, and you will see all the 
veins considerably swelled. The same experiment will 
not produce a proportional effect upon a young man ; lig- 
atures applied show the same difference. 428 
VASCULAR SYSTEM 
In the last years of life the veins become much devel- 
oped compared to what they are in youth ; we can say 
that in this respect, the two extreme ages exhibit an in- 
verse arrangement. In considering the external appear- 
ance in the two ages, we may be convinced by the exami- 
nation of the superficial veins, of the truth of this asser- 
tion. 
Let us not think, however, that this greater develop- 
ment supposes an addition of substance in the venous 
parietes, as for example, the increased size of the bones 
depends upon the super-abundance of the phosphate of 
lime. It is a simple dilatation of these parietes, which 
are weakened, and become more slender, instead of in- 
creasing. This dilatation is owing to the loss of their 
elasticity and to the greater quantity of blood they carry. 
In fact the motion of decomposition evidently predomi- 
nates in old age over that of composition. More sub- 
stance is taken from the organs than is added to them, at 
this period. I know not but that the bones receive a 
greater quantity of the substance that nourishes them. In 
all the other organs, an opposite phenomenon is evident; 
hence their horny hardening, their withering, if I may 
use the term. Now, as the system with black blood is 
that in which is poured all the residue of the decomposi- 
tion of the organs, it is not astonishing that it should be 
dilated in old age; so the system with red blood, which 
carries the materials of their composition, predominates 
in the first year of life. 
The superabundance of black blood in old age however, 
is to a certain degree deceptive; it depends in part upon 
the slowness of the circulation in the veins, in which the 
blood, moved with difficulty on account of the weakness 
of the capillary system, tends to stagnate, and dilate them, 
•as I have said before; so that though there would be less 
III. State of this Systetn in Old Age, WITH BLACK BLOOD. 
429 
black blood returning from the organs, there would be 
more in the veins, than in the adult; the velocity of the 
circulation then would be much less. There takes place 
in the whole system, what exists in a varix, for example, 
in which the blood accumulates because its velocity is 
diminished. It is not necessary then to believe, that the 
superabundance of the black blood in old age, supposes a 
plethora like that of the red blood in infancy, in which, 
on the one hand, the arteries contain more fluid, and on 
the other they propel it with greater velocity. We know 
from this that the dilatation of the veins in old age is a 
further proof of the principles established above; viz. 
that the capacity of the veins is always in an inverse ratio 
to the velocity of the fluids that go through them. It ad- 
mits of but an inaccurate comparison, though it may give 
an idea of what passes in the venous system; a river 
which is very broad above a bridge, flows slowly; but its 
bed being much contracted under the arches, its velocity 
is much increased; so that the equilibrium may be estab- 
lished. So in the veins, there is little velocity and much 
capacity in old age, and much velocity and but little 
capacity in infancy. 
Anatomists know very well the difference of the arte- 
ries and the veins at the two extreme ages of life; they 
choose old subjects to study the veins; on the contrary, 
these subjects are wholly improper for arterial injections, 
which succeed so well, and sometimes too well, in in- 
fants, in whom every thing appears to become vascular, 
and in whom the examination of the veins would be very 
difficult, and even impossible. 
The veins of the inferior parts are generally more di- 
lated in old age than those of the superior; this arises 
from the habitual weight of the column of blood, which 
constantly acting, produces finally a real effect; for, as 
we have said, the venous circulation is much influenced 
by mechanical causes, owing to the want of power in the 430 
VASCULAR SYSTEM 
cause that circulates it; hence why varices are infinitely 
more frequent in the inferior than the superior parts, in 
which they are hardly ever found. 
In women who have had many children, we see this 
dilatation of the veins of the inferior parts in a very evi- 
dent manner; very often there are varices in them. 
Observe that this disease seems to be the companion of 
old age more particularly than that of every other age. 
On the contrary, we rarely see aneurisms in old people. 
The rupture of the veins has been almost constantly ob- 
served at this or the adult age. I hardly know an exam- 
ple of it in infancy. 
The pulmonary artery does not dilate in old age in 
proportion to the veins ; because, removed from the ac- 
tion of foreign bodies, and provided at its origin with an 
agent of impulse formed of a firm and resisting texture, 
it has not been in the habit of yielding like them. 
IV. Accidental development of the Veins. 
The veins are accidentally developed in two ways. 1st. 
In cancerous tumours, in fungi, &c. in which more red 
blood enters, they acquire a size in proportion to that of 
the arteries; now, as they are superficial, we see more 
easily their increase than that of the arteries; this in- 
crease, which has been taken for a characteristic of can- 
cers and other analogous tumours, is only a consequence 
of the increase of nutrition. The motion of the blood is 
as rapid there as in the other veins ; there is no obstruc- 
tion to it. 2d. There are cases on the other hand, in 
which the veins dilate, because the blood cannot easily 
circulate in them, and because the velocity of its course 
is diminished. For example, the whole venous system of 
the abdominal parietes is often increased in ascites ; it is 
not because there is more blood circulated; there is less 
than in the ordinary state ; but it is because the venous 
parietes having in part lost their elasticity, like the neigh- WITH BLACK BLOOD. 
431 
bouring parts, the circulation becomes slower; now the 
slower it is, the more the blood accumulates and the 
more the venous parietes are dilated. It is then a kind 
of general varix in a division of the veins. There is not 
more blood brought by the arteries, as in the preceding 
case ; the same thing in part happens in old age. 
ARTICLE FIFTH. 
REMARKS UPON THE PULMONARY ARTERY AND VEINS. 
Though in the exposition of the two systems of black 
and red blood, I have considered the pulmonary artery as 
making a part with the veins, and the pulmonary veins 
as a continuation of the arteries, yet their nature is 
wholly different. There are in truth but two general 
membranes, forming the two great tubes in which are 
contained the two kinds of blood, which are every where 
of the same nature, from the capillary system to the pul- 
monarj\ The textures added to the exterior of these 
two common membranes are essentially different. Thus 
the texture of the pulmonary artery, though added to 
the membrane with black blood, is, in point of thickness 
nearly of the same nature as that of the aorta and its di- 
visions. So the texture of the pulmonary veins, though 
united to the membrane with red blood, is the same as 
that of the other veins. 
This uniformity in texture supposes an uniformity in 
the functions, and this is really the case. The mechani- 
cal laws of the circulation of black blood are the same 
in the pulmonary artery as those of the red blood in the 
aorta. So the laws of the general venous circulation are 
the same with those of the pulmonary veins; inspection 
proves this ; and, moreover, it must be so, since the re- 432 
VASCULAR SYSTEM 
lation of the heart to the two kinds of vessels, the veins 
and the arteries, is the same. 
Each system of blood, then, has its two modes of cir- 
culation. Sudden motion, generally communicated, and 
not the progressive undulation of the fluid; a pulsation 
by a real locomotion, a general straightening of all the 
divisions of the same trunk at each impulse of the heart; 
these are the general mechanical characters of the artery 
with red blood, as well as that with black. Absence of 
pulsation, slowness in the course of the blood, want of 
straightening, &c.; these are the general attributes of the 
veins of each kind of blood. 
There are no doubt general' modifications that arise 
from local causes. Thus, on account of the short course 
of the pulmonary veins, the weight has scarcely any in- 
fluence upon the blood; they never become varicose; 
the motion of the fluid is more rapid in them, since they 
have less time to lose that which is communicated to the 
blood in the pulmonary capillary system, &c.; thus the 
artery of the same name, whose branches are less tortu- 
ous, does not seem to me to have pulsations as evident as 
those of the aorta, 8ic. But these general phenomena 
are always the same; they are but different modifica- 
tions. 
This is why the general arrangement is nearly the 
same in the veins and in the arteries, whether they cir- 
culate red blood or black. Thus, for example, each of 
the two arteries go off from a ventricle by a single ori- 
fice, necessary for the unity of the impulse of the blood, 
for the uniformity of its course in the divisions of its great 
vessels, and for the simultaneous pulsations in all the di- 
visions. On the contrary, the veins pour into the heart 
the red and black blood by many separate orifices; this 
is of no consequence, since, as we have seen, the motion 
of this fluid in the veins is not uniform, but may be acce- 
lerated or retarded in a part, by the influences it receives : WITH BLACK BLOOD. 
433 
thus, it may pass with velocity through the opening of 
the vena cava superior, and slowly through that of the 
vena cava inferior, &c. 
From the preceding considerations, it seems, that if 
we have no regard but to the mechanism of circulation, 
that it is almost of no consequence whether we consider 
with the ancients the small and great circulations by 
studying first the course of the blood in the artery and 
the pulmonary veins, then in the aorta and the general 
venous system ; or of studying, as we have done, the 
course of the blood, first in the pulmonary veins and the 
aorta, then in the general veins and the pulmonary artery. 
But if we consider this great function in the important 
relations of nutrition, secretions, exhalations, for which 
they furnish the materials, of the general stimulus it car- 
ries to all parts, and which is indispensable to the support 
of life, of the introduction of foreign fluids in the body 
of the animal, and of the change of these fluids into its 
own substance; then I think it must be described as I 
have done it. 
ARTICLE SIXTH. 
ABDOMINAL VASCULAR SYSTEM WITH BLACK BLOOD. 
Situation, Forms, General Arrangement, Anastomoses, &c. 
There is in the abdomen a system of black blood 
wholly independent of the preceding, arranged precisely 
like it, with the difference, that its course is shorter, and 
that it has no agent of impulse. This system, usually 
known by the name of Vena Porta, is found in most ani- 
mals. 
It arises from that part of the general capillary system 
which belongs to the intestines, the stomach, the omen- 434 
VASCULAR SYSTEM 
turn, the spleen, the pancreas, Sic. and generally to all 
the abdominal viscera connected with digestion. This 
origin is remarkable. The viscera in the abdomen, for- 
eign to the phenomena of digestion, are also foreign to 
the origin of this system. The kidnies and their depen- 
dancies, as the glandulae renales, the ureters, the bladder, 
the urethra, &c. the genital organs, the diaphragm, Sic. 
the abdominal parietes themselves, Sic. Sic. pour their 
black blood into the preceding system. Why are the 
digestive viscera, in their whole extent, different from 
the others, in the destination of their black blood? To 
answer this question, we must know the uses of the sys- 
tem of which we are treating; now, of these we are 
ignorant. 
Thus rising from the whole gastric apparatus, this sys- 
tem forms into two or three trunks, which soon unite 
into a single one, which occupies the superior and right 
part of the abdomen below the liver. 
This common trunk soon divides again into many 
branches, which spread in the liver into an infinity of 
ramifications, and are spent upon the texture of that 
organ. 
This system, then, presents the same general arrange- 
ment as the preceding; it is composed of two trees uni- 
ted by their lopped summits, that intermix with each 
other. Place an agent of impulse at these summits, the 
arrangement will be the same as in the two preceding. 
The blood is moved from one capillary system to another. 
Divided at first into small streams, it is formed into masses 
constantly increasing to a certain point, then it is divided 
again, and is carried in streams not larger than the first. 
In the abdominal portion, the ramifications, the small 
branches, the branches and the trunks are arranged very 
nearly as in the general venous system. The ramifica- 
tions are found in the organs, the small branches in their 
interstices, most of the branches are situated in the laver? WITH BLACK BLOOD. 
435 
of the peritoneum, there accompanying the arteries, and 
the trunks wind along the subjacent cellular texture. As 
to the hepatic portion, contained wholly in the liver, it is 
divided there nearly like the preceding. 
The anastomoses present the following arrangement in 
the system of which we are treating. 1st. Its hepatic 
portion appears to want them ; all the branches, smaller 
branches, and ramifications, go separately. As the circu- 
lation is not subject in the liver to increase or diminution, 
the solid texture of this organ protecting the vessels, the 
blood has no occasion for the means by which it can de- 
viate from one place to another. Thus the great divi- 
sions of the pulmonary artery and veins, which go imme- 
diately into the lungs where they are wholly distributed, 
do not communicate with each other. Thus the branches 
of all the arteries and of all the veins contained in the 
interior of a viscus, as in the kidney, the spleen, &c. 
are most commonly without communication. 2d. As to 
the abdominal tree, its anastomoses are very frequent in 
the smaller branches. We see all along the small intes- 
tines arches exactly like those of the mesenteric arteries; 
less frequent in the great intestines, they are, however, 
very evident in them, as upon the stomach; in the 
branches and the trunks they do not exist. 
The anastomoses in the system of black abdominal 
blood are necessary there from the frequent delays that 
this fluid may experience. For observe, that the circu- 
lation is performed for the abdominal portion according 
to the same laws as in the other veins, and that conse- 
quently that the force that can circulate the blood there, 
can yield to the least effort. Now in the different mo- 
tions of the small intestines, often too great a fold, the 
pressure of these organs filled with aliments upon the 
veins, when we are lying on the back or the side, and 
which pressure the veins support only by their resistance, 
and a thousand other causes, impede the course of the 436 
VASCULAR SYSTEM 
blood in one branch, and force it to flow by anastomoses 
into others. Observe also, that an obstacle which is of 
no consequence to the red blood, on account of the very 
strong impetus that is given to it, is very important to 
the two circulations of black blood, which receive but a 
feeble impulse. 
The influence of gravity is evident in the blood of 
this system, as in that of the preceding. Thus you see 
the hemorrhoidal veins, more exposed than all the others 
to this influence by their position, become much more 
frequently varicose; and it is even rare to find dilatations 
in the superior mesenteric veins, splenic, gastro-epiploic, 
&c. &c. whilst there is no part in which they exist more 
often than in the hemorrhoidal. Thus we have seen the 
preceding system dilated rarely above, but very frequently 
below. 
The system with black abdominal blood communicates 
but very little with the general system ; if there are 
anastomoses, it is only in the last divisions; do these 
anastomoses exist ? I believe we may consider these 
two systems as independent of each other. 
Organization, Properties, fyc. 
Many authors, Haller in particular, considering that 
the system of which we are treating is destitute of an 
agent of impulse, have admitted in them a force of struc- 
ture superior to that of the other veins; but after exam- 
ining it attentively, 1 am convinced that it is precisely 
the same. The cellular covering, of a peculiar nature, 
which surrounds it, and which is analogous to that of the 
other vessels, is only a little more evident; this makes 
these veins at first appear thicker; but by raising this 
covering we sec that the internal membrane is of the 
same nature, only perhaps a little less extensible. We 
do not discover the venous longitudinal fibres so well 
as in the preceding system; I doubt even if they exist WITH BLACK BLOOD. 
437 
in the trunks, in which we should be able to see them 
better. 
The two portions of this system, the hepatic and abdo- 
minal, appear to be completely uniform in their struc- 
ture. Only the first is every where accompanied by a 
kind of membrane, which appears to be cellular, but 
whose nature is not yet well known, and which is called 
the capsule of Glisson. This capsule, intimately connect- 
ed with the substance of the liver, adheres more loosely 
to the veins ; so that when they are empty, there is often 
a space between them and it; it is this that makes them 
fold up when we cut the liver in slices. I think that we 
are entirely ignorant of the object of this anatomical ar- 
rangement. 
The analogy between the systems with black blood, 
the abdominal and general, supposes them the same in 
properties, sympathies, affections, &c. I have often irri- 
tated the mesenteric veins, upon which it is extremely 
easy to act, by drawing through a small wound of the ab- 
domen a portion of the intestinal canal; the results have 
always been the same as in the preceding system. Only 
when we inject air, the animal docs not struggle, does 
not appear to suffer, and the experiment is not fatal ; 
this proves still more, that it is not by its contact upon 
the veins or the heart, that the air is injurious, but by its 
action on the brain. 
The common membrane of the system of which we 
are treating, is distinguished from that of the preceding, 
in this, that it is wholly destitute of valves. This appears 
to be owing to two causes, 1st, to this, that the course of 
the blood being shorter, it has less need of being support- 
ed ; and 2d, to this, that the middle part of this system, 
wanting an agent of impulse, there is no reflux as in 
the preceding system. In fact, at every contraction, the 
right auricle sends, as I have said, a portion of its blood 
into the veins, which resist by the valves. Here, on the 438 
VASCULAR SYSTEM 
contrary, the course of the fluid is always uniform from 
one capillary system to the other; there is no cause of 
retrograde motion. 
Remarks upon the motion of the Black Abdominal Blood. 
This uniformity in the course of the motion of this 
black blood, is not merely the result of the absence of the 
agent of impulse, but also of this, that the liver does not 
present as many obstacles to it, as the lungs do to the pre- 
ceding black blood. Observe also that the liver occupies 
in regard to this system, the same place as the lungs in 
regard to the other; it is the termination of the circula- 
tion of which we are treating. Having no dilatation or 
contraction, deprived of the fluid which acts incessantly 
upon the lungs, and which, loaded with different foreign 
substances, can often alter the vital forces of these organs, 
so as to interrupt the passage of the blood, &c. The 
liver, having a solid and granulated substance, in which 
no extraordinary motion can take place, except those of 
the general locomotion of the organ, is evidently incapa- 
ble of frequently interrupting the course of the black blood, 
which the abdominal system sends there. Add to this the 
want of the agent of impulse, and you will understand, 
1st. why, when the abdomen is open, we never see a pul- 
sation, a reflux in the veins of the abdominal system, as 
we observe in those of the other system ; 2d. why we 
always find there nearly the same quantity of blood ; 3d. 
why, consequently, we do not discover, either in the com- 
mon trunk that corresponds to the heart, or in its branches, 
the numberless varieties of dilatation and contraction, 
which the right side of the heart, and all the great venous 
trunks so frequently exhibit, so that scarcely two subjects 
are alike in this respect, whilst here the arrangement is 
always nearly the same ; 4th. why the liver is not subject 
to the innumerable varieties in size that the lungs are. 
This deserves a particular consideration. You will rarely WITH BLACK BLOOD. 
439 
find the lungs twice containing the same quantity of blood ; 
the weight varies enormously in this respect. Now this 
arises from the greater or less obstacles the blood has met 
with in passing through these organs in the last moments 
of life. We can make them more or less heavy in an 
animal, by making him die of asphyxia or hemorrhage, 
consequently by filling with blood, or emptying the ex- 
tremities of the pulmonary artery. Whatever on the con- 
trary is the kind of death, the hepatic extremities of the 
abdominal system, contain always nearly the same quan- 
tity of blood; suppose, that more remains than usual in 
this system at the moment of death, it is generally distri- 
buted, because there is no agent of impulse, which, at the 
last moments, drives the greatest quantity to the liver, as 
happens to the lungs. We understand from this, why the 
liver exhibits a firm, resisting texture, not extensible like 
that of the lungs. Sometimes the blood enters it in greater 
or less quantity, it is even, more or less heavy according 
to the kind of death. But these varieties belong only to 
the hepatic veins, which enter into the vena cave infe- 
rior just below the heart; they arise from the greater or 
less reflux of blood that takes place there, as in all the 
great venous trunks; they consequently arise almost al- 
ways from the lungs; so that when we see that they are 
loaded with blood, the right auricle consequently distend- 
ed, we may also be sure that the liver contains more of 
this fluid than usual. But this phenomenon, of which I 
shall speak when treating of the liver, is wholly discon- 
nected with the system which 1 am describing. 
The mechanism of the circulation of the abdominal 
part of this system, is precisely the same as that of the 
veins. As to that of the hepatic part, it is unlike that of 
any other part of the economy. It has no analogy to 
that of the arteries, for in them the heart is almost every 
thing, and here there is nothing to correspond to that sys- 
tem ; for certainly there is no kind of contraction in the 440 
VASCULAR SYSTEM 
common trunk of the two trees, as I have been frequently 
convinced. It is then the same motion, which is continu- 
ed from the gastric viscera to the liver. There is still 
much obscurity to be removed concerning this motion, as 
well as the preceding. Every judicious mind perceives 
that there is a great void, in reading what has been written 
upon the motion of the general venous blood, and upon 
this. 
We cannot deny but that external agents do much in 
this last circulation as in the first. The uniform eleva- 
tion and depression of the diaphragm, the corresponding 
motion of the abdominal parietes, the alternate dilatation 
and contraction of the hollow viscera of the abdomen, the 
constant locomotion of the small intestines, &c. all these 
causes certainly have an influence upon the motion of the 
black abdominal blood ; and 1 even think, that the absence 
of most of them contributes to retard this motion in the 
hemorrhoidal veins, and to occasion varices in them. 
This influence is not however such as Boerhaave 
thought, that the circulation could not go on without it. 
In fact, when the abdomen of an animal is opened, the 
blood is transmitted the same to the liver, and spouts in 
the same manner from an open,vessel; but we observe a 
sensible weakness in a short time, and this before the gen- 
eral circulation is enfeebled. 
Remarks upon the Liver. 
The use of the liver, in being the termination of the 
black abdominal blood, as the lungs are that of the black 
blood of all the rest of the body, gives it an importance 
unknown to all the other secretory organs. Some authors, 
in observing the enormous size of this viscus compared to 
the quantity of fluid secreted by it, have suspected that it 
had another use, besides the secretion of this fluid. This 
suspicion appears to me, to amount almost to certainty. 
Compare the hepatic excretories and reservoirs, with the WITH BLACK BLOOD. 
441 
same parts in the kidnies, the salivary glands, the pancreas 
even, and you will see that they hardly surpass them, and 
that they are inferior to those of the first. Then compare 
the size of the liver with that of the kidnies, of the sali- 
vary glands, &lc. and you will see the difference. If on 
the other hand, we examine the bile, voided with the 
stools which it colours, if we open the intestines at the 
different periods of digestion, as I have done, to see the 
quantity of this fluid that is poured out; if we keep an 
animal without food in order to let it accumulate by itself 
in the intestines; if we tie the ductus choledochus to re- 
tain the bile, &c. it is impossible not to be convinced, 
that the quantity of this fluid is disproportioned to the 
size of the liver. This viscus is alone equal in size to all 
the other glands united ; now, place on one side, the bile, 
and on the other, all the secreted fluids, the urine, the 
saliva, the pancreatic juice, the mucous juices, &c. you 
will see how enormous the difference is. 
Since then the secretion of bile is not the only object 
of the liver, it must have some other use in the economy. 
What this is we are ignorant; it is however undoubtedly 
connected with the existence of the system with black 
blood of which it is the termination, and is especially rela- 
tive to this system. The following considerations appear 
to prove that this use is among the most important. 
1st. The liver exists in all classes of animals. In those 
even in which most of the other essential viscera are very 
imperfect, it is well developed. 2d. Most of the passions 
affect it particularly, many of them have an exclusive 
effect upon it, whilst a great number of the other glands 
hardly perceive them at all. 3d. In diseases, it takes as 
evident a part as the first viscera in the economy. In 
many nervous affections, in hypochondria, melancholy, 
&c. it has a great influence compared to other glands. 
We know how easily its functions are deranged. It has 
undoubtedly no connexion with some affections called 442 
VASCULAR SYSTEM 
bilious, and which are seated exclusively in the stomach, 
but it certainly has a part in most of them. Since there 
is no doubt that the jaundice depends wholly upon a se- 
rious affection of this viscus, we ought certainly to con- 
clude that the yellow tinge of the face in many of these 
affections, arises from a cause existing in this viscus, and 
which is not sufficiently powerful to produce jaundice. 
Whether in order to produce this tinge, the bile circulates 
or not with the blood, is of no consequence ; it is incon- 
testible that it is occasioned by affections of the liver; 
now the numerous cases in which it takes place, prove 
how much this viscus is often affected ; there is certainly 
no gland in the animal economy so frequently. 4th. Shall 
I speak of organic affections? compare in the examina- 
tion of bodies, those of the liver, with those of all the 
other organs of the same class, and you will see that there 
is no one equal to it in this respect; the kidney approaches 
it, in the frequency of the alteration of its texture, but it 
is far from being equal to it. 5th. Who does not know 
the influence of the liver upon temperaments? Who does 
not know that its predominance gives to the external ap- 
pearance, the functions, the passions, the character even, 
a peculiar shade which the ancients have noticed, and 
which modern observations have confirmed ? Now see if 
the other glands have a similar influence in the economy. 
6th. The liver is, with the heart and the brain, the organ 
that is first formed ; it precedes all the other organs in its 
development; it is incomparably superior, in this respect, 
to all the glands. 
From all these considerations, and from many others that 
I might add, we may conclude, I think, that the unknown 
part which the liver performs in the animal economy, be- 
sides the secretion of bile, is among the most important. 
The study of this part, is one of the points most worthy 
of arresting the attention of physiologists. WITH BLACK BLOOD. 
443 
It has been said latterly, that the liver corresponded to 
the lungs in their functions of removing from the blood 
its hydrogen and carbon. I know not how this fact can 
be proved by experiment; but I am positive that the liver 
does not turn the black blood of the abdominal system into 
red. 1st. The blood of the right auricle is of the same 
colour as that of the vena cava inferior ; now if the blood 
went red from the hepatic veins, it would certainly give a 
brighter tinge to that of the auricle. 2d. Having opened 
the abdomen and thorax of a dog, I tied with a curved 
needle the vena cava at its entrance into the heart and 
above the kidney, then by detaching the liver from be- 
hind, I cut the portion intercepted between the two liga- 
tures, and where the hepatic veins opened ; the blood 
came out as black as that of the rest of the system. 3d. 
Tear out the liver of a living animal, examine immediately 
its veins, you will see that they contain a blood analogous 
to that of the others. 4th. This viscus, cut in slices in a 
living animal, pours out behind an analogous fluid, except 
some small red streams furnished by the last small branches 
of the hepatic artery ; this is wholly different in the same 
experiment made upon the lungs. 
If the black abdominal blood receives any modifications 
of its nature in the liver, they certainly have no influence 
upon its colour, its consistence, or sensible qualities. 
The general opinion is that the black abdominal blood 
serves for the secretion of bile, and that the hepatic artery 
is only destined to nourish the liver; this is what Haller 
has adopted ; I have also admitted it; but I am far from 
considering it as clearly demonstrated as it has generally- 
been thought to be; the following observations prove, 
that we ought to consider it as an hypothesis somewhat 
uncertain. 
1st. It is said that the hepatic blood, blacker, more 
oily, impregnated with the vapours of the excrements, of 
a bitter taste even, approaches nearer the nature of bile 444 
VASCULAR SYSTEM 
than the arterial blood, and that it is consequently more 
proper to form it. I do not know whether this blood 
has been analyzed comparatively; but I have certainly 
not found any difference in its external attributes; 1 did 
think that in an experiment I observed fatty drops swim- 
ming in it; different experiments have convinced me 
that it was an error. 1 doubt whether it could ever be 
demonstrated that the alkaline particles of aliments and 
of excrements pass into the vena porta ; this passage is a 
gratuitous supposition. 2d. It is said that the volume of 
the liver is considerable compared to the hepatic artery ; 
this is true; but it is not with the size of this viscus that 
we should compare that of this artery, to know if it fur- 
nishes the materials of secretion, since we have seen that 
it is impossible that the whole substance of the liver 
should be destined to secrete bile; it is with the biliary 
ducts and their reservoir, that we should make the com- 
parison ; now this artery is exactly proportioned to these 
ducts; there is between them nearly the same relation as 
between the renal artery and the ureter; on the contrary, 
the biliary ducts are manifestly disproportioned to the 
vena porta. 3d. It is said that the slow motion in this 
vein, is favourable to the secretion of bile. But upon 
what positive data is this assertion founded ? Why is 
slowness of motion more necessary for this secretion than 
for others? 4th. It is said that the hepatic artery having 
been tied, the secretion of bile continued. But when 
we know the relation of parts, the least reflection is suffi- 
cient to convince us, that a ligature of this kind cannot 
he made without producing a derangement that will pre- 
vent us from distinguishing any thing. I attempted it 
once, but could not finish it; I was almost persuaded of 
it before. 5th. It is said that the black blood is more 
proper to furnish the materials of the bile than the red. 
But what is the reason of it ? is it because this blood 
contains more carbon and hydrogen ? But it is then the WITH BLACK BLOOD. 
445 
black blood that furnishes the fat also ; now all anatomists 
are agreed, that it is exhaled from the exhalant extremi- 
ties of the arteries; the same is true of the marrow, the 
wax, and in general of all the oily fluids. 6th. A fine 
injection, made in the hepatic portion of the abdominal 
system with black blood, passes into the biliary vessels. 
But a similar passage takes place in an injection from the 
hepatic artery. 7th. It is said that the black abdominal 
blood in the spleen has qualities essential to the bile. 
But the secretion of this fluid can evidently take place 
without the spleen ; many experiments prove this. 8th. 
It is said that at the instant the vena porta is tied, bile 
ceases to be secreted; it is undoubtedly less difficult to 
tie the trunk of this vein below the duodenum than the 
hepatic artery. How can we examine what is going on 
in the liver ? Do we judge by the fluid flowing from the 
hepatic duct ? But open the duodenum, and you will not 
very often see the bile running out at the opening of the 
ductus choledochus, undoubtedly because the air contracts 
and irritates this duct. This phenomenon, observed after 
a ligature is applied, is not then conclusive ; moreover 
there does flow towards the time of digestion but too lit- 
tle bile by the ductus choledochus, to be able to estimate 
it. In fine, what inference can be drawn from an animal 
whose abdomen is open ? 
These different reflections prove, I think, that we have 
not sufficiently direct proofs, to decide whether the secre- 
tion of bile is from the abdominal black blood or the red. 
I do not attribute this function more to one than the 
other ; 1 say that these things should be subjected to a 
new examination, and that this example is a proof that 
the opinions most generally received in physiology, those 
consecrated by the assent of all celebrated authors, often 
rest upon very uncertain foundations. We are yet far 
from the time when this science will be only a series of 
facts rigorously deduced from each other. 446 
VASCULAR SYSTEM 
The hepatic artery has been said to resemble the 
bronchial, and the hepatic vena porta the pulmonary ar- 
tery; this is true in the general arrangement; but what 
is the proof of it as it regards the functions ? On the con- 
trary, I have proved above that those of the two last 
vessels are not similar. Let us wait, before deciding, for 
further andfcpositive researches; let us doubt till then; 
let us not attribute the secretion of bile to the hepatic 
artery, nor the vena porta, nor to them unitedly. Cer- 
tainly it is by one of these three means; but which? 
what vessel furnishes the secretion of bile? what part 
does the black abdominal blood perform in the liver, if it 
is not from it that this fluid is secreted? what, in fine, is 
the function of the hepatic artery, if it is not connected 
with this secretion ? These are questions to be resolved. 
Physicians have also hazarded opinions upon the in- 
fluence of the black abdominal blood in diseases. Un- 
doubtedly the expression, vena portarum, porta malorum, 
contains a very true meaning ; but certainly in the pre- 
sent state of our knowledge, it is, in a strict sense, only a 
play upon words. If we would express by it the fre- 
quency of affections of the liver, it is without doubt just; 
but if it is employed to express the influence of the vena 
porta in diseases, it is vague and does not rest upon any 
positive fact. The more we open dead bodies, the more 
we shall be convinced, I think, of the necessity of a pre- 
cise and accurate language, freed from all these ingenious, 
hypothetical ideas, which do honour, it is true, to their 
author, but which retard science, by introducing into it a 
manner of seeing hypothetically, and contrary to the 
spirit of observation. 
Remarks upon the course of the Bile. 
Though this question may he to a certain degree for- 
eign to my object, yet as the black abdominal blood has 
perhaps a real influence upon the secretion of the bile, WITH BLACK BLOOD. 
447 
as my experiments upon this point determine with pre- 
cision the course of this fluid, I do not think it useless to 
relate them here. All that is known further upon the 
uses, mechanism, &c. of this secretion is to be found in 
works of physiology, to which I refer. 
There has been much discussion to ascertain if there 
was cystic and hepatic bile, if one was of a different na- 
ture from the other, if their quantity increased or varied, 
&c. Contrary and even opposite opinions have been 
supported by numerous experiments made upon living 
animals, as Haller has observed. These experiments, 
though at first view contradictory, are not so, however, 
as I was convinced by repeating them at different periods 
of digestion and during the abstinence of the animal; it 
had not been done with precision. The following is what 
I have observed in dogs, which I have used in my experi- 
ments. 
1st. During abstinence, the stomach and small intes- 
tines being empty, we find the bile in the ductus hepaticus 
and ductus choledochus yellowish and clear ; the surface 
of the duodenum and jejunum tinged by bile which has 
the same appearance; the gall-bladder much distended 
by a greenish, bitter bile, much deeper coloured and 
more abundant if the abstinence has been long. 2d. 
During digestion in the stomach, which may be prolong- 
ed for a length of time, by giving to a dog large pieces of 
meat, which he swallows without masticating, things are 
nearly in the same state. 3d. At the beginning of the 
intestinal digestion, we find the bile of the hepatic duct 
always yellowish, that of the ductus choledochus deeper 
coloured, the gall-bladder less full and its bile already be- 
coming clearer. 4th. At the end of digestion and imme- 
diately after, the bile of the hepatic duct, of the ductus 
choledochus, that in the gall-bladder, and that which is 
found upon the duodenum, are of precisely the same 
colour as the common hepatic bile, that is, of a clear yel- 448 
VASCULAR SYSTEM 
low, and a little bitter. The gall-bladder is about half 
full; it is flaccid, not contracted. 
These observations, repeated a great number of times, 
evidently prove that this, during abstinence and digestion, 
is the manner in which the flow of bile takes place; 1st, 
it appears that at all times the liver secretes a certain 
quantity, which is increased during digestion ; 2d, that 
which is furnished during abstinence is divided between 
the intestine that is always coloured with it, and the gall- 
bladder which retains it, without pouring out any portion 
of it by the cystic duct, and in which, thus retained, it 
acquires an acrid character and a deep colour, necessary, 
no doubt, to digestion which is to follow. 3d. When the 
aliments, having been digested by the stomach, pass into 
the duodenum, then all the hepatic bile, which was before 
divided, flows into the intestine, and even in greater 
abundance. On the other hand, the gall-bladder pours 
also that which it contains upon the alimentary mass, 
which is then completely penetrated with it. 4th. After 
intestinal digestion, the hepatic bile diminishes, and a 
part begins to flow into the duodenum, and a part to flow 
back into the gall-bladder, in which, if then examined, it 
is found clear and in small quantity, because it has had 
neither time to be coloured or accumulate. 
There is then this difference between the two biles, 
that the hepatic flows almost in a continued manner into 
the intestine, and that the cystic flows back, except dur- 
ing digestion, into the gall-bladder, and flows, during this 
function, towards the duodenum ; or rather it is the same 
fluid, of which a part always preserves the same charac- 
ter that it had at its exit from the liver, and the other 
assumes a different one in the gall-bladder. The diver- 
sity of colour in the cystic bile, according as it has been 
retained long or not, has much analogy to the colour of 
the urine, which is found more or less deep coloured, as 
it has been for a longer or shorter time in the bladder. WITH BLACK BLOOD. 
449 
As to the course of the bile in relation to the stomach, 
1 believe that this viscus contains a certain quantity of it 
at all times. When empty, we find there a mixture of 
gastric juices and mucus more or less abundant, some- 
times mixed with small bubbles of hydrogen, which burn 
when brought in contact with flame, and almost always 
tinged with a yellowish colour from the bile that has 
flowed up through the pylorus. Haller says that this 
reflux of bile into the stomach does not always happen; 
Morgagni says that it always does in men. 1 have never 
opened a dog, in whom it has not been seen when the 
stomach was empty, especially if it had been so for some 
time. Human dead bodies are not proper to decide this 
question, because the kind of disease alters almost inevi- 
tably the course, the nature, and even the colour of the 
bile. I shall say in another volume what conclusion we 
should draw from this, as it respects bilious vomitings. 
In a state of fulness, it has sometimes appeared to me 
impossible to estimate the reflux of the bile; in other 
states, between the alimentary mass and the parietes of 
the stomach, I have seen yellowish, gastric fluids; but 
this mass itself never has this colour. 
The bile that flows into the stomach has always ap- 
peared to me to be hepatic bile, from its light colour. 
I think that 1 have opened a sufficient number of living 
animals to convince me, that this bile is hardly ever found 
very green, and that it acquires this colour from the gall- 
bladder; and that it is this that is brought tip by vomit- 
ing in some affections. The reflux of this bile appears 
to be an effect of the affection itself. This observation 
agrees with that made above, viz. that the hepatic bile 
alone flows into the duodenum in abstinence. It alone 
can then, as we may be convinced, flow into the sto- 
mach. During intestinal digestion, in which the cystic 
bile flows, it is evident, that the aliments going continu- 
ally out of the pylorus, prevent it from passing there and 450 
VASCULAR SYSTEM 
entering the stomach ; that which we find during fulness, 
was there then, or entered there before the peristaltic 
motion had begun to evacuate this organ. 
When we open the gall-bladder in a dead body, we sec 
that the bile there exhibits, according to its diseases, a 
variety of shades of colour, from that which is black as 
ink to a kind of transparent fluid. Ought we then to be 
astonished, if the vomitings in which the cystic bile is 
brought up, that has flowed into the stomach against the 
ordinary course of things, should contain matters of such 
various colours ? 
Development. 
In the foetus, the system of black abdominal blood is 
not insulated; it becomes a part of the two others, by 
means of the ductus venosus. There is then truly but 
one vascular system in the foetus, whilst after birth, there 
are three separate ones, two with black blood and one 
with red. 
In the foetus, it is especially with the umbilical vein 
that the abdominal system with black blood is continued. 
The liver is a centre, in which both arrive from two dif- 
ferent sides, and in which they unite, in a common trunk. 
The two columns of blood that they circulate, do not 
meet directly; their course forms a very remarkable 
angle. 
When we examine attentively the orifice of the ductus 
venosus in the trunk, made by the union of these two 
veins, we see that it presents itself naturally to the blood 
of the umbilical vein ; that that of the vena porta, on 
the contrary, cannot enter there. In fact, there is a lit- 
tle fold in the form of a valve, less evident, it is true, 
than many others, but yet existing. This fold is only a 
kind of projection, placed between the end of the vena 
porta and the ductus venosus, and which contracts the 
orifice of this, so that it is evidently narrower than the WITH BLACK BLOOD. 
451 
caliber of its own canal. The blood coming from the 
vena porta and passing at the side of this fold, presses it 
against the orifice, and thus forms an obstacle; that com- 
ing from the umbilical vein, falling, on the contrary, per- 
pendicularly on this orifice, removes this fold, and enters 
the canal. 
It hence follows that the ductus venosus is evidently 
destined to carry to the vena cava the residue of the 
blood of the umbilical vein; I say the residue; in fact, 
as this vein is very ljrge and the ductus small in propor- 
tion to it, it is evident that the greatest part of the blood 
penetrates the liver, by the different ramifications that 
enter its substance. 
The abdominal vascular system is less developed in 
the foetus than afterwards ; it consequently carries less 
blood to the liver; this is the same arrangement as in 
all the other veins. I would observe, that the small 
quantity, however, which the liver receives in this way, 
is more than compensated by that of the umbilical vein. 
This viscus is, then, habitually entered in the foetus, by a 
greater quantity of fluid than at any of the other ages. 
Hence, 1st, why its nutrition is so developed and its size 
so great; 2d, why it is, in proportion to its size, heavier 
than in the after ages; 3d, why when we cut it in slices, 
there flows out a greater quantity of blood ; 4th, why, 
when we dry slices of the liver of a foetus, of the same 
thickness as others taken from the liver of an adult, and 
especially of an old person, they are reduced to a less size. 
The disproportion of the size of the liver of the foetus 
is more evident, the sooner it is examined after concep- 
tion ; this is the same as with the brain. As the foetus ad- 
vances towards birth, the liver approximates in its propor- 
tions to the other organs, that which it will have in the 
adult. From the observations of Portal, it is especially 
till the seventh month, that the liver is predominant. 
This circumstance appears to arise from this, that the 452 
VASCULAR SYSTEM 
umbilical vein transmits as much more blood in propor- 
tion to the foetus, as it is less advanced in age. 
At this age, the blood of the umbilical vein and that of 
the vena porta evidently mix, at least in a great measure, 
in the common trunk. Is their nature analogous ? There 
is no experimental knowledge upon this point. But Bau- 
deloeque has many times observed that that of the umbil- 
ical vein is redder, and even approximates the nature of 
arterial blood. 1 have not accurately observed this tact 
in any animals except guinea pigs, in whom the want of 
transparency in the cord does not allow us to see a great 
difference in the blood of the arteries and of the umbilical 
vein; but this difference can be in fact more evident in 
man; now, in this case, the umbilical blood appears to 
lose this redness in the liver, for very certainly it is uni- 
form beyond this viscus in the circulation of the foetus, as 
I have often ascertained. 
At the period of birth, the blood ceasing to come by 
the umbilical vein, the liver becomes only the termina- 
tion of the black abdominal blood. Then a kind of revo- 
lution takes place in this viscus. The different tubes that 
carried to it umbilical blood do not close up, but they trans- 
mit exclusively that of the vena porta, which increases a 
little in size, because digestion, which begins in the gas- 
tric organs, calls to them more arterial blood, and conse- 
quently more is returned by the veins. This slight in- 
crease does not compensate for the absence of theumbili- 
cal blood; thus the liver diminishes proportionally in 
size in an evident manner. 
As to the ductus venosus, it is obliterated by the effect 
of the contractility of texture. The blood coming in 
the vena porta, has not, as I have said, any tendency to 
pass through it, because this canal is not in its direction ; 
it passes rather into the hepatic vessels, and the circula- 
tion of the liver is established then, as it will always 
continue to be. WITH BLACK BLOOD. 
453 
This then is the difference that birth brings to the he- 
patic circulation ; 1st, less blood and only one kind enter- 
ing the liver; 2d, an interruption of all communication 
between the general and abdominal black blood ; 3d, 
proportional diminution of the size of the liver. Hence 
there is an inverse phenomenon for this organ and for 
the lungs. The latter increases, the other diminishes in 
activity and size. 
The great quantity of blood that enters the liver before 
birth, and the size of this organ, compared to the small 
quantity of bile that escapes from it, are an evident proof 
then that it is destined for other uses besides the secre- 
tion of this fluid. There cannot be a doubt upon this 
point; it is a proof moreover, that in the adult the dis- 
proportion of the organ to the fluid, though less sensible, 
supposes also in it another important function of which 
we are ignorant. 
There ought to be a precise relation between the oblit- 
eration of the ductus venosus, of the foramen ovale and the 
ductus arteriosus, between the increased activity of the 
lungs and the diminished activity of the liver at birth, &c. 
We judge of this relation, without knowing it, because a 
veil is still spread over the circulation of the foetus. I 
would only observe that the predominance of the liver 
before birth, does not suppose any in the system of black 
abdominal blood ; it arises exclusively from the umbilical 
vein ; thus the proportional volume of this organ is con- 
stantly diminishing afterwards, especially on the left side, 
where this vein is distributed, as Portal has observed. It 
is difficult to name the period, at which the equilibrium is 
generally established. 
In youth, the abdominal system of black blood, like 
the general, is weak. It is towards the thirtieth or for- 
tieth year, that it seems to be in its greatest activity; this 
is the age of gastric diseases, of hemorrhoids, and of mel- 
ancholy, which is connected with the state of the liver. 454 
VASCULAR SYSTEM WITH BLACK BLOOD. 
In old age, the dilatation of the system of black abdo- 
minal blood is much less sensible than that of the pre- 
ceding system; its vessels have nearly the same caliber 
as in the adult age; which supposes a less diminution in 
the velocity of the course of its blood, from the princi- 
ples established above. It never becomes the seat of any 
kind of osseous incrustation, a phenomenon that evidently 
assimilates its common membrane to that of the veins, and 
distinguishes it in a peculiar manner from that of the 
arteries. 
END OF VOL. I.