wmsmBUiL AHittt<D£inr» 
APPLIED TO 
* 
ah© is©!©®® i 
BY XAVIER BICHAT, 
n, 
PHYSICIAN OF THE GREAT HOSPITAL OF HUMANITY AT PARIS, AND 
PROFESSOR OF ANATOMY AND PHYSIOLOGY. 
CramsIateO from tje jftencf). 
BY GEORGE HAYWARD, M. D. 
FELLOW OF THE AMERICAS’ ACADEMY OF ARTS AMD SCIENCES, 
AND OF THE MASSACHUSETTS MEDICAL SOCIETY. 
/.V THREE VOLUMES. 
VOLUME III. 
BOSTON: 
PUBLISHED BY RICHARDSON AND LORD. 
J. H. A. FROST, PRINTER. 
1822. DISTRICT OF MASSACHUSETTS, to vrit : 
District 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 of America, Richardson Sr 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 III. 
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. MUSCULAR SYSTEM OF ORGANIC 
LIFE. 
THIS system is not as abundantly spread out in the 
economy as the preceding. The whole mass which it 
forms, compared with the whole of the other, which is 
more than one third of the body, presents in this respect 
a very remarkable difference. Its position is also differ- 
ent; it is concentrated, 1st, in the thorax, where the 
heart and oesophagus belong to it; 2d, in the abdomen 
where the stomach and intestines are in part formed by 
it; 3d, in the pelvis where it contributes to form the 
bladder and even the womb, though this belongs to gen- 
eration, which is a function distinct from organic life. 
This system then occupies the middle of the trunk, is 
foreign to the extremities, and is found far from the 
action of external bodies, whilst the other superficially 
situated, forming almost alone the extremities, seems, as 
we have said, almost as much destined in the trunk to 
protect the other organs, as to execute the different mo- 
tions of the animal. The head contains no part of the 
organic muscular system ; this region of the body is 
wholly devoted to the organs of animal life. 4 
MUSCULAR SYSTEM 
ARTICLE FIRST. 
OF THE FORMS OF THE MUSCULAR SYSTEM OF ORGANIC 
LIFE. 
All the muscles of the preceding system take in gen- 
eral a straight direction. These are all on the contrary 
curved upon themselves ; all represent muscular cavities 
differently turned, sometimes cylindrical as in the intes- 
tines, sometimes conical as in the heart, sometimes round- 
ed as in the bladder, and sometimes very irregular as in the 
stomach. No one is attached to the bones ; all are desti- 
tute of tendinous fibres. The white fibres arising from 
the internal surface of the heart, and going to be attached 
to the valves of its ventricles, have by no means the 
nature of the tendons. Ebullition does not easily reduce 
them to gelatine; desiccation does not give them the 
yellowish appearance of these organs ; they resist macer- 
ation longer than them. 
It is in general a great character that distinguishes the 
muscular organic system from that of animal life, that it 
does not arise from, nor terminate in fibrous organs. All 
the fibres of this last are continuous either with tendons, 
or aponeuroses or fibrous membranes. Almost all those 
of the first go on the contrary from the cellular texture, 
and return to it after having run their course. I at first 
thought that the dense and compact texture which is be- 
tween the mucous membrane and the fleshy fibres of the 
intestines, the bladder, the stomach, &c. was an assem- 
blage and net-work of many small tendons corresponding 
to these fibres, and interwoven in the form of an aponeu- 
rosis ; the density of this layer deceived me at first view. 
Ebullition, maceration, and desiccation have since taught 
me, that this layer, completely foreign to the fibrous sys- 
tem, should be referred, as Haller has said, to the cellular, OF ORGANIC LIFE. 
5 
which is only more dense and compact there than else- 
where. It is this layer, which I have designated, in the 
cellular system by the name of the sub-mucous texture. 
Many fibres of the system of which we are treating ap- 
pear to form an entire curve, which is not crossed by 
any cellular intersection; some layers of the heart ex- 
hibit this arrangement, which is in general very rare; so 
that there is almost always an origin and termination of 
the fibres, upon an organ of a nature different from their 
own. 
We can hardly consider in a general manner the forms 
of the system of which we are treating ; each organ be- 
longing to it is moulded upon the form of the viscus to 
the formation of which it contributes. In fact, the or- 
ganic muscles do not exist in distinct fasciculi, like those 
of animal life ; all, except the heart, form but a third, a 
quarter and often even less in the structure of a viscus. 
The greatest number has a thin, flat and membranous 
form. There are layers more or less broad, and hardly 
ever distinct fasciculi. Placed at the side of each other, 
the fibres are rarely one above another; hence it happens 
that occupying a very great extent, these muscles form 
however a very small volume. The great gluteus alone 
would be larger than all the fibres of the stomach, the in- 
testines and the bladder, if they were united like it into 
a thick and square muscle. 
ARTICLE SECOND. 
ORGANIZATION OP THE MUSCULAR SYSTEM OF ORGANIC 
LIFE. 
The organization of the involuntary muscles is not as 
uniform as that of the preceding. In these all is exactly 6 
MUSCULAR SYSTEM 
similar excepting the differences of the proportion of the 
fleshy fibres to the tendinous, of the length of the first, 
of the prominence of the fasciculi, of their assemblage 
into flat, long or short muscles ; in whatever place we ex- 
amine them, their varieties are in their forms and not in 
their texture. Here on the contrary, there is in this tex- 
ture marked differences; the heart compared with the 
stomach, the intestines with the bladder are sufficient to 
convince us of this. It is by virtue of these different 
textures, that the contractility and sensibility vary as we 
shall see in each muscle, that the force of the contraction 
is not the same, and that life is different in each, whilst it 
is uniform in all those of animal life. We shall now 
consider in a general manner the organization of the in- 
voluntary muscles. 
I. Texture peculiar to the Organization of the Mus- 
cular System of Organic Life. 
The organic muscular fibre is in general much finer and 
more delicate than that of the preceding system ; it is 
not brought into as thick fasciculi. Very red in the 
heart, it is whitish in the gastric and urinary organs. 
Besides, this colour varies remarkably. I have observed 
that sometimes maceration renders it of a deep brown in 
the intestines. 
This fibre never has one single direction, like that of 
the preceding muscles; it is interlaced always, or found 
in juxta-position in different directions ; sometimes it is at 
a right angle that the fasciculi are cut, as in the longi- 
tudinal and circular fibres of the gastric tubes ; sometimes 
it is with angles more or less obtuse or acute, as in the 
stomach, the bladder, &c. In the heart, this interlacing is 
such in the ventricles, that it is a true muscular net-work. 
From these varieties of direction, results an advantage in 
the motions of these sorts of muscles, which, being all OF ORGANIC LIFE. 
7 
hollow can by contracting diminish according to many 
diameters the extent of their cavity. 
Every organic muscular fibre is in general short; those 
which, like the longitudinal of the oesophagus, the rectum, 
&c. appear to run a long course, are not continuous; they 
arise and terminate at short distances, and thus arise and 
terminate successively in the same direction or line; no 
one is comparable to those of the sartorius, the gracilis, 
&c. as it respects length. 
We know the nature of their fibres no better than that 
of those of animal life ; but they appear nearly the same 
under the action of the different reagents. Desiccation, 
putrefaction, maceration, ebullition, exhibit in them the 
same phenomena. I have observed upon the subject of 
this last, that once boiled, the fibres of both systems are 
much less alterable by the acids sufficiently weakened. 
After being some time in the sulphuric, the muriatic and 
nitric diluted with water, they soften a little, but keep 
their orignal form, and do not change into that pulp to 
which raw fibres are always reduced in the same experi- 
ment. The last of these acids turns them yellow as be- 
fore ebullition. 
I have also made an observation as it respects the horny 
hardening which is produced the instant ebullition com- 
mences ; it is this, that it is always the same whatever 
may have been the antecedent dilatation or contraction ol 
the fibres. The stomach which at death was so dilated as 
to contain many pints of fluid, is reduced to the same 
size, all other things being equal, as that which is con- 
tracted so as to be no larger than the coecum. Diseases 
have a little influence on the horny hardening. The heart 
of a phthisical patient exhibited to me in the same expe- 
riment this phenomenon much less evidently, than that 
of an apoplectic. 
The resistance of the organic muscular fibre is in pro- 
portion much greater than that of the fibres of the animal 8 
MUSCULAR SYSTEM 
muscular system. Whatever may be the distension of the 
hollow muscles by the fluid which fills them during life? 
ruptures hardly ever take place in them. 
The bladder alone sometimes exhibits this phenome- 
non, which is however very rare in it. In the great 
retentions of the urine, in which ruptures take place, it is 
almost always the urethra that is ruptured, and the blad- 
der remains whole. We meet in practice with a hundred 
fistulas in the perineum, coming from the membranous 
portion, to one above the pubis. We find in authors many 
examples of rupture of the diaphragm ; we know of but few 
of the rupture of the stomach, the intestines and the heart. 
II. Com?non Parts in the Organization of the Muscu- 
lar System of Organic Life. 
The cellular texture is in general much more rare in 
the organic muscles than in the others. The fibres of the 
heart are in juxta-position, rather than united by this tex- 
ture. It is a little more evident in the gastric and urinary 
muscles. It is almost wanting in the womb; thus these 
muscles are not infiltrated, like the preceding, in dropsies ; 
they never exhibit that fatty state of which we have 
spoken, and which sometimes loads the fibres. I have not 
observed in these fibres the yellowish tinge which the 
others often take, especially in the vertebral depressions. 
The blood vessels are very numerous in this system ; 
they are found in it even in greater proportion than in the 
other; more blood consequently penetrates them. This 
fact is remarkable, especially in the intestines, in which 
the mesenteric arteries distribute numerous branches, over 
an extremely delicate fleshy surface. But I would remark 
that this appearance is to a certain degree deceptive, as 
many of these vessels only traverse the fleshy surface to 
go to the mucous membrane. In the ordinary state they 
give to the gastric viscera a reddish tinge, which I have 
rendered at will livid and afterwards brought back to its OF ORGANIC LIFE. 
9 
primitive state, by shutting and afterwards opening the 
stop-cock adapted to the wind pipe, in my experiments 
upon asphyxia. 
The absorbents and exhalants have nothing peculiar in 
this system. 
The nerves come to them from two sources; 1st, from 
the cerebral system ; 2d, from that of the ganglions. 
Except in the stomach in which the par vagum is dis- 
tributed, the nerves of the ganglions predominate every- 
where. In the heart, they are the principal; in the intes- 
tines, they are the only ones; at the extremity of the 
rectum and the bladder, their proportion is greater than 
that of the nerves coming from the spine. 
The cerebral nerves intermix with them, in penetrating 
the organic muscles. The cardiac, solar, hypogastric, 
plexuses, &c. result from this intermixture which appears 
to have an influence upon the motions, though we are 
ignorant of the nature of this influence. 
All the nerves of the ganglions which go to the organic 
muscles, do not appear to be exclusively destined to them. 
A great number of filaments belong only to the arteries; 
such is in fact their interlacing, that they form, as we 
have seen, around these vessels a real nervous membrane, 
superadded to their own, and exclusively destined to 
them. I would compare this nervous envelope to the 
cellular envelope which is also found around the arteries, 
and which is wholly distinct from the surrounding cellu- 
lar texture ; thus it only has communications with the 
nerves of the organic muscles, without being distributed 
to these muscles. Besides as the nerves of the ganglions 
are always the most numerous and essential in them, and 
as their tenuity is extreme, the nervous mass destined to 
each is infinitely inferior to that which is found in the 
voluntary muscles. The heart and the deltoid muscle 
compared together, exhibit in this respect a remarkable 
difference. 10 
MUSCULAR SYSTEM 
ARTICLE THIRD. 
PROPERTIES OF T1IE MUSCULAR SYSTEM OF ORGANIC LIFE. 
Under the relation of properties, this system is in part 
analogous to the preceding, and in part very different 
from it. 
I. Properties of Texture. Extensibility. 
Extensibility is very evident in the organic muscles. 
The dilatation of the intestines and the stomach by ali- 
ments, by the extrication of gas, by the fluids that are 
found there, that of the bladder by the urine, by injec- 
tions that are forced in, &c. are essentially owing to this 
extensibility. 
This property is characterized here by two remarkable 
attributes ; 1st, by the rapidity with which it can be put 
into action ; 2d, by the very great extent of which it is 
susceptible. 
The stomach and intestines pass in an instant from com- 
plete vacuity to great extension. Artificially distended, 
the bladder becomes immediately of a size treble, qua- 
druple even of that which is natural to it. It sometimes 
however resists, but this does not prove its defect of ex- 
tensibility ; it is because the fluid injected irritates it and 
makes it contract; the organic contractility in exercise, 
then prevents the development of extensibility, as it some- 
times cannot be brought into action by stimulants in a 
muscle laid bare, because the animal contractility in exer- 
cise in the muscle, forms an obstacle to it. The muscles 
of animal life are never capable of this rapidity in their OF ORGANIC LIFE. 
11 
extensibility, whether because they are intersected by 
numerous aponeuroses which dilate but slowly, or whether 
because their layers of fibres are very thick, two circum- 
stances that do not exist in the muscles of organic life. 
Hence a remarkable phenomenon that I have observed in 
all cases of tympanites. When we open the abdomen of 
subjects that have died in this state, without wounding 
the swelled intestines, these immediately burst out, swell 
more, and occupy twice as large a space as they were 
contained in in the abdomen ; why ? Because the parietes 
of the abdomen being unable to yield in proportion to the 
quantity of gas that is developed, this has been com- 
pressed in the intestines during life, and expands imme- 
diately by its elasticity when the cause of compression 
ceases. In dropsies in which the distension is slow, the 
abdominal parietes enlarge much more than in tympanites. 
The size of the abdomen would be double in this, if the 
extensibility of the parietes was in proportion to that of 
the intestines. 
As to the extent of the extensibility of the organic mus- 
cles, we can form an idea of it by comparing the empty 
stomach which oftentimes is not larger than the caecum 
in its ordinary state, with the stomach containing some- 
times five, six and even eight pints of fluid ; the bladder 
contracted and concealed behind the pubis, with the blad- 
der full of urine from suppression, rising sometimes even 
above the umbilicus ; the rectum empty, with the rectum 
filling at' part of the pelvis in old people in whom the 
excrements have accumulated in it; the intestines con- 
tracted with the intestines greatly distended. 
It is to the extent of extensibility of the organic mus- 
cles and to the limits placed to that of the abdominal 
parietes, that must be referred a constant phenomenon 
that is observed in the gastric viscera ; viz. that in the 
natural series of their functions, they are never all dis- 
tended at the same time; the intestines are filled when 12 
MUSCULAR SYSTEM 
the matters contained in the stomach are evacuated; the 
bladder is not full of urine in the digestive order, until 
the other hollow organs are empty, &c. In general, that 
is an unnatural order in which all the organs are dis- 
tended at once. 
There is for the organic muscles a mode of extensibility 
wholly different from that of which I have just spoken ; 
it is that of the heart in aneurisms, and the womb 
in pregnancy. The first, for example, acquires a size 
double, treble even sometimes in its left side, and yet it 
increases at the same time in thickness. This size is not 
owing to distension, but to a preternatural growth. The 
aneurismatic heart is to the ordinary heart, what this is to 
the heart of the infant; it is nutrition that makes the 
difference and not distension ; for whenever it is owing 
to this it diminishes in thickness as it increases in extent; 
there is no addition of substance. Besides the aneuris- 
matic heart has not often the cause that distends it, for 
commonly in this case the mitral valves allow a free 
passage to the blood ; whilst when they are ossified the 
left ventricle often remains in a natural state. Moreover, 
the slow progress of the formation of aneurism proves 
that it is a preternatural nutrition that has presided over 
this increase of the heart. You would in vain then empty 
this organ of the blood it contains, it would not contract 
and resume its dimensions, as the inflated intestine does 
which we puncture to allow the air to escape. 
In the womb there are two causes of distension; 1st, 
the sinuses greatly developed ; 2d, an addition of sub- 
stance, a real momentary increase of the fibres of the 
organ which remains as thick and even more so than in 
the natural state. At the time of accouchement, the 
sinuses immediately flatten by the contraction of the 
fibres ; hence the sudden contraction of the organ. But 
as on the one hand nutrition alone can remove by de- 
composition the substances added to the fibres to enlarge OF ORGANIC LIFE. 
13 
them, and as on the other, this function is exerted slowly, 
after the womb has undergone the sudden contraction 
owing to the flattening of its sinuses, it returns but gra- 
dually and at the end of some time to its ordinary size. 
Extensibility is not then brought into action in the womb 
filled by the foetus, and in the aneurismatic heart; these 
organs really become at that time the seat of a more 
active nutrition ; they grow preternaturally, as they have 
grown naturally with the other organs ; but these do not 
then experience an analogous phenomenon, they become 
monstrous in comparison. The womb decreases, because 
the motion of decomposition naturally predominates over 
that of composition after accouchement, whilst it was the 
reverse before this period. The aneurismatic heart re- 
mains always so. 
These dilatations of the heart should be carefully dis- 
tinguished from those really produced by extensibility, 
as in the right auricle and ventricle for example, which 
are found full of blood at the moment of death, because 
the lungs which are weakened, not allowing it to pass 
through them, compel it to flow back to the place from 
which it came. There are but few hearts which do not 
exhibit in very various degrees, these dilatations, which 
we have the power in a living animal of increasing ox- 
diminishing at will, according to the kind of death we 
produce. Two hearts are hardly ever of the same size 
after death ; many varieties are met with, and these de- 
pend moi’e or less on the difficulties which the blood ex- 
periences in the last moments, in passing through the 
lungs. Hence why in the diseases of the heart, there is 
no standard by which we can compare the morbid size, 
especially if we examine the organ as a whole. In fact 
the distension of the right side can give it an aneurismatic 
appearance, and a size even greater than that of some 
aneurisms. If we examine the left side separately, the 
error is more easily proved, because this side is subject 14 
MUSCULAR SYSTEM 
to less variations. But the principal difference consists 
in the thickness. The power of contraction appears to 
increase in proportion to this thickness, which arises 
from the substance added by nutrition. It is this power 
which produces the great beating that is felt under the 
ribs, the strength of the pulse, &c. 
It is in proportion to extensibility. It is often brought 
into action in the ordinary state. It is in virtue of this 
property, that the stomach, the bladder, the intestines, 
&c. contract, and acquire a size so small compared to 
what they have when they are full. In general, there is 
no muscle of animal life, which is capable of such ex- 
treme contractions as those of organic life. 
It should be remarked, however, that life, without 
having contractility immediately dependant upon it, since 
the intestines, the stomach, and the bladder contract after 
death when their distension is removed, modifies it in a 
very evident manner. The causes even which alter or 
diminish the vital forces have an influence upon it; hence 
the following observation that all those accustomed to 
open dead bodies can make. When the subject has died 
suddenly, and the stomach is empty, it is much contract- 
ed ; when, on the contrary, death has been preceded by 
a long disease which has weakened its forces, the stomach, 
though empty, remains flaccid, and is found but very 
little contracted. 
We should consider the substances contained in the 
hollow muscles of organic life, as true antagonists of 
these muscles ; for they have not muscles that act in a 
direction opposite to theirs. As long as these antagonists 
distend them, they do not obey their contractility of tex- 
ture ; when they are empty, this is brought into action. 
It is not, however, upon this property that the mechanism 
o*f the expulsion of matters from these organs turns, as 
Contractility. OF ORGANIC LIFE. 
15 
aliments from the stomach and intestines, urine from the 
bladder, blood from the heart, &c. It is the organic con- 
tractility that presides over this mechanism. It is diffi- 
cult to distinguish these properties in exercise. One oc- 
casions a slow and gradual contraction, which is without 
the alternation of relaxation ; the other, quick and sud- 
den, consisting in a series of relaxations and contractions, 
produces the peristaltic motion, those of systole, diastole, 
&c. It is after the organic contractility has procured 
the evacuation of the hollow muscles, that the contrac- 
tility of texture closes them. In death from hemorrhage 
from a great artery, the left and even the right side of 
the heart send out all the blood they contain ; afterwards 
empty, they contract powerfully, and the organ is very 
small. On the contrary, it is very large when much 
blood remaining in its cavities, distends it, as in asphyxia. 
These are the two extremes. There are, as I have said, 
many intermediate states. 
The contractility of texture is, in the system of which 
we are treating, in proportion to the number of fleshy 
fibres. Thus, all things being equal, the rectum, when 
empty, contracts upon itself with much more force than 
the other large intestines ; the contraction of the ventri- 
cles is much greater than that of the auricles, and that of 
the oesophagus is much greater than that of the duode- 
num, &c. &c. 
II. Vital Properties. 
They are almost in an inverse order of those of the 
preceding system. 
Properties of Animal Life. Sensibility. 
The animal sensibility is slight in the organic muscles. 
We know the observation related by Harvey upon a 
caries of the sternum that laid bare the heart; they irri- 16 
MUSCULAft SYSTEM 
tated, without its being felt by the patient, this organ, 
which only contracted under the stimulant. Remove the 
peritoneum behind the bladder of a living dog, and irri- 
tate the subjacent muscular layer, the animal gives but 
few marks of pain. It is difficult to make these experi- 
ments upon the intestines and the stomach; their muscu- 
lar coat is so delicate that we cannot act upon it without 
at the same time stimulating the subjacent nerves. 
It appears that the organic muscles are much less sus- 
ceptible of the feeling of lassitude, of which the preceding 
become the seat after great exercise. I do not know 
however if in those to which many cerebral nerves go, 
it does not take place; for example, when the stomach 
has been for a long time contracted, it is probable that the 
lassitude of its fibres, produces in part the painful sensa- 
tion that we then have, and which we call hunger, a sen- 
sation that should be distinguished from the general affec- 
tion that succeeds it, and which becomes truly a disease, 
when abstinence has been too much prolonged. We 
know that substances not nutritive then appease this sen- 
sation without remedying the disease, when the stomach 
is filled with them. I refer to the same kind of sensi- 
bility the anxiety and distress which patients experience, 
in whom we keep the bladder in permanent contraction 
by an open sound in the urethra, which transmits the 
urine as fast as it falls from the ureters. This sensation 
does not resemble that of hunger, because the sensibility 
of the bladder and that of the stomach being different, 
their modifications cannot be the same. Thus each of 
these two sensations is different from that of which the 
muscles of animal life, for a long time contracted, become 
the seat; I do not believe that the sensation of hunger 
belongs solely to the cause I have pointed out, and which 
others have not spoken of; but it cannot be denied that 
it has much part in it. Who knows if, after a fever in 
which the action of the heart has been for a long time OF ORGANIC LIFE. 
17 
accelerated, the weakness of tfie pulse which accompanies 
convalescence, is not a sign of the lassitude in which its 
fleshy fibres are, on account of the antecedent motion ? 
We know the painful sensation of fatigue which the 
stomach experiences after the contractions of vomiting. 
Contractility. 
The animal contractility is foreign to the muscles of 
organic life. To be convinced of this, we must recollect 
that on the one hand this contractility always supposes 
the influence of the brain and the nerves, to bring in 
play the action of the muscle, and that on the other, the 
brain, in order to exert this influence, must be excited by 
the will, by stimulants or by sympathies. Now none of 
these causes acting upon the brain, the organic muscles 
cannot contract. 
Every body knows that these muscles are essentially 
involuntary. If some men have had the faculty of arrest- 
ing the motions of the heart, it is not upon this organ that 
the brain has acted ; the action of the diaphragm and the 
intercostals has first been suspended ; respiration has 
ceased for a time ; then consequently the circulation. 
If we irritate the brain with a scalpel or any other 
stimulant, the muscles of animal life become convulsed; 
they are paralyzed if we compress this organ. Those of 
organic life, on the contrary preserve in both cases their 
natural degree of motion. The heart still continues to 
beat, the intestines and stomach move some time after the 
cerebral mass and spinal marrow have been taken away. 
Who does not know that the circulation goes on very 
well in acephalous foetuses; that after the blow that has 
knocked down an animal, and rendered his whole volun- 
tary muscular system immoveable, the heart is still for a 
long time agitated, the bladder rejects the urine, the rec- 
tum expels the excrements, &c. the stomach even some- 
times vomits up aliments ? Opium, which benumbs the 18 
MUSCULAR SYSTEM 
whole animal life, because it acts especially upon the brain 
which is the centre of it, which paralyzes all the volun- 
tary muscles, leaves the others unaffected in their contrac- 
tions. Intoxication produced by wine exhibits the same 
phenomenon. A man staggers after drinking ; his limbs 
refuse to carry him, and yet his heart beats with force ; 
his stomach often heaves and rejects the surplus fluids it 
contains. All narcotic substances also produce this effect. 
If from experiments we pass to observations on the 
sick, we see that all cerebral affections are foreign to the 
organic muscular system. Wounds of the head with de- 
pression, fungi of the brain, effusions of blood, pus and 
serum, apoplexy, &c. affect exclusively the voluntary 
muscles, the action of which they increase, weaken or 
destroy. In the midst of this general derangement of ani- 
mal life, the organic remains unaffected. The paroxysm 
of mania and malignant fever likewise proves this fact. 
Who does not know that in this last the pulse is often- 
times scarcely altered, that sometimes even it is slower ? 
Frequently in diseases of the head, there are spasmodic 
vomitings ; the action of the heart is accelerated in cere- 
bral inflammations, &c. But these are sympathetic phe- 
nomena which happen in the organic muscles, as they do 
in all the other systems ; they may not appear nor be de- 
veloped ; a thousand irregularities are observed in their 
progress. Whereas the contraction of the muscles of ani- 
mal life by affections of the brain is a constant, invariable 
phenomenon, which nothing disturbs, and the develop- 
ment of which nothing prevents, because the means of 
communication are always the same between the affected 
organ and the one that moves. 
If in the examination of the phenomena relative to the 
cerebral influence upon the organic muscles, we follow an 
inverse order, that is to say, that in the affections of these 
muscles we examine the state of the brain, we observe 
the same independence ; consider most vomitings, the OF ORGANIC LIFE. 
19 
irregular motions of the intestines which take place in 
diarrhoeas, those especially which form the iliac passion, 
&c. ; observe the heart in the agitations of fevers, in the 
irregular palpitations of which it becomes frequently the 
seat, &c.; in these derangements of the organic muscles, 
you will very seldom find signs of lesions of the cerebral or- 
gan ; it is calm, while every thing is disordered in organic 
life. Cullen thought that in syncope the action of the 
brain ceased first, and that that of the heart was afterwards 
consequently suspended. It is precisely the reverse in 
the greatest number of cases. The heart, at first affected, 
ceases to act; now its action being essential to that of 
the brain, whether from the motion it communicates to 
it, or from the red blood it sends, the functions of this 
last are suddenly suspended and the whole animal life 
ceases. This is remarkable especially in the syncopes 
that arise from the passions, in those from hemorrhages, 
polypi, great evacuations, &c. I refer upon this subject 
to my Treatise upon Life and Death. 
If from the influence of the brain we pass to that of 
the nerves, we find new proofs of the absence of animal 
contractility in the organic muscles. The most of these 
muscles receive, as we have seen, two species of nerves, 
the one cerebral, the other from the ganglions. 
The heart, the stomach, the rectum and the bladder are 
evidently entered by the first species of nerves; now by 
cutting, or irritating in any way the cardiac filaments of 
the par vagum, the heart experiences no alteration from 
it; its motion is neither retarded, nor accelerated. The 
division of both branches of the par vagum is fatal, it is 
true, but not until after some days ; and I doubt whether 
it is by the heart that death commences in this case. The 
principal phenomena consequent upon this division show 
a great embarrassment in the lungs, a great difficulty of 
breathing; the circulation appears to be troubled only in 
consequence. 20 
MUSCULAR SYSTEM 
The same nerves going to the stomach, the same ex- 
periment serves to prove the cerebral influence upon this 
viscus. Now the division of that of one side is usually 
nothing upon it; that of both soon produces a remark- 
able derangement in it. But this derangement is wholly 
different from that which follows the section of the nerve 
of a muscle of animal life, which becomes suddenly im- 
moveable, whilst that on the contrary the stomach not 
communicating with the brain except by the par vagum, 
seems to acquire in an instant an increase of power; it 
contracts and hence the spasmodic vomitings that are al- 
most always observed during the two or three days that 
the animal survives the experiment, vomitings that I 
have constantly noticed in dogs, and which Haller and 
Cruikshank had before observed. It appears then from 
this, that though the brain has a real influence upon the 
stomach, this influence is of a nature wholly different 
from that which it exerts upon the voluntary muscles. 
I would observe however that the irritation of one branch 
of the par vagum, or of both, makes the stomach imme- 
diately contract, as happens in a voluntary muscle when 
we irritate its nerve. It is necessary, in order to make 
this experiment, to open the abdomen of a living animal, 
and afterwards to irritate the eighth pair in the region of 
the neck, so as to have in sight the organ that we make 
■contract. 
The bladder and the rectum appear to approximate the 
voluntary muscles, in their relation with the brain, more 
than the stomach and the heart. We know that falls on 
the sacrum, from which arises a shock of the inferior part 
of the spinal marrow, produce retention of urine; that 
they strike, as it were, this organ with the same paralysis 
as the inferior extremities, which then also cease to move. 
Yet as the bladder is very powerfully assisted in its func- 
tions by the abdominal muscles, by the levator ani and 
other voluntary muscles which surround it, the immobility OF ORGANIC LIFE. 
21 
of these muscles contributes much to the inability to evac- 
uate the urine. That which makes me think so, is that, 
1st, the irritation of the spinal marrow towards its infe- 
rior part which puts in motion all the voluntary muscles 
of the inferior extremities and of the pelvis, does not pro- 
duce any effect upon this part. I have convinced myself 
of this fact many times upon dogs and guinea-pigs. 2d. 
By irritating the nerves coming from the sacral foramina 
and going to the bladder, nerves that it is often very diffi- 
cult to find, on account of the blood in an animal recently 
killed, I have seen this muscle remain immoveable. On 
the contrary all these nerves having been cut, the injec- 
tion of a fluid slightly stimulant makes it contract with 
force. 3d. In experiments upon living animals, as in surgi- 
cal operations, the violence of the pain which sometimes 
produces spasmodic contractions of all the muscles of ani- 
mal life, frequently occasions an involuntary discharge of 
urine. Now in these cases it is not the bladder that is 
convulsed ; for if in an experiment this phenomenon takes 
place, open the abdominal parietes, in an instant the flow 
of urine ceases, because on the one hand the muscles of 
these parietes cannot act upon the intestines and press 
them against the bladder, and because on the other the 
levator ani which contracts and raises this organ, has no 
resisting point against which it can compress it above. 
Observe in fact that in strong jets of urine, the bladder is 
placed between two opposite efforts, one superior, which 
is the gastric viscera pressed by the diaphragm and the 
abdominal muscles, the other inferior, which is especially 
the levator ani which acts by contracting from below 
above, whilst the opposite effort acts from above below ; 
now these two efforts are evidently under the cerebral in- 
fluence. I have very frequently had occasion to observe 
the bladder full of urine in a living animal whose abdo- 
men was opened ; I have never seen it contract with suf- 
ficient violence to expel the fluid. 22 
MUSCULAR SYSTEM 
I do not deny but that the bladder, by the nerves it 
receives from the sacral plexuses, is to a certain extent a 
voluntary muscle; but I say that it is principally by forces 
accessory to its own and necessary to its functions, that 
it is subjected to the will; that the animal contractility is 
much greater in its functions than the sensible organic 
contractility. How then is the urine retained in this or- 
gan, or expelled from its cavity at will? In this way; 
when the urine falls into the bladder, and is there on the 
one hand hut a short time, and on the other only in small 
quantity, it is not then an irritant sufficiently powerful to 
produce the exercise of the sensible organic contractility. 
The effort which the bladder makes is so small, that it 
cannot overcome the resistance of the urethra, which 
being shut by the contractility of texture, must be dilated 
by the impulse communicated to the urine. In order to 
void this fluid, there must then be added to the contrac- 
tion of the bladder that of the surrounding voluntary 
muscles; now the least effort of these muscles is suffi- 
cient to overcome the resistance of the urethra. But if 
the urine is in great quantity in the bladder, and it has 
acquired by remaining in it a long time that deep colour 
which indicates the concentration of its principles, then 
the irritation that it produces on the organ brings power- 
fully into action the sensible organic contractility ; the 
bladder contracts, and in spite of the animal, there is an 
evacuation of urine. 
In the rectum, in which the excrements have not a 
long canal, but only a simple opening to pass, this is fur- 
nished with a sphincter which is wanting in the urethra. 
This sphincter habitually closed must be dilated by the 
impulse communicated to the excrements. \\ hen they 
are in the rectum a short time and in small quantity, the 
sensible organic contractility is not brought into action 
with sufficient power to expel them; it requires the 
action of the neighbouring voluntary muscles. If this OF ORGANIC LIFE. 
23 
action is not determined by the influx from the brain, tire 
excrements remain in the intestines; hence how, for 
some time, we retain them at will. But as they increase 
in quantity, and become more acrid by remaining and 
consequently more irritating, then the sensible organic 
contractility strongly brought into action, empties the in- 
testine involuntarily. If the sphincter, which is volun- 
tary, is paralyzed, there will be incontinence, because no 
resistance is opposed to the tendency of the rectum to 
contract, a tendency which though feeble as long as it is 
but partly filled, is however always real. 
From what we have said, it appears evidently that the 
bladder and rectum, though receiving cerebral nerves, 
are yet less influenced by the brain than it at first view 
appears, and that there is evidently between them and 
the voluntary muscles a very great difference. They are 
not mixt, as it is called ; they approach the organic muscles 
infinitely nearer than the others; I doubt even whether 
if no accessory power acted with and compressed them, 
the mind could by the nerves which come from the sacral 
plexuses, make them contract at will. I have never seen 
an animal void his excrements when the abdomen was 
open. 
Let us conclude from all that has been thus far said, 
that the cerebral nerves which go to the organic muscles 
have upon them an influence which by no means resem- 
bles that of the cerebral nerves going to the muscles of 
animal life. I am ignorant moreover of the nature of 
this influence. 
All the organic muscles receive nerves from the gang- 
lions, both the preceding ones which are also penetrated 
by the cerebral nerves, and the small intestines, and the 
coecum, colour, &c. which are exclusively pervaded by 
them. Now by cutting, tying or irritating in any man- 
ner these nerves, by stimulating the ganglions from which 
they go, by destroying or burning them with a concen- 24 
MUSCULAR SYSTEM. 
trated acid or alkali, the muscle remains in its natural 
state ; its contractions are neither accelerated nor retarded. 
I have not been contented with ordinary agents in con- 
vincing myself of the deficiency of real action of the 
nerves upon the organic muscles; a fact, which all good 
physiologists have always admitted, notwithstanding the 
opinions hazarded by some physicians who apply the 
vague term of nervous influence to organs which are not 
susceptible of it. 
I have then employed galvanism, and I am convinced 
that it has very little, almost no power, in putting into 
action muscular contractions in organic life, whilst it is 
the most powerful agent in animal life. I shall not here 
relate my experiments upon this subject; they will be 
read in my Researches upon Death. 
We can conclude from all that precedes, that the cere- 
bral and nervous influence upon the organic muscles is 
not known to us ; that it does not act as upon the volun- 
tary muscles. It is however real to a certain extent, since 
it is necessary that the nerves which enter into the com- 
position of these muscles should be of some use ; but we 
are ignorant of this use. 
Organic Properties. 
The organic sensibility is strongly characterized in the 
muscles of which we are treating. Before the sensible 
organic contractility is developed in them, it is necessary 
that this should be put in action. But as these two pro- 
perties are not separated, as in their exercise they always 
succeed each other, what we are going to say of sensible 
organic contractility will apply also to the sensibility of 
the same nature. 
Insensible organic contractility or tone, exists in the 
muscular system, to a degree necessary for its nutrition : 
but it does not exhibit in it any thing peculiar. OF ORGANIC LIFE. 
25 
It is the sensible organic contractility that is the pre- 
dominant property in this system, all the functions of 
which rest almost entirely upon this contractility, as all 
the functions of the preceding muscular system are de- 
rived as it were from the animal contractility. We shall 
now examine more in detail this essential property, with 
regard to which physiology owes so much to the illustri- 
ous Haller. We can consider it in three relations; 1st, in 
the stimuli; 2d, in the organs; 3d, in the action of the 
first upon the second. 
Of the Sensible Organic Contractility considered in 
relation to Stimuli. 
Stimuli are natural or artificial. The action of the first 
is continual during life; upon them turn in part the or- 
ganic phenomena ; they place in action the muscles, which 
without them would be immoveable; they are as it were 
to these organs what pendulums are to our machines; 
they give the impulse. The second can hardly have effect 
until after death, or in our experiments. 
Natural Stimuli. 
These stimuli are blood for the heart, urine for the 
bladder, aliments and excrements for the gastric organs. 
Every organic muscle has a body, which, habitually in 
contact with it, supports its motions, as every animal mus- 
cle habitually in relation w'ith the brain, borrows from it 
its power of motion. The natural stimuli support the 
organs at the same degree of mobility while they remain 
the same. All things being equal on the part of the or- 
gans, the pulse does not vary, the digestive periods con- 
tinue for the same length of time, the intervals between 
the excretion of urine are equal, whilst the blood, the 
chyle or the urine exhibit no differences. But as these 26 
MUSCULAR SYSTEM 
substances experience an infinite number of varieties, the 
organs preserving the same degree of sensibility, have 
yet frequent changes in their motion. 
At the instant chyle enters the blood during digestion, 
the pulse changes, because the heart is differently irri- 
tated. We observe the same phenomenon under dif- 
ferent circumstances ; 1st, in re-absorptions in which pus 
goes into the mass of blood ; 2d, in the injection of dif- 
ferent fluids in the veins, injections that were so fre- 
quently made in the last age, at the period of experiments 
upon transfusion, and which I have also had occasion to 
make with other views which I shall mention ; 3d, in 
inflammatory diseases in which the blood takes a peculiar 
character that is yet but little known, and which occa- 
sions the formation of the pleuritic buff; 4th, in various 
other affections, in which the nature of this fluid is re- 
markably altered; 5th, in the passage of the red blood 
into the system with black blood. I have observed that 
in putting a curved tube into the carotid of one side and 
the jugular of the opposite of a large dog, so that one 
forces blood into the other, the passage of the red blood 
into the veins is not fatal like that of the black blood into 
the arteries; but there is almost always at first an accele- 
ration of the motions of the heart. 
The influence of the degeneracy of the fluids in dis- 
eases has no doubt been exaggerated ; too frequent a 
source of morbid derangements has been placed in this 
portion of the economy. But it cannot be denied, that 
according: to the different alterations that the fluids ex- 
hibit, they may be capable of exciting differently the solids 
that contain them. We know that in the same individual, 
and with the same mass of aliments, digestion varies from 
one day to another in the duration of its periods ; that 
some aliments prolong and others accelerate it; that some 
remain very long in the stomach, as it is said, and others 
as it were only pass through it. Now in all these cases OF ORGANIC LIFE. 
27 
the organ remains the same, the fluid only varies. Accord- 
ing as the kidney secretes urine more or less acrid and 
consequently more or less irritating, the bladder retains 
it for a longer or shorter time. Such is oftentimes its 
stimulating qualities, that the moment it comes into this 
organ it is involuntarily rejected. Shall I speak of emet- 
ics and evacuants by the intestinal canal, the effects of 
which are so variable ? We know that the words drastic, 
purgative, laxative, &c. indicate the different degrees of 
the stimulating qualities which certain substances intro- 
duced into the alimentary canal exhibit, degrees which 
are to be considered abstractedly from those of the sensi- 
bility of the organs ; this in fact can be such, that a laxa- 
tive may produce greater effects than a drastic purge. 
Not only the quality, but also the quantity of the fluids 
contained in the organic muscles, has an influence upon 
their contractility. 1st. The word plethora is certainly 
employed too loosely in medicine ; but we cannot doubt 
that the state which it expresses sometimes exists ; now 
the more blood there is in the heart, the more are its 
contractions accelerated. 2d. I have many times made 
transfusion in dogs, whether with a view to that alone, 
or in researches relative to respiration and circulation. 
Now I have always observed, that by not opening a vein, 
to empty the blood as fast as the external jugular receives 
it (for I always choose this vein for the experiment) by 
thus producing consequently an artificial plethora, I have, 
I say, always observed that the motion of the heart was 
accelerated. I have even seen the eye of a dog become 
bright and as it were inflamed ; in others this pheno- 
menon has not been observed. 3d. We know that in 
running, in which all the muscles by contracting press 
out from all sides the venous blood contained in their tex- 
ture, this which enters the heart in abundance, makes 
it palpitate powerfully. 4th. There is not doubt but 
that the quantity of urine and excrements as much and 28 
MUSCULAR SYSTEM 
more than their quality, is for the bladder and the rectum, 
a cause of involuntary contraction. 5th. We know the 
serious consequences that arise from giving emetics and 
cathartics in too large doses. 6th. A glass of tepid water 
often doe* not produce vomiting when a pint will bring 
it on powerfully, &c. &c. 
Artificial Stimuli. 
The artificial stimuli are in general all the bodies in 
nature. Such is in fact the essence of organic contrac- 
tility, that a muscle because it is in contact with a body 
to which it is not accustomed, instantly contracts. If the 
muscles are not irritated by the organs that surround them 
and with which they are in relation, it is because habit 
has blunted the sensation which arises from this relation. 
But when these organs change their modifications, when 
extracted from the body of the animal, they become cold, 
and are afterwards applied to the organic muscles laid 
bare, they will make them contract. 
Caloric, by its absence which constitutes cold, as by its 
presence from which arises heat, can equally excite the 
muscles and in general all the organs. At the instant wre 
open the thorax or the pericardium of a living animal, 
the heart is agitated with a suddenly increased force ; it 
is because the air acts upon it, and it passes from the 
temperature of the body to another which is different. 
All the aeriform fluids, light, all fluids, &c. are stimuli of 
the muscles. If we see the heart emptied of blood, the 
stomach and intestines deprived of the substances that 
ordinarily enter them, contract with more or less force 
when they have been taken out of the body, it is because 
the surrounding medium, and the substances with wrhich 
it is charged, contribute to produce this effect; they are 
then the stimuli of these organs. 
In general the artificial stimuli act in different ways ; 
1st, by their simple contact ; 2d, by tearing or cutting OF ORGANIC LIFE. 
29 
mechanically the fibres; 3d, by tending to combine with 
them; 4th, there are some of whose mode of action we 
are completely ignorant; such for example is electricity. 
When the stimuli act only by simple contact, the fluids 
are, all things being equal, more efficacious than the 
solids, because they stimulate by a greater number of 
points ; as they irritate not only the surfaces of the organ, 
but penetrate also into the interstices of the fibres. The 
solids produce an effect in proportion to the extent of 
their excitement, to the greater or less pressure that they 
exert, to their density, their softness, &c. They are 
almost always fluid substances that nature employs for 
stimuli in the ordinary state. 
Tearing is a mode of excitement more active than con- 
tact. The heart, the intestines often inert when they are 
only touched by the scalpel, contract powerfully when 
the point of it excites them. Cutting produces a less 
sensible effect than tearing. Cut transversely, the fibres 
oscillate and are agitated only by the sensible organic 
contractility, whilst by the contractility of texture they 
experience an evident retraction. 
Chemical excitement is, in the greatest number of cases, 
the most advantageous; but it is necessary here to distin- 
guish that which belongs to the horny hardening, from 
that which is the effect of irritability brought into action. 
1st. Plunge a frog without skin and alive into a concen- 
trated acid ; instantly every thing is disorganized ; the 
reagent acts so strongly, that we can distinguish neither 
horny hardening nor contractility. 2d. Weaken the acid 
a little and plunge into it, the inferior extremities only 
of a frog ; in an instant they stiffen by the contraction of 
the extensors, which overcome the flexors ; for in this 
experiment, this is almost a constant phenomenon; with- 
draw the animal ; its thighs remain immoveable, life has 
been extinguished in them ; the contraction that has come 
on is a horny hardening, and not a vital phenomenon. A 30 
MUSCULAR SYSTEM 
dead frog plunged into the same liquor experiences the 
same phenomenon. 3d. Weaken the acid still more; the 
instant the animal is plunged into it its limhs contract; 
but relaxation succeeds the contractions; these are alter- 
nate motions ; it is the irritability that begins to be put 
into action. Yet if the acid is not very weak, some 
marks of the horny hardening still remain, and the ani- 
mal has a stiffness in the motions of the inferior extremi- 
ties, the evident result of the first degree of this horny 
hardening. 4th. Finally, if the acid is very weak, it be- 
comes a simple irritant which puts in action the sensible 
organic contractility, without altering the texture of the 
fibres; the animal after coming out of the fluid preserves 
the same power of motion. 
These experiments which it would be easy to multiply 
upon animals with warm blood, but which I have never 
attempted upon them, evidently show what belongs to 
the horny hardening, and what is the effect of vital con- 
traction. Yet there is not an exact limit between them, 
and there is one degree of weakness of the acid in which 
these two causes of motions are confounded. 
There is a mode of excitement to which authors have 
not paid attention ; it may be called negative; it is that 
of which I spoke just now on the subject of caloric, the 
privation of which is oftentimes a very active stimulant. 
In the different experiments that I have had occasion to 
make, this has frequently struck me. Apply a stimulant 
to a muscle, it contracts; but at the end of some time 
the motion ceases, though the contact continues ; remove 
the stimulant, the motion frequently returns in an instant. 
In general, nothing is more common in the heart, the in- 
testines, &c. than their contractions ceasing under the con- 
tinued action of a stimulant, and returning instantly upon 
its absence. I confess that this phenomenon is not as in- 
variable and constant as that of the contraction produced 
by the application of the stimulus which succeeds a state OF ORGANIC LIFE. 
31 
of non-excitement; but this happens very often. We 
might say that the organic sensibility is in this case like 
the animal; that every new state affects it, whether it be 
positive or negative. The passage from non-excitement 
to excitement is more lively; but the opposite passage is 
not less when it is sudden. Moreover this manner of 
describing the sensible organic contractility in exercise, 
deserves some further experiments. 
Of the Sensible Organic Contractility considered in 
relation to the Organs. 
The sensible organic contractility, considered in the 
organ in which it has its seat, exhibits numerous varieties 
which are relative ; 1st, to the diversity of texture ; 2d, 
to age; 3d, to sex; 4th, to temperament, &c. 
First Variety. Diversity of the Muscular Texture. 
The animal contractility is everywhere the same in the 
voluntary muscles, because their organization is uniform. 
All things being equal as to the number and length of 
the fibres, the phenomena of contraction are exactly the 
same everywhere; here, on the contrary, the varieties of 
texture inevitably produce varieties in the vital properties. 
Each involuntary muscle is at first especially in rela- 
tion with the fluid which ordinarily acts as its stimulus. 
The blood alone can regularly support the motions of the 
heart. Let this fluid be altered in any manner, the con- 
tractions become irregular. All foreign substances forced 
into the veins produce this phenomenon. The urine, 
which supports with harmony the motions of the bladder, 
would disturb those of the heart, if it circulated in its 
cavities. The blood, more soft in appearance than the 
urine, can agitate convulsively the bladder, if it happens 
to be in it. I took care with Desault of a patient affected 
for a long time with retention of urine, and whom he had 
cut for a very large stone. After the operation, the urine 32 
MUSCULAR SYSTEM 
remained stagnant in the bladder as long as it was alone, 
but when a little blood entered this organ, it contracted 
involuntarily and the bloody urine was evacuated. The 
excrements, which could continue for a long time in the 
rectum without making it contract, would make the 
stomach heave in an instant, &c. All these phenomena 
are to be referred to varieties of sensibility of the mucous 
membranes, varieties which we shall notice again. They 
prove evidently that each muscle has a degree of organic 
contractility which is peculiar to it, and that this or that 
fluid of the economy can exclusively, in a natural state, 
put it in exercise in a regular manner. 
Foreign fluids exhibit the same result; the emetic 
which makes the stomach contract, is injected with im- 
punity into the bladder; purgatives do not produce vom- 
iting, &c. This relation of foreign fluids with the sensi- 
ble organic contractility takes place, whether, as in the 
preceding case, these fluids are applied to the mucous 
surfaces corresponding to the muscles, or whether they 
come to the muscles by the circulation, as the experi- 
ments have proved which were made in the last age upon 
the introduction of medicinal substances into the veins; 
experiments of which Haller has collected a great num- 
ber of results. We have seen in these experiments, the 
circulation present to all the organs sometimes an emetic, 
and the stomach alone contracts; sometimes a purgative, 
and the intestines only enter into action, &c. Taken in 
by cutaneous absorption, medicinal substances occasion 
the same phenomenon. Applied by friction, purgatives, 
emetics, &c. do not make all the organic muscles contract, 
though the circulation presents them to all, but only those 
with which their sensibility is in relation. 
In the various affections of which they are the seat, we 
see the organic muscles having each a peculiar mode of 
irritation answer to each stimulus, and remaining deaf, if 
we may so say, to the voice of the others. OF ORGANIC LIFKi 
33 
Second Variety. *flge. 
Age modifies wonderfully the sensible organic con- 
tractility. In infancy it is very evident; the muscles 
answer with extreme ease to the stimuli; the bladder 
retains the urine with difficulty ; children void it in sleep 
involuntarily ; the heart contracts with a rapidity of which 
the pulse is the measure; all the digestive phenomena 
are more prompt; hence there is less interval between 
the returns of hunger. It is a phenomenon analogous to 
that of the voluntary muscles, in which the rapidity of 
the motions is found, in the first age, connected with their 
small degree of force. 
After infancy, the susceptibility of the muscles to 
answer to their stimuli, is constantly diminishing; thus 
all the great phenomena of organic life are continually be- 
coming slower. The number of pulsations, the duration 
of digestion, the longer continuance of the urine, &c. are 
the thermometer of this slowness. 
In old age the whole is weakened ; the action of thje 
organic muscles gradually diminishes. Those of the blad- 
der and rectum are the most exposed to lose their con- 
tractile faculty ; hence the retention of urine, which is a 
frequent companion of old age ; hence also the accumula- 
tion of fecal matters above the anus, a disease almost as 
common as the first at this age of life, though it has 
received less attention from practitioners. Rich people 
and those accustomed to the luxury of the table are 
especially subject to it. I have seen much of it, as much 
even as of retention of urine, in the last year of the 
practice of Desault. The intestines and the stomach lan- 
guish more slowly in their functions. It is the heart 
which resists the most; it is the ultimum moriens, as it 
has been the first in exercise ; the duration of its pulsa- 
tions measures exactly the duration of organic life. 34 
MUSCULAR SYSTEM 
Third Variety. Temperament. 
Temperament modifies in a remarkable manner organic 
contractility. We know that in some the pulsations are 
more frequent, the digestive and urinary phenomena more 
rapid ; that in others, every thing is marked by more 
slowness in organic life ; now these varieties have evi- 
dently their primitive source in the varieties of the con- 
tractility of the heart, the stomach, the intestines, &c. 
which have under this relation a great influence in the 
difference of the temperaments. With respect to this 
there are two essential observations to be made; 1st. 
The varieties of force of the organic muscles do not 
always coincide with those of the muscles of animal life. 
Thus we see an individual with feebly developed exterior 
forms, with an evident weakness of the muscles of the 
extremities, whilst the activity of digestion, of the urin- 
ary evacuations, &c. announces the greatest energy in the 
sensible organic contractility. I would remark with 
regard to this, that the heart is more frequently in rela- 
tion of force with the external muscles than the stomach, 
the intestines and the bladder. A full pulse, well de- 
veloped, is usually found with an athletic constitution ; 
whilst often this constitution is united in the same subject 
to a feeble gastric system, and especially the force of this 
gastric system is frequently connected with external 
weakness. This fact, which the different temperaments 
demonstrate to us in man, is evident in the series of ani- 
mals. Those who, like the carnivorous ones, have a very 
powerful animal muscular system, have the parietes of 
the gastric cavities like membranes. These parietes are 
strong in the herbivorous classes; they become very con- 
spicuous in the gallinaceous. In general, mastication over 
which the animal contractility always presides, is in ani- 
mals in an inverse ratio of the force of trituration of the 
stomach, over which the sensible organic contractility 
presides,. OF ORGANIC LIFE. 
2d. The varieties of this property, relative to tempera- 
ments, exhibit another phenomenon almost always foreign 
to the animal muscular system. In fact in this the varie- 
ties are always general; we are able by exercise to 
Strengthen this or that muscular region; but the differ- 
ences of forces which are natural, always influence the 
whole system. The arms and the legs, the thorax and 
the abdomen are uniformly contractile in the different 
divisions of the muscles that belong to them. On the 
contrary, it. is rare to see this uniformity in the involun- 
tary muscles. One almost always predominates over the 
others ; sometimes it is the heart, sometimes the stomach 
and sometimes the bladder. The gastric viscera even are 
frequently not all at the same level as to force. The 
stomach is feeble when the intestines preserve their ordi- 
nary action ; and reciprocally the intestines too contrac- 
tile expel immediately fecal matters and thus produce a 
diarrhoea, though the stomach may perform its functions 
well. This essential difference in the two muscular sys- 
tems arises from the circumstance that the contractility of 
one depends upon a common centre, the brain; whilst 
that of the other on the contrary has its principle insulated 
in each organ in which it exists. 
35 
Fourth Variety. Sex. 
Women in general resemble children in the phenomena 
of sensible organic contractility. The weakness of the 
motions coincides with their greater rapidity in this sex, 
all whose internal muscles, like the external, are more 
delicate and less strongly developed than in man. It 
might he said that the contractile power of the womb has 
been formed at the expense of the forces of all the other 
organs. In experiments, females give results much less 
decided and always less durable than males. The motions 
of the heart, the stomach, the intestines, &c. cease sooner j 36 
MUSCULAR SYSTEM 
these motions are less; it requires stronger stimuli to 
produce them, &c. 
Fifth Variety. Season and Climate. 
In winter and in cold climates, in which the cutaneous 
organ contracted, and having as it were the horny hardness 
from the impression of the surrounding air, has but a 
feeble action, all the internal functions more active, re- 
quire more energy yi the forces that preside over them ; 
all the digestive, urinary and circulatory phenomena are 
more evident. I do not know that there has yet been 
made any comparative experiments upon irritability in 
the different seasons ; but I am persuaded that they would 
give different results. 
Sensible Organic Contractility considered in relation 
to the Action of Stifnuli upon the Organs. 
We have just described separately the stimulant and 
the organ stimulated ; each being separate there is no 
effect upon the sensible organic contractility ; from their 
union alone results the exercise of this property. What 
happens in this union ? We know not. To wish to know 
it, would be to wish to know how one body attracts 
another, how an acid combines with an alkali, &c. In 
attraction, affinity and irritability, we can only trace the 
phenomena to the action of bodies upon each other. This 
action is the utmost limit of our researches. 
But that which ought not to escape us here is, that in 
this last property, the action is never immediate. There 
is always between the stimulus and the organ something 
intermediate which receives the irritation ; this inter- 
mediate organ is a delicate membrane and continuous with 
that of the arteries for the heart; it is a mucous surface 
for the gastric viscera and the bladder. This intermediate 
organ is more susceptible of receiving excitement than 
the muscle itself. I have uniformly observed that by OF ORGANIC LIFE. 
37 
irritating the internal surface of the heart, its contractions 
are greater, than by laying its texture bare externally by 
removing its serous covering and afterwards stimulating 
it. The same is true with regard to the organic muscles 
of the abdomen. 
Is there between the intermediate organ excited and 
the organ which contracts, any nervous communications 
that transmit the impression ? I think not, the cellular 
texture is sufficient. In fact the serous surfaces and the 
organic muscles have only this texture as a means of 
union. The life of the first is in no way connected with 
that of the others, since they often leave them as we shall 
see, and yet they can transmit excitement to them. The 
pericardium and the peritoneum, irritated in their portion 
corresponding with the organ that we wish to move, pro- 
duce a contraction in it. This fact is known to all those 
who have made the least experiment; it is almost always 
in this way that we stimulate the heart, the stomach, the 
intestines, the bladder, &c. By carrying the stimulus 
over the serous surface but very lightly, and so as not to 
communicate the motion to the fleshy fibres, we obtain a 
result. Yet simple contact is not sufficient to transmit 
the irritation ; for example, by leaving the external layer 
of the pericardium applied to the heart and afterwards 
irritating it, the organ remains immoveable. If we sepa- 
rate the peritoneum from above the bladder, so as to 
break all the cellular adhesions, and afterwards reapply 
and stimulate it, the same immobility is observed. 
When the intermediate organ that receives the excite- 
ment is diseased, the contractility is uniformly altered. 
The same stimulus produces slow or rapid contractions, 
according as the affection raises or diminishes the sensi- 
bility of this intermediate organ. A slight inflammation 
of the exterior of the bladder produces a kind of incon- 
tinence of urine; that of the intestines occasions diar- 
rhoea, &c. &c. On the contrary, old catarrhs of the bind- 38 
MUSCULAR SYSTEM 
der, the affections in which weakness of the mucous sur- 
face of this organ predominates, are the frequent causes 
of retention. 
I would observe that the existence of this intermediate 
organ is a remarkable difference between the sensible 
organic contractility and the insensible, for this organ 
does not exist in this last, in which the same system re- 
ceives the impression and reacts upon the body that has 
produced it; for example, in the glandular, serous, cuta- 
neous systems, &c. the fluid which enters them for secre- 
tion or exhalation produces in them the sensation, which 
is instantly followed by the reaction. In the sensible 
contractility on the contrary, one system feels and an- 
other is moved. This kind of mobility is less removed 
from that of animal life, in which the organs of the senses 
and those of the motion being wholly different, are very 
distant from each other. 
Sensible Organic Contractility considered in relation 
to its duration after Death. 
This duration is longer than that of the animal con- 
tractility. When the spinal marrow is irritated, the ex- 
ternal muscles remain immoveable, whilst the internal 
ones are still in activity. There have been so many ex- 
amples related of this duration, Haller has multiplied ex- 
periments so much upon this point, that there is no occa- 
sion for me to give proofs here of a fact of which no one 
can any longer doubt. To this duration are owing the 
evacuations of fecal matter and urine which often take 
place an instant after death ; the vomitings that are ob- 
served in some subjects, if not in as evident a manner 
as during life, at least sufficient to raise the aliments into 
the mouth of the dead body, which is often completely 
filled with them, as I have frequently seen. 
It is necessary, in relation to this duration, as in rcla- 
lion to that of the animal contractility, to distinguish two OF ORGANIC LIFE. 
39 
species of death; 1st, those that take place suddenly; 
2d, those which are the consequence of long disease. 
In every sudden death, produced either by a violent, 
lesion of the brain, as in apoplexy, concussion, compres- 
sion, effusion, &c. or by an affection of the heart, as in 
s\ ncope, a wound, or a ruptured aneurism ; or by a cessa- 
tion oi the action of the lungs, as in asphyxia from dele- 
terious gases, a vacuum, submersion, &c. the duration of 
contractility is very evident; general death comes on 
first, then the organs die partially; each vital force is 
afterwards successively extinguished. 
In every kind of death slowly produced, in all those 
especially which are preceded by a disease of weakness, 
it is the partial death of each organ that first takes place; 
each vital force is weakened and extinguished, gradually, 
before the cessation of them as a whole, which constitutes 
general death, comes on; when this death takes place, 
none of the lives peculiar to each organ remains, whilst 
most of these lives continue for a longer or shorter time 
after sudden death. 
We cannot make these experiments upon dead bodies 
which we rarely have in the hospitals till fifteen hours or 
more after death ; but by killing dogs by hunger, which, 
when long continued, becomes a real disease that lasts in 
these animals eight, ten and even twelve days, I have seen 
the contractility entirely extinguished at the moment of 
death. Dogs have been often brought to me affected with 
different diseases, especially three years since when there 
was a kind of epidemic among these animals ; now by 
opening them at the instant of death, by killing them 
even some time before and thus producing a sudden death 
wrholly different from that which happens in the sound 
state in which all the parts are uninjured in their func- 
tions and consequently in their vital forces, I have always 
seen a constant absence of contractility, or at least so 
greatly weakened that it appeared to be nothing. MUSCULAR SYSTEM 
40 
Many physiologists have spoken of a general convul- 
sion which comes on in the organic muscles at the instant 
of death, of a rising of the heart, the stomach, the intes- 
tines, &c. This excess of action is sometimes real in 
sudden deaths, in those especially that we produce for 
our experiments ; it is very rare in deaths preceded by a 
long disease in which the patient is extinguished, as it 
were, insensibly, and passes gradually from life to death. 
It is a fault common to almost all authors, to generalize 
too much the facts observed under certain circumstances. 
Many false consequences are the results of it. 
Sympathies. 
No organ receives more easily the influence of others, 
than the organic muscles; all however are not equally 
susceptible of it. The heart occupies the first rank in 
this respect; then comes the stomach, then the intestines, 
and finally the bladder. It is in this order that we shall 
now examine this influence. 
It is a remarkable phenomenon, that every kind of 
affection in any degree strong, arising in the economy, 
alters immediately the motions of the heart. The least 
wound, oftentimes the slightest pain are sufficient to pro- 
duce derangements in it; now these derangements are of 
two kinds ; sometimes its action is arrested fora moment; 
hence syncopes, a mode of derangement which happens 
especially in violent and sudden pains. The vulgar ex- 
pression which is employed in these cases, viz. “ my heart 
is failing,” is perfectly true. Sometimes, and this is the 
most common case, this action is accelerated ; hence the 
febrile motions so frequent in all the local affections, mo- 
tions purely sympathetic and which cease when the affec- 
tion disappears. In many local inflammations, the evil is 
too circumscribed to admit an obstacle to the course of the 
blood, an obstacle, which according to Boerhaave, forces 
the heart to redouble its action to surmount it; besides OF ORGANIC LIFE. 
41 
when there is no swelling, but only pain in the part, and 
the febrile motion comes on, it is there clearly a sympa- 
thetic phenomenon. The increase of the action of the 
heart may depend no doubt upon a foreign substance, 
which, mixed with the blood, alters and renders it more 
irritating; it may be owing to an affection of the substance 
of the organ which disposes it to be more irritable; but 
it is certainly very often sympathetic, and depends upon 
that unknown relation which connects all our organs, 
upon that consensus which links together all their actions, 
and places them in reciprocal dependance. 
I shall say as much of the stomach ; though its sympa- 
thetic reaction may not be altogether as frequent as that 
of the heart, yet it becomes very evident under many 
circumstances. Most local affections, especially inflam- 
mations are accompanied with sympathetic vomitings. 
Various fevers have in their commencement similar 
vomitings. It is in the hospitals especially that we fre- 
quently observe these phenomena. Many physicians 
have not considered these vomitings as merely sympa- 
thetic, but as the index of a bilious affection, founded on 
this, that bile is then almost always thrown up. But in 
all the animals that I have opened, I have almost always 
seen the stomach when empty containing a certain quan- 
tity of this fluid which had flowed back from the duo- 
denum ; other authors have also made similar observa- 
tions ; so that it appears that in the state of vacuity, the 
existence of bile in the stomach is a natural phenomenon. 
Hence it is not astonishing, that in the commencement of 
diseases, and even in their course, the stomach being 
sympathetically excited and thus becoming the seat of 
vomiting, more or less of this fluid should be thrown up. 
It would be brought up even in health if vomiting is then 
excited by an emetic ; this is what sometimes happens in 
the morning when the stomach is empty, if any cause 
foreign to an affection of the liver, as the sight of a dis- 42 
MUSCULAR SYSTEM 
gusting object, produces vomiting ; the bile then comes 
out like every thing else that is contained in the stomach. 
1 do not say that oftentimes the liver being sympatheti- 
cally excited in the commencement of diseases, does not 
furnish more bile, that this superabundant bile flowing 
into the s omach, does not make this viscus contract; but 
certainly this is not most commonly the case; we vomit 
bile as we discharge it by the anus, because it is found in 
the stomach and intestines, and not because it is supera- 
bundant. If vomiting was a natural function, the bilious 
evacuations in this way would be as natural as the green- 
ish tinge of the excrements, which is always found in a 
state of health. We see then, from this, that the bilious 
vomitings are, in many cases, purely accessory, and that 
the essential phenomenon is the sympathetic contraction 
of the stomach. 
In the case of which I have just spoken there is no gas- 
tric difficulty ; the sympathetic alteration of the stomach 
only extends to the fleshy fibres. But most frequently 
this gastric difficulty appears at the beginning of diseases 
in which there is local affection ; sand-like substances are 
vomited up ; it is because then the organ essentially affect- 
ed, the lungs for example, if it is in a peripneumony, has 
acted sympathetically not only on the fleshy fibres, but 
also upon the mucous membrane. This excited increases 
its secretion ; hence these sand-like substances, which are 
nothing but the mucous juices mixed with the gastric 
fluid and with the bile; now the presence of these sub- 
stances is often sufficient to make the stomach contract, 
and produce vomiting which expels them. 
From this it is evident that there can be sympathetic 
vomitings without gastric difficulty, and sympathetic gas- 
tric difficulty with a vomiting immediately produced. In 
the first case the fleshy fibres feel the sympathetic influ- 
ence of the affected organ ; in the second it is the mucous 
membrane. But how, when the lungs, the pleura, the OF ORGANIC LIFE. 
43 
skin, &c. being affected, does the stomach come into 
action ? I have said that the word sympathy was only a 
veil for our ignorance in respect to the relations of the 
organs to each other. Vomitings produced by erysipelas, 
phlegmon, pleurisy, peripneumony, &c. are then most 
often an effect exactly analogous to the increase of the 
action of the heart, which produces fever. They resem- 
ble the cerebral derangement from which arises delirium, 
a derangement which is much more rare, &c. All these 
phenomena indicate that the other organs feel by reaction 
the state of that which is affected, &c. Physicians who 
have not viewed all these phenomena in a great and gen- 
eral manner, have confined their treatment to too narrow 
bounds. Much attention was formerly paid to the sym- 
pathetic derangement of the heart, and bleeding was much 
practised in the beginning of diseases ; for some years 
past much regard has been had to the sympathetic de- 
rangement of the stomach, and emetics are frequently 
given ; perhaps before long, more attention will be given 
to the weights of the head, pains in that part, watchful- 
ness, drowsiness, &c. which are very common sympa- 
thetic symptoms, and the treatment will be directed to the 
brain. In these varieties judicious physicians will regard 
all these phenomena in a general manner; they will see 
in all a proof of that general agreement which disposes 
together all the functions, which connects all and thus 
connects their derangements ; they will see each organ 
rise up, as it were against the evil which is introduced 
into the economy, and each react in its own way ; they 
will see these reactions producing effects wholly diflerent, 
according to the organ reacting, fever arising from the 
reaction of the heart, delirium, drowsiness, watchfulness, 
convulsions, &c. from that of the brain, vomiting from 
that of the stomach, diarrhoea from that of the intestines, 
gastric and intestinal derangements, foulness of the tongue 
from those of the mucous membranes, overflowings of 44 
MUSCULAR SYSTEM 
bile from that of the liver, &c. Thus in a machine in 
which the whole is united and connected together, if one 
part is deranged all the others are so also. We should 
laugh at the mechanist who attempted to mend hut one 
of these pieces, and neglected to repair the local de- 
rangement from which all those arose which the machine 
exhibits. Let us not laugh at the physician who attacks 
only a single symptom, without combating the disease, of 
which he oftentimes knows not the principle, though he 
knows that this principle exists; hut let us laugh at him, 
if he attaches to his treatment an importance which is 
nothing compared with that of the disease. 
The intestines next to the stomach are the most often 
sympathetically affected in diseases. The bladder is the 
organic muscle that is the last to feel the influences that 
go from the diseased organ ; this sometimes however 
happens. In fevers, we know that retentions of urine 
from sympathetic and temporary paralysis, are not very 
rare ; incontinence of urine is less often seen. 
Characler of the Vital Properties. 
We see from what has been said, that the vital proper- 
ties are very active in the organic muscles, especially as 
it respects contractility. These muscles are really during 
life, in constant action ; they receive with great ease the 
influence of other organs. Their vital properties are alter- 
ed with the greatest promptness, especially that which I 
have just pointed out; for the insensible contractility is 
rarely altered in them, because it does not perform an 
essential part. Observe in fact that the morbid derange- 
ments of an organ affect always the predominant vital 
force of that organ. Animal contractility is frequently 
altered in the preceding system ; in this it is the sensible 
organic contractility. On the contrary, the insensible 
being very small, the phenomena over which it presides 
remain always nearly the same; nutrition is always uni- OF ORGANIC LIFE. 
45 
form ; lesions of the muscular texture are rare ; when 
they take place, it is rather by communication, as in can- 
cers of the stomach, in which the disease begins upon 
the mucous surface, and in which the fleshy fibres are 
only consequently affected. The heart and the womb are 
the muscles that are the most subject to these morbid 
alterations ; yet in the first they belong oftener to the in- 
ternal membrane than to the fleshy fibres themselves. 
On the contrary in the systems in which the sensible or- 
ganic contractility is incessantly in action, as in the cuta- 
neous, the serous, &c. in which it presides over nutrition 
and exhalation; in the glandular, the mucous, &c. in 
which it produces secretion and nutrition, it is this which 
is especially altered. From these derangements arise 
alterations of texture, organic diseases properly called, 
which are as common in these systems, as they are rare 
in those in which the insensible contractility, is so very 
obscure, as to be only at the degree necessary for nutri- 
tion. 
It is to this that must be referred the infrequency of 
acute inflammations of this system. As this affection is 
frequent in the cutaneous, the serous, the mucous systems, 
&c. so this system, whose functions require but little in- 
sensible organic contractility, presents it rarely. Those 
who open many dead bodies know, that the texture of 
the heart is hardly ever found inflamed. Nothing is 
more common than phlegmasia of the external or serous 
membrane, and of the internal or mucous membrane of 
the stomach, the intestines, &c.; but nothing is more ob- 
scure and less frequently seen than that of their fleshy 
tunic. In rheumatism, there is sometimes when the pains 
cease around the joints, violent cholics, spasmodic vomit- 
ings even, indices perhaps of an acute affection of the 
fibres of the stomach or intestines; but we never find 
marks of these affections; we do not see the muscular 
texture exhibiting the bright red of the inflamed mucous, 46 
MUSCULAR SYSTEM 
cutaneous and serous organs; or at least 1 have never 
observed it. 
Physicians have not paid sufficient attention to the dif- 
ference of inflammations according to the difference of 
systems ; but especially they have not sufficiently observ- 
ed that this difference accords perfectly with that of the 
insensible organic contractility; that where this vital 
force is most characterized, inflammations have the great- 
est tendency to take place, because it is this which pre- 
sides over their formation ; because these affections sup- 
pose its increase; as convulsions suppose the increase of 
animal contractility, as vomitings, accelerated pulsations 
of the heart, suppose that of organic contractility, &c. I 
cannot repeat it too much, that the most frequent diseases 
in each system, put always in action, raise or diminish 
the predominant vital force in that system. It is a new 
pathological view, that may be fruitful in results. 
ARTICLE FOURTH. 
PHENOMENA OF THE ACTION OF THE MUSCULAR SYSTEM 
OF ORGANIC LIFE. 
These phenomena are, as in the preceding system, rela- 
tive to the state of contraction or to that of relaxation. 
I. Force of the Contractions. 
It is never capable of being raised to the point which 
the force of the muscles of animal life sometimes attains. 
Between the strongest and the weakest pulse, between OF ORGANIC LIFE. 
47 
the feeble jet which precedes some retentions of urine, 
and the jet of the most vigorous man, there is much less 
difference than between the langour of the voluntary 
muscles of some women and the power of those of a 
maniac, or a man in anger. The heart and the deltoid 
muscle are nearly equal in respect to their fleshy mass; 
now what would become of the circulation, if the first 
sometimes sent the blood with the force which the second 
uses to raise the superior extremity ? A fit of anger, 
mania, &c. is sufficient to produce aneurisms. On the 
other hand the organic muscles are not affected with those 
prostrations of forces so common in the others; paralysis 
is foreign to them, because they are not within the cerebral 
influence. There is something which answers to convul- 
sions ; it is the irregular agitations which produce so 
many varieties in the pulse of acute fevers, agitations 
which must be distinguished from those produced by an 
organic defect of the heart; but these agitations are 
wholly different from spasms of the voluntary muscles; 
there is even no analogy. 
There is not in the force of the contraction of the mus- 
cles of which we are treating, the waste which is so re- 
markable in that of the other muscles ; the effort is nearly 
proportionable to the acting cause, and the distinction of 
this force into absolute and effective, cannot be applied 
here; only there is required more or less contractile 
energy, according as the body to be expelled from a hol- 
low muscle, is solid or fluid. Hence why the great in- 
testines are provided with longitudinal fibres more charac- 
terized than those of the small intestines ; why the rec- 
tum especially, in which the excrements have their great- 
est degree of solidity, exhibits these fibres in a more 
evident manner than the colon or the caecum, though 
under a different form ; why in diarrhoeas the weakest 
contraction is sufficient to evacuate the intestines, whilst 
the sensible organic contractility of the rectum being in- 48 
MUSCULAR SYSTEM 
sufficient to void very solid excrements, it is necessary 
that the abdominal muscle should aid the expulsion ; why 
when a hard body is introduced into the stomach, and the 
gastric juices do not soften it, it remains there a long 
time before being expelled, and produces an inconvenient 
weight, &c. &c. We know with what rapidity the pas- 
sage of liquids takes place from the stomach to the intes- 
tines, and how long on the contrary solid aliments remain 
in the first. 
The force of the organic muscles is incomparably 
greater in the phenomena of life than in our experiments. 
Once laid bare, the heart communicates only feeble motions, 
and most often irregular ones. There is no proportion 
between the force necessary to produce the jet, some- 
times from seven to eight feet, which the blood exhibits 
coming from the open carotid of a dog, and the force of 
the contractions which the strongest stimuli produce when 
applied to the heart extracted from the body. Nothing 
equals in our experiments the force of contraction neces- 
sary for vomiting, &c. &c. 
Numerous calculations have been made upon the force 
of contraction, in the organic muscles as in the preceding, 
and there has been the same variety of results. Can we 
in fact calculate the degrees of a phenomenon which 
a thousand causes make vary every instant, not only in 
different individuals, but even in the same, which sleep, 
digestion, exercise, rest, tranquillity of mind, violence of 
the passions, day, night, every thing in a word, incessantly 
modifies ? I do not know that we digest twice in exactly 
the same period, if the urine twice remains the same 
length of time in the bladder before being discharged, if 
its jet is twice exactly equal, &c. 
The force of the organic muscles often remains in its 
ordinary degree, or is even increased ; whilst a general 
weakness possesses the others. The force of the pulse, 
vomiting, diarrhoea, &c. coinciding with a general pros- OF ORGANIC LIFE. 
49 
tration of the muscles of animal life, are not rare phenom- 
ena in diseases. 
II. Quickness of the Contractions. 
It varies singularly; very rapid in experiments, when 
death is recent and the stimuli are very strong, the con- 
tractions are in general slower in the natural state; we 
might say that it is in the inverse ratio of the force ; often 
at the instant we open the pericardium, the heart moves 
with a rapidity which the eye can hardly follow, espe- 
cially if we inject an irritating fluid into this serous sac, 
a little before laying the organ bare. The contractions 
increase much in quickness in certain diseases; those of 
the heart, for example, then acquire in the adult a rapidity 
often much greater than they have in the first age ; this 
rapidity is also in this case entirely distinct from the force 
of its contractions ; it is rare even that these two things 
are found united at the highest point. In general w7hen 
the force of the heart is increased, there is a little more 
quickness ; but there is very often a dimunition of force 
with an increase of quickness, or the force remains the 
same, the quickness being much increased. 
We have seen that the voluntary muscles have in gen- 
eral a degree of quickness beyond which they cannot go, 
and that this quickness belongs to the original constitution. 
Is not the same phenomenon observed here ? Often in 
two fevers whose symptoms are the same, whose degree 
of intensity seems to be exactly uniform, the pulse is infi- 
nitely more frequent in one individual than in the other. 
This does not always denote a difference in the disease, 
but in the primitive constitution, an aptitude of one of 
the two hearts to contract much quicker under the same 
stimulant. Who does not know that in experiments, the 
contractile rapidity is infinitely variable under the influ- 
ence of the same causes ? 50 
MUSCULAR SYSTEM. 
Each organic muscle has its degree of quickness ; the 
heart, the stomach, the intestines, the bladder, &c. differ 
remarkably in this respect. 
III. Duration of ike Contractions. 
The heart never remains in permanent contraction, as 
often happens in the voluntary muscles. Though hunger 
seems to prove the contrary in the stomach and the intes- 
tines, yet this phenomenon is not contradictory; in fact, 
the permanent contraction of the empty gastric viscera is 
the result of the contractility of texture. Whenever the 
sensible organic contractility is in action, there is alter- 
nate contraction and dilatation ; this alternation even cha- 
racterizes essentially this last property, and distinguishes 
it from the animal contractility and from that of texture, 
in which the state of contraction is often permanent. 
IV. State of the Muscle in Contraction. 
All the phenomena described for the voluntary mus- 
cles, are almost applicable to these, such as the hardening, 
increase in thickness, diminution in length, expression of 
the blood, &c. &c. But there are some differences be- 
tween the heart and the gastric muscles, in respect to the 
mode of contraction. In fact we see very sensibly in the 
first, 1st, contractions of the whole analogous to those of 
the voluntary muscles, contractions which take place in 
the state of health, which produce the projection of the 
blood, and which are easily made in experiments when 
the animals are still living; 2d, numerous oscillations 
which seize upon the fibres, which agitate the whole of 
them without producing any sensible effect, without con- 
tracting the cavity, without projecting the blood for ex- 
ample. These oscillations are observed at the instant of 
death, when the heart is ceasing to be contractile ; wre 
may then irritate it in vain, there are no more contrac- OF ORGANIC LIFE. 
51 
tions of it as a whole ; though there is a general and very 
evident vibration of its fibres, yet its cavity is not con- 
tracted ; the blood stagnates in it. The heart perfectly 
resembles under this double relation the voluntary mus- 
cles ; it is agitated as we see these muscles in the shud- 
dering, that is called horripilatio, as we see it also in cer- 
tain sub-cutaneous muscles in some individuals. I have 
already, for example, seen many persons affected with an 
habitual trembling of a portion of the solaeus, a trembling 
very evident to the eye through the skin, and which had 
nothing in common with the contraction necessary to the 
extension of the foot. 
The involuntary muscles of the abdomen never exhibit 
this double mode of contraction. Instead of the quick 
and sudden motions of the whole of the muscle, we see 
but a slow contraction in it, often but slightly apparent; 
it is a kind of creeping ; there is not even to speak pro- 
perly a contraction of the whole, like that of the heart 
in which all the fibres of an auricle or ventricle are moved 
at the same time; here each fleshy surface appears to act 
successively. Placed at the origin of the great vessels, 
the bladder and the stomach would be incapable of com- 
municating to the blood those motions by jerks, which 
the jet of an artery exhibits at each contraction. On the 
other hand, at the instant the motion ends in the stomach, 
the intestines and the bladder, we never see in them 
those oscillations, those vibrations which are almost con- 
stant in the heart and the voluntary muscles, and which 
we can even create in them at will. 
Y. Motions imparted by the Organic Muscles. 
There are hardly ever simple motions in these muscles ; 
the different interlacing of their fleshy surface allows them 
to act almost always in three or four different directions 
upon the substances they contain. We can say nothing MUSCULAR SYSTEM 
52 
general upon those motions which compose the diastole 
of the heart, the peristaltic motion of the alimentary canal, 
the contraction of the bladder, &c. Each muscle has its 
mechanism which belongs to the physiological history of 
the function to which it contributes. 
VI. Phenomena of the Relaxation of the Organic 
Muscles. 
In the relaxation of the organic muscles, phenomena in 
general take place that are opposite to the preceding. It 
is then useless to enumerate them ; but there is a question 
here that should he examined, that of knowing the nature 
of that state which succeeds contraction and alternates 
with it. 
In the muscles of animal life, when the contraction 
ceases, the muscle does not in general go back itself to 
the state it was in antecedent to the contraction, but it is 
drawn back to it by its antagonist; for example, when 
the biceps is contracted to bend the fore-arm and its con- 
traction ceases, it becomes passive; the triceps putting 
itself then in motion, extends it and draws it back to its 
natural position, by acting at first on the bones which 
communicate the motion to this muscle. Each muscular 
power of animal life finds then in that which is opposed 
to it a cause of return to the state it had left in order to 
contract. It is not so in organic life ; its muscles, which 
are all hollow, have no antagonists. We have considered 
as such to a certain extent, the substances contained in 
the hollow muscles, substances which oppose the effect of 
contraction ; but incapable most commonly of reacting 
after having been compressed, on account of their want 
of elasticity, these substances cannot perform the same 
offices as real antagonists. 
Most physiologists have admitted as a cause of dilata- 
tion, the entrance of new substances, which replace, in 
the muscular cavities, those expelled by contraction ; thus OF ORGANIC LIFE. 
53 
the entrance of new blood into the heart, aliments into 
the different portions of the alimentary canal, has been 
considered as proper to dilate these organs ; so that ac- 
cording to this opinion the muscles would be purely 
passive when they enlarged. But the following consider 
ations, many of which some authors, Grimaud in particu- 
lar, have already stated, do not permit us to consider in 
this way the dilatation of the organic muscles, that of the 
heart in particular. 
1st. When we lay bare a hollow muscle, the heart, the 
stomach, or the intestines, and empty it entirely of the sub- 
stances that it contains, it contracts and dilates alternately 
as when it is full, if we apply an external stimulant to it. 
2d. If we empty by punctures all the great vessels which 
go to the heart, or come from it, so as to evacuate it en- 
tirely, its alternate dilatations and contractions continue 
for some time. 3d. In order to judge comparatively of 
the degree of force of the contraction and the dilatation, 
we can extract two hearts nearly equal in size from two 
living animals ; place immediately the fingers of one hand 
into the auricles or the ventricles of the first, and grasp 
with the other hand the exterior of the second; you will 
feel that one makes as great an effort in dilating as the other 
does in contracting. This fact already observed by Pech- 
lin, is so much the more remarkable, as the effort of dila- 
tation is often greater than that of contraction. I have 
even observed, in repeating this experiment, that what- 
ever effort we make with the hand, we cannot prevent 
the organ from dilating. 4th. The alternate extension and 
contraction, from which arises the vermicular motion of 
the intestines, is seen during hunger when we open the 
abdomen of an animal. 5th. The hardness of the or- 
ganic muscular texture is as evident during dilatation as 
during vacuity. 6th. I have many times observed that 
at the instant in which I irritated the heart with the point 
of a scalpel, that a dilatation was the first consequence o MUSCULAR SYSTEM 
54 
it, and that contraction was only consequent to it. It 
happens in general more often that contraction begins the 
motions in our experiments ; but certainly, the muscle 
being at rest, it is frequently a dilatation that first mani- 
fests itself. 
It appears then very probable that the dilatation of the 
organic muscles is a phenomenon as vital as their con- 
traction ; that these two states are united in a necessary 
manner; that both of them compose muscular motion, of 
which contraction is but one part. Who knows even if 
each may not be disturbed separately,'if to a regular con- 
traction may not succeed an irregular dilatation and vice 
versa ? Who knows if certain alterations in the pulse do 
not belong to injuries of dilatation and others to those of 
contraction ? I am far from being certain; for in medi- 
cine we must rest our belief on certainty and not on pre- 
sumption ; but we can make this point an object of re- 
search. 
It appears that sometimes the voluntary muscles are 
also the seat of a true active dilatation. 1st. A muscle, 
laid bare and extracted from the body, contracts and after- 
wards dilates, without being drawn to this state of dilata- 
tion by any cause. 2d. In an amputation, we often see 
in the stump the end of the divided fibres alternately 
lengthen and contract; a double motion both of which 
appears to be equally vital. 3d. In many kinds of con- 
vulsions in which the extremities stiffen, in those, for ex- 
ample, which accompany most hysterical fits, it appears 
that there is a very evident active dilatation ; by placing 
in fact the hand upon the muscles which should then be 
relaxed, from the disposition of the parts, we perceive a 
hardness as great as in feeling of the contracted muscles. 
There are many researches to be made upon this mode 
of dilatation of our parts, a mode which undoubtedly is 
not exclusively confined to the muscular system, but 
which appears to belong also to the iris, to the spongy OF ORGANIC LIFE. 
55 
texture of the corpora cavernosa, to the nipples, &e. All 
these organs move by dilating very evidently; contrac- 
tion succeeds in them expansion, as in the common mus- 
cles relaxation does contraction. Expansion is the prin- 
cipal phenomenon. Perhaps also, as some modern authors 
have thought, the sudden swellings of the cellular texture, 
which accompany contusions, bruises, &c. are the result 
of this mode of motion. 
ARTICLE FIFTH. 
DEVELOPMENT OF THE MUSCULAR SYSTEM OF ORGANIC 
LIFE. 
The organic muscular system is wholly the reverse of 
the preceding, as it respects development. This is but 
slightly characterized in the early ages, whereas th& 
growth of the other is precocious. Let us follow it in 
all the ages. 
I. State of the Organic Muscular System in the 
Foetus. 
In the first days after conception, the heart is formed; 
it is the first point of motion, a punctum saliens, as it has 
been called. The researches of different authors, of Haller 
in particular, have rendered clear the successive progress 
of its increase in the early periods. Rather late in their 
formation, the muscles of the interior of the abdomen are 
yet developed before those that form the parietes of this 56 
MUSCULAR SYSTEM 
cavity. It is the size of the intestines, the stomach, the 
bladder, &c. almost as much as that of the liver, which 
gives to the cavity in which these viscera are found, the 
remarkable capacity that it then exhibits. 
Nearly uniform at this age, as it respects the propor- 
tion of their size, all the organic muscles are not as much 
so in regard to that of their texture. The heart is 
evidently firmer and more dense than all the others; its 
texture is very distinct. The fibres of the stomach, intes- 
tines and bladder are soft and loose and resemble exactly 
those of the muscles of animal life; but little blood goes 
to them in proportion to what they are afterwards to re- 
ceive. The fibres of the heart, on the contrary, dense 
and compact, have a power of action in proportion to 
what they are afterwards to have. Their redness is as 
distinct; as much blood penetrates and consequently 
nourishes them. This redness of the heart, analogous in 
the adult to that of the voluntary muscles, forms at this 
period a contrast with the remarkable paleness of these 
muscles. Besides it has, as in all the other parts where 
it exists, a deep tinge, owing to the kind of blood that 
produces it. 
We easily see the reason of the quantity of blood that 
penetrates the heart, as this organ then very active in its 
motions, has need of much force, whilst the others, almost 
immoveable, require but little. 
Yet the sensible organic contractility of the heart in the 
foetus and in the first age has been exaggerated, undoubt- 
edly on account of the extreme rapidity that the circula- 
tion then exhibits. This rapidity depends as much on 
the activity of the tonic forces of the general capillary 
system, as on that of the heart; for the blood, when it 
has arrived in the capillary system, is wholly beyond the 
influence of the heart, as we have seen ; the stay that it 
makes there is wholly dependant upon the forces of the 
system itself; now these forces, at that time very active, OF ORGANIC LIFE. 
57 
accelerate the course of the blood, and send it into the 
venous system, from which it goes to the heart. If the 
excitability of this were double and even treble, and the 
blood entered it but slowly, it would be unable to support 
a rapid and at the same time continuous pulse. Haller 
was drawn to this opinion by believing that the heart 
was the only agent of impulse of the blood circulating 
even in the small vessels. Besides, there is no doubt 
that the sensible organic contractility of the heart is less 
easily put into action by experiments in the foetus, and 
that it is also much less durable. Then the strongest 
stimuli have less effect upon it an instant after death, than 
those of less power exhibit upon the heart of an animal 
that has been born. I have many times established this 
fact upon foetuses of guinea-pigs. Compared with that of 
the voluntary muscles, the mobility of the heart is un- 
doubtedly remarkable in the foetus ; but compared to what 
it will be after birth, it is but slight. / 
It is precisely the same with the contractility of the 
stomach, the bladder and the intestines ; most commonly 
we can produce no motion in these muscles by stimuli. 
Mr. Leveille has already made these important observa- 
tions ; he has also remarked that the urine remained in 
the bladder, and the meconium in the great intestines, 
without producing a contraction sufficient to expel them. 
I do not think however that there could be during life a 
complete immobility of the gastric viscera, and for this rea- 
son ; most commonly the meconium is only met with in the 
great intestines; it must have been formed in them then, 
if there was complete immobility of the gastric muscles; 
now it is much more probable that it is the residuum of the 
bile, of all the mucous juices, &c.; that consequently it 
has been pushed successively by a slow action from the 
superior part towards the inferior of the alimentary canal. 
The softness of the organic muscles renders their exten- 
sibility of texture very great at this period. I would 58 
MUSCULAR SYSTEM 
observe however that the hearts of dead foetuses do not 
exhibit those numberless varieties of size which those of 
adults do in the right side, according to the different 
kinds of death. 
II. State of the Organic Muscular System during 
Growth. 
The first days of existence are marked by an internal 
motion as quick in manifesting itself as the external of 
which we have spoken. The sucking of the milk, the 
evacuation of the urine and meconium, &c. are indices of 
this general internal motion, of this agitation almost sud- 
den of all the involuntary muscles. 
It is not the brain which, entering into action at birth, 
produces the contraction of these muscles, since as we 
have said they are not under its government; it appears 
to depend, 1st, on the sympathetic influence exerted 
upon their system, by the cutaneous organ, which is irri- 
tated by the new medium; 2d, on the excitement made 
upon the beginning of all the mucous surfaces, and upon 
the whole of that of the lungs, an excitement which af- 
terwards reacts upon these muscles ; 3d, on that produced 
by fluids introduced into the stomach ; 4th, on the sud- 
den entrance of the red blood into all these muscles, till 
then penetrated like the others with black; this cause is 
essential; irritability appears to be in part dependant on 
it, or at least to borrow from it a remarkable increase of 
force ; 5th, the excretion of the meconium and the urine 
is also powerfully assisted by the abdominal muscles, 
which then enter into activity with the whole system to 
which they belong. 
The general internal motion which takes place in the 
first moments of existence, and which is produced by the 
suddenly increased activity of the involuntary muscles, 
has an important use with respect to the mucous surfaces, 
which it relieves of the fluids that load them, and whose OF ORGANIC LIFE. 
59 
presence becomes painful. Where the mucous surfaces 
have not around them fleshy layers of the involuntary 
muscles, as in the bronchia, the nasal fossae, &c. the mus- 
cles of animal life more or less distant, perform this func- 
tion, as for example, the diaphragm and the intercostals, 
free the bronchial surface by coughing, and the pituitary 
by sneezing. 
As we recede from the period of birth, the organic 
muscles grow in general much less in proportion than 
the others ; it is this that gradually re-establishes the equi- 
librium between the two systems. I would remark how- 
ever, as it respects the predominance of the first, that it 
is much less conspicuous in the foetus than that of the 
nervous system. The brain, for example, is in propor- 
tion much larger than the heart. 
It is probable that the muscles of which we are treat- 
ing, exhibit, at this period, the same varieties of composi- 
tion as the others, that gelatine especially predominates in 
them, that they have less fibrin, &c. This last substance 
perhaps exists, in the early periods, more abundantly in 
the heart than in the other muscles of this class. 
We have observed two very distinct periods in the 
growth of the other muscles; one is finished when they 
have acquired their length ; the other, when their thick- 
ness is complete. The first has not, in the organic sys- 
tem, a term as distinct; when the stature no longer in- 
creases, the gastric and urinary organs, and the heart still 
lengthen and grow. 
We have considered growth in too general a manner. 
Each system has a different term in this great phenome- 
non. The osseous and muscular systems of animal life, 
and those which depend on them, as the fibrous, the car- 
tilaginous, &c. have especially an influence upon the gen- 
eral stature of the body ; it is these which produce this 
or that height; but this height has no influence upon the 
length of the intestines, or the capacity of the stomach. 60 
MUSCULAR SYSTEM 
the heart, the bladder, &c. The glandular, serous, mucous 
systems, &c. are equally independent of stature ; thus in 
these numerous varieties, it has much more influence 
upon the extremities, than upon the abdomen, the tho- 
rax, &c. A great height indicates the predominance of 
the apparatus of locomotion, but not of those of diges- 
on, respiration, &c. The termination of the growth in 
height, which we consider in a general manner for the 
whole body, is only the termination of the growth of the 
muscles, the bones and their dependancies, and not of 
that of the internal viscera, which still lengthen and be- 
come thicker. It is easy to be convinced of this, by 
comparing the organic muscles of a young man of eighteen 
years, with those of a man of thirty or forty. 
The organic muscles do not appear to be subject to 
those irregularities of growth which the other muscles 
and the bones frequently exhibit. We know that the 
stature often remains stationary for many years, and that 
suddenly it acquires very great dimensions in a very short 
time ; this phenomenon is remarkable especially after long 
diseases. Now notwithstanding these inequalities, the 
heart and all the other analogous muscles grow in an uni- 
form manner; the regularity of the internal functions to 
which these muscles especially contribute, could not 
adapt itself to those aberrations which would be unable to 
disturb the functions of the locomotive organs. Besides, 
if they took place, the circulation, digestion, excretion of 
urine, &c. would exhibit corresponding aberrations; now 
this is never observed. The heart and the gastric mus- 
cles, &c. always grow in an infant whose stature remains 
stationary ; they do not grow suddenly in one who grows 
at once; hence why the thorax and the abdomen become 
large in the first case, and remain contracted in the second 
in proportion to the extremities. 
Besides these two systems are never in precise relation 
of nutrition and power. I have already observed that OF ORGANIC LIFE. 
61 
very large organic muscles often exist with very small 
voluntary ones, and vice versa. 
Let us consider neither the growth nor nutrition in an 
uniform manner ; each system is developed and increases 
in its own way ; all are never found at the same periods of 
this function. Why ? because nutrition, like all the other 
acts over which life presides, is essentially dependant on 
the vital forces, and these forces vary in each system. 
The growth of the involuntary muscular system is not 
uniform in all the organs which compose it. Each in- 
creases more or less, or is differently developed ; one often 
predominates over the others in an evident manner; a 
bladder with strong, fleshy fibres, with columns as they 
are called, is often found in a subject with a debilitated 
stomach, with small intestines, &c. ; reciprocally, the 
stomach, the heart, &c. have often an insulated predomi- 
nance. 
III. State of the Organic Muscular System after 
Growth. 
It is from the twenty-fourth to the twenty-sixth year, 
that the organic muscles are completely developed. Then 
the thorax and the abdomen which contain them have 
their greatest capacity. These muscles are then as they 
are to remain through life ; they have a density much 
greater than in youth ; their power is increased and their 
colour is deeper. In general this is subject in the heart 
to frequent varieties, which coincide very nearly with 
the varieties of the preceding system. Acute and chronic 
diseases have nearly the same influence upon it. It is 
equally the index of the sanguineous, lymphatic temper- 
aments, &c. by the different tinge it assumes. The colour 
of the gastric, intestinal and vesical fibres varies less ; 
their whiteness, more uniform, is rarely influenced by 
diseases. 62 
MUSCULAR SYSTEM 
We cannot increase, by constant exercise, the nutrition 
of the organic muscles. Aliments taken beyond measure, 
making the stomach frequently contract, weaken it instead 
of developing its fibres more, as happens from constant 
exercise given to a superior or inferior extremity. The 
bladder incessantly in action in some cases of inconti- 
nence, is thus gradually weakened and loses its energy. 
We might say that these two systems were in this respect 
in an inverse order. 
It appears that the nutrition of the organic muscles, 
like that of the others, is subject to frequent variations ; 
that at some periods they are more developed and less so 
at others. Diseases have a great influence upon this phe- 
nomenon, which proves, like the softening of the bones 
and their return to the natural state, the constant compo- 
sition and decomposition of which these organs are the 
seat. We find in the dissecting rooms many differences 
in different subjects, as it respects the colour, density and 
cohesion of the muscles. Now what many exhibit then 
at once, the same individual often experiences succes- 
sively ; the same man no doubt has, according to the dif- 
ferent influences to which he is exposed, his heart red, 
dense, large and well nourished at one period of life, and 
feeble, pale and small at another; for the internal organs 
experience the same alterations as the exterior. Now we 
know that the external appearance often changes during 
life. 
IV. State of the Organic Muscular System in Old 
Jige. 
As we advance in age, the muscular system of which 
we are treating becomes weak like all the others ; yet its 
action is more durable ; it survives, if we may so say, 
that of the other. When the old man, almost immove- 
able, crawls about but slowly and with pain, his pulse, 
digestion, &c. have vigour still. This difference of the OF ORGANIC LIFE. 
63 
two systems is so much the more remarkable, as the time 
of activity of the second is almost by half less than that 
of the first; sleep cuts off in fact almost half of the du- 
ration of the voluntary motions, whilst it leaves the in- 
voluntary wholly untouched. This phenomenon of the 
organic muscles as it wrere surviving the voluntary in the 
last periods of life, is derived on a great scale from the 
same principle from which arises on a small one the lassi- 
tude which follows the contraction in an insulated motion. 
A less durable motion is necessary to fatigue the volun 
tary muscles, than to fatigue the involuntary ; the stomach 
empty remains for a long time contracted upon itself with- 
out producing any painful sensation, whilst if we hold a 
body strongly grasped between our fingers for a quarter 
of an hour, all the flexors are soon painfully affected. 
After a convulsion of half an hour, in which all the loco- 
motive muscles have been stiff, the whole body is broken, 
as it is called ; it cannot admit of any motion ; whilst 
after a paroxysm of fever of six or eight hours in which 
the pulse has been violently agitated, the heart often pre- 
serves the natural type of its contractions; it requires 
repeated paroxysms to weaken it. All these phenomena 
of the two muscular systems evidently prove that that of 
animal life is fatigued much the soonest; it is this which 
occasions its intermission. Is it then astonishing that, 
although less often in exercise than the other, it exhausts 
sooner the quantum of force nature has given to it ? is it 
astonishing that the other survives the longest ? Life is 
a great exercise which gradually wears up the organs in 
motion, and which requires their rest; this rest is death ; 
now each moveable organ arrives at it sooner or later, 
according to the different degree of the forces wThich it 
has to expend, and according to its greater or less dispo- 
sition to be wearied by this great exercise. 
Yet the organic muscles are gradually weakened. The 
pulse becomes slower, digestion is longer in old age; the 64 
MUSCULAR SYSTEM 
bladder and rectum first cease to act; then the intestines 
remain inactive ; the stomach and especially the heart die 
the last. 
A long time before death, the muscular cohesion is 
weakened in this system as in the preceding; the fleshy 
texture becomes flaccid ; the parietes of the heart support 
themselves in youth ; they flatten in old age. The gas- 
tric system of a young animal suddenly killed during 
hunger is firm, dense and contracted upon itself; in an 
old one, under the same circumstance, it is but little 
contracted; the stomach and intestines remain much more 
dilated; they are loose and soft; it is the same phenome- 
non as in the preceding muscles, which vacillate under 
the skin, from want of cohesion. The bladder remains 
constantly large, though empty. MUCOUS SYSTEM. 
THIS system, the name of which I borrow from the 
fluid that constantly lubricates it, and which is furnished 
by small glands inherent in its structure, appears every- 
where in a membranous form ; that of fasciculi is wholly 
foreign to it. In speaking of the mucous organs we shall 
designate them almost always under the name of mem- 
branes. Their study is a new object of research. Pinel 
has been among the first, who has perceived the necessity 
of considering them in a general manner as it respects 
diseases. I believe that I am the first who has regarded 
them generally in an anatomical and physiological view. 
Few systems deserve more attention ; upon it take place 
all the great phenomena of digestion, respiration, secretion, 
excretion, &c. ; it is the seat of many diseases. It should 
alone, in a nosography in which diseases are distributed 
by systems, occupy a place equal to that of many. 
ARTICLE FIRST. 
OP THE DIVISIONS AND FORMS OP THE MUCOUS SYSTEM. 
The mucous membranes occupy the interior of the 
cavities which communicate with the skin by the different 
openings this covering has on the surface of the body. 66 
MUCOUS SYSTEM. 
Their number at first view is very considerable; for the 
organs in which they are reflected are very numerous. 
The mouth, the stomach, the intestines, the oesophagus, 
the bladder, the urethra, the womb, the ureters, all the 
excretories, &c. &c. derive from these membranes a part 
of their structure. Yet if we consider that wherever they 
are continuous, wherever we see them originate, by ex- 
tending from each other, as they originated in the first 
instance from the skin, we shall perceive that this number 
must be wonderfully limited. In fact by thus describing 
them, not separately in each part, but at the same time in 
all those upon which they are continued, we see that they 
are reduced to two general surfaces, of which all the 
others are portions, and which, on account of the differ- 
ent parts to which they are distributed, can be called, the 
one gastro-pulmonary, the other genito-urinary. The 
first is found in the head, the neck and the abdomen. 
This last cavity and more especially the pelvis, contain the 
second. 
There is also a small insulated mucous surface ; it is that 
which enters by the openings of the nipples and lines the 
lactiferous tubes. But it is so small that it deserves but 
little attention ; besides, what will be said of the two 
others will be equally applicable to it. It is then useless 
to examine it in a general manner. 
I. Of the two General Mucous Membranes, the Gas- 
tro-Pulmonary and the Genito- Urinary. 
The gastro-pulmonary surface penetrates into the in- 
terior by the mouth, the nose and the anterior face of the 
eye. 1st. It lines the first and second of these cavities, 
extends from the first to the excretory ducts of the parotid 
and sub-maxillary glands, from the other into all the 
sinuses, forms the conjunctiva, dips down into the puncta 
lachrymalia, the nasal duct, the sac of the same name, 
and is continued into the nose ; 2d, it descends into the MUCOUS SYSTEM. 
67 
pharynx, furnishes an elongation to the Eustachian tube, 
then penetrates the internal ear and lines it, as we shall 
see ; 3d, it dips down into the trachea and is spread upon 
all the air-tubes; 4th, it penetrates into the oesophagus 
and the stomach ; 5th, it extends to the duodenum where 
it furnishes two elongations, one destined to the ductus 
choledochus, to the numerous branches of the hepatic and 
cystic ducts and the gall-bladder, the other to the pancre- 
atic duct and its different branches ; 6th, it is continued 
into the small and large intestines and finally terminates 
at the anus where we see it identified with the skin. 
The second general mucous membrane, which we have 
called the genito-urinary, enters in man by the urethra, 
and thence is spread on the one hand upon the bladder, 
the ureters, the pelvis of the kidnies, the infundibula, the 
papillae and the capillary tubes which open on their sum- 
mit ; on the other hand it goes into the excretory tubes of 
the prostate, into the seminal ducts, the vesiculaj semi- 
nales, the vasa deferentia and the branches with number- 
less windings that produce them. 
In woman, this membrane is introduced by the os ex- 
ternum and penetrating on the one hand by the urethra, 
goes as in man upon the urinary organs ; on the other hand, 
we see it enter the vagina, lining it, the uterus and the 
fallopian tubes, and afterwards becoming continuous with 
the peritoneum by the opening of these tubes. It is the 
only example in the economy, of a communication estab- 
lished between the mucous and serous surfaces. 
This manner of describing the course of the mucoufc 
surfaces, by saying that they are elongated, dip down, 
penetrate, &c. from one cavity to another, is no doubt 
not conformable to the progress of nature, which creates 
in each organ the membranes belonging to this organ, and 
does not thus extend them by degrees; but our manner 
Of understanding it is better adapted to this language, 
the meaning of which the least reflection will show. 68 
MUCOUS SYSTEM. 
In thus referring to two general membranes all the 
mucous surfaces, I am not only supported by anatomical 
inspection, but pathological observation has also furnished 
me with points of demarcation between the two, and 
points of contact between the different portions of mem- 
branes of which each is the assemblage. In the different 
descriptions of catarrhal epidemics given by authors, we 
frequently see one of these membranes affected in all 
parts, the other remaining sound ; it is especially not rare 
to observe a general affection of the first, of that which 
extends from the mouth, the nose, the surface of the eye, 
into the alimentary canal and the bronchial vessels. The 
last epidemic observed at Paris, with which Pinal himself 
was affected, was of this character; that of 1761, described 
by Razou, had it also; that of 1752, described in the me- 
moirs of the Society of Edinburgh was remarkable for a 
similar phenomenon; now, we do not see at that time a 
corresponding affection in the mucous membrane that is 
spread upon the urinary organs and upon those of genera- 
tion. There is then here, 1st, an analogy between the 
portions of the first, by the uniformity of affection ; 2d, 
a demarcation between the two by the health of the one 
and the disease of the other. 
We see also that the irritation of any one point of one 
of these membranes, frequently produces a pain in another 
point of the same membrane, which is not irritated. 
Thus a calculus in the bladder occasions a pain at the end 
of the glans penis, the presence of worms in the intes- 
tines causes an itching of the nose, &c. &c. Now, in 
these phenomena purely sympathetic, it is very rare that 
the partial irritation of one of these two membranes 
affects with pain one of the parts of the other ; there are 
however examples of it; such is the singular relation 
that exists, in mucous hemorrhages, between the mem- 
brane of the womb and that of the bronchia. If the 
blood ceases accidentally to flow from one during menstru- MUCOUS SYSTEM. 
69 
ation, the other frequently exhales it and thus as it were 
supplies its functions. 
We ought then, from inspection and observation, to 
consider the mucous surface, in general, as formed by two 
great membranes successively spread upon many organs, 
having between them no communication except by the 
skin, which serves them as an intermediate organ, and 
which, continuing with both, contributes thus with them 
to form a general membrane everywhere continuous, 
covering the animal externally, and extending within 
upon most of its essential parts. We can conceive that 
there should exist important relations between the inter- 
nal and external portion of this single membrane ; and 
that they do will be proved by further researches. 
II. Adhering Surface of the Mucous Membranes. 
Every mucous membrane exhibits two surfaces, one 
adhering to the neighbouring organs, the other free, 
covered with villi, always moistened with a mucous fluid. 
Each deserves particular attention. 
The adhering surface corresponds almost everywhere 
with the muscles, either of animal or organic life. The 
mouth, the pharynx, the whole alimentary canal, the 
bladder, the vagina, the womb, a portion of the urethra, 
&c. exhibit a muscular layer embracing on the outside 
their mucous tunic which is within. This arrangement 
coincides perfectly, in animals with a fleshy membrane, 
with that of the skin, which moreover approximates very 
near, as we shall see, the structure of the mucous mem- 
branes, and which, as we have seen, is everywhere con- 
tinuous with them. This arrangement of the mucous 
membranes occasions them to be agitated by constant 
motions which favour wonderfully the secretion that 
takes place in them, the excretion which succeeds it, and 
the various other functions of which they are the seat. The 70 
MUCOUS SYSTEM. 
insertion of this muscular layer exterior to the mucous 
system, is made, as we have seen, by this dense and com- 
pact texture which I have called the sub-mucous. It is 
from this texture, more compact than the rest of the cellu- 
lar system, that the mucous surface derives its force. It 
is from it that the organ which it lines receives its form ; 
it is this which supports and preserves this form ; the 
following experiment proves it. Take a portion of the 
intestine ; remove from any part of it this layer, as well 
as the serous and the muscular; then inflate it, after hav- 
ing tied it below ; the air produces in this place a hernia 
of the mucous coat. Try afterwards another portion of 
intestine ; deprive this, for a small space, of its mucous 
membrane and of this also; inflation will produce upon 
the serous and, muscular tunics the same phenomenon 
that it did in the preceding on the mucous ; then it is to 
this sub-mucous cellular layer that it owes the resistance 
with which it opposes substances that it contains. The 
same may be said of the stomach, the bladder, the oeso- 
phagus, &c. 
III. Free Surface of the Mucous Membranes. 
The free surface of the mucous membranes, that which 
is continually moistened by the fluid from which they 
borrow their name, exhibits three species of wrinkles or 
folds. 
1st. One inherent in the structure of all the laminae of 
these membranes, is constantly met with, whatever may 
be their state of dilatation or contraction ; such are those 
of the pylorus and the valve of Bauhin. These folds are 
formed not only by the mucous membrane, but also by 
the intermediate tunic of which we have spoken, which 
here has a remarkable density and thickness, and gives 
them solidity. The fleshy tunic enters even into their 
composition, and we see on the exterior, upon the serous 
surface, a depression that indicates their presence. MUCOUS SYSTEM. 
71 
2d. Other folds, only formed by the mucous surface, exist 
also always in a state of vacuity or fulness, less evident 
however than this; they are owing to the circumstance 
that the mucous surface is much more extensive than those 
upon which it is applied, so that it is folded that it may 
not run a longer course ; such are the valvulse conniventes 
of the small intestines, the structure of which we see very 
well by cutting longitudinally one of these intestines. 
The edge of the section exhibits the fleshy layer and the 
serous surface in a straight direction, whilst the mucous 
layer describes a line resembling a loose thread. 
3d. The last species of folds is as it were accidental, 
and is only observed during the contraction of the organ 
which is lined by the mucous surface that is the seat of 
it; such are those of the interior of the stomach, the 
great intestines, &c. In the greatest number of subjects 
brought to the dissecting rooms, these folds of which so 
much has been said as it respects the stomach, cannot be 
perceived in it, because the subject has died after a dis- 
ease that has so altered the vital forces, as to prevent all 
action of this viscus ; so that though it is frequently found 
empty, its fibres are not contracted. In experiments 
upon living animals, on the contrary, these folds become 
very evident, and may be demonstrated in this way ; 
make a dog eat or drink copiously, open him an instant 
after and cut the stomach in the length of its great curva- 
ture ; no fold is then apparent; but soon the viscus con- 
tracts, its edges are turned over and the aliments escape ; 
the whole mucous surface is covered with an infinite 
number of very prominent ridges, which have as it were 
the form of cerebral circumvolutions. We obtain the 
same result by taking out the stomach of an animal 
recently killed, distending it with air and opening it 
afterwards, or by cutting it immediately in its state of 
vacuity and drawing it in opposite directions by its edges; 
it stretches, its ridges disappear, and if we cease to dis- 72 
MUCOUS SYSTEM. 
tend it, they form again immediately in an evident man- 
ner. I would observe on the subject of the inflation 
of the stomach, that by distending it with oxygen, we 
do not produce by the contact of this gas, greater ridges 
and consequently a stronger contraction, than by using 
for the same purpose carbonic acid gas. This experiment 
furnishes a result very similar to what I have observed in 
rendering animals emphysematous by different aeriform 
fluids. It follows from all that we have said upon the 
folds of the mucous membranes, that in the ordinary con- 
traction of the hollow organs which these membranes line 
they undergo but a very slight diminution of surface, that 
they contract scarcely at all, but fold within, so that by 
dissecting them on an organ in contraction we should 
have a surface almost equal in extent to that which they 
exhibit during its dilatation. This assertion, which is 
true as it respects the stomach, the oesophagus and the 
great intestines, is not perhaps as entirely so with regard 
to the bladder, the contraction of which makes the ridges 
within less evident; but they are not sufficient to destroy 
the general law. It is also nearly the same with the gall- 
bladder ; yet here we find another cause. The gall-bladder, 
alternately observed in hunger and during digestion, con- 
tains double the bile in the first case that it does in the 
second, as I have had occasion to see very often indeed, 
in experiments made for this object or with other views. 
Now, when the bladder is in part empty, it does not con- 
tract upon the bile that remains, with the force of the 
stomach when it contains but few aliments, or with the 
power of the bladder when it contains but little urine. It 
is then flaccid; so that its being distended or not has but 
a slight influence upon the folds of its mucous membrane. 
Besides, in saying that the mucous membranes always 
exhibit, with some slight difference, the same surface in 
the extension and contraction of their respective organs, 
I intend to speak only of the ordinary state of the func- MUCOUS SYSTEM. 
73 
tions, and not of those enormous dilatations of which we 
often see the stomach, the bladder, and more rarely the 
intestines become the seat. Then there is no doubt, a 
real extension and contraction, which coincide in the 
membrane with those of the or^an. 
A remarkable observation which the free surface of the 
mucous membranes exhibits, and which I have already 
pointed out, is, that this surface is everywhere in contact 
with bodies heterogenous to that of the animal, whether 
these bodies introduced from without to nourish it have 
not yet been assimilated to its substance, as we see in the 
alimentary canal and in the wind-pipe ; or whether they 
come from within, as we observe in all the excretory 
ducts of the gland'’, which all open into cavities lined by 
the mucous membranes, and transmit without particles 
which, after having contributed for some time to the com- 
position of the solids, become heterogeneous to them, 
and are separated from them by the constant motion of 
decomposition which takes place in living bodies. Idence 
we ought to regard the mucous membranes as limits, and 
barriers, which, placed between our organs and the bodies 
that are foreign to them, defend them from the mis- 
chievous impression of these bodies, and serve conse- 
quently within, the same functions which the skin per- 
forms without, with respect to the bodies which surround 
that of the animal, and which tend incessantly to act 
upon it. 
The organization of the mucous system and its vital 
properties are accommodated to this habitual contact of 
substances heterogeneous to the living economy. That 
which is a foreign body to the other systems, the cellular, 
the muscular, &c. is not so to this. Solid substances, the 
metals, stones, wood, &c. which introduced into our parts 
excite in them inevitably suppuration and an antecedent 
inflammation by their simple contact, pass with impunity 
over this, provided that their angles and asperities do not 74 
MUCOUS SYSTEM. 
tear it; they only augment a little the secretion, as I 
shall say. We can swallow a ball of lead, of wood, &c. and 
pass it by the anus without inconvenience. All the irri- 
tating fluids without being caustic, that we inject into the 
great intestines in enemas, or that we swallow, would 
produce abscesses, &c. if they were forced into the cellu- 
lar system, &c. Surgeons employ the term foreign bodies 
in too general a manner ; that which is so for one system, 
is not for another. Foreign is, in this respect, a term of 
comparison which we should employ only after a know- 
ledge of the peculiar sensibility of each system, and not 
after that of this property described in a vague manner. 
The mucous system not only bears without danger the 
presence of all bodies that are introduced into the eco- 
nomy, but also when it goes out, it can be exposed with 
impunity to the contact of external stimuli. Observe 
what takes place in prolapsus of the womb in which the 
whole membrane of the vagina sometimes becomes exter- 
nal, in those inversions of the intestinal tubes that take 
place through preternatural ani, in prolapsus of the rec- 
tum, &c.; then the mucous surfaces serve really as inte- 
guments ; now in these cases the surrounding bodies pro- 
duce hardly any more pain on them than upon the skin. 
On the contrary, the instant a serous surface is laid bare, 
as for example in the operation of hernia, in which 
the intestine is suffered to come out, on account of an 
opening unfortunately made by the point of a bistoury, 
this surface inevitably inflames. All the cellular, mus- 
cular, nervous, glandular systems, &c. laid bare, exhibit 
the same phenomenon. There is no danger in opening 
the bladder as it respects the contact of the air, whilst 
there is much in permitting this fluid to penetrate into an 
articular cavity, a tendinous groove, a serous sac, &c. 
We know how much in the high operation for the stone, 
wre fear to wound the peritoneum, how uncertain are the 
results of empyema on account of the contact of the air MUCOUS SYSTEM. 
75 
upon the pleura, &c. The dangers of the action of this 
fluid upon these surfaces have been perhaps exaggerated, 
but they are notwithstanding real. 
If a fistula extends from the exterior of the abdomen 
into the intestines, its whole course is lined with callous 
bodies ; these defend the cellular texture and the muscles 
through which the fistula passes. On the contrary, 
nothing similar appears upon the intestinal mucous sur- 
face, because its organization alone is sufficient to protect 
it. The urinary, salivary and lacrymal fluids never 
escape externally by artificial ducts formed in the neigh- 
bouring organs, without there are similar callous bodies 
in the course of these ducts ; on the contrary, they pass 
with impunity over the mucous surfaces. Make in a limb a 
long and straight opening with a pointed instrument, and 
fix in it for a time a sound ; a callous canal will be pro- 
duced by it. Let a sound on the contrary remain in the 
urethra, no alteration of texture will result from it. 
Let us conclude from these different considerations, 
that the mucous system with the cutaneous alone, is 
organized so as to support the contact of all external 
bodies, and not to be affected by their presence, or at 
least experience only an increase of secretion, which is in 
no ways dangerous. Thus these two systems form two 
boundaries, the one internal and the other external, be- 
tween which are placed the organs foreign, by their 
mode of sensibility and by that of their structure, to 
the external bodies. To these boundaries the excitement 
of these bodies is limited ; their influence does not go 
beyond. So long as they do not pass these boundaries, 
the other organs do not feel them. We might say that 
the acute sensibility which each of them enjoys, is a kind 
of sentinel that nature has placed on the confines of the 
organic domain of the mind, to inform it of whatever can 
injure it. 76 
MUCOUS SYSTEM. 
ARTICLE SECOND. 
ORGANIZATION OF THE MUCOUS SYSTEM. 
I. Texture Peculiar to this Organization. 
The mucous system presents two things to be consid- 
ered in its peculiar texture, viz. 1st, a layer more or less 
thick which constitutes principally this texture, and which 
by analogy with the cutaneous corion, may be called 
the mucous corion ; 2d, many small elongations which 
surmount it, and which are called villi or papillas. As to 
the epidermis which covers it, I shall treat of it with the 
cutaneous epidermis. This texture has nothing similar 
to the substance that colours the skin, and which is be- 
tween the papillae and epidermis. We know in fact that 
negroes, as well as whites, have this texture of a bright 
red, which it derives from its vessels. 
Mucous Corion. 
Tliis portion of the mucous texture, which is the most 
important, and which constitutes the thickness, form, and 
even the nature of it, has a soft and spongy appearance. 
We might say at first view that it was a consistent pulp, 
with which the extremely dense cellular texture that is 
subjacent to it had been covered. This softness is a 
character which distinguishes it from the cutaneous corion, 
which moreover has by its intimate nature but little re- 
semblance to it. 
The mucous corion is very various as to thickness; it 
differs in this respect in each organ. That of the gums 
and the palate is the thickest of all. Then come those of MUCOUS SYSTEM. 
77 
the nasal fossae and the stomach, then those of the small 
intestines and the gall-bladder, then those of the large 
intestines, of the urinary bladder, the urethra and the 
other excretories, until it. begins at length to become so 
fine as to appear transparent like a serous surface when it 
is removed with care. Finally, the finest and most deli- 
cate is that of the sinuses of the face and the interior of 
the ear; the arachnoides is often coarser. 
I have called the texture within the ear mucous, though 
all anatomists call the membrane of the cavities of this 
organ periosteum. In fact, 1st, we see it evidently'Con- 
tinued with the pituitary membrane, by means of the 
elongation of the Eustachian tube. 2d. We find it con- 
stantly moistened by a mucous fluid which this canal 
serves to convey out, a character foreign to the perios- 
teum, which, like the fibrous membranes, always adheres 
by both its surfaces. 3d. No fibre can be distinguished in 
it. 4th. Its fungous appearance, though white and soft, 
and the ease with which it is torn, are evident attributes 
of the mucous membranes. Every thing proves that the 
membrane of the tympanum, that of the meatus, &c. be- 
long to the system of which we are treating. Thus in 
catarrhs of the pituitary membrane, and of that of the 
fauces, wre most often find that the ear is affected ; thus 
the ear is, like the mucous surfaces, the seat of hemorr- 
hage, thus polypi arise in it, as in the nose and on the 
surface of the womb. We consider as a sign of deposi- 
tion of pus in the ear, every purulent discharge coming 
from that cavity. I3ut how can we conceive of a puru- 
lent collection in a part in which there is hardl}r any 
cellular texture, in a part wholly osseous ? Besides the 
fibrous system, to which the periosteum of the tympanum 
belongs, hardly ever suppurates, as we know. Every 
thing then induces us to believe that these discharges are 
only the effect of a catarrh of the ear, a catarrh which is 
sometimes acute and sometimes chronic. I have more- 78 
MUCOUS SYSTEM. 
over a recent and decisive fact upon this point; the body 
of a man subject to these discharges during life exhibited 
a remarkable thickness and redness of the membrane of 
the tympanum, but Avithout the least trace of erosion. 
The ear suppurates like the urethra, the vagina, &c. it is 
not a new fluid which is formed by suppuration ; it is 
that which naturally conies from the meatus which in- 
creases in quantity and comes through a preternatural 
opening of the membrane of the tympanum. 
Diseases make the thickness of all the mucous surfaces 
vary remarkably. I have seen them many lines thick in 
the maxillary sinus, and nearly half an inch in the blad- 
der. In great extensions of the mucous sacs, this thick- 
ness diminishes very much ; it increases in their contrac- 
tions. The stomach especially exhibits this phenomenon 
in these two opposite states. 
The softness of the mucous corion is also very variable ; 
in the nasal fossae, in the stomach and the intestines, it is 
really a kind of organized velvet. The name of villous 
membrane is perfectly suited to it. On the contrary, at the 
origins of the mucous system, as in the mouth, upon the 
glans penis, at the entrance of the nose, it is a more dense 
and compact texture, approximating nearer in its nature 
to the cutaneous corion. I am persuaded that like this it 
might be tanned and be useful in the arts if it were in 
larger pieces, whilst I doubt if the action of tanning 
could produce an analogous phenomenon upon the mu- 
cous texture of the deep-seated organs. The softness of 
this would render it incapable of serving for external in- 
teguments. The least cause would be in fact sufficient to 
break and tear it. Its structure being different from 
that of the cutaneous corion is the reason that the vario- 
lus pustules never appear on it, whilst we often see them 
on the mucous surfaces near the openings of the skin, 
especially upon the tongue, the palate and the internal 
surface of the cheeks. MUCOUS SYSTEM. 
79 
Exposed to the action of dry air, so that it may come 
everywhere in contact with it, it becomes dry and very 
thin, but preserves some resistance. In bladders inflated 
and dried, in the stomach, the intestines, &c. thus pre- 
pared, it is this texture which supports these organs, and 
which prevents them from becoming flat, though we per- 
mit the air to escape; it offers even a resistance, from 
which arises a kind of crepitation when we wish to bend 
them in various directions. To be convinced of this, it 
is only necessary to dry the mucous surface separate from 
the serous and muscular that correspond with it; these 
when dried remain pliable like the cellular texture, whilst 
the first has a kind of rigidity. 
In the organs in which the redness of the mucous tex- 
ture is slight, as in the bladder, the rectum, &c. it be- 
comes transparent by drying. Where it is very red as 
in the stomach, it takes a deep tinge, which becomes even 
almost black if there had been an antecedent inflamma- 
tion in it by which much blood had been accumulated ; 
hence it appears that this fluid is the cause of the colour. 
Thus dried the mucous surfaces are smooth ; they lose 
their viscidity at least in appearance ; their folds are 
effaced by adhering to the surface from which they arise; 
thus the valvulae conniventes are marked in a dried intes- 
tine, only by a red line, without any apparent promi- 
nence. Hut if we macerate the intestines in this state, 
the folds form again and become visible. 
Exposed to a moist air, or left with other flesh that will 
not allow it to become dry, the mucous corion putrefies 
with great ease; the odour that it then sends out is very 
fetid. I think the reason why the abdomen of dead bodies 
becomes putrid so soon is in part because it contains sub- 
stances already in putrefaction, and also because the sur- 
faces, in contact with these substances, and which by their 
vitality resisted before their action, then readily yield to 
them. If these substances were contiguous to aponeu- 80 
MUCOUS SYSTEM. 
roses, putrefaction would be much less rapid. The 
mucous system when putrid takes a greyish colour ; and 
as the dense, subjacent cellular texture putrefies much 
less easily, we can then remove from it by the least pres- 
sure, the mucous corion, reduced to a putrid pulp, iti 
which every trace of organization has disappeared, and 
which forms a real pap. 
During life, gangrene of the mucous texture takes place 
in general less frequently than that of the cutaneous. 
The consequences of catarrh, compared with those of 
erysipelas may convince us of this; there are however 
cases in which death appears in this texture, whilst the 
surrounding ones continue to live, as in gangrenous 
angina. 
Exposed to maceration, the mucous texture yields to it 
promptly. I think that next to the brain it is altered 
quickest by the action of water. It is then reduced to 
a reddish pulp very different from that from putrefaction 
in the open air. When we put the whole stomach to 
macerate, this pulp is detached, when the sub-mucous 
texture and the serous membrane have as yet undergone 
but little alteration. 
Ebullition at first extracts from the mucous texture a 
greenish scum, very different from that which the mus- 
cular and cellular textures give when boiled. This scum 
which mixed with the whole fluid in the beginning of 
the boiling, disturbs it and renders it green at first, after- 
wards rises upon the surface where it has small bubbles 
of air mixed with its substance; it often even falls to the 
bottom of the vessel by its weight. Sulphuric acid changes 
the colour of it to a dull brown. 
A short time before the water begins to boil, the mu- 
cous texture crisps and acquires the horny hardness like 
the others, but in a less degree however ; hence why it 
is then wrinkled almost always in different directions. In 
fact, the sub-mucous texture upon which it is applied. MUCOUS SYSTEM. 
81 
contracting at that time much more than it, it must fold 
on account of its length ; thus during life, when the 
fleshy coat of the stomach contracts, its mucous surface 
not contracting in proportion, produces the numerous 
folds of which we have spoken. The action of a concen- 
trated acid crisping the sub-mucous texture more than 
the mucous itself, produces an analogous phenomenon. 
After having been a long time dried, the mucous texture, 
like however almost all those of the animal economy, does 
not lose the faculty of acquiring the horny hardness when 
it is plunged into boiling water; it exhibits this pheno- 
menon, whether we expose it to it dry, or whether we do 
it after having first softened it in cold water. It is a 
means by which all the valvulae conniventes may be made 
suddenly to reappear, which had disappeared by drying, 
and which foim again the instant the intestine contracts. 
This experiment is very curious to witness. 
When the ebullition has been a long time continued, the 
mucous texture turns gradually to a very deep grey, from 
the white which it had first become. It is not softer than 
in the natural state, but it breaks much quicker; the fol- 
lowing experiment is a proof of it. If we draw the mu- 
cous corion, boiled for some time with the subjacent cel- 
lular texture, this last resists the most; so that it remains 
entire, whilst the mucous corion is broken in many places. 
This never assumes the gelatinous appearance of the cuta- 
neous corion or the fibrous and cartilaginous organs when 
boiled and of the others which yield much gelatine. 
However by mixing a solution of tannin with the water 
in which this system taken from an adult has been boiled, 
I have seen an evident precipitate. 
The action of the acids reduces to a pulp the mucous 
texture much sooner than most of the others. During 
life, all the caustics act much more rapidly upon it than 
upon the cutaneous, of which the thick epidermis is an 
intermediate organ which checks their tendency of com- 82 
MUCOUS SYSTEM. 
bining with its corion. Thus the instant the nitric acid, 
a substance which common people almost always choose 
for their poison, as the practice at the Hotel Dieu proves, 
thus the instant I say, that the nitric acid is in contact 
with the alimentary canal, it disorganizes it, it forms 
there a whitish eschar, which, when death does not take 
place immediately, as most often happens, is slowly re- 
moved and detached in the form of a membrane. We 
know that the lips gently rubbed with weakened nitric 
acid, become the seat of a troublesome itching, whilst that 
oftentimes though this acid may have acted upon the skin 
sufficiently to make it yellow, it does not suffer from it. 
The softness of the mucous corion makes me presume 
that it is easily altered by the digestive juices, not that I 
confide in the experiments of Hunter, who pretended 
that these juices could act upon the coat that secretes 
them, but because in general I have observed that the 
textures like it yield very easily to the action of water 
in maceration and are also very easily digested. I have 
not however any experiment upon the subject, and we 
know that in the animal economy analogy is not always 
a faithful guide. 
All the mucous surfaces, but especially that of the 
stomach and intestines, have the property of curdling 
milk, as have many other substances, especially the acids. 
Is it to this property that must be attributed a phenome- 
non which is constant during life, viz. the coagulation of 
milk that enters the stomach for digestion ? or is this 
phenomenon owing to the mixture of this fluid with 
those which are secreted by the surface of this organ ? I 
think that both these causes contribute to it at the same 
time both separate produce in fact this phenomenon. 
Spallanzani has proved it as it respects the gastric juices. 
Every body knows that the mucous membrane dried, and 
consequently deprived of these juices, preserves the pro- 
perty of coagulating milk. Spallanzani has convinced MUCOUS SYSTEM. 
83 
himself that the serous and organic muscular systems of 
the stomach are destitute of it. 
Are aphthae an affection of the mucous corion ? do they 
belong to the papillae ? are they seated in the glands ? are 
they a separate inflammation of these glands, whilst ca- 
tarrhs are characterized by a general inflammation of a con- 
siderable extent of the mucous system ? All these ques- 
tions deserve to be examined. Pinel has perceived the 
void there is in morbid anatomy upon this point. 
Mucous Papillse. 
The peculiar kind of sensibility which the skin enjoys 
is attributed principally, as we know, to what is called 
the papillary body, which commonly is not easy to be 
demonstrated. The sensibility of the mucous membranes, 
somewhat analogous to that of the skin, appears to me to 
have the same kind of organization, which is perceived 
with infinitely less ease. The papillae of this system can- 
not be called in question at its origin, where it dips into 
the cavities, in the commencement even of these cavities, 
as upon the tongue, the palate, the internal part of the 
alae of the nose, upon the glans penis, in the fossa navi- 
cularis, within the lips, &c. Inspection is sufficient to 
demonstrate them there. But it is asked if the papillae 
exist also in the deep-seated parts of this system. Analogy 
indicates it, since the sensibility is as great there as at 
their origin, though with varieties that we shall point 
out; but inspection proves it in a manner not less cer- 
tain. I think that the villi with which we everywhere 
see them covered are nothing but these papillae. 
Very different ideas have been entertained of the nature 
of these villi; they have been considered in the stomach 
and the oesophagus as destined to the exhalation of the 
gastric juice, in the intestines as serving for the absorp- 
tion of chyle, &c. But, 1st, it is difficult to conceive 
how an organ everywhere nearly similar, can perform in 84 
MUCOUS SYSTEM. 
different parts functions so different; I say nearly similar, 
for we shall see that these papillae exhibit differences of 
length, size, &c. without having any of texture or struc- 
ture. 2d. What can be the functions of the villi of the 
pituitary membrane, of the internal coat of the urethra, 
the bladder, &c. if they have not relation to the sensi- 
bility of these membranes ?• 3d. The microscopical experi- 
ments of Leiberkuhn upon the vesicle of the intestinal 
villi have been contradicted by those of Hunter, of Cruik- 
shank and especially of Hewson. I am certain that I 
have never seen any thing similar on the surface of the 
small intestines, at the time of chylous absorption ; and 
yet it would appear that a thing of inspection could not 
vary. 4th. It is true that these intestinal villi are every- 
where accompanied by a vascular net-work, which gives 
them a red colour very different from the colour of the 
cutaneous papillae; but the non-appearance of the cuta- 
neous net-work is owing to the pressure of the atmos- 
pheric air, and especially to the contraction which it occa- 
sions in the small vessels. Observe in fact the foetus as 
it comes from the womb of its mother ; its skin is as red 
as the mucous membranes, and if its papillae were a little 
longer, it would resemble almost exactly the internal sur- 
face of the intestines. Who does not know moreover, 
that the vascular net-work surrounding the cutaneous pa- 
pillae, is rendered evident by fine injections, so as to change 
their colour entirely ? 
That/in the stomach this vascular net-work continuous 
with the exhalants furnishes the gastric juice, and that 
in the intestines it intermixes with the origin of the ab- 
sorbents, so that these embrace the villi, we cannot doubt 
after the experiments and observations of anatomists who 
have recently engaged themselves in investigating the 
lymphatic system. But this does not prevent the base of 
these villi from being nervous, and them from perform- 
ing upon the mucous membranes the same functions that MUCOUS SYSTEM. 
85 
the papillae do upon the cutaneous organ. This manner 
of regarding them by explaining their existence generally 
observed upon all the mucous surfaces, appears to me to 
be much more conformable to the plan of nature, than to 
suppose them in each place with different and often oppo- 
site functions. 
Besides it is difficult to decide the question by ocular 
observation. The delicacy of these elongations conceals 
their structure, even from our microscopical instruments, 
agents from which anatomy and physiology do not ap- 
pear to me to have derived much assistance, because 
when we see obscurely, each sees in his own way and 
according to his own wishes. It is then the observation 
of vital properties that should especially guide us; now, 
it is evident to judge by them, that the villi have the 
nature I have attributed to them. The following expe- 
riment served to demonstrate to me the influence of the 
papillary body upon the cutaneous sensibility ; it succeeds 
also upon the mucous membranes. Remove the epider- 
mis in any part and irritate the papillary body with a 
sharp stilet; the animal is agitated, cries out and gives 
marks of acute pain. Slide afterwards, through a small 
opening made in the skin, a pointed stilet into the sub- 
cutaneous cellular texture, and irritate the internal surface 
of the corion ; the animal remains quiet and makes no 
noise, unless some nervous filaments accidentally struck 
make him suffer. Hence it follows very evidently, that 
it is upon the external surface of the skin that its sensibi- 
lity resides, that the nerves pass through the corion with- 
out contributing to its texture, and that their expansion 
takes place on the papillary body. It is precisely so with 
the mucous surfaces. Observe that this circumstance 
coincides very well with the functions of the two sur- 
faces, which receive by their free portion the action of 
external bodies, to which they are foreign by their ad- 
hering portion. 86 
MUCOUS SYSTEM. 
The papillae exhibit very great varieties. On the 
tongue, in the small intestines, in the stomach and in the 
gall-bladder, they are remarkable for their length. The 
oesophagus, the large intestines, the bladder, all the excre- 
tory ducts have those'that are less evident; these last 
especially and the urethra in particular, are almost smooth 
in their whole mucous surface. We can scarcely distin- 
guish the papillae in the frontal, sphenoidal, maxillary 
sinuses, &c. 
These small nervous eminences are sufficiently distinct 
and separate upon the tongue. In the nasal fossae, the 
stomach and the intestines, they are so near together and 
at the same time so delicate, that the membrane has at 
first view an uniform and smooth apppearance, though it 
is covered with these elongations. Each papilla is sim- 
ple ; no bifurcation is ever observed at its extremity. 
All appear to have a pyramidal form, if we can judge at 
least by those which are the most evident. 
Are they susceptible of a species of erection ? It has 
been believed with regard to those of the tongue, which 
become erect, it is said, to perceive tastes, and with re- 
gard to those of the nose, which receive odours more 
efficaciously in this state of erection, which is in the sen- 
sitive phenomena on a small scale, what the erection of 
the corpora cavernosa is on a large one. I do not believe 
that any exact experiment can prove this fact. More- 
over, it would be necessary then that the intestinal, vesi- 
cal papillae, &c. should be in permanent erection, since 
they are almost always in contact with foreign substances. 
II. Parts common to the Organization of the Mucous 
System. 
-Besides the blood vessels, the exhalants and the absor- 
bents which contribute to the structure of this system as 
to that of all the others, it exhibits also a common organ, MUCOUS SYSTEM. 
87 
which is found almost always separate elsewhere, but 
which is here especially designed for it. This common 
organ is of a glandular nature ; we shall now examine it. 
Of the Mucous Glands and of the Fluids which they 
secrete. 
The mucous glands exist in all the system of this name. 
Situated beneath the corion or even in its thickness, they 
pour out incessantly through imperceptible openings a 
mucilaginous fluid which lubricates its free surface, and 
which defends it from the impression of the bodies with 
which it is in contact, and at the same time favours the 
course of these bodies. 
These glands are very apparent in the bronchia, palate, 
the oesophagus and the intestines, in which they take the 
names of the anatomists who have accurately described 
them, and where they make in many places evident pro- 
jections upon the mucous surface. They are less appa- 
rent in the bladder, the womb, the gall-bladder, the vesi- 
culse seminales, &c.; but the mucus that moistens them 
clearly demonstrates their existence. In fact, since on 
the one hand this fluid is analogous on all the mucous sur- 
faces, and, on the other, in those in which the glands are 
apparent, it is evidently furnished by them, it must be 
secreted in the same way in those in which the glands are 
less evident. The identity of the secreted fluids supposes 
in fact the identity of the secretory organs. It appears 
that where these glands are hidden from our view, nature 
compensates for their delicacy by their number. Besides, 
there are animals in which, in the intestines especially, 
they form by their vast number, a kind of new layer, in 
addition to those of which we have spoken. In man 
this is remarkable in the palatine arch, in the pillars of 
the velum, on the internal surface of the lips, the cheeks, 
&c. &c. There is then this great difference between the 
mucous and the serous membranes, that the fluid which 88 
MUCOUS SYSTEM. 
lubricates one is furnished by secretion, whilst that which 
moistens the others is from exhalation. 
The size of the mucous glands varies; those of the 
velum of the palate, those of the mouth, &c. are the 
largest; they become insensible in the greatest number of 
mucous surfaces. I dissected two subjects that died of a 
pulmonary catarrh, and in them the glands of the trachea 
and bronchia, which are, as we know, very apparent, 
were not enlarged; the membrane alone appeared to be 
affected. Besides, we do not yet know the injuries of 
these glands, like those of the analogous organs, which 
are more apparent from their size. They are in general 
of a rounded form but with many varieties. No mem- 
brane appears to cover them. They have, like the sali- 
vary glands and the pancreas, only the cellular texture for 
an envelope. Their texture is more dense and compact 
than these last glands; but little cellular texture is found 
in them ; they are soft, vascular, and appear when opened 
very much like the prostate gland. I cannot say whether 
nerves penetrate them; analogy indicates it, for all the 
principal glands receive them. 
Mucous Fluids. 
We know but little of the composition of the mucous 
fluids, because in the natural state, it is difficult to collect 
them, and in the morbid, in which their quantity in- 
creases as in catarrhs for example, this composition is 
probably changed. We know that in general they are 
unsavoury, insipid, and but slightly soluble in water, in 
that even which is raised to the highest temperature ; 
they become putrid with difficulty. In fact they remain 
a long time unchanged in the nose, exposed to the contact 
of a moist air; in the intestines, they serve, without 
danger to them, as an envelope for putrid substances, &c.; 
taken from the body and subjected to different experi- 
ments, they give results conformable to these facts. All MUCOUS SYSTEM. 
89 
the acids act upon them and colour them differently ; ex- 
posed to a dry air, they thicken by evaporation, and are 
often even reduced to small shining laminae. The nasal mu- 
cus especially exhibits this phenomenon. Fourcroy has 
given in detail the analysis of this mucus; he has also 
given that of the tracheal mucus. But we must not apply 
rigorously to the analogous fluids our knowledge of the 
composition of these. It is sufficient in fact to examine 
a certain number of these fluids, to be convinced that they 
are not the same in any two places, that more or less 
thick, more or less uniform, different in their colour, 
their odour even, &c. they vary in the principles that 
constitute them, as the membranes which furnish them 
vary in their structure, in the number and size of their 
glands, in the thickness of their corion, the form of their 
papillae, the state of their vascular and nervous systems, 
&c. I am far from being certain that the gastric juice is 
a mucous juice; it is even probable that exhalation fur- 
nishes it, the glands of the stomach throwing out a differ- 
ent fluid by the way of secretion. But this assertion is 
not accurately demonstrated, and perhaps hereafter it will 
be proved that this juice, so different from the other mu- 
cous juices, is however one of them, and that its proper- 
ties are distinct only because the structure of the mucous 
surface of the stomach is not the same as that of the other 
analogous surfaces. 
The functions of the mucous fluids in the animal econo- 
my are not ambiguous. The first of these functions is to 
defend the mucous membranes from the impression of 
the bodies with which they are in contact, and all which, 
as we have observed, are heterogeneous to that of the ani- 
mal. These fluids form upon their respective surfaces a 
layer which supplies, to a certain extent, by its extreme 
tenuity, the absence of their epidermis. Thus where this 
membrane is very apparent, as upon the lips, the glans 90 
MUCOUS SYSTEM. 
penis, at the entrance of the nose and in general at all the 
origins of the mucous system, these fluids are not very 
abundant. The skin has only an oily layer, infinitely less 
evident than the mucous of which we are treating, be- 
cause its epidermis is very distinct. 
This use of the mucous fluids explains why they are 
more abundant where heterogeneous bodies remain some 
time, as in the bladder, at the extremity of the rectum, 
&.c. than where these bodies are only to pass, as in the 
ureters, and the excretory ducts generally. 
Hence why when the impression of a body would be 
injurious, these fluids are poured out in greater quantity 
upon their surfaces. The sound which enters the urethra 
and remains in it, the instrument that is left in the vagina 
to compress a polypus, that which remains some time 
with the same view in the nasal fossae, the canal fixed in 
the lachrymal sac to remove the obstruction, that which 
is introduced into the oesophagus to assist interrupted 
deglutition, always produce, upon the portions of the mu- 
cous surface that corresponds to them, a more abundant 
secretion of the fluid which is constantly poured out, a 
true catarrh. This is one of the principal reasons that 
renders it difficult to keep elastic sounds in the wind-pipe. 
The abundance of the mucus that is then secreted, by 
closing the openings in the instrument, renders frequent 
introductions necessary, and can even threaten the patient 
with suffocation, as Desault himself has observed, though 
however he obtained great advantage from this means, as 
I have shown in his surgical works. I ought even to say, 
that since the publication of the Treatise on the Mem- 
branes, I attempted to fix a sound in the air tube of a dog, 
and that the animal died at the end of some time, having: 
the bronchia filled with a frothy fluid which appeared to 
have suffocated him. 
It appears then that every considerable excitement of 
the mucous surfaces produces a remarkable increase of MUCOUS SYSTEM. 
91 
action. But how ean this excitement, which does not 
take place immediately upon the gland, have so great an 
influence upon it ? for, as we have said, these glands are 
always under the membrane, and consequently separated 
by it from the irritating bodies. It appears that it is 
owing to a general modification of the glandular sensi- 
bility, which is capable of being brought into action by 
any irritation upon the extremity of the excretory ducts, 
as I shall prove in the glandular system. 
It is to the susceptibility that the mucous glands have 
of feeling the irritation made at the extremity of their 
ducts, that must be referred the artificial catarrhs with 
which Vauquelin has been affected by respiring the 
vapours of the oxy-muriatic acid, the mucous discharge 
that attends the presence of a polypus, of any tumour in 
the vagina, of a stone in the bladder, &c. the frequency 
of fluor albus in women who are immoderate in the use 
of sexual intercourse, the more abundant discharge of the 
mucus from the nostrils of those who take snuff, &c. 
In all these cases, there is evidently excitement at the 
extremity of the mucous1 ducts. I refer also to this ex- 
citement the mucous discharge that takes place, from 
stimulating the end of the nipple of a woman who does 
not give suck, the copious secretions which the presence 
of an irritating body produces in the intestines, secretions 
which especially furnish the matter of diarrhoeas, the 
gastric derangements which succeed an indigestion that 
has allowed to remain on the mucous surface of the 
stomach substances not digested and consequently irri- 
tating; these derangements are in fact real catarrhs of the 
membrane of the stomach, catarrhs which most often are 
not connected with bilious turgescence. I Could add 
many other examples of the mucous secretions increased 
by an irritation upon the surface of the membranes, at 
the extremity of the excretory ducts; these will be suf- 
ficient to give an idea of the others. 92 
MUCOUS SYSTEM. 
All these excitements produce a kind of inflammation, 
the peculiarity of which is to contract at first for some 
time the glandular ducts, and arrest the secretion, which 
they afterwards excite in great quantity. When the 
mucous fluids have flowed abundantly for some time, they 
gradually diminish though the cause continues; thus less 
mucus is discharged from the urethra in proportion after 
the sound has remained in it a month, than when first intro- 
duced ; but almost always as long as the cause continues, 
the mucous discharge is greater than in a natural state. 
Blisters are much employed in medicine on the cuta- 
neous organ, to dispel, according to some, the morbific 
humour, and overcome, according to others, a natural 
irritation by an artificial one. Why should we not also 
in many cases irritate the mucous surfaces ? why not act 
upon the pituitary membrane, upon the glans penis, upon 
the membrane of the urethra, upon the pharynx, &c. and 
especially upon the uvula which is so sensible? why, in- 
stead of epispastics upon the perineum and sacrum, should 
wTe not introduce a sound into the urethra for a paralysis 
of the bladder ? Instead of acting in hemiplegia upon 
the cutaneous organ, I have already twice employed the 
following means; I have introduced a sound into the 
urethra, one in each nasal fossa, and at the same time, a 
surgeon irritated at intervals the uvula; the patients ap- 
peared to be much more excited than by blisters. Very 
strong purgative enemas and emetics prove the advantage 
of the excitement of the mucous membranes in this case. 
Would it not often be better in ophthalmia, to produce an 
artificial catarrh in the nostril of the diseased side, than to 
put a blister or seton in the neck ? I have once tried it; 
it did not succeed ; but the ophthalmia was of long stand- 
ing ; I propose to repeat these experiments at the Hotel 
Dieu upon a great number of patients. I think that we 
might often in diseases make use of mucous excitements 
instead of cutaneous, with much more advantage, because MUCOUS SYSTEM. 
93 
in the mucous system the contact of a body is sufficient, 
and it is not necessary to produce, by removing the epi- 
dermis, a kind of ulcer. 
The mucous membranes by the continual secretion of 
which they are the seat, enjoy a principal part in the ani- 
mal economy. We ought to consider them as one of the 
great emunctories by which the residue of nutrition con- 
stantly escapes, and consequently as one of the principal 
agents of the habitual decomposition which removes from 
living bodies the particles that, having for some time con- 
tributed to the composition of the solids, are afterwards 
to become heterogeneous to them. Observe in fact that 
the mucous fluids do not enter the circulation, but go out 
of the body; that of the bladder, the ureters and the 
urethra, with the urine; that of the vesiculse seminales 
and the different ducts with the semen; that of the nos- 
trils by the act of blowing the nose ; that of the mouth, 
in part by evaporation and in part by the anus with the 
excrements ; that of the bronchia by pulmonary exhala- 
tion, which arises principally, as I shall say, from the 
solution of this mucous fluid in the inspired air ; those of 
the oesophagus, the stomach, the intestines, the gall-blad- 
der, &c. with the excrements, of which they often form 
in the ordinary state a part almost as considerable as the 
residue of the aliments, and which they even compose 
almost entirely in some cases of dysentery and fever, in 
which the quantity of matter voided is evidently dispro- 
portioned to that taken in, &c. Let us observe upon this 
subject that there are always some errors in the analyses 
of the fluids in contact with the membranes of which wre 
are speaking, as in that of the urine, the bile, the gastric 
juices, &c. because it is very difficult and even impossible 
to separate the mucous fluids from them. 
If we recollect what has been previously said upon the 
extent of the two general mucous surfaces, which is equal 
and even superior to the extent of the cutaneous organ, 94 
MUCOUS SYSTEM. 
and if we afterwards consider that these two great sur- 
faces are constantly throwing out mucous fluids, we shall 
perceive how important this evacuation must be in the 
economy, and of what mischief its derangement must be- 
come the source. It is undoubtedly to this law of nature 
which wishes to have every mucous fluid thrown out, 
that must be attributed, in part in the foetus, the presence 
of the unctuous fluid of which the gall-bladder is full, 
the meconium which loads the intestines, &c. fluids which 
appear to be but a mass of mucous juices, which being 
unable to pass off, remain until birth, without being ab- 
sorbed, upon the respective organs on which they have 
been secreted. 
The mucous fluids are not the only ones that are thrown 
out, and are in this way excrementitious substances to 
the economy; this is the case with almost all the fluids 
separated from the mass of blood by secretion ; this is 
evident as it respects the greatest part of the bile; prob- 
ably the saliva, the pancreatic juice and the tears are also 
thrown out with the excrements, and their colour alone 
prevents them from being distinguished like the bile. I 
do not even know if, by reflecting on many phenomena, 
we might not attempt to establish as a general principle, 
that every fluid separated by secretion does not enter the 
circulation again, that this phenomenon belongs only to 
the fluids separated by exhalation, as those of the serous 
cavities, of the articulations, of the cellular texture, of 
the medullary organ, &c. ; that all the fluids are thus 
either excrementitious or recrementitious, and that no 
one is excremento recrementitious as the common division 
implies. The bile in the gall-bladder, the urine in the 
bladder, the semen in the vesiculas seminales, are cer- 
tainly absorbed ; but it is not the fluid itself which re- 
enters the circulation ; it is only its most delicate parts, 
some of its princ:ples which we do not exactly know, 
probably the serous and lymphatic part; this does not re- MUCOUS SYSTEM. 
95 
semble the absorption of the pleura and other analogous 
membranes, in which the fluid re-enters the blood as it 
came out of it. 
That which is certain on the subject of the excretion 
of the secreted fluids is, that I have never been able to 
produce absorption of the bile by the lymphatics by in- 
jecting it into the cellular texture of an animal; it pro- 
duces there inflammation and afterwards suppuration. 
We knowr that urine effused is not absorbed and that it 
destroys every part it touches, whilst that effusions of 
lymph and blood are easily discussed. There is as it re- 
spects the composition an essential difference between the 
blood and the secreted fluids. The exhaled fluids on the 
contrary, as the serum, in this respect resemble it very 
much. 
Another very evident proof that all the mucous fluids 
are designed to be thrown out, is, that when they have 
continued for some time in any quantity upon their re- 
spective surfaces, they create there a painful sensation of 
which nature relieves us by various means. Thus the 
cough, which is the constant result of an accumulation of 
mucus in the bronchia, serves to expel it; thus vomiting 
in gastric derangements answers the same purpose as it 
respects the mucous juices accumulated in the stomach, 
whose presence produces a weight and even pain, though 
the membranes be not affected. We cough at will, be- 
cause it is the diaphragm and intercostals by which this 
function is performed ; we do not seek in medicine for 
any means to excite it. But as we cannot vomit at will, 
and as the presence of mucous juices often by fatiguing 
the stomach, does not irritate it sufficiently to produce a 
contraction, art has recourse to various emetics. We 
know what a painful sensation of weight the continuance 
of mucus accumulated in the frontal, maxillary, sinuses, 
&c.,occasions, when there is a catarrh of a portion of the 
pituitary membrane. The region of the bladder is for 96 
MUCOUS SYSTEM. 
the same reason, in catarrhs of this organ, the seat of a 
troublesome and even painful sensation. 
In general, the sensation which arises from the presence 
of the mucous juices remaining too long and in too great 
quantity upon their respective surfaces, varies because, as 
we shall see, each part of the mucous system has its pecu- 
liar mode of sensibility ; so that the pain is not the same 
in each, though produced by the same cause. I would 
only observe that this sensation does not resemble that 
which arises from the tearing or the acute irritation of 
our parts; it is an uneasy, inconvenient sensation, diffi- 
cult to be borne. Every one knows that which arises 
from mucus accumulated in the nasal fossae, when the 
nose has not been blown for a long time, that disagreeable 
one that accompanies gastric derangements, &c. Those 
who have a weakness of the lachrymal sac in which the 
tears, on account of this, accumulate during the night, 
wake up with a sensation of weight, of which they are 
relieved by evacuating the sac by pressure, if the puncta 
lachrymalia are open. 
Blood Vessels. 
The mucous membranes receive a very great number 
of vessels. The remarkable redness that distinguishes 
them would be sufficient to prove it, if injections did not 
demonstrate it; this redness is not everywhere uniform. 
It is almost nothing in the sinuses of the face, in the in- 
ternal ear, of which the membranes are rather whitish, 
and which appear so especially, because their extreme 
delicacy allows the bone upon which they are applied 
to be seen very distinctly. In the bladder, in the great 
intestines, in the excretories, &c. this colour, though still 
very pale, is a little more evident; it becomes very much 
so in the stomach, the small intestines, the vagina and in 
the pituitary and palatine membranes. In the gall-blad- MUCOUS SYSTEM. 
97 
dor we cannot distinguish it, because the bile always 
covers the mucous surface in the dead body. 
This colour depends upon a very extensive vascular net- 
work, the branches of which, after having passed through 
the mucous corion, and ramifying there, divide and spread 
ad infinitum on its surface, embracing the papillary body 
and covered only by the epidermis. 
It is the superficial position of these vessels and con- 
sequently their want of support on one side, that exposes 
them frequently to ruptures from considerable shocks, as 
happens on the surface of the bronchia from a severe 
cough, on that of the ear and the nose from a violent 
blow on the head. We know that hemorrhage of the 
mucous system bordering on the brain, is a common acci- 
dent from concussions and wounds of the head. Hence 
why the least gravel makes the ureters bleed ; why one 
of the signs of stone in the bladder is the passing of blood ; 
why a blunt sound carefully introduced is so often with- 
drawn bloody from the urethra; why the least effort 
made with instruments carried upon polypi, into a fistula 
lachrymal is or into the nostrils, produces hemorrhage. I 
have already observed that we must carefully distinguish 
these hemorrhages from those furnished by the exhalants, 
and which do not suppose any vascular rupture. 
It is also the superficial position of the vessels of the 
mucous system, which makes its portions visible, as the 
red edge of the lips, the glans penis, &c. often serve to 
show us the state of the circulation. Thus in the different 
species of asphyxia, in submersion, strangulation, &c. 
these parts are remarkably livid, an effect of the passage 
of the venous blood, which has undergone no change from 
the want of respiration, into the extremities of the arterial 
system. 
The long continued exposure of the mucous system to 
the air, often makes it lose the redness that characterizes 98 
MUCOUS SYSTEM. 
it, and it then assumes the appearance of the skin, as has 
been observed by Sabatier in treating of prolapsus of the 
womb and vagina, which, from this circumstance, have 
sometimes so misled some people, as to make them be- 
lieve it a case of hermaphrodism. 
An important question presents itself in the history 
of the vascular system of the mucous membranes, viz. 
whether this system admits more or less blood according 
to different circumstances. As the organs within which 
these membranes are spread, are almost all susceptible of 
contraction and dilatation, as we see in the stomach, the 
intestines, the bladder, &c. it has been thought that during 
the dilatation, the vessels being more expanded, receive 
more blood, and that during the contraction on the con- 
trary, being folded up, as it were choaked, they admit 
but a small quantity of this fluid which then flows into 
the neighbouring organs. Chaussier has made an appli- 
cation of these principles to the stomach, whose circula- 
tion he has considered as being alternately inverse of that 
of the omentum, which receives during the vacuity of 
this organ, the blood which this when it is contracted 
cannot admit. An analogous use has also been attributed 
to the spleen since the time of Liejutaud. The following 
is what the inspection of animals opened during abstinence 
and at different periods of digestion, has shown me upon 
this point. 
1st. During the fulness of the stomach the vessels are 
more apparent on the exterior of this viscus, than when 
it is empty. Within, the mucous surface is not more 
red, sometimes it has appeared to me to be less so. 2d. 
The omentum, less extended during the fulness of the 
stomach, exhibits nearly the same number of vessels, as 
long, but more tortuous, than when it is empty. If they 
contain less blood, the difference is hardly sensible. I 
would observe, that in order to distinguish this well, it 
is necessary to take care that in opening the animal, the MUCOUS SYSTEM. 
99 
blood does not fall on the omentum which presents itself, 
and thus prevent its state from being; ascertained. This 
is besides a necessary consequence of the arrangement of 
the vascular system of the stomach. In fact the great 
stomachic coronary being situated transversely between 
it and the omentum, and furnishing branches to each, it 
is evident that when the stomach is lodged between the 
layers of the omentum by separating these layers, and 
this by applying itself upon it becomes shorter; it is 
evident, I say, that the branches which it receives from 
the coronary cannot be equally applied to it also. In 
order to this, it would be necessary that they should go 
from one to the other without the intermediate trunk 
that cuts them at right angles ; then, in distending, the 
stomach would separate them as it does the omentum, 
and would be lodged between them ; whereas it pushes 
them before it with their common trunk, the stomachic 
coronary, and makes them fold. 3d. I am confident that 
there is no such constant relation between the size of the 
spleen and the emptiness or fulness of the stomach, and 
that these two circumstances coincide necessarily, and that 
if the first organ increases or diminishes under different 
circumstances, it is not always precisely the reverse of 
the stomach. I first made, like Lieutaud, experiments 
upon dogs to convince myself of it; but the inequality in 
the size and age of those that were brought to me, making 
me fear that I should not be able to compare their spleens 
correctly, I repeated them upon guinea-pigs of the same 
litter and size, and examined at the same time, some 
when the stomach was empty and others when it was 
full. I have almost always found the size of the spleen 
nearly equal, or at least the difference was not very sen- 
sible. Yet in other experiments, I have seen under 
various circumstances, inequalities in the size of the spleen 
and especially in the weight of this viscus; but it was 
indifferently during or after digestion. MUCOUS SYSTEM. 
100 
It appears from all this, that if during the vacuity of 
the stomach, there is a reflux of blood towards the omen- 
tum and spleen, this reflux is less than it has been com- 
monly said to be. Besides during this state of vacuity, 
the numerous folds of the mucous membrane of this 
viscus leaving it, as we have said above, almost as much 
surface and consequently as many vessels as during ful- 
ness, the blood can circulate in it almost as freely. It; 
has no real obstacles but in the tortuous courses, and not 
in the obstruction, compression and choaking of these 
vessels by the contraction of the stomach ; now this ob- 
stacle is easily surmounted, or rather it is not one as I 
have proved in my Researches upon Death. As to the 
other hollow organs, it is difficult to examine the circu- 
lation of the neighbouring parts during their fulness 
and vacuity, as the vessels of these are not superficial 
as in the omentum, and as they themselves are not insu- 
lated like the spleen. We can only then, to decide the 
question, see the state of the mucous membranes on their 
internal face ; now this face has always appeared to me to 
be as red during the contraction as during the dilatation. 
Besides I only give this as a fact without pretending 
to draw from it any consequence in opposition to the com- 
mon opinion. It is possible in fact that though the quan- 
tity of blood may be nearly always the same, the rapidity 
of the circulation being increased, more of this fluid may 
consequently in a given time enter it when it is full; which 
appears to be necessary to the greater secretion that then 
takes place of the mucous fluids, a secretion excited by 
the presence of the substances in contact with the surfaces 
of the same name. For example, there is no doubt that 
there is three or even four times as much mucus secreted 
in the urethra, when a sound fills it, as when it is empty ; 
now the blood must be in proportion. 
The remarkable redness of the mucous system, the 
analogy of respiration in which the blood flows through MUCOUS SYSTEM. 
101 
the mucous surface of the bronchia the well known ex- 
periment of a bladder fdled with blood and immersed in 
oxygen, by which means the blood becomes red, have 
induced a belief that the blood being separated from the 
atmospheric air only by a thin pellicle or some of the 
mucous surfaces, as upon the pituitary, the palatine, the 
glans penis, &c. assumed there a redder colour, either from 
getting rid of a portion of its carbonic acid gas, or by 
combining with the oxygen of the air, and that these 
membranes thus performed functions accessory to those 
of the lungs. The experiments of Jurine upon the cuta- 
neous organ, experiments adopted by many celebrated 
philosophers, seem to strengthen this conjecture. 
I tried the following experiment to ascertain this fact. 
I drew through a wound made in the abdomen a portion 
of intestine which I tied at one point, I afterwards reduced 
it, keeping out a small portion only which I opened and 
by which I introduced atmospheric air, which filled the 
whole portion situated on this side of the ligature. I 
afterwards tied the intestine below the opening, and re- 
duced the whole of it. At the end of an hour, the 
animal being opened, I compared the blood of the mesen- 
teric veins which arose from the portion of intestine dis- 
tended with air, with the blood of the other mesenteric 
veins arising from the rest of the canal. No difference 
of colour was manifest; the internal surface of the dis- 
tended portion of the intestine was not of a more brilliant 
red. I thought I should obtain a more evident effect, by 
repeating with oxygen the same experiment upon another 
animal; but I perceived no greater variety in the colour 
of the blood. As upon the mucous membranes which 
are ordinarily in contact with the air, this fluid is con- 
stantly changing and is agitated by a perpetual motion, 
and as in the preceding experiment it remained stagnant, 
I attempted to produce the same effect in the intestines. 
I made two openings in the abdomen, and drew out. at 102 
MUCOUS SYSTEM. 
each a portion of the intestinal canal; having opened these 
two portions, I fitted to one the tube of a bladder full of 
oxygen and to the other that of an empty bladder ; I after- 
wards compressed the full bladder, so as to make the 
oxygen pass into the other, by going through this portion 
of intestine, left in the abdomen that the heat might sup- 
port the circulation in it. The oxygen was thus many 
times sent lrom one bladder to another, taking its course 
through the intestine, which, on account of its contrac- 
tility is more difficult than it at first seems to be. The 
abdomen being afterwards opened I found no difference 
between the venous blood returning from this portion of 
intestine, and that which flowed from the others. The 
superficial position of the mesenteric veins, covered only 
by a fine and transparent layer of peritoneum, their size, 
if the animal be rather large, render this sort of com- 
parison very easy. 
I perceive that we cannot infer from what takes place 
in the intestines, what happens in the pituitary, palatine 
membrane, &c. because though analogous, the organiza- 
tion may be different. We cannot here as in the intes- 
tines examine the venous blood returning from the part; 
but, 1st, if we consider that in animals who have respired 
oxygen for some time, we see the palatine and pituitary 
membranes more red ; 2d, if we reflect that the lividity 
of the different parts of this membrane, in those destroyed 
by asphyxia by the carbonic acid gas, depends not on the 
immediate contact of this gas upon the membrane, but 
upon the passage of venous blood into the arterial system, 
as my experiments have, I think, demonstrated ; 3d, if 
we remark finally that in these circumstances the con- 
tact of the air does not change, after death, the lividity 
which the venous blood gives to the mucous membranes, 
although the skin be then much more permeable to every 
kind of aeriform fluid; we shall see that it is at least 
pecessary to suspend our judgment upon the colouring of MUCOUS SYSTEM. 
103 
the blood in the mucous membranes, until further obser- 
vations have decided the question. 
The following experiment may also throw some light 
upon the subject. I have inflated the peritoneal cavity of 
several guinea-pigs with carbonic acid gas, with hydro- 
gen, oxygen and atmospheric air, to see if I could effect 
through a serous membrane what I could not make succeed 
in a mucous; I have not, after these experiments, found 
any difference in the colour of the blood of the abdominal 
system ; it was always the same as in the common guinea- 
pig which I killed for comparison. 
I think however that I have remarked many times, 
both in frogs and animals with red and warm blood, such 
as cats and guinea-pigs, that the infiltration of oxygen into 
the cellular texture gives, at the end of some time, a 
much brighter colour to the blood, than that which this 
fluid exhibits in artificial emphysemas produced by car- 
bonic acid gas, hydrogen and atmospheric air, in all which 
the colour of the blood scarcely differ at all from what 
is natural. But in other cases oxygen has had no influ- 
ence upon the colour of the blood ; so that notwithstand- 
ing having made many experiments upon this point, I am 
unable to give any general result. It appears that the 
tonic forces of the cellular texture and of the parietes of 
the vessels which are spread upon this texture, receive a 
very variable influence from the contact of the gases, and 
that according to the nature of this influence, the fibres 
crisping and contracting more or less, render these parts 
more or less permeable, either to the aeriform fluids that 
tend to escape from the blood in order to unite with that of 
the emphysema, or to this last fluid, if it tends to combine 
with the blood, which no doubt produces the varieties I 
have observed. 
The red colour of the mucous system is analogous to 
that of the muscular system. It does not depend essen- 
tially on the blood circulating in the small arteries of this 104 
MUCOUS SYSTEM. 
system. It arises from the colouring portion of the blood 
combined with the mucous texture, especially in the deep 
part of the organs ; for at the origin of the mucous sur- 
faces, this colour appears to be principally owing to the 
blood in circulation ; in fact asphyxia does not render 
so livid the deep mucous surfaces, as it does those which 
are superficial and in communication with the skin. The 
black blood arrives immediately to these by the last arte- 
ries, and tinges them as we see. In syncope in which 
the heart being affected no longer sends blood into the 
arteries, we know that this portion of the mucous system 
becomes instantly white. 
Besides the red colour of the deeper portions, can, like 
that of the muscles, be removed by repeated washing and 
frequently changing the water. Yet the water in which 
they have been washed is not as red as that used for the 
muscles. 
The instant a mucous surface is plunged into boiling 
water, however red it may be, as that of the intestines 
and the stomach, it instantly whitens. The action of the 
nitric, sulphuric and muriatic acids produces in it also a 
sudden whiteness. 
This colour of the mucous surfaces acquires a remark- 
able intensity in inflammation. The redness becomes 
then extremely deep on account of the quantity of blood 
that is accumulated in the capillary system. It is par- 
ticularly in dysentery that the internal surface of the 
intestines exhibits this phenomenon in a striking degree. 
I ought however to observe to those who open dead 
bodies, that they never should lose sight of the original 
tinge of the portion of the mucous system they examine, 
since each of the divisions of this system exhibits in its 
shades remarkable differences. If the membrane of the 
bladder, the rectum, &c. is found as red as that of the 
stomach in its natural state, then pronounce that there 
had been inflammation ; if the redness of the sinuses MUCOUS SYSTEM. 
105 
equals that which is natural to the bladder and the rectum, 
decide that inflammation had existed in them. There is, 
as I have said, a scale of colour for the mucous system. 
It is then essential to have an accurate knowledge of this 
scale, a type to which we can refer the inflammatory state 
in the examination of dead bodies. 
Exhalants. 
Does exhalation take place upon the mucous surfaces ? 
The analogy of the skin seems to indicate it; for it is 
well proved that the sweat is not a transudation through 
the inorganic pores of the cutaneous surface, but a real 
transmission by vessels of a peculiar nature and continu- 
ous with the arterial system. • 
It appears at first that the pulmonary perspiration 
which takes place upon the mucous surface of the bron- 
chia, which has so much relation with that of the skin, 
which increases and diminishes according as this dimin- 
ishes or increases, and the matter of which is probably of 
the same nature; it appears, I say, that the pulmonary 
perspiration is made at least in great part by the system 
of exhalant vessels, and that if the combination of the 
oxygen of the air with the hydrogen of the blood con- 
tributes to produce it, during the act of respiration, it is 
but in very small quantity, and it is the portion that is 
purely aqueous. Besides, this last hypothesis of modern 
chemists, contradictory to the production of all the other 
fluids thrown out by the mucous surfaces, appears to me 
ill adapted to explain the formation of this. When the 
same phenomenon is produced in many places, and the 
explanation that is given of it is applicable only to one, 
we should be suspicious of this explanation. 
It should be observed in regard to the pulmonary per- 
spiration, that the solution of the mucous fluid which lubri- 
cates the bronchia, in the air constantly inspired and 
expired, furnishes a considerable portion of this vapour 106 
MUCOUS SYSTEM. 
which, insensible in summer, is very evident in winter, 
on account of the condensation of the air. The mucous 
juices are dissolved like every other fluid ; for wherever 
there is atmospheric air, heat and moisture, there is evapo- 
ration. Here this evaporation is even a means which 
nature employs to rid herself, as I have said, of the mu- 
cous juices. If they are too abundant, as in a cold, then 
the quantity of air which serves as a vehicle to them, not 
increasing in proportion, it is necessary that there should 
be another mode of evacuation; this is expectoration 
which compensates for what the air cannot remove by 
solution. 
The intestinal juice which Haller has especially con- 
sidered, but which appears to be in much less quantity 
than he thought it, the oesophagean and gastric juices, 
particularly this last which has been supposed to be dis- 
tinct from the mucous juices, are probably deposited by 
exhalation upon their respective mucous surfaces. But 
in general it is very difficult to distinguish with precision 
what belongs in these organs to the exhalant system, from 
that which is furnished by the system of mucous glands, 
which, as we have said, are everywhere subjacent to 
them. Thus we constantly see the mucous fluids of the 
oesophagus, the stomach and the intestines, mixing with 
the oesophagean, gastric and intestinal fluids. 
As on the one hand the blood vessels ramify almost 
naked on the mucous surfaces, and as on the other these 
vessels are always the origin of the exhalants, it is evi- 
dent, that these have but a short course to run to arrive 
at their surfaces ; they are rather pores than distinct ves- 
sels. Hence why no doubt the blood has so great a 
tendency to escape by the exhalants ; why consequently 
hemorrhages without rupture are so frequent in the mu- 
cous system ; why this affection can be classed in the 
diseases of this system, &c. &c. No other, by the arrange- 
ment of the arteries, ofters to the exhalants so short a MUCOUS SYSTEM. 
107 
course between their origin and termination. Often even, 
as I have said, we make the blood of these vessels ooze 
in the dead body through their exhalants. 
Absorbents. 
The absorption of the mucous membranes is evidently 
proved, 1st, by those of chyle and of drinks on the intes- 
tinal surfaces, of the venereal virus upon the glans penis 
and the canal of the urethra, of the variolous when the 
gums are rubbed with it, of the serous portion of the 
bile, the urine and the semen, when they remain in their 
respective reservoirs. 2d. When, in the paralysis of the 
fleshy fibres that terminate the rectum, substances are 
accumulated at the extremity of this intestine, these sub- 
stances often become hard, an effect probably of an ab- 
sorption of the soft parts. 3d. There have been various 
cases in which the urine has been almost wholly absorbed 
by the mucous surface of the bladder, where there have 
been insurmountable obstacles in the urethra. 4th. If we 
respire, by means of a tube, the air of a large vessel filled 
with the exhalations of turpentine, so that these vapours 
can only act upon the mucous surface of the bronchia, 
the urine has the peculiar odour that always arises from 
the use of this substance, the exhalations from which have 
been introduced into the blood by the means of absorp- 
tion, &c. 
Whatever may be the mode of this absorption, it ap- 
pears that it does not take place in a constant and unin- 
terrupted manner, like those of the serous membranes, in 
which the exhalant and absorbent systems are in a regular 
and continual alternation of action. There is scarcely any 
but the chylous absorption, that of drinks, and that of 
the aqueous portion of the secreted fluids remaining in a 
reservoir as they come from their glands, that constantly 
take place. Nothing is more variable than the other ab- 
sorptions. Under the same influence, the glans takes up 108 
MUCOUS SYSTEM. 
or leaves the venereal virus ; the internal surface of the 
bronchia sometimes admits and sometimes refuses admit- 
tance to contagious miasmata. There are more cases of 
retention in which the urine is not absorbed entirely, 
than there are where this absorption takes place, &c. &c. 
The innumerable varieties of the vital forces of the mu- 
cous membranes, varieties produced by those of the stimuli 
with which they are in contact, explain these phenomena. 
If these forces are raised or diminished a little, the ab- 
sorption is altered, even that which is natural, as that of 
the chyle. Take a purgative ; it contracts, shuts even 
the mouth of the absorbents of the intestinal canal; as 
Ions as the irritation continues, all the drinks that are 
taken pass off by the anus ; at the end of four or live 
hours, the absorbents gradually recover their natural tone 
and absorption recommences. In these cases, the first 
discharges are only the intestinal matters, the others are 
the copious drinks that have been taken. There are many 
diseases in which, the sensibility of the chylous absor- 
bents being too much raised, they are no longer in relation 
with the aliments, they take up with difficulty the resi- 
due of them, &c. Deficiency of action produces the same 
phenomenon ; in absorption in fact it is a middle degree 
of sensibility of the organ which produces it, a degree 
below or above which it cannot take place. 
All the mucous absorbents appear to go to the thoracic 
duct. 
Nerves. 
I would remark that at all the origins of the mucous sys- 
tem, where the animal sensibility is very great and where 
it places us, like the skin, in relation with external bodies, 
cerebral nerves are distributed. The pituitary and pala- 
tine membranes, the conjunctiva, the mucous surface of 
the rectum, the glans penis, the prepuce, &c. exhibit 
this fact very evidently. There are hardly any nervous MUCOUS SYSTEM. 
109 
filaments coming from the ganglions in these different 
places. 
On the contrary, this last species of nerves is the pre- 
dominant one in the intestines, in all the excretories, in 
the reservoirs of the secreted fluids, &c. places where the 
organic sensibility is the most evident. 
ARTICLE THIRD. 
PROPERTIES OP THE MUCOUS SYSTEM. 
I. Properties of Texture. 
Extensibility and contractility are much less in this 
system than they at first appear to be, on account of the 
numerous folds which it exhibits in the hollow organs 
during their contraction, folds which are developed only 
during extension, as we have seen. Yet these two pro- 
perties become very evident in some cases. The excre- 
tories are capable of taking a size much larger than is 
natural to them. This is seen in the ureters in particu- 
lar, which are sometimes found as large as an intestine. 
The ductus choledochus and the pancreatic duct have 
often also these dilatations. The urethra and the salivary 
ducts appear to be less extensible than the others. If 
they haye ever so little obstacles from strictures, con- 
tractions, &c. they break rather than stretch ; hence vari- 
ous urinary and salivary fistulas. 
Hence there is, as we see, many varieties in the degrees 
of the extensibility of the mucous system ; it is the same 
with regard to the contractility of texture. These two- 110 
MUCOUS SYSTEM. 
properties are besides capable of being put rapidly into 
action. We know that the stomach, the intestines, the 
bladder, &c. pass in an instant from a great size to ex- 
treme contraction. Their functions even suppose this 
rapidity, without which they could not be performed. 
The palatine membrane which lines the cheeks, exhibits 
the same phenomenon when the mouth is filled with air, 
aliments, &c. which are afterwards expelled from it. 
When the usual fluids cease to pass through the mucous 
ducts, they remain in permanent contraction ; this is what 
takes place in the intestines below a preternatural anus. 
I have seen in this case the caecum and the rectum re- 
duced to the size of a large quill. Yet there is never then 
an obliteration of their parietes, on account of the presence 
of the mucous juices, of which the patient always passes 
a certain quantity. The urethra, after the operations for 
stone in which the urine passes for a long time through 
the wound, and in the great fistulas in the perineum or 
above the pubis, the salivary ducts in wounds which affect 
them and through which the whole saliva is discharged, 
the nasal canal in fistulae lachrymales, contract also more 
or less, but are never obliterated. We know that the vas 
deferens is often a very long time without having semen 
pass through it, and yet it remains open. This phenome- 
non distinguishes the mucous ducts from the arterial, 
which, when the course of blood is interrupted in them, 
change into ligaments in which every thing like a canal 
disappears. We ought not to lose sight of this phenome- 
non of all the mucous ducts; it proves the incorrectness 
of the practice of those who, thinking that at the end of 
some time it is impossible to re-establish, in fistulas, the 
natural way, think it necessary to make an artificial one. 
The mucous tubes are not only not obliterated when 
they are empty, but when inflamed they do not even con- 
tract adhesions of their parietes, as so often happens in 
the serous cavities, in the cellular texture, &c. Observe MUCOUS SYSTEM. 
111 
how important this fact is to the great functions of life ; 
what would indeed become of these functions, if in 
catarrhs of the intestines, the bladder, the stomach, the 
oesophagus, the excretories, &c. these adhesions were as 
frequent as they are in pleurisy, peritonitis, pericarditis, 
&c. 
II. Vital Properties. 
Few systems live in a more active manner than this 
few exhibit the vital forces in a higher degree. 
Constantly in relation, like the integuments, with ex- 
ternal bodies, the mucous surfaces have occasion for a 
sensibility which would enable the mind to perceive these 
relations, especially at the origin of these surfaces. Thus 
the animal sensibility is very much developed there. It is 
even superior in it in many places to that of the cutaneous 
organ, in which no sensation is as acute as those which 
take place on the pituitary membrane from odours, upon 
the palatine from tastes, upon the surface of the vagina, 
the urethra, the glans penis during coition. But without 
speaking of these exaggerations of sensibility, if I may so 
express myself, all the natural phenomena of the mucous 
surfaces prove this property in an evident manner; it is 
unnecessary however to pause for these phenomena. 
I would only observe that this sensibility, like that of 
the cutaneous organ, is essentially subjected to the power- 
ful influence of habit, which tending constantly to blunt 
the acuteness of the sensation of which they are the seat, 
brings equally to indifference the pain and the pleasure 
they make us experience, and of which it is the medium, 
as we know. 1st. I say that habit brings to indifference 
the painful sensations arising upon the mucous membranes. 
The presence of a sound in the urethra for the first time, 
Properties of minimal Life. 112 
MUCOUS SYSTEM. 
is distressing the first day, painful the second, incon- 
venient the third, and insensible the fourth. Pessaries 
introduced into the vagina, bougies into the rectum, tents 
fixed in the nasal fossae, and a canula kept for a length 
of time in the nasal canal, exhibit in different degrees the 
same phenomena. It is upon this remark that is founded 
the possibility of the introduction of sounds into the wind- 
pipe to aid respiration, and into the oesophagus to pro- 
duce an artificial deglutition. This law of habit can even 
transform into a pleasure an impression at first painful; 
the use of snuff for the pituitary membrane and differ- 
ent aliments for the palatine, furnish well known ex- 
amples of this. 2d. I say that habit brings to indiffer- 
ence agreeable sensations arising on the mucous surfaces ; 
the perfumer, placed in an odoriferous atmosphere, the 
cook, whose palate is constantly affected by delicious 
tastes, do not find in their professions the acute enjoy- 
ments they give to others. From habit can even arise 
the succession from pleasure to painful sensations, as in 
the preceding case it converts pain to pleasure. 
I would however observe that this remarkable influence 
of habit is only exerted upon sensations produced by 
simple contact, and not upon those produced by real in- 
juries, as the tearing, the forced stretching, the cutting or 
pinching of the mucous system ; thus it does not miti- 
gate the pains caused in the bladder by pressure and by 
the tearing a stone occasions, or on the surface of the 
womb, of the nasal fossae, &c. by a polypus, on that of 
the oesophagus or the wind-pipe by a sharp and uneven 
body accidentally lodged there, &c. &c. 
It is to this power of habit over the sensibility of the 
mucous system, that must be in part referred the gradual 
diminution of its functions, which accompanies age. 
Every thing is stimulant in infancy, every thing is blunt- 
ed in old age. In one, the very active sensibility of the 
alimentary, biliary, urinary, salivary surfaces, &c. con- MUCOUS SYSTEM. 
113 
tributes principally to produce that rapidity with which 
the digestive and secretory phenomena succeed each 
other ; in the other, this sensibility blunted by habitual 
contact, connects but slowly the same phenomena. 
Is it not from the same cause that arises this remark- 
able modification of the sensibility of this system, viz. 
that at its origins, as upon the pituitary, the palatine mem- 
branes, the oesophagus, the glans penis, the opening of 
the rectum, &c. it gives us the sensation of the bodies 
with which it is in contact, and that it does not give 
this sensation in the very deep organs which it lines, 
as in the intestines, the excretories, the gall-bladder, 
&c. ? In the interior of the organs, this contact is always 
uniform ; the bladder only knows the contact of the urine, 
the gall-bladder that of the bile, the stomach that of the 
aliments masticated and reduced, whatever may be their 
diversity, to an uniform, pulpy mass. This uniformity 
of sensation produces no perception, because in order to 
perceive, it is necessary to compare, and here the two 
terms of comparison are wanting. Thus the foetus has 
no sensation of the waters of the amnios; thus, the air, 
very irritating to a new born infant, becomes insensible 
to it. On the contrary, at the beginning of the mucous 
membranes, the stimulants vary every instant; the mind 
can then perceive the presence of them, because it can 
establish approximations between their different modes of 
action. What I say is so true, that if in the interior of 
the organs, the mucous membranes are in contact with a 
foreign body, different from that which they are accus- 
tomed to, they transmit the sensation of it to the mind. 
A catheter in the bladder, sounds introduced into the 
stomach, &c. are examples of this. Fresh air, in great heat 
of the atmosphere, suddenly introduced into the trachea, 
carries an agreeable sensation over the whole surface of 
the bronchia; but habit soon renders us insensible to it MUCOUS SYSTEM. 
114 
and we cease to have the perception of it. Yet it is to 
be observed that when the intestines come out in pre- 
ternatural inversions of the anus, their sensibility never' 
becomes so acute as that of the palatine, pituitary sur- 
faces, &c. &c. The absence of cerebral nerves no doubt 
has an influence upon this phenomenon. 
The sensibility of the mucous system is much raised 
in inflammations; acute catarrhs are, as we know, very 
painful. The contact of bodies is then not only felt, but 
is very disagreeable. I would observe however that the 
sensibility never rises so high as it does in the inflamed 
cellular, serous, fibrous systems, &c. A phlegmon, a 
pleurisy, &c. compared with a catarrh, are sufficient to 
convince us of this. We may say that the organs least 
accustomed to feel in the natural state, experience in dis- 
eases the most acute sensations. 
There is no animal contractility in the mucous system. 
Properties of Organic Life. 
Organic sensibility and insensible contractility are very 
evident in the mucous system. They are constantly put in 
action in it by four different causes ; 1st, by the nutrition 
of this system ; 2d, by the absorption that takes place in 
it, either naturally or accidentally ; 3d, by its exhalation ; 
4th, by the constant secretion of its glands. These two 
properties are the original causes of all these functions, 
the increase and diminution of which are truly the indices 
of the state of these glands. As a thousand causes con- 
tinually act upon the mucous surfaces, as a thousand dif- 
ferent stimuli continually excite them, especially at their 
origin, this state is incessantly varying like the functions 
that result from it. 
The mucous system differs then from most of the 
others; 1st, in this, that the organic sensibility and the 
insensible contractility are habitually more exalted in it, MUCOUS SYSTEM. 
115 
on account of the more numerous functions over which 
they preside; 2d, in this, that they incessantly vary, on 
account of the variety of the stimuli. Observe in fact 
that, in the osseous, fibrous, cartilaginous, muscular, ner- 
vous systems, &c. on the one hand, these properties are put 
in action only by nutrition ; and on the other, no stimu- 
lant being in contact with these systems, they always re- 
main at the same degree. 
Hence it is not astonishing that the diseases which espe- 
cially put in action the organic sensibility and the insensi- 
ble contractility of the same species, should be so frequent 
in the mucous organs. All the catarrhal affections, both 
acute and chronic, all the hemorrhages, various and 
numerous tumours, polypi, fungi, &c. all kinds of excoria- 
tions, ulcers, &c. of which they are the seat, are derived 
from the various alterations of which their organic pro- 
perties are susceptible. 
It is also to these alterations that must be attributed a 
remarkable phenomenon, viz. the innumerable varieties 
the mucous fluids exhibit in diseases. Take for example 
those that are thrown off from the internal surface of the 
bronchia, those that are brought up by expectoration, and 
which we can examine better than others, because they 
are mixed with no foreign substance ; observe how they 
differ, in the different affections of the chest; sometimes 
they have a yellowish and as it were bilious tinge ; some- 
times they are frothy in the vessel which receives them ; 
sometimes they adhere to it with tenacity, and at others 
they are easily detached from it. Viscid or liquid, fetid 
or without odour, grey, white, green or even black in the 
morning, they have a thousand external appearances which 
evidently denote differences in their composition, differ- 
ences which chemists have not yet explained to us. I 
do not speak of the cases where as in phthisis, hemopty- 
sis, &c. foreign substances are mixed with these mucous 
juices. Now it is evident that all these varieties depend 116 
MUCOUS SYSTEM 
only upon the varieties of the organic sensibility of the 
bronchial glands or of the membrane upon which they 
pour out their fluids. According as the property is dif- 
ferently altered in the mucous system, it is in relation 
with different substances, admits some and rejects others. 
The same organ, the same vessels can there, according to 
the state of the forces that animate them, separate from 
the mass of blood many different substances, rejecting 
one to-day and admitting it to-morrow, &c. 
Do you wish for other proofs of the innumerable varie- 
ties which the different modifications of the organic sen- 
sibility of the mucous membranes produce in their func- 
tions ? Observe the urethra; in the ordinary state it lets 
the urine pass freely ; in the excitement in which its 
forces are in erection, its sensibility repels it and admits 
only the semen. Who does not know that in one species 
of epiphora, the mucous passages for the tears are open, 
and that the diminution only of their vital forces prevents 
this fluid from flowing in them ? The sensibility of the 
mucous surfaces is oftentimes so altered that their glands 
refuse to admit every kind of fluid ; this happens in the 
beginning of some peripneumonies, in which expectora- 
tion is entirely suppressed, it is always a serious begin- 
ning, and even an indication of death, if the state of the 
sensibility does not change, unless a relaxation, as it is 
commonly called, takes place. 
In general, I think that there are but few systems 
which deserve, more than this of which we are treating, 
to fix the attention of physicians, on account of the in- 
numerable alterations of which it is susceptible, altera- 
tions which almost always suppose those of the predomi- 
nant vital properties of this system, as the alterations of 
the muscular, nervous systems, &c. most often put in ac- 
tion the properties which more particularly belong to 
them, viz. animal contractility for one, and the sensibility 
of the same species for the other. MUCOUS SYSTEM. 
117 
The sensible organic contractility does not appear to be 
the attribute of the mucous system ; yet there is often in 
it something more than the insensible oscillations which 
compose the other organic contractility. For example, in 
the emission of semen, in which there is no agent of im- 
pulse at the extremity of the urethra, as in the evacuation 
of urine, it is very probable that this is spasmodically 
contracted to produce the jet, oftentimes very strong, 
which then takes place. The following phenomenon 
which I have observed in myself appears to belong to the 
same cause. In gaping, there sometimes escapes from the 
mouth then wide open, a small jet of fluid, which coming 
from the lateral parts of this cavity that it passes over, is 
thrown at some distance ; if a surface is then before the 
mouth, as when we read a book, this fluid is spread in 
small drops upon this surface ; it is the saliva which the 
excretory duct of Steno throws out with force. Now on 
the one hand this duct is almost wholly mucous, and on 
the other it has not at its posterior part a muscular agent 
of impulse. Perhaps the excretories which pour out their 
fluids in the deep parts of the organs, exhibit the same 
phenomenon. We know that the milk is also sometimes 
subject to a kind of ejection, when it is very abundant, 
an ejection which supposes a powerful contraction of the 
lactiferous ducts. In general, these different motions 
analogous to that of the dartos, of the cellular texture, 
&c. appear to hold a middle place between those of tone 
and those of irritability. 
Sympathies. 
There are few systems that sympathize more frequently 
with the others than this. Now in its sympathies, it 
sometimes influences and sometimes is influenced. The 
first Tissot calls the active mode of sympathy, the second 
the passive. Let us make use of this classification. 118 
MUCOUS SYSTEM. 
Active Sympathies. 
One point of the mucous system being inflamed, irri- 
tated or stimulated in any way, all the vital forces can 
enter separately into action in the other systems. 
Sometimes it is the animal contractility that is brought 
S37mpathetically into action ; thus the diaphragm, the in- 
tercostal and abdominal muscles contract to produce sneez- 
ing from irritation of the pituitary membrane, or cough 
from the irritation of the membrane of the bronchia, or 
from that even of the surface of the stomach, which pro- 
duces stomachic coughs, which, as we know, have nothing 
to do with affections of the chest. We know the general 
spasm that seizes all the muscles the instant a foreign 
body passes between the mucous edges of the epiglottis. 
Stones of the bladder and the urethra, by making the 
cremaster contract sympathetically, produce retraction of 
the testicle. Physicians might, I think, profit by the 
knowledge of these mucous sympathies. In apoplexy, 
in which the bronchia is sometimes filled with mucus 
that the patient cannot evacuate, the action of ammonia 
upon the pituitary membrane produces the double effect, 
1st, of stimulating the brain as blisters do ; 2d, of free- 
ing, by the cough it occasions, the surface of the bron- 
chia, which being obstructed, is an obstacle to the passage 
of the air. 
Sometimes it is the animal sensibility that is put into 
action by an affection of the mucous surfaces. The stone, 
that irritates that of the bladder, causes an itching at the 
end of the glans penis. That of the intestines being irri- 
tated by worms, an inconvenient itching is felt at the end 
of the nose. Whytt has seen a foreign body introduced 
into the ear, affect painfully the whole corresponding side 
of the head ; an ulcer of the bladder, produce every time 
the patient passed water, a pain on the superior part of 
the thigh, &c. &c. MUCOUS SYSTEM. 
119 
The sensible organic contractility is often sympatheti- 
cally excited by the affections of the mucous system. I 
might at first refer to this subject what I have observed 
respecting the organic muscles, almost all of which move 
trom an excitement of a contiguous mucous surface; but 
that is a natural phenomenon ; there are many others that 
are preternatural. A stone that irritates the internal sur- 
face of the pelvis of the kidney produces vomiting, which 
is, as we know, produced any time at will by an irrita- 
tion of the uvula. The instant the semen passes the 
urethra in coition, the action of the heart is commonly 
accelerated. Tissot speaks of a stone which, being en- 
tangled in the duct of Warton, produced a sympathetic 
discharge from the bowels. I saw at the Hotel Dieu two 
women, who, whenever they menstruated, and the mucous 
surface of the womb was consequently in activity, could 
retain the urine but a short time in the bladder, which 
contracted involuntarily to expel it the moment it enter 
ed it. At ordinary times, there was nothing peculiar in 
the evacuation of this fluid. 
As to the sympathies of insensible contractility and of 
organic sensibility, they take place when a mucous sur- 
face being irritated towards the extremity of an excretory 
duct, the gland of this duct is brought into action, when, 
for example, the saliva flows in greater abundance by the 
action of sialagogues upon the extremity of the Stenonian 
duct. Whenever there is a gastric derangement and the 
mucous surface of the stomach consequently sutlers, the 
surface of the tongue is sympathetically affected ; the 
glands situated under this surface increase their action 
and hence that white mucous coat, that is commonly call- 
ed a foul tongue, which is a real sympathetic catarrh, but 
which can however exist idiopathically. Here also is to 
be referred the remarkable influence of the mucous sys- 
tem upon the cutaneous; thus during digestion, in which 
the mucous juices pour out abundantly from all sides into MUCOUS SYSTEM. 
120 
the stomach and the intestines, and in which the mucous 
membranes of the gastric viscera are consequently in 
great action, the fluid of insensible transpiration is lessen- 
ed remarkably, according to the observation of Sanctorius; 
it is in very small quantity three hours after the meal, so 
that the action of the cutaneous organ is evidently less 
energetic. Thus during sleep, in which all the internal 
functions become more evident and are exerted to their 
utmost, and in which the sensibility of the mucous mem- 
branes is consequently strongly developed, the skin seems 
to be struck with a species of atony ; it becomes cold 
more easily, it allows less substances to escape from it, 
&c. To these sympathies also can be referred many phe- 
nomena of hemorrhages. We know with what facility 
the mucous surface ceasing, from any accidental cause, to 
throw out blood, as happens so often on that of the womb, 
another is immediately affected and discharges this fluid; 
hence hemorrhages from the nose, the stomach, the chest, 
&c. from the suppression of those of the uterus, &c. 
Passive Sympathies. 
In many cases, the other systems being irritated, the 
animal sensibility of this is brought into action. Among 
the numerous examples of this fact, the following is a re- 
markable one. In many diseases in which organs foreign 
to the mucous system are affected, we experience a sensa- 
tion of burning heat in the mouth, the stomach, the in- 
testines, &c. and yet the mucous surface, the seat of this 
sensation, does not disengage more caloric than usual; 
we may be convinced of this by placing the fingers in 
the mouth. This sensation is of the same nature as that 
which we refer to the glans penis when there is a stone 
in the bladder, as that which is experienced at the end of 
the nose from worms in the intestines, &c. There is no 
material cause of pain, and yet there is suffering. Thus 
in intermittent fevers we experience a cutaneous shiver- MUCOUS SYSTEM. 
121 
ing, though the skin may be as warm as usual ; I would 
observe in respect to this, that the mucous membranes are 
hardly ever the seat of an analogous sensation of sympa- 
thetic cold, but it is almost always a sensation of heat 
that the aberrations of the vital forces produce in them. 
Whence arises this difference between them and the 
cutaneous organs ? I know not. I attribute also to a 
sympathy of animal sensibility the great thirst which 
takes place in all the severe affections of any part. In 
all great wounds, after severe operations, in experiments 
on living animals, &c. we observe this thirst which de- 
pends upon a sympathetic affection of the whole mucous 
surface that extends into the mouth, the stomach and the 
oesophagus. 
Animal contractility cannot be put sympathetically 
into action in the mucous system, since it does not exist 
in it. 
The same is true of the sensible organic contractility. 
It is possible that sometimes the kind of motion we have 
noticed, and which resembles this property, may be sym- 
pathetically excited; I know no example of it. 
The insensible organic contractility is here very fre- 
quently in sympathetic activity. It is the skin especially 
which exercises by means of this property, a great influ- 
ence upon the mucous system. 1st. In hemorrhages of 
the mucous surface of the womb, the nostrils, &c. a cold 
body applied to the skin in the neighbourhood, contracts 
this surface and stops the blood. 2d. Wrho does not 
know that the production of most catarrhs is often the 
sudden consequence of the action of cold on the cutane- 
ous organ ? 3d. In various affections of the mucous 
membranes, baths which relax and expand the skin, fre- 
quently produce happy effects. 4th. When the tempera- 
ture of the atmosphere benumbs the cutaneous tone, that 
of the mucous system receives a remarkahle increase of 122 
MUCOUS SYSTEM. 
energy. Hence why in winter and in cold climates, in 
which the functions of the skin are very much diminish- 
ed, all those of this system increase in proportion. Hence 
the more evident pulmonary exhalation, the more abun- 
dant internal secretions, a more active digestion, more 
quickly performed and consequently an appetite more 
easily excited. 5th. When on the contrary the heat of 
the climate and the season relax and expand the cutane- 
ous surface, the mucous surface is in proportion contract- 
ed ; in summer, at noon, &c. there is a diminution of the 
secretions, of that of the urine especially, a slowness in 
the digestive phenomena from a defect in the action of 
the stomach and intestines, an appetite slow to return, 
&c. 6th. In various general affections of the skin, cer- 
tain portions of the mucous membranes are almost always 
affected. In scarlet fever, the throat most usually suffers 
sympathetically. This phenomenon is very common in 
small pox. 7th. In the latter periods of organic affections 
of the viscera, as in phthisis, diseases of the heart, en- 
largements of the liver, cancers of the womb, &c. the 
mucous membranes are affected like the serous surfaces. 
The kind of atony in which they then are, produces a 
more copious flow of mucous juices in them which are 
altered, become more fluid, &c. ; • hence the diarrhoeas 
that are called colliquative, which are then to the mucous 
surfaces, what dropsies are to the serous ones. 8th. It is 
also to this atony that must be attributed the pectoral 
hemorrhages which so frequently take place in the last 
periods of organic diseases, in those of the heart espe- 
cially. During the short time that I have been at the 
Hotel Dieu, there has already died more than twenty 
patients whom I have opened, of these affections almost 
forgotten by all practitioners before the time of Corvi- 
sart; I have only observed four examples in which 
passive hemorrhage of the lungs was not the precursor of 
death. MUCOUS SYSTEM. 
123 
From what we have thus far said, it is evident that the 
mucous system is one of those of the whole economy, in 
which life is the most‘’active. Always in contact with 
substances that stimulate and irritate it, it is as it were 
like the skin, in continual action. Yet the life is not the 
same in all its parts ; it undergoes in each remarkable 
modifications, which no doubt depend on those we have 
pointed out in the organization of this system, in the 
nature of its corion, in the arrangement of its papillae, in 
the distribution of its vessels and its nerves, in that of 
its glands, &c.; for as we have seen, none of these essen- 
tial bases of the mucous system is everywhere arranged 
in the same manner. There is an organization common 
to the system, and one peculiar to each of its divisions. 
It is the same in regard to its life ; there is a life com- 
mon to the system, and as many peculiar ones as there 
are parts to which it is extended. We know how much 
the animal sensibility of the pituitary membrane differs 
from that of the palatine, how powerfully the membrane 
of the glans penis and the urethra is stimulated by the 
passage of the semen which makes no impression upon 
any other mucous surface. The same is true in regard to 
the organic sensibility and the contractility of the same 
species. Each mucous surface, in relation with the fluid 
it is accustomed to, would bear the others with difficulty. 
The urine would be a stimulant for the stomach and the 
gastric juice for the bladder; the bile that remains in the 
gall-bladder would produce a catarrh upon the membrane 
of the nose, in the vesicula? seminales, &c. 
From these varieties in the vital forces of each division 
of the mucous system, it is not astonishing that the dis- 
eases of this system should also he very variable. Each 
has a general character, but this is modified in each mu- 
cous surface. There is an order of symptoms common 
Character of the Vital Properties. 124 
MUCOUS SYSTEM. 
to all catarrhs; but each has its peculiar signs, each has 
its different products. The fluid from a pulmonary- 
catarrh does not resemble that from a nasal one ; that 
coming from a urethral, vesical catarrh, &c. is wholly dif- 
ferent from that from an intestinal one. These fluids 
exhibit in their morbid changes the same differences that 
we have pointed out in their natural composition, differ- 
ences which are derived like them, from the different 
vitality of each portion of the mucous system. 
It is to these varieties of life and the vital forces that 
must be referred also those of the sympathies. Each 
portion of this system has a peculiar sympathetic action 
upon the other organs. The pituitary alone being irri- 
tated produces sneezing. You would excite in vain the 
extremity of the glans penis, the rectum, &c. you would 
never produce vomiting as you do by stimulating the 
uvula. 
An important remark should here be made in regard 
to the stomach. We know that there is no organ which 
performs a more important part in the sympathies than 
this. The least affection of this important viscus, the 
least gastric derangement, spread over the whole animal 
economy a painful influence; all the other parts feel it. 
I do not believe even that there is any uneasiness more 
fatiguing and general than that which we then experience 
in certain cases. The general weakness which takes 
place in hunger almost instantaneously, is sympathetic ; 
the alteration of nutrition has not had time to produce it. 
The same is true with regard to the sudden increase of 
the forces which results from the contact of the aliments 
upon the mucous surface of this viscus, an increase which 
cannot be attributed to the passage of the chyle into the 
blood, which has not yet had time to take place. 
I think the stomach owes this important part in the 
sympathies principally to its mucous surface. In fact, 
1st, its serous surface has no connexion with it, since it is MUCOUS SYSTEM. 
125 
there of the same nature as in all the rest of the perito- 
neum, besides in what is called inflammation of the abdq- 
men, and in which this serous surface is especially affect- 
ed, we do not observe such numerous sympathetic rela- 
tions. 2d. The fleshy coat appears to be the same as that 
of the whole intestinal canal; why then should it have 
different influences ? 3d. As it respects blood-vessels and 
nerves of the ganglions, the stomach is nearly organized 
like the rest of the alimentary tube. 4th. It has besides 
the par vagum ; but is this nerve alone capable of producing 
such numerous phenomena ? It can contribute to them ; 
but certainly the peculiar modifications which it experi- 
ences in the mucous surface, the peculiar nature of this 
membrane contribute also much to it. No membrane is 
organized like that of the stomach. Though we do not 
see perfectly at first view its organic differences, reflection 
is sufficient to convince us of them ; thus on the one hand 
no one separates so great a quantity of fluid, and on the 
other none furnishes one of a nature analogous to that of 
the gastric juice. 
ARTICLE FOURTH. 
DEVELOPMENT OF THE MUCOUS SYSTEM. 
I. State of the Mucous System in the First .ftge. 
The development of the mucous system follows in 
general the laws of that of the organs to which it belongs 
Early in the gastric apparatus, later in the pulmonary and 126 
MUCOUS SYSTEM. 
that of generation, it seems in its growth rather to obey 
the impulse it receives, than to give one to what sur- 
rounds it, an arrangement common to almost all the sys- 
tems which contribute to form the different apparatus. 
Observe in fact that there is always in the growth certain 
parts to which all the others refer; thus in the cerebral 
apparatus, the early size of the brain produces that of the 
bones of the cranium, of the dura-mater, the pia-mater, 
the arachnoides and the vessels ; thus it is on account of 
the spinal marrow, that the vertebral canal is so evident 
in the foetus ; thus all the serous surfaces have a growth in 
proportion to that of their respective organs, &c. &c. I 
would remark however that the early growth of the sys- 
tems which are only to follow that pf the parts to which 
they are destined, is only in the dimensions of length, 
breadth, &c. The thickness most commonly does not 
correspond with these dimensions. Thus the bones of 
the cranium though broader in proportion than those 
of the pelvis in the foetus, are not thicker. The extent of 
the dura-mater is in proportion greater than that of the 
albuginea which belongs to the same system ; but the 
organization is no further advanced. 
In the foetus, the delicacy of the mucous texture is ex- 
treme, the papillae are hardly perceptible. But by carry- 
ing the hand over a mucous surface, we feel there an 
extremely delicate velvet and such as is not equalled by 
the finest velvet. The redness of this system is not then 
as evident, because no doubt less blood penetrates it, as 
the various functions which are afterwards to take place 
upon these surfaces, as digestion, the excretions, respira- 
tion, &c. are but feeble or entirely wanting. At this 
age, the quantity of blood seems to be in an inverse ratio 
in the skin and in these surfaces. The mucous red is 
then like the muscular, of a very deep tinge, often even 
livid, on account of the nature of the blood circulating in 
the arteries. Then the adhesions of the mucous texture to MUCOUS SYSTEM. 
127 
the subjacent cellular are less ; those especially of this 
last with the surrounding parts are very slight; thus it is 
very easy to draw out whole the internal portion of the 
intestines of the foetus, from the external covering that 
contains it, so as to see two cylindrical canals, one of 
which is muscular and serous, the other cellular and mu- 
cous. The stretching destroys in this experiment all the 
valvulae conniventes, and the small intestines are as smooth 
on the interior as the large, in the canal artificially ex- 
tracted. If we subject this canal to ebullition, much 
more scum arises from it than in the adult; this scum is 
white and never green. The crisping that takes place a 
little before the first boiling, diminishes more in propor- 
tion the length of the canal, and consequently appears to 
be stronger. 
At birth, when respiration and digestion suddenly com- 
mence, the secretions increase, the mucous system ac- 
quires a remarkable degree of activity. It is instantly 
excited powerfully by the many new substances with 
which it is in contact. It is by it and by the cutaneous 
system that bodies foreign to ours then immediately stim- 
ulate it, and so much the more efficaciously, as the double 
surface which receives the excitement is not accustomed 
to it. Then the red blood which penetrates the mucous 
system, gives it an increase of energy and sensibility, 
which renders it still more proper to receive impressions. 
Thus the mucous juices which till then stagnated upon 
their respective surfaces, without fatiguing and irritating 
them, are suddenly for them, on account of their increase 
of sensibility, stimulants which excite them, and force 
the subjacent muscles to contract. Then the urine be- 
comes for the bladder a cause that promotes the contrac- 
tion of it. A few instants after birth, all the openings 
in which the mucous membranes begin, open and permit 
to escape the meconium, the urine and all the mucous 
juices. This internal and general shock that empties all 128 
MUCOUS SYSTEM. 
the mucous cavities, renders them fit to become the seat 
of the great functions which are soon to take place in 
them. 
When all the internal functions are in activity, the mu- 
cous surfaces experience no more sudden changes, analo- 
gous to that of which I have spoken. They grow like 
the other viscera in a slow and insensible manner; they 
preserve for a long time their original softness, which is 
remarkable, especially in the nose, the stomach, &c. and 
which during lactation, is not adapted in the infant, to 
the solid substances with which the adult is nourished. 
Is this softness the cause of the mucous affections which 
are in general so common at that age ? We know that 
then the mucous juices abound ; the pituitary membrane 
is more moist; the stomach and intestines are frequently 
affected with a species of catarrh which is the cause of 
the looseness that we have so often to combat in infancy. 
The membrane of the bronchia is also frequently diseased. 
The two extreme ages of life resemble each other by the 
abundance of the mucous juices secreted upon their re- 
spective mucous surfaces. 
In youth the mucous system is in very powerful action. 
The active hemorrhages of this system are very frequent 
at this age; those of the nose, the bronchia and even the 
stomach often take place ; those of the portions of this 
system, subjacent to the diaphragm, are then less com- 
mon. Observe that in man, hemorrhages of the gastro- 
pulmonary surface are infinitely more frequent than those 
of the genito-urinary surface, which on the contrary, are 
much more numerous in woman in whom one of them is 
natural to a part of this surface, viz. menstruation. 
At the period of puberty, the development of the 
genital parts in both sexes, gives much activity to a part 
of the genito-urinary surface ; then menstruation begins 
upon that of the womb ; then the sensibility of the 
urethra is raised in order to feel acutely the passage of MUCOUS SYSTEM. 
129 
the semen. Observe that this increase of energy is not 
attended with a weakness of the other parts, as happens 
in many cases ; on the contrary, all the systems, all the 
apparatus seem to borrow, from the force which the genital 
parts acquire, an increase of action. 
II. State of the Mucous System in the subsequent 
Ages. 
In the years which succeed youth, the mucous system 
continues to grow, thicken and become firmer. Its vital 
energy seems still to predominate for some time, in the 
superior surfaces, as in the pituitary, the membrane of 
the bronchia, &c.; thus the affections of these parts are 
more frequent until the thirtieth year. But as we ad- 
vance in age, the abdominal mucous surfaces appear to 
predominate over the others, as in general all the organs 
of this region do. 
Besides, a thousand causes in the course of life, make 
the state of the mucous system vary. We do not find it 
in two subjects, with the same shade of colour, with the 
same density, with the same external appearance. By 
taking any surface upon many subjects, that of the stomach, 
for example, we easily see these differences, with which 
we must be struck if we have opened dead bodies but 
ever so little. 
The redness of the mucous texture is very bright until 
the thirtieth year ; after that, it begins to alter. This tex- 
ture becomes more and more pale in old age; the blood 
enters it but in small quantity ; it acquires more consis- 
tence and density. The fingers carried over it no longer 
perceive that softness, that velvet so remarkable in the 
first age. Its forces, which grow languid, render diffi- 
cult, in the excretories, the exit of the fluids which pass 
through these tubes to be thrown out. Yet the mucous 
glands still secrete their fluids in very great abundance. 130 
MUCOUS SYSTEM. 
Often even these fluids increase in proportion which con- 
stitutes the catarrhal affections, so common in old age. 
But these affections then have the same character as the 
functions of the whole system ; secretion takes place 
slowly ; the disease is always chronic ; most often it ter- 
minates only with life. 
The mucous absorption is, at this age, slow and diffi- 
cult, like all the others ; the various contagions are taken 
much less easily, either by the respiratory surfaces, or by 
the contact of contagious miasmata upon the neighbour- 
ing surfaces of the skin. The chyle slowly absorbed, 
makes the digestive periods longer. SEROUS SYSTEM. 
THIS system, the name of which I borrow, like that 
of the preceding, from the fluid that constantly lubricates 
one of its surfaces, is always like it arranged in the form 
of membranes, and never in fasciculi like the muscular 
system, or in round bodies like the glandular. It is form- 
ed by the peritoneum, the pleura, the pericardium, the 
arachnoides, the tunica vaginalis, &c. The term serous 
membrane will then be very often used to designate it. 
No one, I believe, before the publication of my Treatise 
on the Membranes, had considered in a general manner 
these organs, which perform a less important part in the 
functions than the mucous, but which in diseases are 
almost as frequently affected. Pinel, who has perceived 
the analogy of their inflammations, has taken this system 
as a character of one of the classes of his phlegmasise. 
ARTICLE FIRST. 
OP THE EXTENT, FORMS, AND FLUIDS OF THE SEROUS 
SYSTEM. 
The serous system occupies the exterior of most of 
the organs of which the mucous lines the interior ; such 
are the stomach, the intestines, the bladder, the lungs, 132 
SEROUS SYSTEM. 
&c. We see it around all those that are essential to life, 
as around the brain, the heart, all the gastric viscera, the 
testicles, the bladder, &c. It does not form, like the mu- 
cous system, a surface everywhere continuous upon the 
numerous organs on which it is spread. But it is always 
found insulated in its different divisions which never 
have any communication. The number of these divi- 
sions is somewhat considerable. By considering in one 
view all the different serous surfaces, we see that as a 
whole they exceed the mucous surfaces viewed also in 
a general manner. One consideration is sufficient to 
convince us of it. The mucous and serous surfaces ac- 
company each other in a very great number of parts, 
as in the stomach, the intestines, the lungs, the bladder, 
the gall-bladder, &c. so as to exhibit in them nearly the 
same extent. But on the one hand, the mucous surfaces 
extend where the serous are not met with, as in the nasal 
fossae, the oesophagus, the mouth, &c. &c. ; and on the 
other, there is a very great number of serous surfaces 
existing separately from the mucous, as the pericardium, 
the arachnoides, &c. Now if we compare the extent of 
the separate serous surfaces, with that of the separate 
mucous surfaces, we shall sec that the first is much greater 
than the other. 
These considerations, apparently minute, deserve how- 
ever particular attention, on account of the relation of 
functions existing between these two surfaces taken as a 
whole, a relation which is especially connected with the 
exhalation of the albuminous fluids produced by one, 
and with the secretion of the mucous fluids, of which 
the other is the seat. Besides, in examining the extent 
of each serous membrane in particular, we see great 
varieties from the peritoneum which has the greatest sur- 
face, to the tunica vaginalis which has the least. 
The serous surface taken as a whole, compared with 
the cutaneous surface, is also evidently superior to it in SEROUS SYSTEM. 
133 
extent; so that in this respect, the quantity of albuminous 
fluids constantly exhaled within, appears to he much 
more considerable than that of the fluid which is inces- 
santly thrown off by insensible transpiration ; 1/ say in 
this respect, for different circumstances, by increasing the 
action of the cutaneous organ, can re-establish the equili- 
brium in the exhalation of these two fluids, one of which 
re-enters by absorption into the circulation, and the other 
is wholly excrementitious. I do not know even if the 
pulmonary and cutaneous exhalations united are not less 
than those which take place upon the serous surfaces. 
Every serous membrane represents a sac without an 
opening, spread upon the respective organs that it em- 
braces, and which are sometimes very numerous, as in 
the case of the peritoneum, sometimes single, as in the 
case of the pericardium, covering these organs so that 
they are not contained in its cavity, and so that if it was 
possible to dissect them from their surface, we should 
have this cavity whole. This sac has in this respect the 
same arrangement as those night caps, which are folded 
within themselves ; a trifling comparison, but which gives 
an accurate idea of this sort of membranes. 
From this general arrangement, it is easy to under- 
stand that the serous membranes are never opened to 
permit the vessels and nerves to penetrate the respective 
organs to which they go or from which they come off, 
but that they always wind round them and accompany 
them to the organ, and thus form for them a sheath which 
prevents them from being contained in their cavities; 
this removes the danger of infiltration of serum which 
lubricates them, an infiltration which would take place 
through the neighbouring cellular texture, especially if 
they were dropsical; if, as in the fibrous membranes, they 
were pierced with foramina for the passage of these ves- 
sels and nerves. This arrangement, exclusively remark- 
able in the membranes of which we are treating, and in 134 
SEROUS SYSTEM. 
the synovial ones, is evident at the entrance of the ves- 
sels of the lungs, the spleen, the intestines, the stomach, 
the testicles, &c. We see it very well in the arachnoides, 
a membrane essentially serous, as I have demonstrated 
elsewhere. 
From the general idea that we have given of these 
membranes, it is also easy to understand how almost all 
are composed of two distinct parts, though continuous, 
and embracing, the one the internal surface of the cavity 
where they are found, the other the organs of this cavity; 
thus there is a costal and pulmonary pleura, a cranial and 
cerebral arachnoides, one portion of peritoneum spread 
upon the gastric organs, and another upon the abdominal 
parietes, a free portion of the pericardium, and one ad- 
hering to the heart. The same arrangement exists in the 
testicles, &c. 
Though the serous membranes may be separate, yet 
there sometimes exists communications between them ; 
that for example of the cavity of the omentum with that 
of the peritoneum, that of the cavity of the arachnoides 
with the cavity of the membrane which lines the ventri- 
cles by the canal that I have discovered, and the external 
orifice of which is seen below and at the posterior part 
of the corpus callosum ; whilst the internal one is seen 
above the pineal gland, between the two rows of small 
round bodies which are usually found in this place. 
There is but one example of continuity between the 
serous and mucous membranes, that which exists, by 
means of the Fallopian tube, between the peritoneum 
and the uterine surface. How does the respective nature 
of the two membranes change here ? 
Free Surface of the Serous Membranes. 
Every serous membrane has one of its two surfaces 
free, everywhere contiguous to itself, and the other adher- 
ing to the neighbouring organs. The first is remarkable SEROUS SYSTEM. 
135 
for its polish, which especially distinguishes this system 
and the following, from all the other membranes. All the 
organs which exhibit this arrangement owe it to the cover- 
ing they borrow from it. The liver ceases to be smooth 
and shining at its diaphragmatic edge where the perito- 
neum abandons it. There is in this respect a great dif- 
ference in the appearance of the anterior and posterior 
face of the caecum. The bladder is rough wherever the 
peritoneal covering is wanting. The cartilages of the 
ribs have not the polish of those of the articulations which 
the synovial membrane covers. 
Does this remarkable attribute of the serous membranes 
depend on the compression exerted upon them ? Their 
situation in places where they are exposed to continual 
friction, would seem to make it probable. Bordeu thought 
so, when he said that all the parts of the abdomen are origi- 
nally covered with cellular texture, which by pressure is 
afterwards changed into membranes ; so that the perito- 
neum is formed partially upon each gastric organ, and its 
different parts give birth, by uniting, to the general mem- 
brane. This explanation of the formation of the perito- 
neum is applicable, according to him, to the pleura, the 
pericardium, and all the analogous membranes. But if this 
is the progress of nature, 1st, why, whatever be the period 
at which we examine the foetus, do we find the perito- 
neum and the serous membranes as much developed in 
proportion, as their corresponding organs ? 2d. How are 
the numerous folds of these membranes formed, such as 
the mesentery, the omentum, &c. ? 3d. Why are there 
parts where they do not exist though they are exposed 
to as great friction as that of the parts where they are 
found ? Why, for example, are the sides of the bladder 
destitute of it, whilst it covers its superior part ? 4th. 
Why does it not also form serous surfaces around the 
great vessels of the arm, the thigh, &c. which impart to 
the neighbouring organs an evident motion ? 5th. Why 136 
[SEROUS SYSTEM. 
does not the thickness of the serous membranes increase 
where the motion is strongest and diminish where it is 
weakest? Why for example does the thickness of the 
tunica vaginalis equal that of the pericardium ? 6th. 
How can friction internally produce an organized body, 
whilst externally it constantly disorganizes the epider- 
mis ? 7th. How can we associate the vascular lymphatic 
texture of the serous membranes with the pressure that 
produces them ? The impossibility of resolving these 
numerous questions proves, that it is not to mechanical 
pressure that must be attributed the formation of the 
serous membranes and the polish of their surface; that 
their mode of origin is the same as that of the other 
organs; that they commence and are developed with 
them ; that this polish is an evident result of their organi- 
zation, as the mucous papillae depend upon the texture of 
the surfaces to which they belong. What would be said 
of a system in which these papillae should be attributed 
to the pressure of the aliments upon the stomach, of the 
urine on the bladder, the air on the pituitary mem- 
brane, &c. ? 
The free surface of the serous membranes separates 
entirely from the neighbouring organs those upon which 
these membranes are spread ; so that they are to these 
organs real boundaries, barriers, if I may use the term, 
or integuments, if it should be preferred, very different 
however from those which are external. Observe in fact 
that all the principal viscera, the heart, the lungs, the 
brain, the gastric viscera, the testicles, &c. limited by their 
serous covering, suspended in the middle of the sac that 
it forms, only communicate with the adjacent parts where 
their vessels enter; everywhere else there is contiguity 
and not continuity. 
This insulation of position coincides very well with 
the insulation of vitality which is remarked in all the 
organs, and especially in those that we have just noticed. SEROUS SYSTEM. 
137 
Each has its peculiar life, which is the result of a parti- 
cular modification of its vital forces, a modification which 
necessarily establishes one in the circulation, nutrition 
and temperature. No part feels, is moved and nourished 
like another, unless it belongs to the same system. Each 
organ executes on a small scale the phenomena which 
take place on a large one in the economy ; each takes 
from the circulation the aliment that is proper for it, 
digests it, throws back into the mass of blood, the portion 
which is heterogeneous to it, and appropriates to itself 
that which can nourish it; it is digestion in miniature. 
No doubt the ancients wished to give an idea of this 
truth which has been so well explained by Bordeu, when 
they said that the womb wras a living animal within 
another. A very important use then of the serous mem- 
branes is to contribute, by rendering independent the 
position of their respective organs, to the independence 
of the vital forces, life and functions of these organs. 
Let us not forget to consider under the same point of 
view, the moist atmosphere with which they are con- 
stantly surrounded, an atmosphere analogous to that which 
the cellular texture forms for various other organs. In 
this atmosphere all the morbific emanations of the organ 
go and are lost, if we may so say, without these emana- 
tions injuring the other organs. We have seen that this 
atmosphere in the cellular system is sometimes the seat 
of phenomena wholly different, and serves to transmit 
diseases from one organ to another. Now the serous 
membranes are a barrier much less easily surmounted, 
because they have not filaments which go from one organ 
to another, there is only contiguity as I have said, with 
the organs that they surround. We very rarely see in 
the abdomen a disease of the liver communicated to the 
intestines, one of the spleen passing to the stomach, &e. 
The smoothness of the free surface of the serous system 
greatly facilitates the motions of the organs which it 138 
SEROUS SYSTEM. 
covers. We have already observed that nature employs 
two principal means for this object, viz. the membranes 
and the cellular texture. By distributing externally the 
second of these means, it has designed the first especially 
for internal motions. The smoothness and moisture of 
the serous surfaces are singularly favourable for them. 
These internal motions are usually regarded only in an 
insulated manner, as relating to the functions of the organ 
that executes them, as in relation to the circulation for 
the heart, respiration for the lungs, digestion for the 
stomach, &c. But they should also be considered in a 
general manner; they should be regarded as carrying 
through the whole machine a continual excitement which 
supports and animates the forces and the action of all the 
organs of the head, the chest and the abdomen, which 
receive less sensibly than the organs of the extremities, 
the influence of external motions. It is these internal 
motions that excite, sustain, and develop within, the nutri- 
tive phenomena, as the motions of the thigh, the arm, &c. 
Avithout, favour the nutrition of the muscles which are 
found there; this is seen very evidently in bakers and 
other mechanics who exert more particularly this or that 
part. It is thus that the serous membranes contribute 
indirectly to the nutrition and growth of their respective 
viscera ; but they never have a direct influence upon this 
nutrition, because their organization and life are different 
from the life and organization of these viscera. 
The free surface of the serous system differs essentially 
from that of the mucous, in this, that it contracts fre- 
quent adhesions. The pleura is of all the serous organs, 
that in which these adhesions are the most evident. We 
find almost as many dead bodies in which they exist, as 
we do those in which they do not. Next to the pleura 
is the peritoneum, then the pericardium, then the tunica 
vaginalis, then the arachnoides, which is that of all the 
serous surfaces in which adhesions are the least frequent, SEROUS SYSTEM. 
139 
though I have observed them in it. These adhesions 
exhibit many varieties which can be studied best on the 
pleura, which are as follows. 
1st. Sometimes the costal and pulmonary portion are 
so identified at many points or in every part, that they 
make but a single membrane, and are united as closely 
as the two edges of the lip in a hare-lip that has been 
operated upon with success. 2d. At other times the ad- 
hesion is so slight, that the least effort is sufficient to 
destroy it. I have many times noticed this fact in the 
pericardium. I saw it once in the tunica vaginalis of a 
man who had been operated upon for hydrocele by means 
of injection, at the time I was surgeon for operations at 
the Hotel Dieu. Separated then from each other, the two 
surfaces were uneven ; they lost their polish. 3d. Fre- 
quently between the costal and pulmonary portion of the 
pleura, between the surfaces of the peritoneum, &c. there 
are several elongations of various lengths, which form a 
kind of loose bridles, traversing the serous cavity, having 
the same organization and polish as the membrane of 
which they appear a kind of fold, containing in their 
interior a species of small canal, because they are formed 
by two layers united together, resembling very much the 
elongation of the synovial membrane of the knee, which 
goes from the posterior part of the patella to the space 
between the condyles of the femur, having also an appear- 
ance analogous to the different natural folds of the peri- 
toneum. We can hardly conceive that these filaments so 
regularly organized can result from inflammation. I am 
inclined to believe that they are owing to an original con- 
formation. 4th. Frequently between the two portions of 
the pleura, there are seen many other elongations wholly 
different, which are not smooth, and do not form canals, 
but which appear to be flocculent and really analogous to 
the cellular layers; so that where they exist it may be 
6aid, that the membrane is entirely changed into this tex- 140 
SEROUS SYSTEM. 
ture, which is besides, as we shall see, the essential base 
of its organization. 5th. I do not speak of the adhesions 
produced by false membranes, by albuminous flakes, inter- 
mediate to the two portions of a serous surface, &c. These 
adhesions are to a certain point foreign to these surfaces. 
II. Adherent Surface of the Serous System. 
The external surface of the serous membranes adheres 
almost everywhere to the neighbouring organs ; it is rare 
in fact to see these membranes detached on both sides. 
The arachnoides at the basis of the cranium, and some 
other examples are exceptions. This adhesion of the 
serous membranes to their respective organs, is wholly 
different from that of the fibrous membranes. In this 
last, the passage of the vessels so unites the two parts, 
that their organization seems to be common, and when 
one is removed, the other almost always dies, as is seen 
in the periosteum in relation to the bones, &c. On the 
contrary, every serous membrane is almost foreign to the 
organ it surrounds ; their organization is different. The 
following are proofs of it; 
1st. We very often see these membranes abandon and 
cover again successively their respective organs; thus 
the broad ligaments, at a great distance from the womb 
in the ordinary state, are to it like a serous membrane 
during pregnancy. An intestine when distended borrows 
from the mesentery a covering that quits it when it con- 
tracts. The omentum is by turns, as Chaussier has well 
observed, a loose membrane in the abdomen and a cover- 
ing of tbe stomach. The peritoneal envelope of the 
bladder often leaves it almost entirely. Has not the her. 
nial sac of those enormous tumours of gastric viscera 
originally served to line the parietes of the abdomen ? 
Now it is evident, since the different organs can exist 
separate from their serous membranes, that there is no SEROUS SYSTEM. 
141 
connexion between their organization. 2d. It is always a 
loose texture, easily stretched in every direction, that 
serves as a means of union, and never a sanguineous vas- 
cular system, as in most of the other adhesions. 3d. 
The affection of an organ is not a necessary consequence 
of that of its serous membrane, and reciprocally the organ 
is often affected and the membrane does not become dis- 
eased. For example, in the operation for hydrocele, the 
testicle remains almost always sound in the midst of the 
inflammation of its tunica vaginalis. The inflammation 
of the mucous membrane of the intestines is not a conse- 
quence of that of their peritoneal covering ; and recipro- 
cally in the various acute catarrhal affections of the organs 
with a mucous membrane within and a serous one with- 
out, this last is never found inflamed. In a word, the 
affections of the mucous membranes are everywhere very 
distinct from those of the serous, though most commonly 
both contribute to the formation of the same organ. It 
is evident that a line of demarcation so great in the affec- 
tions supposes one of course in the organization. The 
life of the serous membranes then is entirely distinct 
from that of their corresponding organs. 
Yet there are cases where these membranes do not pre- 
sent this loose adhesion, and where they become so united 
to the organs which they line, that frequently the most 
delicate scalpel cannot separate them. Observe the tunica 
vaginalis on the albuginea, the arachnoides on the dura- 
mater, and other membranes which form what I have 
called the sero-fibrous, &c. ; such is the connexion of 
these different surfaces, that many have been mistaken to 
the present time for a single membrane. There is how- 
ever no more identity in the organization, than where the 
serous membranes are more loosely attached to their re- 
spective organs, as is seen in the peritoneum, the pleura, 
&c. Diseases sometimes make this difference very evi- 
dent. I have seen the arachnoides in a subject that had 142 
SEROUS SYSTEM. 
been affected with a chronic inflammation, evidently thick- 
ened on the internal surface of the dura-mater, without 
this having experienced the slightest alteration ; it was 
detached without difficulty and torn with great ease. 
III. Serous Fluids. 
Every serous membrane is moistened on its internal 
surface by a fluid almost the same as the serum of the 
blood. The exhaling orifices constantly pour it out and 
it is constantly taken up by the absorbents. Its quantity 
varies. A mere dew in the natural state, it is exhaled in 
vapour when the serous surfaces are laid bare and allow 
the air to dissolve it. It is in general more abundant in 
dead bodies than in the living, because on the one hand 
the transudation which the tonic forces prevent, then 
easily takes place from the destruction of these forces, 
and supplies the place of the vital exhalation, by trans- 
mitting mechanically by their weight, the fluids of the 
surrounding organs to the different serous cavities, and 
because on the other hand, this destruction of the tonic 
forces prevents every kind of absorption ; hence the 
stagnation and accumulation of this fluid. We know to 
what an extent this increases in various dropsies, espe- 
cially in that of the abdomen. 
Does this quantity vary according to the different states 
of the organs which the serous membranes cover? It 
has been long said, that the synovia is exhaled in greater 
abundance in the motion of the articulations, than in their 
state of rest. I have no data on this point founded upon 
experiment; but I am certain that I have many times ob- 
served in living animals, that the exhalation of the serous 
surface of the abdomen does not increase during diges- 
tion, or at least if it is greater, absorption becomes more 
active, and thus the surface of the peritoneum is not more 
moist than at another time. I have opened the thorax of SEROUS SYSTEM. 
143 
many small guinea-pigs, after having first made them run 
a long time in the chamber in order to accelerate their 
respiration, and I have not observed greater moisture on 
the pleura. Yet it cannot be doubted, as we shall see, 
that the quantity of the serous fluids may be very variable 
in the different acute diseases ; that the serous membranes 
exhale more or less of them, according to the manner in 
which they are sympathetically affected. 
In the first periods of inflammations, in which the ex- 
halants of the serous membranes are full of blood which 
is preternaturally introduced into them, the serum does 
not ooze in greater quantity from their free surface. Then 
as they are on the one hand very sensible, and very dry 
on the other, the motions of the organs that they cover 
are wonderfully painful. It is in these first periods that 
adhesions take place. If they are not formed either on 
account of the motion, or for other reasons, and if resolu- 
tion of the inflammation does not take place, then hap- 
pens to the serous surfaces what happens to a wound not 
united; they suppurate, but this suppuration is never at- 
tended with ulceration or erosion of their substance. 
However abundant the purulent collections may be, these 
membranes always remain sound; their texture is only 
more or less thickened ; pus is thrown out by them, like 
the natural serous fluids, that is by exhalation. We know 
how much this fluid varies in consistence from milky 
serum, to the thickest false membrane that adheres 
strongly to the surface that has exhaled the materials of it. 
The nature of the fluids of the serous system is very 
evidently albuminous. The instant one of the mem- 
branes of this system is plunged into boiling water, I 
have observed that it is covered with a white layer which 
is concrete albumen, and which being removed some 
time after, leaves the surface nearly of its original col- 
our. All the substances which coagulate albumen pro- 
duce a similar layer upon the serous surfaces. The ex- 144 
SEROUS SYSTEM. 
periments of Hewson, who has collected some spoonsful 
of these fluids in the great animals, confirm their albumi- 
nous nature. Rouelle and Fourcroy who have analyzed 
the water of dropsies have also found albumen predomi- 
nant in it. Observe upon this subject that all the white 
flakes swimming in this water, that the false membranes 
that form in it and the white fluids which give it the ap- 
pearance of milk, appear to be only albumen which is 
found in different degrees of consistence. It might be 
said that the heat of inflammation has produced the same 
phenomenon during life, that common caloric does upon 
the white of an egg, the water of dropsies, &c. I shall 
not treat of the other accessory principles that enter into 
the composition of the serous fluids. 
ARTICLE SECOND. 
ORGANIZATION OP THE SEROUS SYSTEM. 
The first characters of the structure of these mem- 
branes are a white, shining colour, less brilliant than that 
of the aponeuroses ; a variable thickness, very evident 
upon the liver, the heart, the intestines, &c. hardly dis- 
coverable upon the arachnoides, the omentum, &c. ; a re- 
markable transparency whenever these membranes are 
raised for a considerable extent, or are examined where 
they are detached on both sides, as on the omentum. 
All have but a single layer which it is possible, at the 
places where it is thick, to raise from the cellular layers, 
but which can never be neatly divided into two or three 
portions ; a character essentially distinct from those of 
the mucous membranes. The action of a blister on their SEROUS SYSTEM. 
145 
external surface first laid bare, for example, on a portion 
of intestine drawn out in a living animal, does not make 
a pellicle rise upon it, as upon the skin, a pellicle under 
which the serum is collected. I have frequently made 
this attempt. What is the immediate structure of this 
single layer of the serous membranes ? I shall now ex- 
amine it. 
I. Cellular Nature of the Serous Texture. 
Every system is in general, as we have thus far seen, 
an assemblage, 1st, of common parts, which are especially 
the cellular texture, the blood vessels, the exhalants, the 
absorbents and the nerves, which form as we have said 
the outline and the frame of it, if I may so express my- 
self ; 2d, of a peculiar fibre formed by a substance which 
is deposited in this outline, by gelatine, for example, for 
the cartilages, by gelatine and phosphate of lime for the 
bones, by fibrin for the muscles, &c. That which makes 
these organs resemble each other then is the cellular 
organ, the vessels and the nerves; that which distin- 
guishes them, is their peculiar texture, which depends 
itself upon a peculiar nutritive matter. A bone would 
become a muscle, if, without changing its texture at all, 
nature had imparted to it the faculty of secreting fibrin, 
and of encrusting itself with it, instead of separating the 
phosphate of lime and being penetrated with it. But 
the serous system does not appear to have in it a distinct 
nutritive matter, and consequently a peculiar texture. It 
is only formed of the mould, the outline of others, and 
is not penetrated by a substance that characterizes it. 
Almost wholly cellular, it does not differ from this sys- 
tem in its common form, except by a degree of conden- 
sation, by an approximation and union of cells which are 
found scattered in the ordinary state. 
The following are the proofs that the texture of the 
serous system is wholly cellular. 1st. There is an iden- 146 
SEROUS SYSTEM. 
tity of nature where there is an identity of functions and 
diseases ; now it is evident that the uses of these mem- 
branes and of the cellular texture, as it respects the con- 
tinual absorption and exhalation of lymph are completely 
the same, and that the phenomena of the various dropsies 
are common to them, with the difference only of the 
effusion in the one and infiltration in the other. 2d. The 
inflation of air into the texture subjacent to these mem- 
branes terminates by bringing them almost to a cellular 
state, when it succeeds and is pushed for some time ; an 
experiment which is frequently very difficult. 3d. Mace- 
ration, as has been remarked by Haller, produces at length 
the same effect, but in a still more evident manner. 4th. 
The various cysts, hydatids, &c. whose appearance, tex- 
ture and nature even are entirely the same as in the serous 
membranes, as we have seen, always arise in the midst 
of the cellular texture, grow at its expense and are wholly 
formed of it. 5th. No fibre is found in the serous mem- 
branes ; a character that distinguishes it from all the other 
organs and analogous to that of the cellular texture. 
To these various proofs of analogy, of identity even of 
the cellular and serous systems, we can add the action of 
different reagents, which give results precisely similar in 
both. 1st. Ever}7 serous membrane when dried, becomes 
transparent, does not turn yellow like the fibrous and 
the mucous membranes, preserves a pliability foreign to 
these membranes when dried, and gradually resumes 
its original state when it is immersed in water. 2d. It 
becomes putrid much slower than the mucous surfaces, 
the muscular layers, the glands, &c. This is remarkable 
;n the abdomen, upon the peritoneum which is frequently 
almost untouched, when every thing is putrid around it, 
as may be seen by removing it; for its transparency 
would make you believe at first view that it was altered, 
if you examine it upon the fleshy and mucous surfaces. 
3d. Maceration at the ordinary temperature of cellars, re- SEROUS SYSTEM. 
147 
duces with great difficulty to a pulp the serous mem- 
branes. The omentum, the finest and most delicate of 
these membranes has resisted it for a very long time in 
my experiments. This phenomenon is particularly strik- 
ing when compared with the maceration of tendons which 
are so resisting, and which support such great efforts 
during life. These become pulpy in wrater before the 
omentum is touched. The same phenomenon takes place 
with regard to all the other serous surfaces. 4th. In boil- 
ing water, these surfaces acquire the horny hardness like 
the fibrous system, but furnish infinitely less gelatine ; 
they do not become yellow like it. The pleura in those 
portions of the thorax of animals that are brought to our 
tables, has almost its ordinary appearance ; only it is less 
shining, has lost the faculty of crisping from the action 
of caloric, is no longer affected in the same way by acids, 
&c. If it was of a fibrous nature it would have disap- 
peared in gelatine, on account of its delicacy. I shall 
say the same of the external membrane of the spleen, the 
liver and the lungs. Compare these membranes, that are 
brought to our tables, when boiled with the intermuscu- 
lar aponeuroses, the tendons, &c. you will see that it is 
impossible to confound, as has been done, all the white 
textures together, in regard to their nature. 
If we compare the different effects of agents the most 
known upon the serous system, with those that we have 
observed upon the cellular system, we shall see that they 
are entirely the same ; that these two systems are con- 
sequently analogous, and even identical. 
The serous system when it putrefies in the open air 
does not become green like the skin, but is of a dull and 
very deep grey. During life, on the contrary, its black- 
ness is very evident in gangrene which is sometimes the 
result of an acute inflammation, sometimes of those chro- 
nic inflammations, attended with many small white tuber- 
cles, which are so frequently found upon these membranes. 148 
SEROUS SYSTEM. 
This difference arises from the circumstance, that in the 
dead body these surfaces are not penetrated with blood at 
the time they become putrid ; whereas they contain much 
during life, when putrefaction succeeds inflammation which 
has filled the exhalants with it. Many other facts prove, 
that the greater the quantity of blood there is in a part 
when it putrefies, the more livid and black it becomes. 
In the many dead bodies that I have opened, I have never 
yet observed gangrene except in the peritoneum. I have 
never seen it in the pleura, the arachnoides, the pericar- 
dium, the tunica vaginalis; it no doubt takes place in 
them ; but I think I have opened dead bodies enough 
to allow my observation to establish as a general princi- 
ple, that the peritoneum is more subject to it than all the 
other analogous organs. 
Though the different considerations offered above estab- 
lish much analogy between the cellular and the serous 
systems, they exhibit however real differences. First 
their external appearance is not the same. Then there is 
something in their intimate nature that we are unacquaint- 
ed with, and which differs also; for whenever two organs 
are identical in their nature, they are subject to the same 
affections; now there is a disease of the serous surfaces 
that is not seen in the cellular system; it is those slow 
inflammations of which I spoke just now, a disease which 
should not be ranked in the class of the phlegmasiae, and 
which the production of the small tubercles that attend 
it, especially characterizes. Authors who have not suf- 
ficiently attended to it, have denominated it chronic 
enteritis in the peritoneum, latent inflammation in the 
pleura, &c. though however foreign to every subjacent 
organ, except in the latter periods when it is propagated 
by the cellular texture, it has its seat exclusively in the 
serous membranes, and is an affection peculiar to these 
membranes, as miliary eruptions are to the cutaneous 
surfaces, as aphthae to the mucous surfaces, &c. Add SEROUS SYSTEM. 
149 
to this difference that of the pus which the cellular tex- 
ture and the serous surfaces secrete ; this fluid is not the 
same in the two systems. The difference of its nature is 
not known; but its external appearance is by no means 
the same. 
II. Parts common to the. Organization of the Sei'ous 
System. Exhalants. 
A very evident exhalation is constantly going on upon 
the serous surfaces. A particular order of vessels is the 
agent of this exhalation, the matter of which is the fluid 
mentioned above. These vessels are very distinctly de- 
monstrated in this system; it is the only one in which 
the eye of the anatomist can accurately trace them. The 
following are the means of seeing them; 1st, in a living 
animal, draw out an intestine from the abdomen; it will 
have a reddish tinge owing to the vessels under the serous 
coat, and hardly at all to the vessels in this coat itself. 
Irritate it, and reduce the intestine after attaching a 
string to it, as in the operation of hernia where there is 
gangrene, draw it out again at the end of six and thirty 
or eight and forty hours ; it will exhibit many reddish 
lines, running over this serous surface, and showing in it 
plainly the exhalants wrhich were insensible in the natural 
state, on account of the transparency of their fluids. 2d. 
Very fine injections cover in an instant all the serous sur- 
faces with an infinite number of lines of the colour of the 
injected fluid, lines which are evidently exhalants full of 
this fluid. 3d. In these injections an extremely fine dew is 
made to ooze out upon the smooth surface of the serous 
membranes, a dew which takes place without rupture or 
transudation, and of which the exhalants are the sources. 
4th. If a serous surface is laid bare in a living animal, 
and wdped dry, it is soon after covered with new serum, 
which the exhalants furnish. 150 
SEROUS SYSTEM. 
Absorbents. 
From the texture of the serous membranes, it is evident 
that the lymphatic system enters essentially into their 
formation, and that they are probably only a net-work of 
exhalants and absorbents ; for we have seen that the cellu- 
lar organ is an assemblage of them. But this assertion 
which analogy dictates is also supported by direct proofs. 
1st. The fluid of the dropsies of the different cavities 
varies in density and colour; now Mascagni has always 
observed that the lymphatics in their neighbourhood con- 
tained a fluid exactly analogous. 2d. The same author 
has found in two dead bodies, with a sanguineous effusion 
in the thorax, the absorbents of the lungs loaded with 
blood. 3d. In a man who had become emphysematous 
after having been poisoned, these vessels were distended 
with air. 4th. Coloured fluids injected into the abdomen 
or thorax are soon after found, it is said, in the neigh- 
bouring lymphatics, with the same colour. I have often 
repeated this experiment; the injected fluid has been 
soon absorbed, but not the matter which coloured it; so 
that this matter, more condensed after absorption, tinged 
the serous surface, the lymphatics being as transparent as 
usual. It is necessary in general to choose the abdomen 
for these experiments, because the absorbents being much 
exposed on the liver, can be more easily examined there. 
This absorbent faculty is preserved some time after death ; 
but care should be taken, in order to obtain then the 
effect more cei’tainly, to keep the animal, if a warm blood- 
ed one, in a bath of nearly its own temperature; I have 
had frequent opportunities of being convinced of this 
truth, and of observing with Cruickshank, that what Mas- 
cagni has said upon the absorption of dead human bodies, 
fifteen, thirty, forty-eight hours even after death, is at 
least very much exaggerated. 5th. The following experi- 
ment I make every year to demonstrate the absorbents ; SEROUS SYSTEM. 
151 
I macerate for five or six hours the heart of an ox in 
water; at the end of this time, the serous membrane of 
this organ, which hardly allowed these vessels to be per- 
ceived, appears to be covered with them. 6th. When 
the serous membranes are inflamed, the subjacent lym- 
phatics are distended, like them, by the red globules of 
blood, &c. &c. 
It appears then to be demonstrated, 1st, that the absor- 
bents open by an infinite number of orifices upon the 
serous membranes; 2d, that their origins a thousand times 
intermixed with each other, and with the orifices of the 
exhaiants, contribute especially to form their texture; 
3d, that the difficulty of distinguishing the absorbent 
and exhalant pores is no reason for denying their exist- 
ence, this difficulty arising from their extreme delicacy 
and from the oblique direction in which they open be- 
tween the layers of these membranes ; thus the obliquity 
of the insertion of the duct of Warton, and of the ductus 
choledochus even would render the inspection of them 
very difficult, though these ducts were infinitely larger; 
4th, that from this structure, the serous membranes, al- 
ways arranged as we have seen in the form of sacs with- 
out an opening, should be regarded as great reservoirs 
between the exhalant and absorbent systems, in which the 
lymph in going from one remains some time before enter- 
ing the other, in which it undoubtedly undergoes various 
preparations of which we shall always be ignorant, be- 
cause it would be necessary to analyze it comparatively 
in these two orders of vessels, which is almost impossible, 
at least for the first, and finally in which it serves dif- 
ferent uses relative to the organs around which it forms 
a humid atmosphere. 
Blood Vessels. 
Do blood vessels enter into the structure of the serous 
membranes ? These vessels are very numerous around 152 
SEROUS SYSTEM. 
them, as is seen in the peritoneum, the pericardium, the 
pleura, &c.; they wind upon their external surface and 
ramify there. But I have always doubted whether the 
greatest number of those which are thus contiguous to 
them, really make a part of their texture, and I am even 
convinced of the contrary. The following considerations 
support my opinion. 1st. When these vessels are inject- 
ed, they can be easily raised with a scalpel from the exter- 
nal face of these membranes, without injuring their con- 
tinuity, which can never be done in the fibrous or mucous 
membranes. 2d. No blood vessel is discoverable on these 
membranes which are free on both faces. The arach- 
noides at the base of the cranium furnishes an example of 
this. 3d. The vessels frequently change relations with 
these membranes. I have proved above that when the 
omentum is applied to the stomach when it is full, the 
vessels that are between its layers, do not mount with it 
upon this viscus, on account of the great stomachic coro- 
nary which opposes it. When dead bodies having large 
hernias are injected, the vessels that wind in the ordi- 
nary state upon the surface of the peritoneum which 
corresponds to the ring, are not seen extending below 
upon the hernial sac. Certainly the vessels that are 
observed in the broad ligaments of the womb, do not 
follow them in the great displacements they undergo in 
pregnancy. 
I think it then very probable that the serous membranes 
have but very few blood vessels ; what are called arteries 
of the peritoneum, the pleura, &c. are but trunks wind- 
ing on their external surface, capable of abandoning it 
when they are displaced, being as it were foreign to them, 
not entering immediately into their structure, to which 
the absorbent, exhalant and cellular systems almost alone 
contribute. No doubt communications exist between the 
arterial system and the serous membranes, by means of 
the exhalants; but nothing precise is yet known upon the SEROUS SYSTEM. 
153 
nature, arrangement, and to a certain extent even, the 
functions of these vessels. 
III. Varieties of Organization of the Serous System. 
We have seen the mucous system exhibiting in each 
part where it is found, numerous differences of structure 
and varying in each region and in each organ. The serous 
system varies also, though less than the preceding. 1st. 
Each membrane has its peculiar structure. Compare for 
example, the arachnoides and the peritoneum ; the one 
fine, delicate and transparent, yields to the least effort, 
has no resistance, tears almost as soon as it is touched, 
never remains whole at the base of the cranium, where 
it is free, if the brain is raised ever so little, and has, 
when pressed between the fingers, a remarkable softness. 
The other, thicker and more compact, bears without 
breaking all the efforts imparted to the abdominal viscera; 
it can be pulled with impunity. Its texture is wholly 
different. 2d. The different portions of the serous mem- 
branes have not the same organization ; the omentum is 
for example evidently dependant upon the peritoneum 
and yet it does not resemble it. I have observed that the 
intestinal portion of this membrane is much more delicate 
than its hepatic, mesenteric portions, &c. That the half 
of the tunica vaginalis which lines the albuginea and is 
identified with it, is certainly not the same as the half 
which is free on the side of the dartos muscle. I can- 
not say precisely in what these differences consist; but 
the external appearance is sufficient to establish them. 
Ought we then to be surprised, if all the serous sur- 
faces are not equally subject to the same diseases ; if 
inflammation attacks them with such different degrees of 
violence ; if it takes place ten times upon the pleura to 
once that it appears upon the arachnoides ; if in the peri- 
cardium, the tunica vaginalis and the peritoneum, it does 154 
SEROUS SYSTEM. 
not exhibit the same symptoms; if dropsies vary also 
wonderfully in each ; if the slow inflammations attack 
them differently, &c. ? The pericardium is subject to an 
affection which I have seen upon no other serous surface, 
and which is yet extremely frequent upon this; I refer 
to the white layers, more or less broad, that are formed 
on its internal surface, which would be thought at first 
view to belong to its texture, which can however be 
raised from it leaving it sound. I do not know whence 
these layers come ; do they correspond to the false mem- 
branes of the pleura ? 
Neither should we be surprised at what has been said 
of the varieties which the same membrane exhibits in its 
diseases. Frequently the whole of the peritoneum is dis- 
eased, and the omentum remains sound and vice versa. 
The layers of which I have just spoken are seen upon the 
cardiac portion, and not upon the free portion of the peri- 
cardium. 
Observe however that all the diseases of this system 
have a common character which is evidently derived from 
the analogy of organization. This and the synovial are 
the only ones in which large serous collections take place, 
in which slow and tubercular inflammations are formed. 
The most of their modes of adhesion belong only to the 
serous system. Inflammation has a peculiar and distinc- 
tive character in it, of which all the serous membranes 
partake with some modifications. The inflammation of 
the meninges had been classed among the serous phleg- 
masias, from the analogy of the symptoms, before I had 
demonstrated that the arachnoides, one of these meninges, 
belongs essentially to the serous system. It is on account 
of this membrane, and not on account of the dura-mater 
which is of a fibrous nature, that phrenitis should be 
referred to the diaphanous membranes. SEROUS SYSTEM. 
155 
ARTICLE THIRD. 
PROPERTIES OP THE SEROUS SYSTEM. 
I. Properties of Texture. Extensibility. 
The serous membranes are endowed with an exten- 
sibility much more limited, than the enormous dilatations 
of which they are capable in certain cases, would at 
first lead us to believe. The mechanism of their dilata- 
tion evidently proves it. This mechanism depends upon 
three principal causes ; 1st, upon the development of the 
folds that they form, and this is the most powerful of the 
three causes. Hence why the peritoneum, which of all 
the membranes of this class, is the most exposed to dila- 
tations, as from pregnancy, ascites and visceral enlarge- 
ments, more frequent there than elsewhere; hence, I say, 
why the peritoneum exhibits so great a number of these 
folds, such as the mesentery, the mesocolon, the meso- 
rectum, the two omentums, the fatty appendices, the fold 
of the cajcal appendix, the broad ligaments of the womb, 
the posterior ones of the bladder, &c. &c. Hence why 
also these folds are seen around organs subject to habitual 
alternations of dilatation and contraction, as around the 
stomach, the intestines, the womb and the bladder ; very 
evident in the second state, but slightly apparent in the 
first. 2d. The enlargement of the serous cavities belongs 
to the displacements of which their membranes are capa- 
ble. Thus when the liver is considerably enlarged, its 
serous membrane increases its extent in part at the ex- 
pense of that of the diaphragm, which being drawn is SEROUS SYSTEM. 
detached and applied upon the enlarged viscus. f have 
seen, in an aneurism of the heart, the pericardium which 
had been able to yield but very little, detached in part 
from the portion of the gi'eat vessels which it covered. 
3d. Finally, the texture of these membranes undergoes a 
real distension and elongation. But it is in general the 
least sensible cause of the enlargement of their cavity; 
it is only in the great enlargements that it has an evident 
influence ; in common cases, the two first causes are almost 
always sufficient. 
I will make an important remark upon the subject of 
the displacements of which the serous membranes arc the 
seat in the motions of their respective organs ; it is that 
these displacements are very painful when these mem- 
branes are inflamed. When the dilated intestines separate 
the two diseased layers of the mesentery to lie between 
them, when the stomach goes between those of the omen- 
tum, &c. when the peritoneum is inflamed, the patient 
suffers much. Hence why flatulence is then so painful, 
why it is then necessary to avoid taking at once a great 
quantity of drink. We know the acute pain that a long 
inspiration produces in pleurisy ; it is because the lungs 
then dilate the pleura, and tend to go between the folds 
which accompany the great pulmonary vessels. 
Contractility. 
It corresponds with the extensibility; it is less con- 
sequently than it at first appears to be. When the peri- 
toneum for example is contracted, its different folds are 
formed ; it returns to its place after having experienced 
locomotions. But it cannot be denied that in great dilata- 
tions these two properties are very sensible ; for example, 
in hydrocele as the water is evacuated, the tunica vagi- 
nalis evidently contracts. The peritoneum after the para- 
centesis of the abdomen exhibits the same phenomenon. SEROUS SYSTEM. 
157 
At the time of performing the operation of empyema, 
the pleura does not experience it so sensibly, not from 
defect of contractility, but because on the one hand it 
adheres to the ribs which do not contract, and on the 
other if the effusion is of long standing, the lungs are so 
flattened by the pressure, that the air can no longer dilate 
them, so that there remains a space between the costal 
and pulmonary portion, which is filled with air. A simi- 
lar space would also remain at the moment of the opera- 
tion, if the serum of hydrocephalus was evacuated. 
After long distensions, the serous membranes no longer 
contract; the tunica vaginalis remains flaccid after fre- 
quent punctures, the peritoneum after frequent preg- 
nancies, &c. &c. 
II. Vital Properties. 
The serous surfaces, being removed from the action of 
external bodies, do not enjoy in the natural state the pro- 
perties which put the living organs in relation with exter- 
nal bodies; they have neither animal sensibility nor con- 
tractility. Thus they would be very improper for exter- 
nal integuments, or for linings of the organs which the 
mucous membranes cover; they would give in fact no 
other sensation than that of an obscure and indistinct 
feeling. They answer very well for envelopes, integu- 
ments for internal organs, but not for sensible envelopes. 
We have a proof of it in living animals in whom we can 
irritate these membranes with impunity. I have many 
times seen dogs in whom I had left the spleen drawn out 
of the abdomen, in order to observe the phenomena arising 
from it, tear this organ without being in a state of fury, 
eat it even and be thus nourished by their own substance. 
They also often tear without pain the exterior of their 
intestines when in experiments these are drawn out, and 
the animals are left some time to themselves. 158 
SEROUS SYSTEM. 
When external bodies are in contact with the serous 
system, they change its natural state ; they inflame it, as 
we see in the peritoneum, in the tunica vaginalis laid 
bare, as we observe also always when a foreign body in- 
troduced into the system acts upon them. Surgeons, as 
we know, even employ this means to which they would 
in vain have recourse in the mucous membranes, in order 
to procure artificial adhesions between the parietes of 
these membranes. The different morbid irritations in- 
flame much more frequently the serous surfaces which 
in this state acquire a very acute sensibility, greater even 
than that of the integuments ; so that these inflamed 
surfaces would be equally improper to serve for integu- 
ments, because external bodies would excite them pain- 
fully. 
The sensible organic contractility is nothing in the 
serous system ; but the insensible and the corresponding 
sensibility are kept in permanent exercise in it, 1st, by 
the continual exhalation and absorption that are going on 
there ; 2d, by. nutrition. These two properties are then 
those which predominate in this system ; thus upon their 
alterations all its diseases turn. Acute inflammations, 
chronic inflammations with tubercles, adhesions, dropsies, 
exhalations of pus, of milky serum, &c. &c. are all de- 
rived from an excess, a defect or an alteration of these 
two properties of the serous system. It is then also almost 
exclusively that sympathies are put into action in it; so 
that the serous membranes diseased either idiopathically 
or sympathetically exhibit always a series of phenomena 
all of which suppose an increased internal motion, or loss 
of tone in the exhalant and absorbent capillaries, and in the 
peculiar texture of those membranes; whilst in the animal 
muscular, the organic muscular systems, &c. these pre- 
dominant affections which are marked by convulsions and 
paralysis in one, and by irregular motions of irritability 
in the other, do not suppose this internal alteration of the SEROUS SYSTEM. 
159 
texture of the diseased organ. Hence why these two last 
systems, though frequently disturbed during life, exhibit 
but few changes after death, whilst the serous system is 
a vast field for the morbid anatomist. 
Sympathies. 
The serous surfaces are capable of being influenced by 
the affections of the other organs ; this is very evident in 
the organic diseases of the heart, the lungs, the liver, the 
spleen, the stomach, the womb, &c. organs, which with- 
out having any known connexion of functions with the 
serous surfaces, influence them however so that all their 
morbid defects of organization are accompanied, in the 
latter periods, by different serous collections in the great 
cavities, collections evidently owing to a derangement of 
the organs which constantly exhale this fluid. I shall 
make upon this point two observations ; the first is that 
the serous surfaces nearest the diseased organ, are in 
general the most susceptible of being influenced by it. 
Thus in the diseases of the heart and the lungs, the serous 
collections take place especially in the thorax, whilst as- 
cites is always the first consequence of enlargements of 
the liver, the spleen, &c. the pleura and the pericardium 
being filled subsequently. We know that most sarcoceles 
are complicated with dropsies of the tunica vaginalis; 
whence results hydro-sarcocele, a disease which surgeons 
consider separately, but which is the same as those of the 
preceding cases, which might in this respect be called 
hydro-phthisis, chronic hydro-hepatitis, hydro-carcinoma 
of the womb, &c. 
The second observation that I have to make is, that 
whenever the serum is thus collected in the cavities, in 
consequence of an organic disease of a viscus foreign to 
the membrane, this serum is limpid, transparent, and 
probably of the same nature as that which circulates in SEROUS SYSTEM. 
160 
the lymphatic vessels. The exhalants which form it not 
being then in fact diseased, their action not being increas- 
ed or that of the absorbents diminished except by sym 
pathy, the fluid must remain the same. Thus though there 
is suffering at the end of the glans from a stone in the 
bladder, the glans is perfectly sound, and the mucous 
fluid that escapes from it is of the same nature as in the 
ordinary state. On the contrary, when dropsies depend 
upon a disease of texture of the serous surfaces, as for ex- 
ample upon a tubercular inflammation, or even an acute 
one, which has degenerated, &c. the effused serum is 
almost always altered ; it is milky, or there are albumi- 
nous flakes in it, or a false membrane, &c. I have made 
this observation, which I think interesting, upon nearly 
all the bodies I have opened. 
In acute diseases, the serous surfaces receive also equally 
the sympathetic influence of the affected organs. If we 
could then see them, we should find that they were like 
the skin, more or less moist, more or less dry, according 
to the different periods of the disease. What proves it 
is, that at the death which follows the disease, the serum 
of the pleura, the pericardium, the peritoneum, &c. varies 
remarkably. Sometimes it is evidently increased, at 
others it is almost nothing; this depends upon the time 
in which the subject died. If it is whilst exhalation is 
very abundant, we find much serum ; it is almost nothing 
if life has been sufficiently prolonged to allow absorption 
to take place. If the surrounding air did not dissolve 
the sweat, or if the skin was in the form of a sac, we 
should find it with very variable degrees of moisture, 
according as the subjects had died in sweat, or with a 
suppression of the cutaneous exhalation. SEROUS SYSTEM. 
161 
ARTICLE FOURTH. 
DEVELOPMENT OF THE SEROUS SYSTEM. 
I. State of this System in the First Jlge. 
All the serous surfaces are extremely delicate in the 
foetus. In opening the thorax by a longitudinal section 
of the sternum and examining the pleura in the medias- 
tinum where it is free on both sides, it is found to have less 
thickness than the transparent layers of the omentum or 
the arachnoides in the adult. The peritoneum is a little 
thicker in proportion, but yet its delicacy is very great. 
The comparison of soap bubbles is hardly sufficient to 
convey an idea of the fineness of the texture of the 
omentum and the arachnoides. 
At this period the fluid that lubricates the serous sur- 
faces is much more unctuous and viscid than it is after- 
wards ; by carrying the fingers over these surfaces at the 
different ages, the difference is' easily perceived. It might 
almost be said that the tangible qualities of the serous 
fluids then approximate those of the synovia. I know 
not to what this difference belongs. 
Besides, the quantity of these fluids does not appear to 
be so great in proportion as that of the cellular fluids, 
with which they have however so much analogy ; which 
is probably owing to this, that the internal motions being 
less numerous, on account of the inaction of most of the 
organic muscles, less fluid is necessary to lubricate the 
surfaces. 
The growth of the serous system is always in propor- 
tion to that of the organs which it covers. The arach- 162 
SEROUS SYSTEM. 
noides is larger in proportion than it will be in the adult; 
it seems even, like the brain, to become then the seat of 
a more active labour ; thus diseases are more frequent in 
it. The increase of exhalation is more common in it 
than in all the other serous sacs ; hence hydrocephalus. 
At birth, when the internal motions become suddenly 
very numerous, on account of respiration, digestion and 
the excretions, I presume that the serous surfaces become 
the seat of a more active exhalation. Besides, as very 
little blood penetrates them, the sudden production of the 
red blood and its entrance by the arterial system, where it 
succeeds the black blood, produces less changes upon them 
than upon the mucous surfaces and the muscular system. 
The serous membranes grow like the other organs; 
for a long time delicate and diaphanous, they gradually 
thicken as we advance in age, and become of a dull white. 
Their suppleness diminishes as their density increases; 
they resist the different reagents so much the less as the 
subjects are younger. In infants, maceration and ebullition 
reduce them much more quickly to a homogeneous pulp. 
I have observed that in the foetus which has become 
putrid, there is often collected different gases in the serous 
cavities, as may be proved by opening these cavities under 
water ; a phenomenon much less evident in the adult, 
in whom the cellular texture is often wholly emphyse- 
matous by the putrefactive motion, without the escape 
of any thing by the canula of a trochar which is plunged 
into the peritoneal cavity or into that of the pleura, as I 
have many times ascertained. In general, there is dis- 
engaged much more aeriform fluid from the organs of the 
foetus, than from those of the adult, in the experiments 
of maceration. 
II. Stale of the Serous System in the after Ages. 
In the adult, the serous system remains a long time 
without undergoing any very sensible change ; its mem- SEROUS SYSTEM. 
163 
branes follow only the laws of the organs they surround. 
Thus in the age nearest youth, the serous surfaces of the 
chest are the most frequent seat of inflammations, drop- 
sies, &c.; whilst in that bordering on old age the inferior 
surfaces like the peritoneum, are the more often affected. 
In old age, the serous system becomes dense and com- 
pact ; its adhesions to the neighbouring parts are more 
evident; thus it is less capable of the different locomo- 
tions of which we have spoken. Its forces, which are 
weakened, render absorption in it less easy ; it is the fre- 
quent seat of dropsy. When it is affected with some 
diseases, its want of energy imparts to them a remark- 
able chronic character. There are many old people at 
the Hotel Dieu with tubercular inflammations of the 
peritoneum, which they have had for a long time, whilst 
young persons are overcome much quicker by the same 
inflammations. Thus cancers in aged persons often re- 
main almost inert, they frequently are not even painful, 
whilst their periods are usually most rapid in adults. 
The serous effusions are more rare than the infiltrations 
of the sub-cutaneous cellular texture in old people; but 
they take place more commonly than those of the inter- 
muscular texture. 
The serous system becomes ossified, but not like the 
arterial, the cartilaginous, &c. from the natural effect of 
age. Its membranes are not constantly found osseous in 
old age, and when this phenomenon takes place, it hap- 
pens at every age. It is a disease, a real tumour, whilst 
in the arteries and the cartilages it appears to belong to 
a natural series of functions. I have a preparation in 
which the arachnoides is evidently osseous in many points, 
and as it is upon the dura-mater that these productions 
are formed, their existence serves very well to prove that 
the arachnoides is distinct from it; for at the place 
where they are found, they can be easily separated from 
each other. 164 
SEROUS SYSTEM. 
III. Preternatural Development of the Serous System. 
I shall not repeat here what I have said, in speaking of 
the cellular texture, upon the formation of the different 
cysts. These cysts, completely analogous to the natural 
serous membranes, should be really considered as a pre- 
ternatural development of these membranes in the econo- 
my ; they have the same appearance and almost the same 
texture, furnish their fluid according to the same laws, 
and appear to he the seat of a constant exhalation and ab- 
sorption ; since they are in vain emptied by puncture, 
their fluids are always reproduced, until they are remov- 
ed. For example compare the cyst which has grown 
preternaturally along the spermatic cord, with the tunica 
vaginalis filled with water in hydrocele. If the size of 
these tumours, which are often found together, is the 
same, it is impossible to discover any difference in their 
form, appearance, texture, properties, functions, &c. SYNOVIAL SYSTEM. 
I PLACE this system at the side of the serous, be- 
cause it has the greatest analogy with it, under the rela- 
tions, 1st, of its form, which is in each of these organs 
that of a sac without an opening; 2d, of its texture, which 
appears to be essentially cellular ; 3d, of its functions, 
which consist in an alternation of exhalation and absorp- 
tion. 
What establishes a real line of demarcation between 
these two systems is, 1st, that the fluids which lubricate 
their membranes appear to differ in their composition, 
though there is much resemblance between them. 2d. 
In dropsical diatheses which affect at the same time the 
cellular texture and all the serous surfaces of the peri- 
toneum, the pleura, &c. the affection does not extend to 
the synovial membranes, which indicates a difference of 
structure, though we do not know what this difference is. 
3d. And reciprocally in dropsies of the articulations, an 
affection in general very rare, and in those of the tendi- 
nous synovial capsules, there is no concomitant affection of 
the membranes of the great cavities. 4th. The fluid of 
the articular dropsies does not resemble that which fills 
the great cavities in the same disease. 5th. The synovial 
membranes are much more rarely than the serous, the 166 
SYNOVIAL SYSTEM. 
seat of those slow and tubercular inflammations which the 
serous surfaces so often exhibit. I have however seen 
two examples of it in the synovial membrane of the knee. 
I believe that these two systems are the only ones in 
which this disease is observed ; so that it is by its exist- 
ence a character of resemblance, and by its rarity or fre- 
quency, a distinguishing attribute. 6th. The different 
kinds of adhesions of which I have spoken as taking place 
on the serous surface, are not met with on the synovial 
surfaces, where we see only that which identifies these 
two adhering surfaces, a mode which frequently takes 
place in anchylosis, which is also as often occasioned by 
it, as by the stiffness of the parts surrounding the articu- 
lation. 7th. The synovial surfaces are not as often as the 
serous, the seat of those remarkable locomotions of which 
we have spoken ; which depends on this, that the articu- 
lar organs ai’e not, like the most of those covered with 
serous surfaces, subject to alternate dilatations and con- 
tractions. 
The synovial system exhibits evidently two great divi- 
sions. To one belongs the articular system, to the other 
that of the tendinous grooves. Each shall be examined 
separately. 
ARTICLE FIRST. 
ARTICULAR SYNOVIAL SYSTEM. 
I believe that I first described this essential portion of 
the synovial system. I shall relate here what I have said 
of it elsewhere. I shall examine first how it is separated SYNOVIAL SYSTEM.' 
167 
from the blood, afterwards the fluid itself, and then 1 shall 
describe the organ which furnishes it. 
I. How the Synovia is separated from the mass of 
Blood. 
Every fluid differing from the blood, can be separated 
from it to be afterwards transmitted to an orgai;, but in 
one of the three following ways ; 1st, by secretion, a func- 
tion characterized by the existence of a gland interme- 
diate to the blood vessels that bring the materials to it, 
and the excretories which carry off the result; 2d, by 
exhalation, a function distinguished from the first, by the 
absence of this intermediate gland, and by the immediate 
continuity of the blood vessel and the exhaling duct; 3d, 
by transudation, a phenomenon purely physical, almost 
always happening after death, rarely observed during life, 
a simple transmission of a fluid by the pores of an organ, 
towards which it is mechanically determined. Let us 
examine which of these three modes is that chosen by 
nature to deposit the synovia upon the articular surfaces. 
Is the synovia transmitted by secretion to the articu- 
lar surfaces ? 
We are indebted to Clopton Havers for the system 
which places in the glands the sources of the synovia. 
Many authors had designated obscurely before him these 
organs in the articulations; but he made them the parti- 
cular object of his researches, described them in the dif- 
ferent articulations, divided them into two classes, the 
one principal, the other accessory, and assigned them 
characters so evident, that according to him, they could 
not be forgotten. Reddish bunches, spongy, formed by 
membranes folded upon themselves, situated sometimes 
without, and sometimes within the articulations, always 
arranged so as to be protected from too strong a compres- 
sion, and pouring out through ducts in the form of fringe 168 
SYNOVIAL SYSTExVT. 
the fluid they secrete ; such are the characters drawn by 
Havers, which all anatomists since him admire, and the 
correctness of which the most modern and distinguished 
authors have acknowledged in their works. 
Some anatomists of this age have however thrown 
doubts upon these glandular bodies. Lieutaud confounds 
them with the fatty cellular texture. Desault did not 
distinguish them from it. Every thing confirms me in 
the same opinion, which many considerations appear to 
establish in an undoubted manner. The following are 
these considerations; 1st, these reddish bunches are met 
with only in certain articulations. There are many of 
them in which their existence cannot be established but 
by supposition. 2d. The greatest number of the synovial 
membranes of the tendons certainly do not exhibit any 
of them, though Havers, Albinus, Juncke and Fourcroy 
admit them in all, founded no doubt upon analogy and 
not upon inspection. Yet the synovia is separated equally 
in both cases, and lubricates the surfaces of the articula- 
tions and of the tendinous sheaths ; this separation is then 
independent of glandular action. 3d. If the best marked 
synovial glands are examined, such as that of the cotyloid 
cavity, no trace can be discovered there of this paren- 
chyma of an unknown nature, but remarkable for its 
structure, which composes in general the glands, and 
which distinguishes them from every other part and forms 
their true organic character. 4th. No excretory duct can 
be demonstrated in these organs. Those in the form of 
fringes, admitted by Havers, are imaginary. Bertin him- 
self has acknowledged this truth, though he attributed to 
these bodies a glandular structure. The transudation of 
the fluids injected by the arteries in the neighbourhood 
of the articulation, proves the existence of these ducts no 
better than it establishes them in the cavities of the 
serous membranes in which it also takes place, and yet 
in which it is well proved that no gland pours out the SYNOVIAL SYSTEM. 
169 
albuminous fluid that constantly lubricates these cavities. 
5th. Inflation resolves completely these fatty bunches into 
cellular texture'. Maceration produces the same effect. 
When gradual and long continued ebullition has removed 
all the fat from them, there remains only a mass of cells 
pressed together, and similar to those of the common 
cellular texture. 6th. The glandular character is mani- 
fested in certain morbid cases, by a peculiar swelling and 
hardening, of which the other organs except the glands, 
such as the muscles, the tendons, &c. never offer an exam- 
ple. The liver, the kidneys, the salivary organs, all the 
considerable glands are remarkable for this. So true is this 
character, that it serves to indicate glands, the delicacy 
of which conceals them in the natural state. For exam- 
ple, the existence of the cryptae of the stomach, the 
urethra, and several other mucous membranes, is founded 
first upon the analogy of the other membranes of this 
class, but principally upon the preternatural development 
which these cryptae acquire in certain diseases. Never 
on the contrary, do the pretended synovial glands pre- 
sent to the observer a similar development. Always in 
the diseases of the articulations, a common swelling seems 
to identify them with the neighbouring cellular texture. 
They have not like the other glands, affections distinct 
from those of this texture, no doubt because they have 
not a peculiar vitality, because being mere elongations of 
the neighbouring cellular texture, they partake of its 
nature and properties, and ought consequently to partake 
of all its conditions, as it in its turn ought immediately to 
receive the influence of their affections. 
The considerations which I have just offered succes- 
sively form, I think, sufficient data to resolve the problem 
proposed above, by establishing as an incontestable propo- 
sition, that the synovia is not transmitted by secretion to 
the articular surfaces. 170 
SYNOVIAL SYSTEM. 
Let us examine the second mode of transmission statfed 
by authors. 
Is the synovia transmitted by transudation to the 
articular surfaces ? 
It was an opinion anciently received, that the marrow 
of the long bones oozes through the pores of their ex- 
tremities and through those of the cartilages which termi- 
nate them, to lubricate the articular surfaces. Havers 
renewed this idea forgotten at the time he wrote, united 
this source of the synovia to that which had placed it in 
the glands, and thus formed of this fluid a mixture com- 
posed of two fluids differently transmitted to the articula- 
tion. The most of those who succeeded him partook of 
his opinion upon this point. Those even, such as De- 
sault, who rejected the existence of the articular glands 
and the secretion of synovia, admitted the transudation 
of it founded upon the following observations. 1st. A 
long bone, stripped of its soft parts and exposed to the 
air, allows a fatty oozing to pass through the pores of its 
cartilages which does not cease till the medullary juice is 
completely exhausted. 2d. The mechanical compression 
of the cartilaginous extremity of a long bone produces 
for a moment the same effect. Arc these facts, which 
are evident in the dead bone, also real in the living one ? 
Different considerations, which I will now state, induce 
one to believe the contrary. 
1st. The vital forces, the effect of which is to impart 
to all the organs which they animate a degree of tone 
sufficient to resist the entrance of the fluids, leave, when 
they are extinct, the fibres of these same organs in a state 
of laxity that renders them everywhere permeable. Thus 
transudation is now considered as hardly any thing else 
than a phenomenon that takes place only after death, 
which, if transformed into a vital one, would offer an evi- 
dent exception to the laws of nature that are especially 
characterized by simplicity and uniformity. 2d. The SYNOVIAL SYSTEM. 
171 
fatty oozing takes place in the experiment noticed above, 
not only through the pores of the cartilages, but also 
through those of the whole surface of the bone ; so that 
by reasoning from what has been here observed upon the 
dead body, it is evident that during life the whole bone 
would be, if you may so say, immersed in an atmosphere 
of synovia, a consequeuce, which being proved false 
by the most simple inspection, demonstrates the falsity 
of the principle deduced from it. 3d. The articulations 
of the cartilages of the larynx are lubricated like those of 
the bones, by the synovial fluid; and yet here all transu- 
dation of marrow is impossible, as it does not exist in the 
substances of the cartilages. 4th. The marrow is almost 
always sound in diseases which, affecting the articulations 
alter the fluid that lubricates them. And reciprocally the 
synovia does not take a different character in the affections 
of the interior of the bones, which have an influence 
especially upon the medullary organ. 5th. Finally, the 
experiment that I have made, and which has been stated 
in the article upon the marrow, evidently proves the 
non-transudation of this fluid. 
Desault, in order to explain the manner in which the 
synovia is separated from the blood, added to this pre- 
tended transudation of the marrow, an oozing furnished 
by all the parts contained in the articulation, such as the 
capsular and inter-articular ligaments, the internal fat, the 
cartilages, &c. A comparison will suffice to show the 
value of this hypothesis. What should we say of a sys- 
tem in which to explain the production of the serous fluid 
of the abdomen, the source of it should be placed in the 
liver, the spleen, the intestines, and in general in all the 
organs of this cavity ? No doubt we should answer, 
that a fluid of the same nature, could not be furnished by 
parts of such different structure, that it is much more 
simple to search for a single source in the single mem- 
brane that covers all the gastric viscera. The application 172 
SYNOVIAL SYSTEM. 
is exact and the analogy perfect between it and the artic- 
ular cavity. 
We can, I believe, without fear of error, conclude from 
all that has been said above, that the synovia is not trans- 
mitted by transudation to the articular surfaces. 
I will now examine the last mode pointed out for the 
separation of the synovia. 
Is the synovia transmitted by exhalation to the ar- 
ticular surfaces ? 
The solution of the two preceding problems seem natu- 
rally to lead to that of the question which we here pro- 
pose. The certainty of the two following data may, I 
think, be relied on ; 1st. Secretion, exhalation and trans- 
udation are the only means by which a fluid different from 
the blood can be transmitted to an organ. 2d. Secretion 
and transudation are foreign to the transmission of the 
synovia. Now from these two certain data, can we not 
draw this conclusion as certain, that exhalation is the 
mode by which the synovia is carried to the articula- 
tions ? But let us add to these negative proofs some con- 
siderations which establish this proposition positively. 
The most striking relations are observed between the 
syno.via and the fluid that lubricates the parietes of the 
serous membranes. 1st. The relation of composition. 
These two fluids are essentially albuminous. Albumen pre- 
dominates in both, though a little different in each, as Mar- 
guerron has demonstrated. Havers had previously point- 
ed out this analogy; he knew that these two fluids are co- 
agulable by alkohol, the acids, and caloric, without know- 
ing the principle to which this property is owing. 2d. 
The relation of functions. Both are destined to lubricate 
surfaces on which much motion takes place, to diminish 
the friction which is the inevitable consequence of it and to 
prevent fatal adhesions. Both are in the same state on 
their respective surfaces ; it is merely a dew spread upon 
these surfaces, and soon taken up from them. 3d. The SYNOVIAL SYSTEM. 
173 
relation of affections. Inflammation dries up the source of 
both, and produces adhesions, more common in the serous 
membranes and more rare in the articulations in which 
they produce anchylosis. Both are subject to preter- 
natural enlargement, which is designated by a common 
word, viz. dropsy. 4th. The relation of absorption. The 
lymphatic system is for both the way by which they re- 
enter the circulation, after having remained sufficiently 
long upon their respective surfaces. 
Do not these various resemblances, which with some 
slight differences of composition only, so evidently con- 
nect the synovia with the fluid of the serous membranes, 
lead to this very simple consequence, viz. that these 
two fluids being analogous in all other respects must be 
so also as to the manner in which they are separated from 
the mass of blood ? Now it is a point in physiology at 
the present day generally acknowledged, that the fluid of 
the serous membranes is brought to them by exhalation ; 
then we are evidently lead by induction to this which 
answers the question proposed above ; The synovia is 
transmitted by exhalation to the articular surfaces. 
This rigorous and accurate conclusion drawn from ob- 
vious and uniform facts will become, I think, a demon- 
strated truth, when to the analogies already established 
we shall add that of the membranous organ, the essential 
seat of the exhalation of the synovia. 
II. Remarks upon the Synovia. 
Thus separated from the mass of blood, the synovia has 
the appearance of a white, viscid and transparent fluid. 
It ropes, like some syrups, when it flows from the articu- 
lations. This unctuous property renders it peculiarly fit 
to lubricate the articular surfaces which rub together, and 
to protect them from violent shocks. 
Its quantity varies ; there are articulations which con- 
tain much of it; that of the ankle has always appeared to 174 
SYNOVIAL SYSTEM. 
me to have the most of it. Then come the ilio-femoral, 
the scapulo-humeral, the humero-cubital, &c. There are 
others in which there is scarcely any ; such are the sterno- 
clavicular, the sterno-costals, the costo-vertebrals, &c. It 
is not the smallness of the synovial surfaces that occasions 
in these articulations the constant dryness that is observed 
in them; for the synovial sacs of the larynx, which are 
much smaller, are much more moist. 
Besides, the synovia does not vary in quantity in each 
articulation, like the serum in the serous membranes. 
Those who have opened peritoneums, pleuras, pericar- 
diums, &c. must have seen that hardly two are similar ; 
sometimes there is only a mere dew, at others there is a 
real collection of fluid. Here on the contrary there is 
always nearly the same quantity; which is owing to this, 
that the synovial surface does not feel as easily as the 
serous surfaces, the sympathetic influences of the other 
organs when diseased. 
The synovia is not subject to the different alterations 
which the serous fluids exhibit. I have never seen upon 
the articular surfaces what are called false membranes 
from inflammation. The preternatural collections of syno- 
via never contain those white flakes, so common in the 
serous collections. 1 do not know of an example of 
milky serum effused in an articulation. One of the most 
frequent alterations of the synovia is that, I think, in 
which it takes the consistence of a jelly and is of a reddish 
colour, analogous, if I may be allowed the comparison, to 
currant jelly. Now this alteration is wholly foreign to 
the serous fluids. 
These essential differences whicli the synovia and the 
serum exhibit in their alterations, evidently suppose a 
diversity of nature in the principles which compose them 
in the natural state. The viscidity of one and the greater 
fluidity of the other, also declare it, as Fourcroy has ob- 
served. This diversity of nature appears to depend espe- SYNOVIAL SYSTEM. 
175 
cially upon a peculiar substance which enters into the 
composition of the synovia, which few animal fluids 
possess, which Marguerron who has observed it desig- 
nates by the name of albumen of a peculiar nature, and 
which should be the object of new researches. 
I shall not give here the details of the analysis of the 
synovia; they belong to animal chemistry. 
III. Of the Synovial Membranes. 
We have seen all the great cavities lined by the serous 
membranes, which form by their folds species of sacs 
without an opening, and which embrace both the organs 
and the parietes of these cavities. There exists in all the 
moveable articulations membranes precisely analogous, the 
uses of which are the same, the nature of which is not 
different and which I call synovial, because their parietes 
constantly exhale and absorb synovia. 
Forms. 
Every synovial membrane then should be considered 
as a sac without an opening, spread upon the organs of 
articulation, upon the diarthrodial cartilages, upon the 
internal face of the lateral and capsular ligaments, upon 
the whole of the inter-articular ligaments when they exist, 
upon the prominent fatty bunches in some articular cavi- 
ties, &c. It is from it that these different organs borrow 
the smooth, polished and shining appearance which char- 
acterizes them in these cavities, and which they have 
not elsewhere. Just as by dissecting carefully the gastric 
organs, the peritoneum can be removed, its sac remain- 
ing whole, so we can conceive of the possibility of sepa- 
rating this membrane, notwithstanding the intimate adhe- 
sions it forms in some places. All the parts that it em- 
braces are out of the articular cavity, though projecting 
into this cavity, as the lungs are found on the exterior of 176 
SYNOVIAL SYSTEM. 
the sac formed by the pleura, the liver on the exterior of 
the peritoneal sac, &c. &c. 
The synovial membrane is found in all the moveable 
articulations, the greatest number of which has only it 
and the lateral ligaments. What is commonly called the 
fibrous capsule is only met with around some of the ar- 
ticular surfaces. The connexions of the humerus, the 
femur, and one or two other bones, the extremities of 
which are joined by enarthrosis, present the only exam- 
ples of it. There are seen in these articulations two very 
distinct coverings. One which is fibrous is external, and 
is found arranged in the form of a sac open above and 
below, embracing by its two great openings the surfaces 
of the two bones, and being intermixed around them 
with the periosteum, the fibres of both interlace with each 
other. The other cellular, which is the synovial mem- 
brane, lines the first on the interior, separates afterwards 
from it when it arrives towards the two diarthrodial 
cartilages, and is reflected upon them, instead of being 
united to the periosteum. Boyer has pointed out this 
arrangement in regard to the femur. 
In all the ginglymoid articulations, as in those of the 
elbow, the knee, the phalanges, the hand, the foot, &c. 
&c. the fibrous capsule is wholly wanting. The fibres, 
instead of extending and interlacing in the form of a mem- 
brane, are collected into fasciculi more or less thick, which 
form the lateral ligaments. There is only found in them 
the internal layer of the enarthrodial articulations, that is to 
say the synovial membrane, which does not contract here 
any adhesion with the periosteum, but is reflected upon 
the cartilages. By taking it at the place of this reflection, 
it can be detached far enough to prove that it has an 
external organization wholly different from that which 
the idea of a capsular ligament at first presents to the 
mind. This arrangement is very easily perceived by 
the least dissection, at the knee behind the tendon of the SYNOVIAL SYSTEM. 
177 
eruneus and the inferior ligament of the patella, at the 
elbow under the tendon of the triceps, at the phalanges 
under that of the extensor, &c. All the arthrodial articula- 
tions have also an analogous organization, as will be seen in 
the Descriptive Anatomy ; so that it is ascertained that 
the fibrous capsules exist but in a very small number of 
articulations, that almost all have only synovial sacs 
which are spread out and reflected upon the osseous sur- 
faces, without being attached around them, as all authors 
have said. 
I have proved this remarkable difference of the articula- 
tions by many dissections. Some anatomists were in the 
way to discover it, when they observed that the differ- 
ent capsules appeared to be wholly formed of cellular tex- 
ture. It is in fact the texture of the synovial membrane, 
which differs essentially in this from the fibrous capsules. 
The mode of capsule for all articulations may be pre- 
served, if it is wished, but different ideas must then neces- 
sarily be attributed to it. Compare, for example, the 
fibrous capsule of the femur with the synovial capsule of 
the knee; you will find on the one hand, 1st, a cylin- 
drical sac with two great openings for the osseous extre- 
mities, and with many small ones for the vessels; 2d, a 
fibrous interlacing, similar to that of the tendons, the 
aponeuroses, &c.; 3d, a mode of sensibility analogous to 
that of these organs ; 4th, the use of retaining strongly 
in place the articulated bones, which have only this bond 
to strengthen their union. On the other hand you will 
observe, 1st, a sac without an opening; 2d, a cellular 
structure, the same as that of the serous membranes ; 3d, 
a sensibility of the same nature as theirs ; 4th, the simple 
function of containing the synovia and separating it, the 
bones being tied by strong ligaments. Besides, the dif- 
ferent reagents have upon the fibrous capsules an influence 
wholly different from that which they exert upon the 
synovial. Ebullition yellows them, renders them semi- 178 
SYNOVIAL SYSTEM. 
transparent, softens them like tendons and gradually melts 
them like gelatine. The synovial ones boiled remain 
whitish, and furnish but little of this substance. I would 
observe that the yellowish tinge and semi-transparency 
of the boiled fibrous capsules are a certain means of dis- 
tinguishing the articulations in which they exist and those 
which are destitute of them. 
The existence of the synovial capsule in the greatest 
number of articulations in which it is found alone, is 
placed beyond a doubt by the slightest inspection. In 
those in which it is united to a fibrous capsule, it is very 
clearly distinguished in several places. Thus in the thigh, 
it is found upon the interarticular ligament, upon the 
fatty bunch in the cotyloid cavity, and upon the neck of 
the bone at the places where it leaves the fibrous capsule, 
to be reflected upon the cartilages, &c.; but its adhesion 
to these cartilages and to the internal face of the capsule, 
may excite some doubts as to its arrangement in the form 
of a sac everywhere closed, which we have attributed to 
it; it is then essential to offer some considerations that 
may dissipate these doubts. 
1st. However strong the adhesions of the synovial mem- 
brane may be, they can be destroyed without a solution of 
continuity, by a slow, careful dissection begun at the place 
where the membrane is reflected from the cartilage upon 
the capsule. It can be taken away in parts after long con- 
tinued maceration. 2d. In consequence of certain inflam- 
mations, this membrane acquires a thickness and opacity 
which enable us to distinguish it from all the neighbour- 
ing organs, from those even to which it adheres the most. 
3d. The synovial bags are all as adherent as the articular 
synovial one, to the cartilages of their sheath and to this 
sheath itself; yet every one acknowledges their distinct 
existence. 4th. There are articulations with a fibrous 
capsule, in which the fibres are separated so as to leave a 
space between them through which the synovia would SYNOVIAL SYSTEM. 
179 
escape, if the synovial membrane did not line them. 
When air is forced into the articulation, this membrane 
rises up in these spaces and exhibits a texture wholly 
different from that of the capsule. Bertin observed this, 
but thought that these pellicles were insulated, and did 
not see that they depended upon the continuity of the 
membrane which is extended over the whole articulation. 
5th. We have observed in the article upon the serous 
system, that the smooth and polished appearance which 
the surface of the organs and the cavities exhibit, is 
always given to them by these membranes, and that 
they never derive it from their peculiar structure; now 
we shall see that the synovial membrane has almost the 
same texture as the serous ; then it appears that in the 
places in which the articular organs exhibit this charac- 
ter, it is from it that they receive it, though it cannot be 
distinguished as well upon these organs, as where it is 
free. Besides, the articulations that are evidently desti- 
tute of this membrane, have not this smooth and polished 
appearance. Such are the surfaces of the symphysis pubis, 
and of the sacro-iliac symphysis which are found, though 
contiguous, unequal, rough, &c. We have also proved 
that this organic form is never owing to compression. 
From these different considerations we may be easily 
convinced, I think, that notwithstanding the adhesion 
of the synovial membrane at different points, it should 
be considered in a manner precisely analogous to that of 
the serous membranes, that is to say as a real sac without 
an opening, everywhere contiguous and spread upon all 
the organs of the articulation. Besides, do not the ftbro- 
serous membranes exhibit similar adhesions, though the 
separate existence of the two layers which compose them 
is generally admitted? 
From the idea we have formed of the synovial mem- 
brane, it is easy to conceive how certain organs pass 
through the articulation,, without the escape of the syno- 180 
SYNOVIAL SYSTEM. 
via by the opening which receives or by that which trans- 
mits them The synovial membrane then reflected around 
these organs, forms for them a sheath which separates 
them from the fluid and keeps them distinct from the 
articulation. Thus the tendon of the biceps is no more 
contained in the articulation of the arm with the scapula, 
than the umbilical vein, the urachus, &c. are in the perito- 
neal cavity. With the least, care it may be separated from 
the portion of membrane which forms its. sheath. 
The preceding considerations lead us also to find a per- 
fect identity in the synovial capsules of the tendons and 
the articular synovial ones. In the preceding example, 
these two kinds of membranes are evidently continuous ; 
for the capsule of the groove of the biceps is of the same 
nature as that of the tendons which have a separate one 
from it, as the flexors, for example. 
Organization. 
We have just seen, that the synovial membrane resem- 
bles very much in its external conformation the class of 
serous membranes, it does not less so in its internal organi- 
zation. This organization is cellular, as is proved by 
dissection, inflation and especially maceration. The sac 
which the ganglions form is evidently only a production 
of the cellular organ ; now it is known that this sac exhales 
and contains a fluid similar to the synovia. Wherever 
the synovial membrane is free, it is attached externally to 
this organ and is confounded with it in so direct a man- 
ner, that by raising successively its different layers they 
are seen to be gradually condensed and finally united 
together to form it. So that in the serous membranes no 
fibre is visible. It becomes transparent when it is sepa- 
rated accurately on both sides, which is easily done at 
the knee to a great extent. 
I shall not go back to the various proofs which establish 
the cellular structure of the serous system; almost all SYNOVIAL SYSTEM. 
181 
these proofs are applicable to the synovial system, which 
appears to be but a net-work of absorbents and exhalants. 
Hence it is easy to understand what the red and fatty 
bunches are that are found around the articulations. 
They perform in regard to this membrane the functions 
of the abundant cellular texture which envelops the peri- 
toneum, the pleura, &c. &c. It is there that the blood 
vessels divide ad infinitum before arriving at the mem- 
brane where their ramifications, successively decreasing, 
finally terminate in the exhalants. 
If a remarkable redness sometimes distinguishes these 
bunches from the cellular texture, it is because the vessels 
are more concentrated and nearer together in them. For 
example, in the articulation of the hip, the synovial 
membrane of which, almost everywhere adherent, only 
corresponds in the fissure of the cotyloid cavity with the 
cellular texture, nature has placed there almost all the 
arterial ramifications that furnish the synovia ; hence the 
reddish tinge of the cellular bunch that is found there. 
On the contrary, at the knee where much cellular texture 
surrounds the whole external face of the synovial sac, the 
vessels more scattered leave to this texture the same 
colour as that of the external face of the serous mem- 
branes, &c. This redness of some pretended synovial 
glands, the only character that distinguishes them, is then 
as it were merely accidental ; it no more indicates their 
glandular nature, than it proves it in the pia-mater, in 
which it is owing to the same cause. 
Though the synovial membrane is very analogous to 
the serous surfaces, it must however exhibit differences 
of texture, since the fluid it exhales is a little different. 
In fact, by examining it at the femoro-tibial articulation, 
where it can be found in considerable pieces, it is seen to 
be more dense and compact than the serous membranes. 
Its texture has not the suppleness of theirs ; when dried, 
it is much more brittle; it remains stiff, whilst the serous 182 
SYNOVIAL SYSTEM. 
texture is moved in all directions without the least effort. 
It resists maceration longer. 
Properties. 
The properties of texture become evident in articular 
dropsies, in which the synovial membranes are at first 
much distended, and in which they contract after the 
puncture, an operation however that is very rare. Yet 
it appears that these membranes are only susceptible of a 
slow and gradual extension. We know that suddenly 
separated in luxations, their parietes tear instead of stretch- 
ing ; they unite again after the reduction. 
Among the vital properties, the organic sensibility is tbe 
only one of this system in the ordinary state, as I have 
proved by many experiments on living animals in which 
these surfaces have been laid bare and irritated by various 
agents. But the increase of life which inflammation pro- 
duces by raising this sensibility, transforms it into animal 
sensibility ; this is what is observed, 1st, in the wounds in 
which these membranes are exposed to the contact of the 
air; 2d, in the long continued irritation they experience 
from foreign bodies preternaturally developed in the ar- 
ticulation ; 3d, in the various affections of the articular 
surfaces, &c. 
This kind of sensibility of the synovial membranes 
serves to confirm what I have already established above, 
viz. that most of the articulations, the ginglymoid espe- 
cially, are destitute of fibrous capsules. In fact, I have 
observed that these capsules, as well as the lateral liga- 
ments, have a kind of animal sensibility, which is de- 
veloped by pulling them ; so that if all the neighbouring 
organs of an articulation, except the synovial membrane 
and the lateral ligaments, are removed and this articu- 
lation afterwards twisted, the animal gives signs of the 
most acute pain. But afterwards cut the ligaments, and 
leave only the synovial membrane, the twisting no longer SYNOVIAL SYSTEM. 
183 
gives pain ; then there is no fibrous capsule united to the 
synovial. This experiment, which is easily repeated 
upon the fore or hind legs, enables us to recognise every- 
where the articulations in which the synovial membrane 
exists alone, and those in which it is found united to a 
fibrous capsule. This being of the same texture as the 
lateral ligaments, produces the same pains when it is 
pulled, as is proved elsewhere by experiments made upon 
the articulations clothed with these capsules. 
The alternate exhalation and absorption which takes 
place upon the serous surfaces, prove the insensible con- 
tractility in them. 
I have already observed that the synovial surfaces per- 
form but a small part in the sympathies, that they feel 
but very slighly the affections of the other organs. Whilst 
in the acute affections of the important viscera, the skin, 
the mucous surfaces, the cellular texture, the nerves, &c. 
&c. have a greater or less sympathetic derangement, all 
the synovial membranes remain unaffected; they do not 
become the seat of irregular pains, nor of a more active 
or slower exhalation. They resemble in this respect the 
osseous, cartilaginous, and even fibrous systems. Thus 
it is not necessary that the physician should seek in the 
synovial system a frequent seat of the accessory symp- 
toms in diseases, of that class of symptoms which does 
not belong to the injury of the diseased organ itself, but 
to its relations with other parts. 
In the pains of the articulations, there are certainly cases 
in which the synovial membrane is diseased, and others 
in which the fibrous organs alone are affected. The dis- 
tinction of these cases should be sought. 
Functions. 
The synovial membrane adds nothing to the solidity 
of the articulation. The fibrous capsules and the lateral 
ligaments alone serve this purpose. The smooth surface 184 
SYNOVIAL SYSTEM. 
which the articular extremities derive from this mem- 
brane, favours their motions; it can even in this way 
assist the muscular action ; thus the portions of synovial 
membrane which are found at the knee behind the cru- 
raeus, at the elbow under the triceps, at the phalanges 
under the flexors, &c. perform in respect to these muscles, 
the same functions as the tendinous synovial bags. They 
are to their tendons, what the cellular sac which separates 
the tendons of the psoas and the iliacus from the crural 
arch, is to them. 
The principal use of the membrane of which we are 
treating is in relation to the synovia. It exhales by 
numerous orifices this fluid which remains there for some 
time, and afterwards re-enters the circulation by absorp- 
tion. Its parietes are then the seat of exhalation, as the 
kidneys, for example, are that of the secretion of urine. 
The reservoir of the exhaled fluid is the sac without open- 
ing which it forms, as the bladder is that of the urine that 
comes from the kidneys. The excretory vessels of this 
same fluid are the absorbents which carry it into the mass 
of blood, as the urethra carries the urine from the bladder. 
There is under these different relations more analogy than 
there at first seems to be, between secretion and exhalation. 
The phenomena of the continuance of the synovia in 
this membranous reservoir, have relation to the synovia 
itself or to the articular surfaces. The first consist in a 
peculiar but unknown alteration which it undergoes be- 
tween the exhalant and absorbent systems. The second 
contribute to facilitate the articular motions. The unctu- 
ous and slippery coat which the serous surfaces receive 
from the synovia, is remarkably adapted to this use, as I 
have observed. 
In the foetus and in infancy most of the synovial mem- 
branes are much larger in proportion than in the after 
Natural Development. SYNOVIAL SYSTEM. 
185 
ages, because the articular surfaces have a greater extent 
in the cartilaginous than in the osseous state; but they 
are then extremely delicate. The synovia is not, as the 
serous fluids are at this age, more unctuous and of great- 
er consistence ; it appears even to be less so. Before 
birth it is in small quantity, no doubt because the motions 
are trifling. 
In old age I have observed that the synovial membrane 
becomes more dense and compact. It loses in part its 
white colour and becomes grey ; less synovia is exhaled 
from it. It is not like the serous surfaces, exposed to 
dropsies. The rigidity it acquires makes motion painful. 
It never ossifies except preternaturally. The phosphate 
of lime which gradually invades cartilage, does not take 
hold of it. I do not know an instance of an old person 
in whom bone has been found naked in an articulation. 
Preternatural Development. 
I have already observed in the article on the fibrous 
capsules, that when the head of a bone remains displaced 
in a luxation, it is not a membrane analogous to these 
capsules that is developed around it; it is a real cyst, 
smooth on its internal surface, moistened with serum, 
formed at the expense of the cellular texture, and present- 
ing, with a little more thickness, the true appearance of 
the synovial membranes; it is a preternatural synovial 
membrane. The motions imparted to the displaced limb 
appear to increase the serous exhalation in this new mem- 
brane ; hence no doubt the great advantage of these mo- 
tions, in order to re-establish in part the mobility of the 
bones which remain out of their sockets. I have seen a 
dancer, the head of whose humerus wras lodged in the 
hollow of the axilla, after a luxation that was not reduced, 
perform very varied motions with it. 186 
SYNOVIAL SYSTEM. 
ARTICLE SECOND. 
SYNOVIAL SYSTEM OF THE TENDONS. 
This system noticed -by many authors and described 
by Fourcroy, Soemmering, &c. is precisely of the same 
nature as the preceding, from which it differs only by its 
situation ; it is often even confounded with it. Thus the 
synovial membrane of the tendon of the biceps is con- 
tinuous with that of the scapulo-humeral articulation; 
thus those of the gemelli are so with the synovial mem- 
brane of the femoro-tibial articulation ; it is the same 
membrane which belongs at the same time to the tendon 
and to the articulation. A remarkable example of it is 
seen in the extensors of the leg and the ham, to the ten- 
dons of which the same articular synovial membrane of 
the knee serves for a capsule. 
But very few tendinous synovial membranes are found 
in the trunk; almost all are on the extremities where they 
serve to assist the slipping of the tendons. They are 
met with, 1st, where a tendon is reflected at an angle 
upon a bone, as around those of the great lateral peroneus, 
the peroneus medius, the obturator internus, the great 
oblique of the eye, &c. ; 2d, where a tendon slips upon 
an osseous surface without being reflected, as at the ex- 
tremity of the tendo Achillis, as under that of the great 
glutseus, and those of the psoas and iliacus united; 3d, 
where a tendon slips in a fibrous capsule, as in those of 
all the flexors, &c. Their extent is uniformly in propor- 
tion to that of the tendons upon which they are spread. 
Forms; Relations ; Synovial Fluid. 
The tendinous synovial membranes, are, like the articu- 
lar ones, sacs without an opening, spread on the one SYNOVIAL SYSTEM. 
187 
hand on the tendon and on the other upon the neighbour- 
ing organs. These sacs are differently shaped according 
to the arrangement of the tendon, but their general con- 
formation is uniform. We see from this that every ten- 
dinous synovial membrane has two faces, one which 
forms the interior of the sac, which is everywhere free 
and contiguous to itself, the other which lines the adja- 
cent organs. 
The free surface is constantly moistened by a fluid pre- 
cisely similar to that of the articulations, furnished like 
it by exhalation, and not as authors have said by red 
bodies situated in the neighbourhood, bodies of which 
oftentimes there is no trace visible, and which, when 
they exist, have nothing glandular in them. This fluid 
is in general much less abundant than in the articulations, 
at least in the dead body. But there are varieties in the 
different synovial bags ; those of the tendo Achillis, of 
the tendons of the psoas and iliacus united, of that of the 
obturator internus, &c. are always more moist than those 
of the flexor tendons, &c. 
Is it to the absence of synovia that must be attributed 
the species of crepitation which the tendons sometimes 
make in their motions ? I know not. I would only 
observe that this crepitation has some analogy with the 
crackling noise of the joints of the fingers when they are 
bent quickly, a noise, which does not depend, as might 
be supposed, on the friction of the osseous surfaces; in 
fact, when it has been once produced, it cannot be again, 
though there may be friction again. Besides it is known 
that this crackling noise arises from the forced elonga- 
tion of the phalanges, and consequently from the separa- 
tion of their articular surfaces, as well as from the flexion. 
The increase of the fluid of the tendinous synovial 
membranes forms a species of dropsy which is called 
ganglion, a tumour which never exists in the synovial 
membranes of the fingers, no doubt on account of the want 188 
SYNOVIAL SYSTEM. 
of extensibility of the fibrous capsules. It should not be 
thought however that all these tumours, which are cured 
by bursting them by strong pressure and thus effusing the 
fluid into the cellular membrane, have for their base a 
natural synovial membrane. Most frequently they are 
preternatural; they are cysts which are formed in the cel- 
lular texture. In fact these tumoursAare often found in 
the course of the great extensor of the thumb, where there 
is no synovial membrane. After rheumatic pains I have 
seen a considerable collection of fluid in the small syno- 
vial membrane of the tendo Achillis ; it gradually disap- 
peared. I have observed another analogous one in the 
bag of the psoas of a dead body. The fluid was reddish 
and of the consistence of currant jelly. The action of 
nitric acid immediately coagulated it into a white mass, 
analogous to the white of an egg hardened. 
The adhering surface of the tendinous synovial mem- 
branes is spread, 1st, on the one hand upon the tendons, 
with which it is more or less intimately united. It is 
easily detached from those of the internal obturator, the 
psoas, &c. It is closely connected with those of the flex- 
ors. 2d. On the other hand, it commonly lines the peri- 
osteum, which, in this place, is penetrated with gelatine, 
and forms a fibro-cartilage. Its mode of relation is there 
analogous to that of the articular synovial membrane with 
the cartilage of the bone. Sometimes it is reflected upon 
a fibrous capsule after having lined the tendon; such are 
those which are in the neighbourhood of the scapulo- 
humeral articulation. In some cases, after having lined 
the tendon, they mount up to the fleshy fibres, as on the 
obturator internus. 3d. By reflecting from the tendon 
upon the neighbouring organs, they answer in general in- 
stead of much cellular texture ; but in the grooves of the 
flexors, it is the fibrous sheaths which they clothe. 
In all the great motions, the tendinous synovial mem- 
branes, stretched more or less, undergo various locomo- SYNOVIAL SYSTEM. 
189 
tions, always less however than those of the serous sur- 
faces. 
The very various forms, which the sac without open- 
ing of the tendinous synovial membranes exhibits, can 
be reduced to two general modifications. 1st. Some are 
rounded sacs, species of bladders ; such are those upon 
the supra-spinatus, the psoas, iliacus, obturator internus, 
&c. All these membranes are remarkable for this, that 
they never cover the tendon entirely, but only on one 
side; that they never form internal folds and that they 
are never surrounded by fibrous sheaths. 2d. The others, 
belonging especially to the flexors, and to the different 
tendons which traverse the sole of the foot, form at first 
a kind of cylindrical sac which lines the canal half fibrous, 
half cartilaginous in which the tendon slips ; then they 
are reflected around it, cover it wholly and form for it a 
true sheath which prevents it from being moistened by 
the synovia. This kind of tendinous synovial membrane 
represents then truly two canals, at the superior and in- 
ferior extremities of which are found two cul-de-sacs 
which unite them and complete the sac without an open- 
ing. Internal folds are here frequently found going from 
one canal to the other. All the synovial membranes of 
the flexors have one of them under the tendon. 
Organization ; Properties ; Development. 
The organization of the tendinous synovial membranes 
is precisely analogous to that of the articular ones. Prin- 
cipally cellular, the texture of these membranes is with- 
out any apparent fibre ; its softness is very evident; very 
few blood vessels are distributed to it, though the con- 
trary has been said; absorbents and exhalants especially 
predominate in it. These, filled with blood in inflamma- 
tion, give to the membrane, a reddish tinge, more or less 
deep. In this state the synovia is not exhaled ; sometimes 190 
SYNOVIAL SYSTEM. 
even adhesions are formed, as I have observed in a sub- 
ject in whom the fibrous sheaths and their tendons of the 
index and the middle finger seemed to be united. The 
inflammatory phenomena of the tendinous synovial mem- 
branes are especially remarkable in whitlows, a 
one species of which has evidently its seat in the syno- 
vial membrane of the fingers, is analogous to the inflam- 
mation of the pleura, the peritoneum, and to that of the 
articulations. It is more dangerous than the inflamma- 
tion of the synovial membranes in the form of bladders 
or bags, because the fibrous sheath which surrounds the 
inflamed membrane, not being able to stretch and yield 
to the swelling, like the cellular texture which surrounds 
the synovial bags, produces real strangulations, which it 
is often necessary to remove. I do not know whether 
the synovial texture of the tendons is exposed to the slow 
and tubercular inflammations, common to the articular 
serous and synovial systems. Its vital properties and 
those of texture appear to be precisely the same as those 
of this last. Like it, it receives with difficulty the sym- 
pathetic influence of the other organs; it is unaffected 
during the derangement of the other systems in acute 
diseases ; it remains sound in their alterations arising from 
chronic affections. I would observe also that all its affec- 
tions are almost local. For example, there is not, as in 
the serous system, species of dropsical diathesis, that is 
to say of cases in which all the synovial sacs are filled 
at the same time. 
The tendinous synovial membranes, fine and delicate 
in the fcetus and in infancy, readily yield to the nume- 
rous motions which constantly succeed that age. More 
dense and compact in the adult, they become rigid in old 
age, exhale less fluid, are dry, and do not contribute a 
little, by the state in which they are, to the general slow- 
ness of the motions which that age brings with it. SYNOVIAL SYSTEM. 
191 
There are many synovial membranes the existence of 
which is variable ; such as, for example, that of the great 
glutaeus, in the place of which there is often found only 
a cellular mass. These membranes are in general very 
dry when they exist. Synovia can scarcely be discover- 
ed in them. They resemble in this respect the articular 
synovial membranes of the vertebrae, the clavicle, &c. GLANDULAR SYSTEM. 
THIS system, one of the most important in the ani- 
mal economy, differs from most others in this, that the 
texture which is peculiar to it is not precisely the same 
in all the organs that compose it. The fibres of a muscle 
of animal life would as well serve for the structure of 
any other muscle of the same system. The tendinous 
fibres, the cartilaginous, osseous textures, &c. are every- 
where the same. On the contrary, the texture of the 
liver would not serve to compose the kidney, nor that of 
this last the salivary glands. The glandular system then 
has a resemblance in its different parts only by certain 
general attributes which have many exceptions. 
Authors have given the name of glands to organs to 
which it does not belong; such as the thyroid, the pineal, 
the lymphatic glands, those especially that are in the 
neighbourhood of the bronchia, the thymus, the supra- 
renal, &c. We should call by this name only a body 
from which flows, by one or many ducts, a fluid which 
this body separates from the blood which it receives by 
the vessels that go to it. 1st. On the head, the salivary, 
the lachrymal, the Meibomeian and the ceruminous glands 
of the ear, and the amygdalae; 2d, the mammae on the 
thorax ; 3d, in the abdomen, the liver, the pancreas and 194 
GLANDULAR SYSTEM. 
the kidneys ; 4th, in the pelvis, the prostate and the testi- 
cles; 5th, on the whole trunk and the face, the very 
numerous collection of mucous glands ; these are nearly 
all that are dependant upon the glandular system ; all the 
other organs which belong to it by this name, are foreign 
to it in their texture, their properties, their life and their 
functions. In this point of view, the division of Vicq 
d’Azyr is inaccurate. 
The extremities contain nothing which belong to this 
system, no doubt because the fluids which it separates 
almost all serve for the functions of organic life, whilst in 
the extremities every thing is in relation to animal func- 
tions. 
ARTICLE FIRST. 
SITUATION, FORMS, DIVISION, &C. OF THE GLANDULAR 
SYSTEM. 
The glands have two different positions. Some of them 
are sub-cutaneous, as the mammae, the salivary glands, &c.; 
the others deep seated, as the liver, the kidneys, the pan- 
creas and almost all the mucous ones are removed from 
the action of external bodies. The greatest number oc- 
cupy places where there is constantly much motion, as 
the salivary glands on account of the jaw, the mucous on 
account of the neighbouring fleshy layer, the liver on ac- 
count of the diaphragm, &c. It is this which has made 
it believed that this motion, foreign to their functions, 
was destined to produce the excretion of their fluids. GLANDULAR SYSTEM. 
195 
But, 1st, the glands of the palatine arch, the pancreas, the 
testicles, the kidneys even, can hardly borrow accessory 
aid on account of their position. 2d. We know that the 
sight alone of grateful food makes the saliva flow. 3d. 
Sialagogues produce the same effect. 4th. When the 
bladder is paralytic, the mucous juices pour into it as be- 
fore, oftentimes more copiously. 5th. The semen flows 
involuntarily. 6th. The excretion of the mucous juices 
is as easy in the pituitary membrane as any where else, 
though the fleshy layer, almost everywhere spread under 
the mucous system, is wholly wanting here. A thousand 
other analogous facts prove this truth placed beyond a 
doubt by Bordeu, viz. that the vital action is the essen- 
tial cause of every excretion. 
Accessory aid should not however be entirely rejected. 
In fact, in salivary fistulas, there is evidently more fluid 
thrown out during mastication than at any other time. It 
is evident that in the excretion of urine, the abdominal 
muscles perform the principal part. When the gall-blad- 
der is emptied, I believe that the neighbouring motions 
are much assistance to it. In general, whenever the 
fluids are found in considerable quantities, if the parietes 
of the organs which contain them are not very strong, 
like those of the heart, the motions of the neighbouring 
organs are necessary to overcome the resistance which 
they offer. On the contrary, in the capillary vessels in 
which the fluids are in small quantities, the organ that 
contains them is sufficient, by its reaction, for the motion. 
There are single glands like the liver, the pancreas, 
&c. ; and others in pairs, as the' kidneys, the salivary, 
lachrymal glands, &e. These resemble each other in gen- 
eral on both sides ; but their resemblance is not to be 
compared for precision to that of the organs in pairs of 
animal life. One of the kidneys is lower than the other; 
their arteries, veins and nerves are not analogous either 
in length or size; frequently fissures exist in one that are 196 
GLANDULAR SYSTEM. 
wanting in the other, &c. The same observation is true 
with respect to the salivary glands. 
The glandular forms are not fixed and invariable; they 
exhibit a thousand different modifications in their size, 
direction and proportions ; they have never the precise 
and exact conformation of the organs of animal life. 
This fact can be disputed by no one who has examined a 
number of dead bodies. The following are the means 
by which I have made this most evident to myself. We 
know that the organs vary much in size, in different in- 
dividuals ; now, in these varieties the proportions are 
always accurately kept in animal life, whilst it is rare 
that they are so in organic life. Let us take an organ for 
example in each of the two lives. I have always seen 
that in a small brain the corpus callosum, the thalami 
nervorum opticorum, the corpora striata, &c. are in pro- 
portion to the whole size of the organ. On the contrary, 
nothing is more common than to see a large lobe of Spi- 
gelius with a small liver, and vice versa a large liver 
with a small lobe. There is no anatomist who has not 
had frequent occasion to make this remarkable observa- 
tion. A kidney is larger sometimes in its superior part, 
sometimes in its inferior, &c. It is in the whole of the 
organ that these varieties of size take place in animal life; 
it is oftentimes in insulated parts only in organic life. 
The reason of this appears to me to be that the harmony 
of action is necessary, as I have demonstrated, for the 
animal functions; so that if one side of the brain is more 
developed than the other, if one eye, one ear, one pitui- 
tary membrane, &c. are more developed than their cor- 
responding organs, the perception, the sight, the hearing, 
the smell, &c. would be inevitably deranged ; whilst the 
secretion of bile, of urine, &c. takes place equally well, 
though one part of these glands may be larger or smaller 
than the other parts. GLANDULAR SYSTEM. 
197 
There is a remark to be made respecting the glands 
with regard to these varieties of form, it is, that those 
which are covered by a membrane, as the liver, the kid- 
neys, even the pancreas, are less exposed to them than 
those which are buried in cellular texture without having 
around them a membranous covering, as the salivary, the 
lachrymal, the mucous glands, &c. I have often examin- 
ee1 these last in the mouth and in the course of the trachea; 
I never found them alike in two subjects. We know 
that the parotid sometimes extends upon the masseter, 
and sometimes does not, that it descends more or less 
into the neck, that it is of a greater or less size there, &c. 
When one gland of a pair is wanting or becomes 
diseased, sometimes the other increases considerably in 
size, as I have seen in the kidneys. This takes place also 
in the treatment by compression of salivary fistulas, a 
treatment which does not however always succeed. In 
other cases, the sound gland increases its action and 
secretes more fluid, without increasing in size. 
The exterior of the glands not covered by membranes 
is unequal and lobulated ; it conforms to the muscles, the 
vessels, the nerves, and even the bones, as the parotid 
which is placed under the angle of the jaw. Less cellu- 
lar texture is in general found around them, than around 
organs with great motion. That which is in contact with 
them is more dense and compact than that of the organic 
interstices. It closely resembles the sub-mucous texture, 
that exterior to the arteries, the veins, the excretories, 
&c. but it is not however so resisting. It receives fat 
with difficulty, and forms a kind of membrane, which, 
insulating to a certain extent the vitality of the gland, 
performs in great measure in this respect the functions of 
the peritoneum around the liver, of the peculiar mem- 
brane of the kidneys, the spleen, &c. 198 
GLANDULAR SYSTEM. 
ARTICLE SECOND. 
ORGANIZATION OF THE GLANDULAR SYSTEM. 
I. Texture peculiar to the Organization of this Sys- 
tem. 
The glandular texture is distinct from most of the 
others in this, that the fibrous arrangement is wholly 
foreign to it. The elements that compose it are not 
placed at the side of each other, in longitudinal or oblique 
lines, as in the muscles, the fibrous bodies, the bones, the 
nerves, &c. They are found agglomerated, united by 
cellular texture, and adhere but very slightly. Thus 
whilst the organs with distinct fibres resist much, espe- 
cially in the direction of their fibres, these are torn with 
the least effort, and break even with ease. Their rup- 
ture is unequal, full of prominences and depressions, a 
difference which distinguishes them from cartilage, the 
ruptyre of which is in general smooth. This rupture is 
not equally easy in all the glands. The prostate, the 
amygdalae, the mucous glands resist much more than the 
liver or the kidneys, which principally exhibit this phe- 
nomenon. The pancreas and salivary glands yield a little 
without breaking, when they are pulled ; but it is not 
their texture which is the scat of this phenomenon, it is 
the abundant cellular texture that penetrates them ; thus 
their different lobes are then separated, in proportion as 
the filaments which are between them become longer. 
The glandular texture, which is very commonly called 
parenchyma, is in general arranged in three different 
ways. 1st. In the pancreas, the salivary and lachrymal GLANDULAR SYSTEM. 
199 
glands, there are distinct lobes, separated by cellular tex- 
ture, resulting from smaller lobes which are agglomerated 
together and which are composed of still less lobes, that 
are called glandular grains ; the scalpel traces with ease the 
first., second, third and even fourth divisions. 2d. In the 
liver and the kidneys there is found no trace of the first 
of these divisions, of those into principal and even secon- 
dary lobes. The glandular grains all in juxta-position, 
having between them an equal quantity of cellular tex- 
ture, a quantity which is very small, as we shall see, pre- 
sent an uniform texture without inequality, which is 
broken with ease, as I have said, and the rupture of 
which exhibits species of granulations. 3d. The pi'os- 
tate, the amygdalae and all the mucous glands have a soft 
parenchyma, like pulp, without the appearance of prin- 
cipal or secondary lobes, or even glandular grains, not 
breaking, yielding much more under the finger that com- 
presses it, than that of the other glands. The simple in- 
spection of the glandular system is sufficient to enable 
any one to perceive the triple difference which I have 
just pointed out, and which is essential. The testicles 
and the mamm® have a peculiar texture which cannot be 
referred to these differences. 
Authors have been much occupied with the intimate 
structure of the glands. Malpighi admitted that there 
were small bodies in them, which he believed were form- 
ed of a peculiar nature. Iluysch determined that they 
were all vascular. Let us neglect all these idle questions, 
in which neither inspection nor experiment can guide us. 
Let us begin to study anatomy where the organs can 
be subjected to our senses. The exact progress of the 
sciences in this age is not accommodated to all these 
hypotheses, which made general anatomy and physio- 
logy but a frivolous romance in the last. 
There is no doubt that the excretories communicate 
with the arteries which penetrate the glands. Injections 200 
GLANDULAR SYSTEM. 
made in these escape with great ease by the first, with- 
out there being any trace of extravasation in the gland. 
The blood flows often naturally by the excretories, and 
produces sometimes bloody urine, saliva, &c. But do 
these facts prove that there are only vessels in the glands, 
that the peculiar parenchyma of which they are the re- 
sult does not depend on a substance which is peculiar to 
them? The glands, like all the other organs, as the 
muscles, the bones, the mucous membranes, &c. have 
their peculiar texture which especially characterizes them, 
which belongs only to them, a texture in which the 
arteries communicate with the veins and the excretories. 
Let us not push our researches further; if we do, we 
shall be inevitably entangled in conjectures. Let us con- 
fine ourselves to examining what phenomena distinguish 
this texture from all the others when subjected to the 
different reagents. It is much to know the characteristic 
attributes of the glandular system, without seeking to un- 
derstand its intimate nature, which, like that of all the 
other systems, is concealed by an impenetrable veil. 
The glandular parenchyma dried in the air after hav- 
ing been cut in slices, loses its original colour, takes a 
deep one, black even in the liver and the kidneys, in 
which it is owing especially to the blood which pene- 
trates these glands, since if they are dried after having 
been deprived of it by repeated washing, they remain 
grey after their drying. No s}Tstem becomes harder or 
more brittle than this by this preparation. It diminishes 
then less in size than most of the others. When im- 
mersed in water after being thus dried, it becomes soft, 
resumes in part its original appearance and its tendency to 
putrefaction, which takes place immediately if it is left 
in the open air. 
The glandular texture, when exposed to the air so that 
it does not dry, becomes putrid very quickly, and gives 
out an odour more fetid than most of the others. More GLANDULAR SYSTEM. 
201 
ammonia appears to be disengaged from it. The liver 
especially produces an insupportable odour when putrid. 
I do not know any organ, kept in a vessel full of water 
to macerate, which gives out more disagreeable emana- 
tions. The kidney becomes putrid much less quickly; 
this varies however a little. 
When boiled, the glandular texture furnishes in the 
first moments of ebullition, a great quantity of grey sub- 
stance, which mixes at first perfectly with the water 
which it renders turbid and then collects into a copious 
scum on the top of this fluid. It is this texture, the 
fleshy, the mucous and the cellular which give the most 
scum in boiling, as it is the cartilaginous, the tendinous, 
the aponeurotic, the fibro-cartilaginous, &c. which give 
the least of it. It should not be believed, moreover, that 
this first product of stewing is uniform in its nature ; it 
varies in each system in quality as well as quantity. At 
least I have observed that its appearance is never the 
same, that it has nothing constant but its frothy state, 
which also varies much and which is even almost always 
nothing in the mucous system. 
The liquor which results from the boiling is very much 
changed in colour, and appears to contain ma.ny more 
principles than that made with the white organs. An 
accurate analysis of the liquor in which each system had 
been boiled would be an interesting subjeci of research. 
I have found that in almost all the appearance, the taste 
and the colour were different. 
The glands exhibit a phenomenon when cooking that 
especially distinguishes them. They harden at the mo- 
ment of the first ebullition, and acquire the horny hard- 
ness like all the other systems; but whilst most of these 
soften again from long-continued stewing, so as to become 
pulpy, the glands uniformly become harder, so that after 
five or six hours boiling, they are three or four times as 
hard as they naturally are. I have very often made this 202 
GLANDULAR SYSTEM. 
experiment, which is also well known in our kitchens, in 
which when a gland is cooked, care is taken that the 
stewing should not continue too long. Beef kidney 
finally becomes soft; those of sheep and of man remain 
hard for a much longer time. They soften hoAvever more 
than the texture of the liver, which is of all the glands 
that which exhibits the hardness in the greatest degree. 
Another phenomenon which especially distinguishes 
the ebullition of the glandular system, is that when it is 
taken out at the moment it has undergone the sudden 
horny hardening, common to almost all the animal solids 
plunged into boiling water, it has not like the others ac- 
quired elasticity. Draw in an opposite direction a ten- 
don, a serous or mucous membrane or a muscle that have 
undergone the horny hardening, they stretch and after- 
wards suddenly contract the instant the extension ceases; 
on the contrary, a slice of liver that has the horny hard- 
ness breaks when it is drawn and never contracts. The 
texture of the prostate appears to be more capable of then 
acquiring a little elasticity. The non-fibrous disposi- 
tion of the glands seems to have much influence upon 
this phenomenon. 
Exposed to the sudden action of a very bright fire as 
in roasting, the texture of the liver and the other glands 
crisps and contracts on the exterior. There results from 
it on the surface a kind of covering impermeable in part 
to the juices contained in the organ, which in this way 
becomes cooked in these juices which soften it in the in- 
terior. This phenomenon is however common to all the 
solids. Hence why care is taken to expose what is roast- 
ing, whether it be muscular or glandular, at first to the 
action of a very quick fire ; afterwards when the horny 
hardning of the surface has been produced, it is diminish- 
ed, and the organ is cooked with a small fire. 
The glands macerated in water yield differently to its 
action. The liver resists it longer than the kidney, GLANDULAR SYSTEM. 
203 
which after an experiment of two months made in vessels 
placed in a cellar has been reduced to a reddish jelly 
swimming in the water ; whilst the first preserved for 
the same time and a little longer, its form and density, 
and had only changed its red colour to a blueish brown, 
whereas the kidney retains its colour in maceration. The 
salivary glands contain much of this white, unctuous and 
hard substance, which all the cellular parts when long- 
macerated exhibit. It is not the glandular texture that 
has changed, but only the fat contained in the cellular 
texture, which is here very abundant. 
The acids act upon the glandular texture nearly the 
same as upon all the others. They reduce them to a pulp 
which varies in its colour and the rapidity of its forma- 
tion, according to the acid employed. The sulphuric is 
uniformly the most efficacious in producing this pulp 
which it blackens, whilst the nitric yellows it. All the 
acids act with much more difficulty upon the glandular 
texture when stewed, than when raw. My experiments 
have convinced me that but few systems exhibit this dif- 
ference in a more remarkable manner. 
The glands are much less digestible than many other 
animal substances, especially when stewed, which pro- 
duces in them in this respect an effect entirely different 
from what it does in the cartilages, the tendons, and all 
the fibrous organs, which by it lose their density, be- 
come soft, gelatinous, viscid even and are easier dissolved 
by the gastric juice. I believe in general that we should 
digest the glands much easier by eating them raw. 
Every one knows that the more the liver is cooked, the 
more indigestible it becomes. This induced me to make 
a comparative experiment upon this organ cooked and 
raw ; when one portion in the second state was reduced 
to a pulp in the stomach of a dog, the other portion in 
the first state swallowed at the same time had just begun 
to be altered. 204 
GLANDULAR. SYSTEM. 
Of the Excretories, of their Origin, of their Divi- 
sions, 8,-c. Of the Glandular Reservoirs. 
All the glands have ducts destined to carry off the fluid 
which they secrete from the mass of blood; now as they 
are only found in the glands, they should be considered 
with the peculiar texture of these organs. The origin 
of these ducts is uniform in all the glands. They arise, 
like the veins, by an infinite number of capillaries, which 
form the last ramifications of a kind of tree, these rami- 
fications appear to begin at each glandular grain, where 
these grains exist; so that for each there is one of these, 
an artery and a vein. Arising thus from the whole of the 
interior of the gland, these ducts soon unite and form 
larger ducts, which usually go in a straight line though 
the glandular texture, converge towards each other, unite 
with other ducts still larger and terminate differently. 
In respect to this termination, glands should be divid- 
ed into three classes. 1st. Some transmit their fluids by 
many ducts, each of which is the assemblage of smaller 
ducts, opening at the side of each other, but all entirely 
distinct and without communication. Sometimes at the 
place where these ducts terminate, a more or less con- 
siderable prominence is observed, as on the breast, as also 
on the prostate, of which the verumontanum is a kind of 
nipple. Sometimes there is a depression, a sort of cul- 
de-sac which is found at the place of these orifices, as in 
the amygdala, upon the tongue, &c. Sometimes the sur- 
face on which the different ducts of a gland open, is 
smooth and even, as is the case with that on which those 
of the lachrymal, sublingual and almost all the mucous 
glands open. 2d. Other glands pour out their fluid by a 
single duct, as the parotids, the pancreas, the sublinguals, 
&c. ; this arrangement is only a modification of the pre- 
ceding ; where the duct opens, no inequality is usually GLANDULAR SYSTEM. 
205 
discovered, the surface is smooth. 3d. There are glands 
which, before throwing out their fluid by their excre- 
tories, deposit it for some time in a reservoir where it 
remains to be afterwards expelled ; such as the kidneys, 
the liver, the testicles, &c. Here there are alwa}'s two 
excretories, one which goes from the gland to the reser- 
voir, the other from the reservoir outwards. These re- 
servoirs are evidently a part of the same system to which 
their excretory ducts belong. 
Though the first and second species of glands have no 
reservoir, yet the different ramifications of their excre- 
tories may to a certain extent be considered as such. In 
fact, these ramifications, as well as those of the excre- 
tories of the glands with a reservoir, are constantly full 
of the fluid which is secreted in these organs. Whatever 
may have been the kind of death, the fluid of the prostate 
may be always made to ooze out by compressing the 
gland ; I have often even by pressure produced a very 
evident jet. The papillae of the kidney also uniformly 
give out urine when pressed. The liver cut in slices 
allows natural bile to escape from the divisions of the 
hepatic duct. The semen is uniformly found in the wind- 
ings of the vas deferens. The lactiferous vessels keep the 
milk in their cavity, till it is evacuated, and it has even 
no other reservoir. The greater or less size of the mam- 
mae during lactation is owing to the greater or less fulness 
of these vessels. It is also to this circumstance that must 
be referred the peculiar taste of each glandular texture, 
which always borrows some sapid particles from the fluid 
it secretes. We know that the kidney has always an 
urinous odour, especially in old animals. It is to this 
also that I refer the difference of putrefaction which I 
have observed between this organ and the liver. We 
know that the bile undergoes putrid fermentation sooner 
than the urine; this, when it is very acid, can even pre- 
serve it to a certain extent from putrefaction ; expose GLANDULAR SYSTEM. 
206 
then the liver and the kidney to it, the latter will almost 
always be the last to become putrid, as I have said. 
It appears in general that the course of the fluids in 
the excrctories is much less rapid than that of the blood 
in the veins and even than that of the lymph in the ab- 
sorbents ; the following considerations place this beyond 
a doubt. The urine flows continually by the ureters, as 
is evidently proved by fistulas in the loins ; now, in the 
time taken to fill the bladder by this uninterrupted flow- 
ing, there would flow from a vein of a diameter equal to 
that of the ureter ten times as much blood, and much 
more lymph from the thoracic duct. Yet this rapidity of 
motion is subject to many varieties; during the period of 
inactivity of the glands, it is not half as great as during 
their activity ; the salivary fistulas are a proof of this. 
We know how promptly the ureters transmit the urine 
from the drinks that are taken. 
Size, Direction arid Termination of the Excretories. 
The size of the excretories varies. 1st. Those which 
go out in considerable number from a gland are very 
small, often hardly perceptible. They commonly run 
their course in a straight line, do not anastomose with 
each other and open immediately upon going out of the 
gland. 2d. Those that are single are larger, always in 
proportion to the size of their gland, except however the 
hepatic which is evidently very small in comparison with 
the liver. They run their course out of their glands, and 
arise from ducts as large as those of the preceding ones; 
so that if a single trunk arose from the excretories of 
these, they would resemble the others in every respect. 
They differ only in this, that their secondary excretories 
open directly on their surface, whereas they unite in a 
common trunk in the others. The pancreas is the only 
one in which this common trunk goes concealed in the GLANDULAR SYSTEM. 
207 
gland itself. It is only in the testicles that it is tortuous, 
and in which, on this account, it is longer than the course 
which it has to run. 
Whatever may be their arrangement, the excretories 
pour all their fluid either on the exterior, as the urethra, 
and ureters, the lactiferous tubes, and the ducts of the 
sebaceous glands ; or on the interior of the mucous mem- 
branes, as the mucous, salivary, pancreatic, prostate and 
hepatic excretories. The cutaneous and mucous surfaces 
are the only ones then on which the excretories termi- 
nate, the only ones which their fluids moisten. These 
ducts are never seen opening upon the serous or synovial 
surfaces. The excretories of the pretended articular glands 
would be, if they existed, an exception to the laws of the 
general organization. The excretories never open in the 
cellular texture ; if this happens preternaturally, either 
abscesses take place from the irritation which results from 
it, as in urinary fistulas, or a callus forms in the course of 
the excreted fluid, and thus defend the cellular system 
from a troublesome infiltration. 
Hence the mucous tube of the intestines should be con- 
sidered as a kind of general excretory added to the pan- 
creatic, hepatic excretories, &c. and which throws out 
all the fluids which are separately poured by these ducts 
into it. In fact, all the secreted fluids appear to be des- 
tined, as I have said, to be thrown out of the body. 
Separated from the mass of blood, they are foreign to it, 
and do not enter it in a natural state. Though still con- 
tained in cavities with mucous surfaces, they may be 
truly considered as being out of our parts. These sur- 
faces are really true internal integuments, destined to de- 
fend the organs from the contact of the substances which 
they contain, a contact which would inevitably be inju- 
rious to them. 208 
GLANDULAR SYSTEM. 
Remarks on the Secreted Fluids. 
The fact that the secreted fluids are destined to be 
thrown out, a fact which is incontestable with regard to 
the urine, the bile which colours the excrements, the 
saliva, &c. has made me for a long time believe that the 
introduction of these fluids into the sanguineous system, 
would produce the most serious consequences. I was be- 
sides confirmed in this, 1st, by my experiments, in which I 
have always seen, as I have said, the urine, the bile, &c. 
injected into the cellular texture, remain without being 
absorbed, but producing abscesses; 2d, by the infiltra- 
tion of the urine in the neighbourhood of the bladder, 
from which abscesses always arise; 3d, by the serious 
consequences from the effusions of this fluid in the perito- 
neum from the high operation for the stone, and of the 
bile on the same surface in certain penetrating wounds, 
in both these cases these fluids never re-enter the blood 
by way of absorption, like the peritoneal serum, but almost 
always occasion death; 4th, by an experiment in which 
I had seen a dog die shortly after the injection of urine 
into the jugular. All these considerations made me sus- 
pect that the secreted fluids, introduced again into the 
mass of blood, were always fatal at the end of some time, 
and that, as some physicians whose opinion is of great 
weight have thought, ail that has been said of the bile’s 
being poured into the blood in bilious diseases, is but a 
consequence of vague ideas of the reality of which there is 
no proof. Yet the importance of this question, in regard 
to medical theories, has induced me to resolve it by 
experiments, so as to leave no doubt upon the subject. 
1 have then injected into the jugular veins of many 
dogs bile taken from the gall-bladder of other dogs which 
I opened at the same time. For the first few days they 
appeared to be weary, did not eat, were much altered, 
their eyes were heavy, and they were constantly lying GLANDULAR SYSTEM. 
209 
down ; but after some time they gradually regained their 
former vigour. I afterwards employed human bile in 
these experiments; the result was the same, except that 
many times the animal had hiccough and vomiting some 
time after the injection. In one instance a dog died in 
three hours after the experiment; but it was because I 
made use of that extremely hlack fluid that is sometimes 
found in the gall-bladder instead of bile which resembles 
thick ink, and which appears to form a considerable part 
of those black vomitings that sometimes take place. 
These experiments induced me to try some with the 
saliva, and I obtained the same result from them t only the 
languid state that succeeded the injection was less evident. 
I afterwards made use of nasal mucus suspended in a 
sufficient quantity of water, for it can hardly be dissolved 
in it. Finally urine itself was many times injected, not 
that which comes immediately from drink and is only 
aqueous, but that which is of slow formation. In this 
experiment the dogs have been sicker, but only one died, 
and that happened on the seventh day. I have many 
times repeated it, on account of that which I performed 
three years ago; the same result has always taken place, 
which makes me think that being but little used at that 
time to make experiments, I introduced by accident a 
bubble of air through the syringe, which is sufficient to 
produce the death of the animal. 
A question then is evidently settled by the experiment. 
The secreted fluids, though destined to be thrown out in 
the natural state, can re-enter the circulation, without 
causing the death of the animal, which is only more or 
less affected according to the nature of the fluid injected. 
Whether the bile circulates or not with the blood in 
bilious fevers, I have not examined ; but it certainly can 
circulate with it after having been absorbed in its canals. 
T do not doubt but that in purulent reabsorptions, the pus 210 
GLANDULAR SYSTExM. 
circulates in its natural state in the sanguineous system; 
I confess that I have not made experiments upon the 
injection of this fluid, but I intend to immediately. 
We exaggerate every thing. No doubt the solids in 
which the vital forces are especially inherent, are particu- 
larly affected in diseases; hut why should not the fluids 
be affected also ? Why should we not seek in them causes 
of disease as well as in the solids? 
There are cases in which these are primarily affected, 
and in which the fluids are so in consequence ; thus in 
cancer, in the affections of the liver, the spleen, &c. in 
most organic lesions, the various yellowish, grey, brown 
and even greenish shades of the face, are an index of the 
consecutive alterations which the fluids experience in 
their colour and consequently in their nature. 
In other cases the affection commences with them; as 
when the venom of the viper is introduced into the blood, 
as when reabsorption of pus takes place from external 
abscesses, or in phthisis, and as when there is absorption 
of various contagious principles. There is no doubt that 
the different substances which can be introduced with the 
chyle into the blood, may be the cause of various dis- 
eases. Is it not the blood which carries to the brain the 
narcotic principles which produce sleep ? does it not 
carry turpentine and cantharides to the kidneys, mercury 
to the salivary glands, &c. ? Inject opium, wine, &c. into 
the veins, and you will stupify the animal the same as if 
you had given them by the stomach. 
Physiologists at one time were much engaged with the 
introduction of medicinal infusions into the veins of living 
animals. They circulated by these infusions purgatives, 
emetics and a thousand other foreign substances, the con- 
tact of which the blood bore, without occasioning any 
other accident to the animal than that of vomiting or 
alvine evacuations if they were emetics or purgatives, and 
a greater or less general derangement if they were other GLANDULAR SYSTEM. 
211 
foreign substances which had no affinity with any particu- 
lar organ. 
The caustics, as the nitric and sulphuric acids and other 
very irritating substances, have alone caused death in 
these curious experiments of which Haller has given us 
a sketch, and which prove that various substances wholly 
foreign to the blood can circulate in it, and that it is a 
common mass in which are found many principles differ- 
ing from each other, and which cannot be always essen- 
tially the same. In these experiments the most impor- 
tant part has been neglected, that of the infusion of the 
different animal fluids, particularly the secreted ones, and 
those also which are preternaturally produced in diseases. 
I think that the different reabsorptions would be much 
elucidated by the infusion of the various kinds of pus, 
sanies, &c. But we have already sufficient facts to con- 
vince us that the fluids and especially the blood can be 
diseased ; that the various foreign substances mixed with 
it can act in a fatal manner upon the solids. In fact, every 
acrid, irritating matter, without being mortal, accelerates 
the action of the heart and produces a true fever, if inject- 
ed into the veins. In all these cases, it is always necessary 
that the solids should act; for all the morbid phenomena 
suppose their alterations ; but the principle of these altera- 
tions is in the fluids. They are the excitants, and the 
solids the organs excited. Now if there are no excitants, 
there is no excitement, and the solids remain unaffected. 
Finally there are cases in which the whole economy 
both solids and fluids seem to be simultaneously affected ; 
such are adynamic fevers, in which at the same time that 
there is a general prostration of the first, the second ap- 
pear to be really decomposed. 
Let us not exaggerate then medical theories; let us 
regard nature in diseases as she is in a state of health, in 
which the solids elaborate the fluids and are at the same 
time excited by them. There is a reciprocal action, 212 
GLANDULAR SYSTEM. 
every thing succeeds each other, every thing is connected 
together. Our abstractions hardly ever exist in nature. 
We usually adopt a certain number of general principles 
in medicine, and we accustom ourselves afterwards to de- 
duce from these principles, as necessary consequences, all 
the explanations of diseases. There is in physical phe- 
nomena a regularity and uniformity which never deceive. 
In morals even, there is a certain number of principles 
acknowledged by all men, which direct them and regu- 
late their actions ; hence a constant uniformity in our 
manner of considering moral and physical phenomena ; 
hence the habit of going always from the same principles 
in reasoning upon them. We have carried this habit into 
the study of the living economy, without considering 
that it incessantly varies its phenomena, that under the 
same circumstances they are hardly ever the same, that 
they are continually increased and diminished and have a 
thousand different modifications. Nature seems at every 
instant to be irregular, capricious and inconsequent in 
their production, because the essence of the laws which 
preside over these phenomena, is not the same as that of 
the physical laws. 
I would observe that the experiments the result of 
which I have just given for the secreted fluids, differ 
from those which I published the last year, and in which 
these fluids have always been fatal, the instant they were 
forced towards the brain by the carotid. This is a phe- 
nomenon general to all the irritating fluids, whether drawn 
from the economy, or foreign to it; they destroy life 
when they arrive at the cerebral organ, by a direct in- 
jection and without having undergone any alteration, 
whilst we can inject them with impunity into the veins, 
as the experiments of the physicians of the last age have 
proved. We can even without danger, as I have observ- 
ed, introduce them into the arterial system, on the side 
opposite to the brain, as in the crural artery, for example. GLANDULAR SYSTEM. 
213 
Do the fluids mixed with the black blood rid themselves 
of some principles by respiration, before they arrive at 
the brain, or is the preceding phenomenon owing to other 
causes ? I know not. I would only observe that every 
thing which is not arterial blood, as the black blood and 
even serum, produces death when forced into the carotid. 
Water alone is injected with impunity. When the irri- 
tating principles are much diluted in this fluid, their con- 
tact is less injurious. I have seen very light coloured 
urine not produce death. 
Structure of the Excretories. 
All the excretories have an internal membrane which 
is mucous, and which is a continuation of the mucous or 
cutaneous surfaces, upon which they terminate. But be- 
sides this, they all exhibit an external covering which 
forms the shell, as it were, of this mucous canal. This 
shell is very thick in the vas deferens, in which it ex- 
hibits a texture but little known. In the urethra it is 
of a spongy nature, containing much blood and analogous 
to the glans of which it is a continuation. In the ureters, 
in the hepatic, salivary ducts, &c. it is this extremely 
dense and compact cellular texture of which we have 
spoken, which, by its structure, resembles that of the 
arterial and venous cellular texture, and which differs es- 
sentially from the ordinary cellular texture, as from the 
intermuscular. It does not appear that there is in these 
ducts a membrane differing from this dense texture and 
the mucous surface. 
Each excretory has its vessels. The ureters evidently 
receive branches from the renal, spermatic arteries, &c. 
&c. The hepatic gives them to the ductus choledochus ; 
the transverse artery of the face supplies the duct of Steno. 
Various nerves coming from the ganglions accompany the 
corresponding arteries and veins. Yet I have uniformly 214 
GLANDULAR SYSTEM. 
observed that there is never around these ducts a plexus 
as evident as there is around most of the arteries. 
The excretories have principally the vital properties 
of the mucous system which forms them in great part. 
Their sympathies are also nearly of the same nature. 
II. Farts common to the Organization of the Glandu- 
lar System. Cellular Texture. 
The glands differ much in the cellular texture which 
enters into their structure. We may even, in this respect, 
divide them into two classes. 
In all the salivary glands, in the lachrymal, in the pan- 
creas, in all the glands with a granulated and white paren- 
chyma, it is very abundant. Each glandular body is divid- 
ed into lobes very distinctly separated by grooves which 
this texture fills, and which produce the lobulated appear- 
ance on the exterior of this species of gland ; not only each 
lobe, but each lobule, each glandular grain even, has also 
the cellular texture for a boundary. In this respect, this 
sort of gland is truly an assemblage of small distinct 
bodies, which, separated from each other, would also 
perform well their functions. This is what is seen in the 
parotids, in which different accessory glands are often 
found in the course of the duct of Steno, and are perfect- 
ly independent of the principal gland. Sometimes there 
is a continuity, sometimes there is a separation between 
the sub-maxillary and the sub-lingual glands. The cellu- 
lar texture is often loaded with much fat in this species 
of gland. This is especially remarkable in the mammae, 
the size of which is owing sometimes to the glandular 
texture, as in young people in whom this texture predomi- 
nates over the fat; sometimes to the predominance of this 
fat, as we see after the fortieth year, when this gland 
preserves a considerable size. The difference is easily 
perceived by the touch by the softness and flaccidity of GLANDULAR SYSTEM. 
215 
the organ in the second case, and by its resistance and 
firmness in the first. In the age of puberty often, it is 
also the fatty cellular texture which increases the size of 
this organ. Hence why there is often but little milk 
from a large breast, and a much greater quantity from a 
smaller one. In the voluptuous sensations which we 
experience at the sight of this organ, we distinguish very 
well, without being conscious of it, the breast whose pro- 
minence is real, from that which is not, and in which the 
fat only raises the skin of the breast. It is rare in the 
salivary glands, the pancreas, &c. that the cellular texture 
predominates so much, that the fat accumulates in them 
in so considerable a quantity. I have however seen cases 
in which the parotid resembled a fatty muscle ; but there 
was no increase of size. 
In the testicle, whose parenchymatous portions are 
separated as in the preceding glands, the cellular texture 
is not the medium of union. There is found between 
each grain species of threads which appear to be excre- 
tories, and not real cellular laminae. 
In the glands with a compact parenchyma, as the liver, 
the kidney, the prostate, the mucous glands, &e. &c. there 
is very little cellular texture ; by tearing them in different 
directions, they break without exhibiting intermediate 
laminae. Fat is never found accumulated in their paren- 
chyma. The fatty state of the liver which takes place in 
many diseases, and which is not, as has been thought, an 
affection necessarily attendant upon phthisis, exhibits a 
phenomenon wholly different from the mammae and the 
salivary glands when they have become fatty. The fat 
enters then like an element into the texture of the organ; 
it is in this respect like the colouring substance, whose 
place it has as it were taken; it is not found in cells. 
Moreover much of it can be extracted bv ebullition, and 1 
have observed that much of it swims on the surface of 
the water in which livers of this kind are boiled. The 216 
GLANDULAR SYSTEM. 
kidney also has fat in its interior ; but it is around the 
pelvis and not in its peculiar parenchyma. The amyg- 
dalae, the prostate, the mucous glands, &c. never have it. 
Serum is never effused into the texture of the glands with 
a compact parenchyma. The most complete leucophleg- 
masia leaves them sound in this respect. 
Yet it cannot be doubted that the cellular texture exists 
in these glands ; maceration demonstrates it in them. In 
the fungous tumours that grow out of them, there is much 
of it. It is principally around the vessels that it is found ; 
the capsule of Glisson is an example of this. It often 
happens even, as I have been led to observe, that this 
texture becomes diseased, whilst that of the gland remains 
sound. Thus we see steatomatous tumours developed in 
the liver, serous cysts in the kidney, hydatids in both, 
and various productions in the other glands, without 
deranging the secretion in the least. It is upon the liver 
especially that these observations are best made ; its size 
is trebled, even often quadrupled by internal tumours, 
without an increase of its texture ; this texture dilated 
forms between these tumours, species of partitions in 
which the bile is secreted as usual. The same thing takes 
place in the kidney, in which serous cysts are found. 
Sometimes these cysts grow there till the whole glandu- 
lar texture is destroyed, and there remains only a large 
sac separated by membranous partitions, and filled with 
serum. I have preserved three kidneys of this kind. 
Blood Vessels. 
All the glands not covered by a membrane, receive their 
arteries from all sides. Numerous branches coming from 
the neighbouring vessels, penetrate the whole surface of 
the pancreas, the salivary and lachrymal glands, &c. 
These arteries wind at first in the interstices between the 
lobes, ramify afterwards between the smaller lobes and 
finally penetrate the glandular grains. Each of them has GLANDULAR SYSTEM. 
217 
its own artery; all communicate together; so that those 
of the sub-maxillary and the sub-lingual are filled by in- 
jection made by means of small tubes into the sub-mental, 
the external maxillary or the lingual, as well as by an in- 
jection of the trunk even of the external carotid. 
In the glands surrounded by a membrane, as the liver, 
the kidney, the testicle, &c. the arteries enter only at one 
side, usually in a fissure, and by a single trunk which is 
very considerable, and which is sometimes divided into 
many branches more or less large. This part of the gland 
in which the artery enters is always the most distant from 
the action of external bodies, a remark common to all the 
important organs, as the lungs, the intestines, the spleen, 
&c. which always present externally their convex sur- 
face, that on which the vessels are the most ramified ; so 
that the place where an injury can happen to them is 
that where hemorrhage is the least to be feared. The 
principal artery, after it has entered the gland, is soon 
divided into different branches which separate and are 
subdivided as they approach the convexity. They give 
off in their course many branches to the body of the gland 
and then terminate by a great number of capillaries on 
the convex part of the gland. They often even pierce 
the organ and ramify between it and the membrane which 
covers it. For example, by injecting the hepatic artery, 
if the liver is bare, many small blackish striae suddenly 
appear on its convexity, which are owing to this cause. 
The best means of seeing the glandular arterial system, 
is to inject a kidney with a solid substance, and after- 
wards destroy its parenchyma by maceration or some- 
thing else. The arterial system is then bare and entirely 
by itself. Many of these preparations are found in anato- 
mical museums. 
The great arterial trunks winding in the glands, com- 
municate to them an internal motion very favourable to 
their functions. This motion is so much the more evi- 218 
GLANDULAR SYSTEM. 
dent, as almost all these organs very near the heart by 
their position in the trunk, are, if we may so say, under 
the immediate jar of it's contractions. The salivary glands, 
the mucous ones of the mouth and the lachrymal on the 
one hand, the testicle, the prostate and the mucous ones 
of the genital parts on the other, exhibit the extremes of 
this position. Another cause which favours the jar of 
the glands by the entrance of the blood, is that almost all 
the arteries that go to them run but a very short course 
before they enter them. The spermatic alone is an ex- 
ception to this rule ; thus, every thing in the secretion of 
semen seems to be characterized by a remarkable slow- 
ness. To this constant motion imparted to the glands by 
the entrance of the blood, should be added that which is 
communicated to them by the neighbouring organs, and 
which keeps them in a constant excitement, which is 
more necessary to their secretion than to their excretion. 
In considering the action of organs, the constant motions 
with which they are agitated has been too much neglect- 
ed. The example of the brain ought however to fix the 
attention of physiologists upon this point. 
The veins, everywhere continuous with the arteries, 
follow the same distribution in the glandular system, and 
accompany them almost everywhere. We do not see 
superficial and deep-seated veins, as we do in many other 
organs. The liver is the only example in which the 
red blood enters at one side, and the black goes out at 
the opposite. 
Most of the veins of the glandular system pour their 
blood into the general system of black blood, and as many 
glands are very near the heart, they feel the reflux which 
this system often experiences. This phenomenon is par- 
ticularly remarkable in the liver, as the hepatic veins 
open but very little below the right auricle. Hence why 
whenever this auricle is considerably distended, as in 
asphyxia and in death in which the lungs being crowded GLANDULAR SYSTEM. 
219 
present an obstacle to the blood, the liver has a much 
greater quantity than usual. I have uniformly made this 
observation. Weigh comparatively this organ when the 
auricle is full and when it is empty in the dead body, 
after having first tied all its vessels ; you will find a very 
great difference. For the same reason, you will observe 
a constant relation between the weight of the liver and 
that of the lungs, provided a morbid alteration of texture 
of one of them be not the cause of death. The veins 
of many glands, as those of the mucous ones of the 
stomach and the intestines, as those of the prostate, &c. 
pour their blood into the system of abdominal black 
blood. There are hardly any in the system of which 
we are treating, but these veins, those especially of the 
glands situated in the pelvis, which become varicose. 
Varices of the prostate are frequent, as we know. 
Of the Blood of the Glands. 
The quantity of blood that is constantly found in the 
glands varies remarkably ; they may even be divided in 
this respect into three classes. 1st. In the pancreas, the 
salivary, lachrymal glands, &c. there is found but very 
little. It does not furnish the colouring matter to these 
organs, which are white, and which, when macerated, 
tinge with red but two or three waters. 2d. In the mu- 
cous glands, the prostate, the testicles, and the amygdalae, 
there is found a little more. 3d. The liver and the 
kidneys contain so great a quantity of it, that there is not 
in this respect any proportion between them and the rest 
of the glandular system. This is owing in a small degree 
in the first to the cause pointed out above ; thus it often 
contains more than the second, but it is not the essential 
cause. After death by hemorrhage in which there was 
no reflux, in the 'liver or the kidney suddenly taken from 
a living animal, &c. we observe the same thing. In 
macerating these glands, it is necessary to renew the 220 
GLANDULAR SYSTEM. 
water at least a dozen times before it ceases to be bloody. 
Hence why when they are preserved in alkohol on 
account of an organic disease of which they were the 
seat, they must be first macerated for a long time; if not, 
the liquor soon becomes turbid from the blood. It is 
this quantity of blood which gives to these glands a 
greater weight in proportion than that of the other parts. 
It is from this that their redness is derived, a colour 
which no other part exhibits to the same degree, but 
which is not more strongly inherent in their texture, than 
it is in the mucous surfaces or the muscles. In fact, we 
remove it with the same ease by repeated washing. Then 
the liver assumes a greyish appearance, which appears to 
be the colour inherent in its texture, as white is that of 
the fleshy fibre. The kidney seems a little less to derive 
its colour from the blood. It remains in part red when 
macerated ; the pulp even which is the product of it, 
after remaining some months in water, that has been often 
changed, still exhibits in some degree this colour, much 
less however than in a natural state. 
Does the state of the secretions make the quantity of the 
glandular blood vary ? Does more of this fluid enter the 
kidney when it furnishes much urine, than when it 
secretes but little, or if the same quantity is brought by 
the arteries, is less returned by the veins in the first than 
the second case ? This is an interesting subject for expe- 
riment. 
Is the nature of the blood changed when it arrives at 
the glands ? Has it a peculiar composition before enter- 
ing each of them ? Much has been said of this change 
necessary to secretion ; but that this may take place, there 
must be a cause to produce it; now what is this cause 
here ? Does not the blood circulate in the trunks which 
go to the glands, as in the others ? It would be necessary 
then that the gland should be surrounded with an atmos- 
phere which acts upon the blood at a certain distance GLANDULAR SYSTEM. 
221 
from the place where it is ; a vague idea, which has no 
solid foundation, and which is met with only in the books 
of those who have never made experiments. I have 
drawn blood from the carotid, spermatic, hepatic and 
renal arteries ; it is equally red and coagulabl'e. In the 
same animal, it is impossible for the senses to discover 
the least difference. 
I would observe that secretion differs essentially from 
nutrition in this, that it always draws the materials of 
its fluids from the red blood, whereas the second often 
takes its own from the white fluids, as we see in the ten- 
dons, the cartilages, the hair, &c. 
Nerves. 
The glands receive two species of nerves. 1st. The 
cerebral are found almost exclusively in the salivary and 
lachrymal glands, the amygdalae, &c. 2d. The testicles, 
the prostate gland and the liver receive them in an al- 
most equal proportion from the brain and the ganglions. 
3d. The kidneys and most of the mucous glands receive 
scarcely any but those of the ganglions. What is now 
said of the nerves should be understood only of those 
that are free and independent of the arteries ; for each 
arterial trunk that enters a gland, is surrounded by a 
nervous net-work belonging to the system of the gan- 
glions, which is very evident in the great glands, as in the 
liver and the kidneys where this net-work comes from 
the semilunar ganglion, in the salivary glands where it 
comes from the superior cervical, in the testicles where 
it comes from the lumbar ganglions, &c. 
Compared with the size of the glands, the nerves are 
in small proportion, notwithstanding what Bordeu has 
said. It is not necessary in fact to judge of this propor- 
tion by those of the parotid and sub-maxillary glands, 
which merely pass through these glands without stopping 222 
GLANDULAR SYSTEM. 
in them, and leave only some branches there. For ex- 
ample, there is certainly no organ in the economy, among 
those which receive nerves, that, in proportion to its size, 
has so few as the liver. 
Besides,' the nerves enter the glands nearly in the same 
way as the blood-vessels, that is so say, 1st, on all sides, 
in those that have no membrane; 2d, by a groove only in 
those that are covered with one. They divide and sub- 
divide after entering it, and are soon lost sight of. Gan- 
glions never exist in the interior of the glands. 
Have the nerves an influence upon secretion ? It is 
probable they have, as every gland is provided with 
them ; but they by no means exert so immediate an in- 
fluence upon this function as many physicians have pre- 
tended. 1st. It is said that the nerves of the parotid 
glands have been cut, and that the secretion of the saliva 
has been suppressed. This division is evidently impossi- 
ble, since the gland must be extirpated before removing 
its nerves. 2d. I have divided the nerves of the testicle 
of a dog, the only gland in which this experiment can be 
made. I could not obtain any result, because an inflam- 
mation of the gland came on and it suppurated ; but this 
suppuration even supposes that the nervous influx is not 
actually necessary for secretion, since suppuration is ac- 
complished by a mechanism analogous to that of this 
function. All physicians know that a paralyzed limb can 
inflame and suppurate. 3x1. Erection and the ejection of 
semen take place in paralysis of the lower half of the 
body, in which at least the nerves of the prostate gland 
are completely paralyzed. Mr. Ivan related to me the 
case of a soldier who took gonorrhoea in this state. 4th. 
We know that when the bladder is perfectly paralyzed 
and its nerves have no longer any action, its mucous 
glands still continue to secrete their fluid so as even to 
produce a catarrh. 5th. The nostril of the affected side 
in hemiplegia is as moist as usual. The ear of this side GLANDULAR SYSTEM. 
223 
has its ordinary quantity of wax. 6th. In paralysis of 
the uvula, the action of its glands continues. 7th. 
When the eighth pair of one side of a dog is cut, the 
bronchia is found some days after to contain as much 
mucus as common. 8th. During the convulsions of the 
different parts in which there are glands, and when conse- 
quently the nerves of these glands are more excited, their 
secretion is not increased. 9th. If we weigh the proofs 
given by Bordeu of the influence of the nerves on secre- 
tions, we shall see, that they either rest upon false facts, 
like those of the section of the nerve, of sleep, &c. or 
upon vague data. In general physicians attach no pre- 
cise idea to the term nervous influence ; the habit of ex- 
perimenting shows how much they have abused it. When 
a nerve being cut, paralyzed or irritated in any manner, 
the organ which receives it undergoes no derangement in 
its functions, we certainly are unable to appreciate the 
nervous influence upon this organ. I do not say that 
it does not exist, but I maintain that we know nothing 
about it, and that we ought not to employ at hazard a 
word to which we cannot attach any precise idea. What 
word will you employ then to express the influence of 
the nerves upon the organs of the senses, upon the vol- 
untary muscles, &c. if the same one is used to express an 
action which has no relation with this, and which per- 
haps even does not exist ? 
Exhalants and Absorbents. 
This kind of vessels is but little known in the interior 
of the glands, where they perform only the purposes of 
nutrition. 224 
GLANDULAR SYSTEM. 
ARTICLE THIRD. 
PROPERTIES OF THE GLANDULAR SYSTEM. 
I. Properties of Texture. 
These properties are in general very inconsiderable in 
this system, which appears to me to be particularly owing 
to its non-fibrous texture. In fact, in order to be elon- 
gated and afterwards contracted and preserve their integ- 
rity, it is necessary that the particles of an organ should 
possess a certain degree of adhesion and cohesion ; now, 
it is to the fibre that especially belongs this double attri- 
bute. Observe also that the glandular system is sub- 
jected to much less frequent causes of distension and 
contraction, than the systems with distinct fibres. It 
is scarcely ever found distended except when puru- 
lent deposits, serous, steatomatous collections, &c. are 
formed in its interior, as often happens in the middle of 
the liver, kidney, &c. ; now in these cases it does not 
yield like the skin, the muscles, &c. ; its particles are 
separated; it is the cellular texture with which they are 
surrounded that is uniformly dilated ; the glandular tex- 
ture is even soon destroyed. It is very evident when 
the collections are formed near the convexity of the 
glands ; if the tumour be at all large the texture of the 
organ disappears; there remains only a cellular and mem- 
branous cyst. Hydatids so frequent on the exterior of 
the kidneys present us with * examples of it. If it is in 
the middle of the gland that the cyst is formed, the de- 
struction also takes place, but it is much less evident. GLANDULAR SYSTEM. 
225 
A strong proof of the small degree of extensibility of 
the "lands, is what takes place in the liver in dead bodies. 
I have said above that it is more or less loaded with 
blood, according as the system with black blood had been 
more or less embarrassed in the last moments. Now 
whatever may be the quantity of blood it contains, its 
size remains nearly the same; only its texture is more or 
less compressed by the vessels, whilst on the contrary 
the greater or less size of the lungs, which is very appa- 
rent, always indicates its state of fulness or vacuity. It 
is probable even that it is this difference which has made 
all physicians neglect the infinitely various states of en- 
gorgment in which the liver may be found at death, 
whilst they have had a particular regard to the varieties 
of the lungs. 
The veins of the kidneys, further from the heart, are 
less exposed than those of the liver to the reflux that 
takes place in the last moments in which the black blood 
is obstructed in the lungs. Yet it however takes place, 
and we see very great varieties in the quantity of blood 
in the great renal vessels, a quantity independent of that 
which is constantly found in the organ, and which, as I 
have said, is very considerable. Now the size of the 
kidney hardly corresponds to these varieties, because its 
extensibility is almost nothing. 
As to the glands situated at the two extremities, as on 
the one hand the testicles, and on the other the salivary 
glands, we hardly observe in them the sanguineous stag- 
nation, because the reflux is not sufficiently evident. We 
cannot then, in this way? judge but by analogy of their 
extensibility and contractility. 
Yet the engorgements of the testicles, consequent upon 
gonorrhoea, and the various swellings of the parotid glands 
prove that these properties exist to a certain extent. Are 
the liver, the kidneys and other internal glands subject to 
those acute swellings that are often seen in the sub-cuta- 226 
GLANDULAR SYSTEM. 
neous ones ? It is very probable ; perhaps even physicians 
have not paid sufficient regard to the accessory symptoms 
which may arise for a moment from the pressure of these 
swelled organs on the neighbouring parts. Besides, this 
swelling and the contraction that follows it, may take 
place especially in the cellular texture of the gland, and 
Consequently suppose less extensibility of the glandular 
texture than they at first seem to. 
II. Vital Properties. Properties of Animal Life. 
The animal contractility is evidently nothing in the 
glandular texture. Does the sensibility of the same kind 
exist in it ? The following facts are connected with this. 
1st. A compression of the parotid is to a certain degree 
painful. I have even been obliged, in a particular case, 
to give up the method of compression that Desault had 
advised for a salivary fistula, on account of the pain the 
patient experienced; but the numerous nerves which 
traverse this gland may be the cause of these pains. 
2d. We know that the instant the lithotome cuts the 
prostate, or the stone and forceps pass over it, the patient 
suffers very much. 3d. Stones lodged in the kidneys 
occasion horrible pains. 4th. Any considerable pressure 
of the testicle is very painful. 
On the other hand we can cut the texture of the liver 
and the animal will give no signs of pain. Haller, after 
many experiments, ranked the glands among the insen- 
sible parts. What is to be concluded from this ? That 
the animal sensibility, modified in a thousand ways, ap- 
pears to exist in many organs in which certain agents 
cannot put it in action, and in which others develop it 
remarkably. We know that the various morbid altera- 
tions render it very evident in the glands. The inflam- 
matory pain of these organs has even a peculiar charac- 
ter ; it is obtuse and dull in the greatest number of cases. GLANDULAR SYSTEM. 
227 
Thefe is never experienced in them the acute sensation 
which characterises cellular inflammation, or the sharp 
and biting pain of which the skin is so often the seat. 
Properties of Organic Life. 
Of the properties of organic life, the sensible contrac- 
tility is wanting in the glandular system. But the two 
other properties are developed in it to the highest degree. 
They are in constant activity ; secretion, excretion and 
nutrition keep them in incessant action there. It is by 
its organic sensibility that the gland distinguishes, in the 
mass of blood, the materials which are proper for its 
secretion. It is by its insensible contractility, or its tonic 
forces, that it contracts to throw out those which are 
foreign to this secretion. The first is on a small scale in 
each gland, what the animal sensibility of the tongue and 
the nostrils is on a large one, which allows only aliments 
suitable for the stomach to be introduced into its cavity ; 
the other does insensibly, what is effected in so evident 
a manner by the glottis, when it rises up convulsively 
against a foreign body that attempts to enter it. The 
blood contains the materials of all the secretions, of the 
nutrition of all the organs, and of all the exhalations. 
Each gland draws from this common reservoir what is 
necessary to its secretion, as each organ does what is 
proper for its nutrition, and as each serous surface does 
what is suitable for its exhalation. Now it is by its or- 
ganic sensibility that each living part of the body distin- 
guishes what its functions require. 
When the fluids enter the small vessels of the gland, 
this sensibility is the sentinel that’gives notice of it, and the 
insensible contractility is the agent which opens or closes 
the gates of the organ, according to the principles that 
are presented. This comparison, if I may be allowed the 
use of it, gives an idea of what then takes place. Every 
glandular action turns then especially upon these two 228 
GLANDULAR SYSTEM. 
properties, and as this action is almost permanent, they 
are then constantly in exercise. 
From this it is evident, that all the glandular diseases 
ought to suppose a derangement in these properties ; for, 
as we have often seen, they are the predominant properties 
of an organ, those, the exercise of which constitutes its 
peculiar life, which especially determine its diseases, by 
their alteration. This is in fact what observation shows us. 
Here we see these properties increased or diminished, 
sometimes produce an increase of secretion, as in diabetes, 
mercurial salivation, immoderate flow of bile, &c.; some- 
times a diminution, a suspension even of this function, 
as in acute diseases in which all the ducts are closed as it 
were in a moment, as in the suppression of urine, dry- 
ness of the mouth, &c. It is the alteration in the nature 
of the glandular sensibility that puts it in relation with 
fluids foreign to the glands in a natural state ; hence the 
innumerable varieties of the secreted fluids especially in 
diseases. I have spoken of these varieties as it regards 
the mucous fluids. The liver and the kidneys particu- 
larly do not experience less numerous ones. The taste, 
the colour, the consistence and odour of cystic bile ap- 
pear in a thousand different states in dead bodies. Who 
is ignorant of the innumerable alterations of which the 
urine is susceptible? The saliva is less variable; but in 
diseases how different is it from its natural state. It is 
sufficient to have noticed for some time the various evacua- 
tions in diseases, to see of how many modifications they 
are capable. Nothing less resembles the urine and bile, 
than the fluids sometimes thrown out by the bladder and 
the liver; whence do these varieties arise ? From this, 
that the variable organic sensibility places the organ in 
relation with substances to which it was foreign in a 
natural state; and from this, that the insensible contrac- 
tility allows substances to enter the organ which it be- 
fore excluded. The same gland without changing its tex- GLANDULAR SYSTEM. 
229 
ture, by a modification only of its vital forces, can then 
be a source of an infinite variety of different fluids ; I be- 
lieve even that the kidney, by taking a sensibility analo- 
gous to that of the liver, may secrete bile. Why may it 
not secrete it, if it can secrete other fluids so different 
from its own ? 
In health, each gland has a mode of sensibility nearly 
uniform, a mode which changes but little ; thus each 
secreted fluid has an appearance, a consistence and a 
nature always nearly the same. But in diseases, a thou- 
sand causes change this mode at every instant. An hyste- 
rical paroxysm strikes the kidneys ; in an instant they 
repulse all the principles that colour the urine, and this 
comes out limpid ; the paroxysm passes off, the organ 
resumes its ordinary sensibility, and the urine returns to 
its usual state. The influence of the epileptic paroxysm 
extends to the sensibility of the salivary glands ; in a 
moment, a thick, copious and frothy saliva, wholly differ- 
ent from the natural, comes from the mouth ; after the 
paroxysm, the sympathetic storm is calmed in the gland, 
and the saliva returns to its ordinary state. If I may be 
allowed the comparison, the glands are in diseases like 
the atmosphere in the equinoxes. At these periods, the 
winds which succeed each other and incessantly change, 
often make rain, hail and snow succeed each other in a 
very short time ; so the forces of the glandular life, con- 
stantly variable in diseases, make the different products 
of secretion vary with rapidity. 
It is not only to secretion that the various alterations 
of the organic sensibility and the insensible contractility 
of the glands extend ; these alterations when long con- 
tinued, have an influence also upon their nutrition ; they 
disturb the course of it; hence the changes of texture, 
the tumours of different kinds, the organic diseases, &c. 
that are so frequent in the glandular system, a system 
which presents the greatest field for morbid anatomy. 230 
GLANDULAR SYSTEM. 
The great number of organic diseases which it exhibits, 
in our dissecting rooms, compared with most of the other 
systems, is very striking. The glandular, the cutaneous, 
the mucous', the serous, the cellular systems, &c. hold the 
first rank in this respect. Observe also that it is in them 
that the organic sensibility and the insensible contractility 
are raised to the highest degree, because they are the 
only ones in which these properties are brought into action 
not only by nutrition, but also by various other functions 
that are going on in the insensible capillary system, viz. 
by exhalation, absorption and secretion. 
Sympathies. 
Few systems are more frequently the seat of sympa- 
thies than this. In examining them I shall adopt the 
same order as in the preceding system. 
Passive Sympathies. 
The glandular texture is affected with extreme ease by- 
all the others. This constitutes its passive sympathies. 
They take place, 1st, in a natural state; 2d, in diseases. 
I say first that there are certain cases in the natural state, 
in which the other organs being excited, the glandular is 
brought into action. This is especially remarkable in the 
mucous system. We have seen that almost all the ex- 
cretory ducts terminate upon the mucous surfaces. Now 
when one of these surfaces is irritated in the neighbour- 
hood of an excretory duct, the gland of this duct in- 
creases its action. 1st. The presence of aliments in the 
mouth produces an abundant flow of saliva. 2d. A sound 
in the bladder, irritating the ureters or their neighbour- 
hood, increases the flow of urine. 3d. The irritation of 
the glans penis and the extremity of the urethra in coition, 
produces a kind of spasm in the testicle from which arises 
a copious secretion of the seminal fluid. 4th. Every 
irritating fluid applied either to the conjunctiva, or the GLANDULAR SYSTEM. 
231 
pituitary membrane occasions a more'or less considerable 
flow of tears. 5th. By making; experiments upon the 
state of the gastric viscera during digestion and during 
hunger, I have observed that as long as the aliments are 
only in the stomach, the flow of bile is inconsiderable, 
but that this flow increases when they pass into the duo- 
denum, so that much of it is then found in the intestines. 
During hunger, the gall-bladder is much distended ; but 
little bile flows from it. At the end or even during diges- 
tion, it contains but half as much bile. Yet it might be 
emptied much more easily during abstinence, as the fluid 
which is then found in it is of a deep green, very bitter, 
very acrid and consequently very irritating. On the 
contrary, during or immediately after digestion, it is 
much milder, of a bright yellow and less irritating. There 
must then be another stimulus for it during digestion; 
this stimulus is the food that is passing by the extremity 
of the ductus choledochus. I have pointed out in a long 
note in my Treatise on the Membranes, the course of the 
cystic and hepatic bile. 
Let us conclude from these numerous considerations* 
that one of the principal means which nature employs to 
increase the action of the glands, and to produce that of 
the excretory ducts is the sympathetic irritation of the 
extremity of these ducts or of the neighbourhood of the 
point of the mucous surface where they come out. It is 
to this also that must be referred the various catarrhs pro- 
duced by an irritating body remaining upon one of these 
surfaces. The infant in sucking and irritating the nipple, 
produces a secretion of milk at the same time that he 
draws it out. In a morbid state the glands are also very 
frequently the seat of passive sympathies. It is almost 
always then the organic sensibility and the insensible 
contractility that are brought into action in them. It 
is rare, that the animal sensibility, excited by sympa- 
thies, occasions pains in the glands. 232 
GLANDULAR SYSTEM. 
We have said that the varieties the glands exhibit in 
diseases are innumerable, either as it respects the quantity 
or the quality of the fluids they secrete. Now all these 
varieties are especially owing to sympathetic influence. 
Observe the salivary glands moistening the mouth or leav- 
ing it dry, filling it with a viscid or limpid fluid, frothy 
or thin, the mucous glands of the tongue furnishing some- 
times a thick whitish substance, and sometimes a black 
crust. Physicians consider the state of the tongue as a 
constant index of that of the stomach ; this is most often 
true. Nature has established such a sympathetic relation 
between these two parts, that when the mucous surface of 
the stomach is disordered, and is the seat of that kind 
of catarrh which is called derangement, fulness of the 
stomach, &c. that of the tongue is also affected and fur- 
nishes more mucous juices, which alter and destroy the 
appetite, and thus prevent the taking of aliments which 
the stomach could not digest, and which often even it 
would not bear. The tongue is then, as in a state of 
health, a kind of sentinel placed over the stomach, to re- 
fuse that which would injure, and to admit that which is 
suitable for it. This is no doubt the cause of this singu- 
lar influence which the stomach exerts upon it in diseases. 
But let us also remark that sometimes the tongue is foul, 
when the stomach is in the ordinary state. This phe- 
nomenon is frequent in hospitals ; it happens to me very 
often. And vice versa, nausea, &e. sometimes takes place 
without a catarrh of the tongue. 
Shall I speak of the innumerable influences that the 
liver, the kidney and the pancreas receive ? When an 
organ is diseased in the animal economy, these immedi- 
ately perceive it; their secretion is increased, diminished 
or altered, and oftentimes even the sympathetic affection 
does not extend to these functions, but produces inflam- 
mation, suppuration, &c. We know that abscesses are 
formed in the liver from wounds in the head, &c. Shall GLANDULAR SYSTEM. 
233 
I speak of the innumerable varieties of the flowing of 
tears in acute diseases, in inflammatory and malignant 
fevers, &c. ? Who does not know that the eye is then 
more or less moist, that it is often constantly weeping ? 
Now whence arise these varieties? from the sympathetic 
influence which the lachrymal gland receives. The dis- 
ease itself is often foreign to it; but the unknown con- 
sensus which connects the glands with the diseased parts, 
makes them then enter into action. We weep from a 
variety of passions, from grief especially ; how does this 
happen ? Because the influence of the passion is first 
carried to the epigastric region, as the violent sensation 
experienced there, proves ; and the affected organ reacts 
upon the lachrymal gland. We weep in the same way 
as we sweat from fear, or spit copiously in anger, a phe- 
nomenon which the vulgar express by these words, foam- 
ing with rage. 
The testicles and the prostate are much less often sym- 
pathetically influenced in diseases than the other glands. 
Whilst every thing is disturbed in the glandular system, 
they most frequently remain calm and tranquil. Why ? 
because they are insulated by their functions from the 
other glands. The salivary glands, the pancreas, the kid- 
neys, the liver and almost all the mucous glands contri- 
bute to one common object, viz. digestion. This object 
is connected with the existence of most of the other 
organs. When these are diseased, it is not wonderful 
that the glands feel it. On the contrary, the testicles, 
destined only to the purpose of generation, entering later 
into action and ceasing to act sooner than the other glands, 
having great intermissions in their action, cannot in their 
affections be thus connected with the diseases of the other 
organs. Sometimes however they are. We know that 
some affections of the lungs dispose to venereal pleasures ; 
that in a natural state, a lively excitement of certain parts 234 
GLANDULAR SYSTEiM. 
of the skin, of that of the glutaei muscles especially brings 
into activity the whole genital system, &c. &c. 
We know the remarkable sympathy that renders the 
mammae dependant upon the womb. It is well known, 
that they swell a little every month, at the beginning of 
menstruation ; that cancers are often formed in them at 
the cessation of this natural discharge ; that the voluptu- 
ous sensation of coition sometimes extends even to them, 
&c. All physicians have observed this sympathetic rela- 
tion which appears to be of a peculiar kind and to depend 
upon the analogy of the functions of the sympathizing 
organs. 
After severe acute diseases, especially idiopathic fevers, 
the glandular action is oftentimes much increased ; there 
are great evacuations ; these are the crises ; it is, accord- 
ing to the opinions of most, the morbific humour that is 
expelled. This is a phenomenon that should be examin- 
ed, and which certainly in many cases does not depend, 
as I shall prove, on the cause to which it has been attri- 
buted. 
Though I consider many of the secretory derangements 
in diseases as sympathetic, I am far from thinking that all 
are so. Certainly in many cases, there is a general affec- 
tion of the whole system, an affection in which the glands, 
like all the other parts, participate ; this is what takes 
place in idiopathic fevers. But when one system is espe- 
cially affected, as the cutaneous in the small pox, the 
measles, scarlatina, &e. the serous in pleurisy, peritonitis, 
&c. the cellular in phlegmon, the nervous in convulsions, 
&c. I call the derangement which the others experience 
sympathetic, and which does not depend upon an injury 
of their texture. 
Other ideas may be attached to the word sympathies, 
but these are what I have connected with it in diseases. 
The word is of but little consequence, provided what it 
expresses is understood. QL4NDULAR SYSTEM. 
235 
Jlctive Sympathies. 
These sympathies are less frequent than the preceding. 
In the diseases of the glandular system, we see however 
examples of them. The history of inflammations of the 
kidneys, the salivary glands, the liver, &c. shows us many 
phenomena arising sympathetically in the other systems 
on account of the diseases of this. I do not speak of the 
derangement of digestion and the circulation, functions 
which, naturally connected with the secretions, are inevi- 
tably when these are; I speak of the organs, 
which having no direct relation with the diseased glands, 
are yet affected, as we see in convulsions, spasms, wan- 
dering or fixed pains in different places, sweats, &c. 
The testicles in health exert a remarkable influence 
upon the organs of the voice. We know that it becomes 
more harsh the moment they enter into action, and that 
it changes when they are removed by castration; this 
phenomenon is constant and invariable. Barthez believed 
that it arose from the ordinary sympathetic phenomena ; 
in fact, it appears to be but a particular modification of 
that general influence which the testicles exert on all the 
vital forces, which are uniformly debilitated or strength- 
ened, according as their action is feeble or strong. Yet 
some organs are more disposed than others to feel these 
affections. The pectoral mucous system is an example of 
this. Passive hemorrhage of this system is frequently 
the consequence of excessive excretion of semen ; phthisis 
even is often the fatal effect of it. 
Characters of the Vital Properties. First Character. 
Life peculiar to each Gland. 
The glandular life, the result of the preceding forces 
considered in exercise, is not uniform in the whole sys- 
tem, no doubt because its texture differs in each gland, 
and because to each texture is given a peculiar modifica- 236 
GLANDULAR SYSTEM. 
tion of vitality. Many phenomena result from these 
differences which have been well observed by Bordeu. 
1st. Bach gland has certain substances, with which it is 
exclusively in relation in the natural state. Hence why 
the salivary glands do not secrete bile, and the liver allows 
the materials of urine to pass in its vessels without sepa- 
rating them ; from this results the diversity of secre- 
tions. Hence also why cantharides affect exclusively the 
kidneys; why mercury acts especially upon the salivary 
glands ; why certain substances affect the testicles in a 
peculiar manner, increase their secretion and even pro- 
mote the excretion of the semen ; why some aliments 
give more milk than others. I am persuaded that cer- 
tain substances act upon the mucous glands and dispose 
them to a greater secretion. 
2d. Each gland has its peculiar mode of sympathies. 
We have seen that the testicles sympathize especially with 
the pectoral organs, and the liver with the brain. The 
kidneys, when affected with acute pain, have an influence 
peculiarly on the stomach, and occasion vomiting. The 
mammae and the womb are directly and particularly con- 
nected in sympathies. 
3d. The inflammation of each gland has a particular 
character. That of the kidneys does not resemble that 
of the liver, the testicles, &c. The prostate gland when 
inflamed produces symptoms wholly different from those 
of the testicles, &.c. I do not speak of the differences 
resulting from the diversity of the fluids, but only of 
those which arise from the difference of texture. 
4th. Each gland has its peculiar diseases, or such at 
least to which it is disposed more than the others. Hyda- 
tids are very often found near the convexity of the liver; 
they are never seen in the salivary glands or the testi- 
cles. Though the parotid glands are as much exposed 
to the action of external bodies as the testicles, there are 
twenty sarcoceles to one scirrhus of these glands. The GLANDULAR SYSTEM. 
237 
liver alone exhibits that peculiar state that is called fatty ; 
no gland is more frequently the seat of steatomatous 
tumours. Physicians who have opened hut few bodies, 
employ the vag’ue and insignificant word obstruction, 
&e. for every kind of glandular swelling. But observe 
that most commonly these swellings have nothing in com- 
mon among them but the increase in size; their nature 
is wholly different, and yet observe how ignorant many 
are in medicine; they perceive by the touch that there is 
a hardness of the liver, and immediately aperients, the 
acetate of potash, &c. are the common means which they 
oppose to hydatids, to steatomatous tumours, to scirrhi 
with granulations like marble, to fatty livers and to a 
hundred different alterations from which the increase of 
size may arise, as if it was this increase and not the 
kind of tumour that produced it, which they had to com- 
bat. Give then also aperients when the liver displaced 
by hydrothorax projects unnaturally, and you wfill act 
almost as rationally. 
5th. Each gland exhibits peculiar modifications in those 
evacuations that are called critical, of which it is some- 
times the seat after long diseases, &c. &c. 
6th. It is also to the difference of vitality of the dif- 
ferent parts of the glandular system, that must be referred 
the following phenomenon ; certain glands enter suddenly 
into action, either from a direct irritation, or a sympa- 
thetic excitement, as the lachrymal for example, which 
from a state of remission passes suddenly from the influ- 
ence of the passions, to that of copious secretion. On 
the contrary, it requires some time to excite the other 
glands, as for example the kidneys, pancreas, &c. which 
cannot suddenly pour out their fluids, whatever may 
be the excitement they experience. The same stimulus 
applied to the conjunctiva, produces a flow of tears, and 
at the same time increases the action of the Meibomian 
glands; but the first effect takes place before the other. 238 
GLANDULAR SYSTEM. 
The same stimuli applied to the mucous surfaces can 
never produce a catarrhal discharge till the expiration of 
some time. 
Second Character. Remission of the Glandular Life. 
The second character of the glandular life, is that of 
being subject to habitual alternations of increase and dimi- 
nution. Sleep extends especially to the animal functions; 
they alone are completely suspended in the ordinary state, 
and it is this which constitutes sleep. But the glands 
sleep also to a certain extent, though there is never a 
complete suspension except in diseases. I would com- 
pare the sleep of animal life to the intermissions of inter- 
mittent fevers in which the apyrexia is complete, and the 
sleep of the glands to those of remitting fevers in which 
the paroxysm is only moderated, though it always con- 
tinues. 
The saliva is copiously poured out when aliments enter 
the mouth, at other times it only moistens this cavity. 
Whilst the chyme is passing through the duodenum, the 
pancreas and liver moisten it abundantly ; they are also 
in action during hunger, but in an infinitely less degree. 
I have convinced myself of this by many experiments 
upon the comparative state of digestion and hunger, the 
substance of these experiments I have given elsewhere. 
We know that it is some time after eating before the 
kidneys commence their action. The intermissions of 
the action of the mammas are almost as real as those of 
the organs of animal life. Each mucous gland has its 
time of secretion; it is that in which the surfaces, to 
which the excretories go, are in contact with any sub- 
stance that is remaining there, or that is only passing. 
The glands then must be considered as continually sep- 
arating a fluid from the blood, and as being at certain 
periods in greater activity, and consequently as furnish- 
ing more fluids. GLANDULAR SYSTEM. 
239 
This remission of the glands appears to be owing to a 
cause nearly analogous to that of sleep, which, in animal 
life, is produced by the weariness the sensitive and loco- 
motive organs experience, after long continued action. 
The kind of weariness which the glands are capable of 
experiencing, is not in general attended with a painful 
sensation, as in animal life ; its nature appears to be 
wholly different. Yet women, after nursing too long, feel 
a pain in the breast that warns them to leave off. The 
testicles become the seat of a painful sensation, when the 
emission of semen has been many times forced. 
Third Character. The Glandular Life is never simul- 
taneously raised in the whole system. 
The vital properties of the glands are never simultane- 
ously excited in all. When one is in action, the others 
are in remission. We might say, that there is but a de- 
terminate quantity of life for all, and that one cannot live 
more without the others living less. To this law is the 
digestive order accommodated. In the first period the 
salivary glands furnish at first a great quantity of fluid; 
in the second, the parietes of the stomach ; in the third, 
in which the chyme passes into the small intestines, 
the liver and the pancreas are principally in action ; in 
the fourth, it is the mucous glands of the great intestines 
which especially act; and finally the kidneys enter into a 
particular action in order to evacuate the residue of the 
fluids. All the glands cannot act at the same time ; it is 
as in the external motions in which certain muscles always 
rest whilst the others contract. The most improper time 
for coition is that of digestion, because we then make 
the mucous, hepatic, pancreatic secretions, &c. coincide 
with that of the testicles. In diseases one gland increases 
its secretion only at the expense of the others. Observa- 
tion proves this every day. 240 
GLANDULAR SYSTEM. 
We might, as I have said, make use of this remark, 
by producing in various glandular and other affections, 
artificial catarrhs, a disease which we can always produce 
on the mucous surfaces by the introduction of a foreign 
body. I have for some time past made much use of 
ammonia respired by the nose. Pinel prescribes it be- 
fore the paroxysms of epilepsy. There are an infinite 
number of other cases in which it is very efficacious, as 
in some kinds of cephalalgia, in ataxic fevers, in certain 
apoplexies, in various comatose affections, &c. A blister 
does not act till the expiration of some time; it requires 
four, five, six hours even for it to produce an irritation. 
Who does not know that oftentimes in diseases in which 
the forces are much prostrated, it has no action on the 
cutaneous system? On the contrary, the excitement of 
the pituitary membrane by ammonia is always sudden on 
the one hand and always efficacious on the other. Its 
effect, it is true, is only instantaneous, but this is pre- 
cisely its advantage ; for in many cases a blister is only 
useful the moment it irritates the skin; hence the use of 
drying it immediately and reapplying it. The employ- 
ment of ammonia or of any other strong stimulant upon 
the pituitary membrane, can be repeated every quarter of 
an hour, every five or six minutes or even every minute, 
if habit renders the patient less sensible to its excite- 
ment, we can replace it by another irritating substance, 
whereas we cannot thus change the cutaneous excitement 
by a blister.* What I have said of the pituitary surface is 
applicable to Ihose of the rectum, the urethra and stomach, 
on which we can in many cases apply in diseases excite- 
ments in a more advantageous manner than is clone upon 
the skin by means of blisters. 
Moreover, the character of the glandular life of which 
we are treating, is only an insulated modification of a 
character general to all the vital properties, a character 
which consists in this, that they are weakened in one GLANDULAR SYSTEM. 
241 
place when they are raised in another. Hence why the 
great collections of pus, large tumours and dropsies are 
always attended with a weakness in the glandular action. 
It is upon this character that rests the use of vesicatories, 
setons, moxa, cauteries, &c. which do not act, as has been 
said, by evacuating the morbific matter, but by making 
the irritation of the diseased part cease by that which is 
produced elsewhere. 
Fourth Character. Influence of climate and season 
on Glandular Life. 
Another phenomenon is also derived from the pre- 
ceding character, and it is one that may be likewise con- 
sidered as characteristic of the glandular system; viz. 
that in general it is in greater activity in winter than 
summer, in cold climates than in warm. In fact, heat 
which expands the cutaneous system increases the action 
of it at the expense of that of the glands, and recipro- 
cally cold which contracts it, by preventing the constant 
exhalation that is going on there, forces the glandular 
system to supply this action. Hence why the same fluid, 
introduced into the economy, goes out with the urine in 
winter and with the sweat in summer ; why, if we wish 
to produce an immediate discharge of urine in summer, 
it is necessary to suppress the perspiration by the sudden 
application of cold to the surface of the skin, by descend- 
ing into a cellar, or some other subterraneous place ; so 
that in summer we can, after digestion, make the product 
of the fluids pass off with the urine or the sweat, accord- 
ing to the temperature of the atmosphere in which we 
digest; why teas and diuretics forbid the use of each 
other, and why a physician who should employ them at 
the same time would know but little of the laws of our 
economy; why most of the diseases that are attended 
with an immoderate discharge of the secreted fluids, are 
almost always characterized by a diminution of the ex- 242 
GLANDULAR SYSTEM. 
haled fluids ; why in some seasons diseases have a greater 
tendency to be characterized by sweats, and in others by 
urinary, mucous evacuations, &c. It is to the greater 
degree of the vital activity of the glandular system in 
the winter, that must then be referred the frequency of 
catarrhs, diseases most of which suppose an unnatural in- 
crease of its action, the greater facility with which the 
kidneys are influenced by cantharides, &c. Physicians 
should have these considerations particularly in view in 
their treatment. It is necessary to act more upon the 
glandular system in winter, and the cutaneous in sum- 
mer, because each system is as much more disposed to 
answer to the excitements made upon it, as it actually is 
in greater activity. 
Fifth Character. Influence of Sex upon Glandular 
Life. 
Is the life of the glandular system more active in man 
than in woman ? As it respects the glands destined to 
digestion, the secretion of the tears, the evacuation of 
urine, &c. there is but little difference in the two sexes. 
As to genital glands, man has testicles and the prostate ; 
woman has mammae, so that in this respect they seem to 
be equal. Observe however that the influence of the 
first upon the economy, is much greater than that of the 
second. It is from the womb that go forth in woman 
the irradiations which correspond with those which the 
testicles send to all the other organs. GLANDULAR SYSTEM. 
243 
ARTICLE FOURTH. 
DEVELOPMENT OF THE GLANDULAR SYSTEM. 
I. State of this System in the Foetus. 
Though the secretions are not active in the foetus, the 
glandular system is in general much developed. All the 
salivary glands and the pancreas are larger in propor- 
tion than afterwards; the liver is enormous ; and the 
kidneys have a size much greater in proportion than they 
have in the adult. The same probably is true of the 
mucous glands, though I have not made any very pre- 
cise researches upon this point. The form is different in 
many; the kidney for example is evidently uneven, 
whilst afterwards its surface is almost smooth. The colour 
is not the same ; this is particularly striking in the salivary 
and lachrymal glands. These glands which are white 
in the adult, have in the foetus an extreme redness which 
they lose by washing, which is not owing to the blood 
circulating in their vessels, though there is much of it in 
their vessels, but it is really inherent in their texture. 
This colour is never as great in the pancreas, though its 
texture is nearly the same. The texture of the glands 
is extremely soft and delicate at this age, which is the 
case with all the parts. They are divided and yield with 
great ease, and their vessels, which are large, carry into 
them a very great quantity of fluid. 
Then they are, if we may so say, in a state correspond- 
ing with that of remission in the adult; they secrete even 
less fluid, though they appear however to be in constant 244 
GLANDULAR SYSTEM. 
action. In fact, all the reservoirs would be insufficient 
to contain their fluids, if in a given time, as much flowed 
from them as after birth. Is this because the black blood, 
which then enters their parenchyma, is unfit to furnish 
the materials of the secretions? This may have an influ- 
ence, and I have elsewhere imagined it, from the circum- 
stance that this blood is unable to support many other 
functions. But the principal reason appears to me to be, 
that in the foetus the nutritive motion of composition pre- 
dominates evidently over that of decomposition, which 
is very inconsiderable. Almost every thing which arrives 
in the organs remains in them and continues to furnish the 
materials of the rapid growth which is then taking place in 
the body; now, the secretions being principally destined 
to carry off the residue of nutrition, must then be very 
inactive. 
Besides, digestipn does not introduce into the blood any 
of those principles which, being useless to nutrition, 
must on this account go out as they entered, that is to say 
without making a part of our organs; such are for exam- 
ple most of the drinks, which only pass into the mass of 
blood, and go out immediately with the urine. 
The glands of the feetus are then like the brain at that 
age ; though much developed, they remain inactive ; they 
are in the expectation of action. 
II. State of the Glandular System during Growth. 
At birth, the glandular system increases suddenly in 
energy; it takes a life which until then was foreign to 
it, and begins to pour out more fluid. It owes this change, 
1st, to the difference of the blood which enters it, and 
which till then black and consequently venous, then be- 
comes red and charged with principles that are new to 
it; 2d, to the general and sudden excitement carried to 
the extremity of all the excretories, by the aliments to 
those which open upon the canal that extends from the GLANDULAR SYSTEM. 
245 
mouth to the anus, by the air to the mucous ducts of the 
bronchial and pituitary surfaces and to the lachrymal 
gland, by the various frictions of the extremity of the 
glans penis and even by the air which acts also upon it, 
to the kidneys and the bladder. 
■ All the glands are so much the more sensible to this 
sudden excitement, as they are unaccustomed to it. Their 
sensibility, heretofore torpid, is roused ; they feel the 
contact of the blood which enters them and which till 
then had made only a feeble impression upon them. 
This sensation is so much the more acute, as on the one 
hand the organic sensibility of the glands becomes more 
evident, and as on the other the red blood is a more 
powerful stimulus than the black ; for, as I have already 
had occasion to observe, the blood that arrives in an or- 
gan produces two effects in it, one of which is to excite 
it, either by the motion it communicates, or by the con- 
tact of the principles it contains, and the other is to 
furnish materials for the different functions, as for exha- 
lation, secretion, nutrition, &c. The first effect is com- 
mon to all the organs which the blood enters; the second 
is peculiar to each. 
I would observe however that many of the secretions 
are muck less active during the first years, than they are 
afterwards ; such are those of the salivary glands, the 
liver, &c. The kidneys being destined to throw out the 
residue of digestion, as much and more often than that of 
nutrition, are in a state of activity in proportion to that 
of the first function. The infant often passes urine, as 
he frequently voids excrements. It is not because many 
substances, returning from the organs which they have 
nourished, present themselves to the kidneys, to be 
thrown out by this part. 
The affections of the glandular system are not the pre- 
dominant ones in early age. 1st. It is not the parotids 
that are enlarged in the frequent swellings that take place 246 
GLANDULAR SYSTEM. 
in their neighbourhood, but it is almost always the lym- 
phatic glands. 2d. We know that an excessive flow of 
bile, and the affections which arise from it, are then very 
rare. 3d. All the secretions relating to generation ai’e 
absolutely nothing. 4th. In the same proportion in which 
the organic affections of the liver and the kidnevs are 
common in the adult, are they rare in the infant. Then 
it is in what are improperly called lymphatic glands, in 
the brain, &c. that the morbid anatomist finds materials 
for his researches ; for observe that the organs which are 
particularly in action in one age, are those which are most 
often attacked by acute and chronic diseases at that age, 
and that on the contrary they seem to forget those in 
which but little is done. 5th. Surgeons know that sar- 
coceles, hydroceles by effusion, varicoceles and all the 
diseases of the testicles are as rare before the period of 
puberty, when nutrition only is going on in these glands, 
as they are common in the subsequent years. 
It appears that it is the mucous glands which are then 
the most commonly affected and are consequently in the 
greatest activity. The lachrymal glands are also ver}r 
frequently in action. The infant weeps more often than 
the adult ; we might say that all the passions which agi- 
tate this age have but one uniform mode of expression, 
and this mode is weeping. If the infant suffers, if he is 
jealous or frightened he weeps; if he is furious, he weeps 
because he is not very strong. This influence of the pas- 
sions upon the lachrymal gland in the early years, seems 
to take place at the expense of the influence exerted upon 
the other glands. It is rare that fear or fright give to 
infants a sudden jaundice, or that they excite bilious 
secretions. At this age they do not pass water and void 
their excrements from fright as often as in the after ages; 
they have not the spasmodic vomitings that are so fre- 
quently occasioned by the passions of the adult; they do 
not become pale or red as much in anger ; thus the coun- GLANDULAR SYSTEM. 
247 
tenance is not to the same extent the moveable picture 
upon which is painted the emotions of the mind. The 
eye does not sparkle in anger and is not expressive in 
friendship. It is the lachrymal gland which then most 
often serves in the face, for the expression of the passions. 
Observe that this expression is that of weakness and want 
of power, it is that of woman, who resembles the infant 
in so many phenomena. The feeble stag opposes his tears 
to the dogs, who seize upon him to devour him. 
The glandular texture remains for a long time soft and 
delicate in the infant. At birth and in the foetus, neither 
the liver nor the kidneys have the singular property of 
hardening by boiling. They remain during this experi- 
ment very tender and yield easily to the least impression. 
If the boiling be ever so long continued, they do not lose 
this character, which is gradually weakened as we ad- 
vance in age, and which at this period makes the glands 
fit for some uses in our kitchens to which they are not so 
proper in the adult. 
III. State of the Glandular System after Growth. 
Puberty commences about the period that growth fin- 
ishes. A gland till then inactive in man, enters suddenly 
into activity. The prostate follows it in its development. 
In woman the breasts swell, separate, and acquire in a 
short time a size which they would not have done in 
many years, if they had grown according to the same 
laws as in the preceding state. The other glands, far from 
being weakened, in proportion as these become strong- 
er, increase their action also ; they become stronger, and 
gradually lose the softness that characterized them in in- 
fancy ; they moreover grow harder. 
Till then composition had predominated over decompo- 
sition in the general nutritive motion. Then almost as 
many substances are constantly thrown from each organ, 248 
GLANDULAR SYSTEM. 
as enter its interior to nourish it. Now as the glands 
are the great emunctories which throw out the residue of 
nutrition, they then pour out more fluids in proportion 
than before. 
During youth it is the genital glands which predomi- 
nate over the others ; they seem to be a centre whence 
go irradiations that animate the whole machine. We 
might say most often that they are, in the mechanism of 
our moral actions, the spring which puts every thing in 
motion. 
As we recede from youth, the influence of the genital 
glands becomes weaker, because they are in less activity. 
Towards the thirty-sixth or fortieth year, it is especially 
the glands destined to digestion which predominate over 
the others, and among these the liver in particular seems 
to be in activity. Then the bilious affections are predom- 
inant; then the passions to which the bilious tempera- 
ment seems to dispose us, more frequently agitate the 
mind. Ambition, hatred and jealousy are often the sad 
attendants of this age. These passions are then more 
durable. The levity of youth and the passions arising 
from the influence of the genital glands, which predomi- 
nate at this age, had for a time suppressed these, or rather 
had prevented them from being developed. Then they 
remain alone, the others having escaped in smoke with 
the fire of youth. Then also the influence of the lively 
emotions of the mind affects especially the glands and the 
abdominal viscera. Then is felt that contraction at the 
epigastric region, the painful effect of the bad passions; 
jaundice occasioned by sorrow is then more frequent. 
This age is that of the organic affections of the glands, 
of all the numerous changes of texture, of all the ex- 
crescences which destroying as it were the nature of these 
organs, transform them into bodies of a different texture. 
In infancy, leucophlegmasia is most often produced by an 
engorgement of those lymphatic bunches that are called GLANDULAR SYSTEM. 
249 
glands, which resembles tabes mesenterica, the engorge- 
ment of the bronchial glands, &c. In the adult on the 
contrary, it is with the diseases of the liver, of the spleen, 
of the kidneys, that it is most often seen. 
IV. State of the Glandular System in Old •dge. 
In old age, the glands become more firm and hard. 
Before that period even, the glandular system of animals 
ceases to be used at our tables. The liver, the kidneys, the 
spleen, &c. are mixed with the fleshy texture in common 
boiled meat, only to communicate to it some salts, some 
savoury principles that are foreign to this texture. They 
are not eaten, or at least they are not, agreeable to the 
taste. The lungs which contain so great a quantity of 
mucous glands, do not afford a very digestible aliment ex- 
cept those of the calf; those of the ox are not brought 
to our tables, especially when the animal is old. I would 
observe upon this subject that the muscular and glandular 
systems are in an inverse order as it respects digestion, 
at least in the stewed state to which they are reduced for 
nourishment. In fact, the glandular system has not an 
agreeable taste and is not very digestible except in young 
animals, whilst at this age the muscular is insipid, and 
does not become savoury food till towards the middle of 
life. 
In extreme old age, the colour of the glands changes 
less than that of most of the other organs. We find the 
liver, the kidneys, &c. almost as full of blood as in the 
adult; they are as red, whilst the muscles pale and colour- 
less announce by their appearance that but little blood 
enters them at the latter periods of life. We might say 
that this fluid first abandons the skin and the muscles of 
animal life which in the trunk are subjacent to it, and 
which in the extremities are found very distant from the 
heart, or at least that it diminishes much in the two sys- 250 
GLANDULAR SYSTEM. 
terns, and is concentrated in the organs in the neighbour- 
hood of the heart; thus the secretions are still very- 
abundant in old people, whilst the muscular, nervous 
forces, &c. are considerably weakened. The kidneys 
still secrete much urine ; the liver pours out much bile, 
though this gland loses in part the kind of predominance 
it exercised in the economy towards the fortieth year. 
We know that the very frequent catarrhs that then take 
place, indicate an increase of action in the mucous glands. 
The functions of the testicles and mammae have long 
since ceased. 
The activity of the glands remaining in exercise, appears 
to be owing to two causes. 1st. The decomposition being 
very great at this age, many substances are presented to 
the glailds to be thrown out. An old person decreases 
by a phenomenon opposite to the rapid growth of the 
foetus, in which the glandular system throws out scarcely 
any thing from the economy. 2d. The skin having the 
horny hardness and being contracted, ceasing in part to 
be an emunctory of the products of decomposition, the 
glands supply the place of these functions. The cutane- 
ous and glandular systems are then in the same relation 
as in winter and in cold countries, in which, we have 
seen, that the second constantly supplies the place of the 
first. 
In general, the glandular system is one of those in 
which life is the most slowly extinguished. In the dead 
bodies of old people we find the bile still filling the gall- 
bladder, the bladder full of urine, &c. All the glands 
when compressed, the prostate itself, permit a large 
quantity of fluid to escape from their excretories. I have 
even observed that in this compression, we uniformly 
press out more fluid in an old subject than in a young 
one. The older the animals are, the more their kidneys, 
as we know, preserve the urinous smell. The lungs, 
which abound so much in mucous surfaces and conse- GLANDULAR SYSTEM. 
251 
quently in mucous glands, are not withered and have not 
the horny hardening in old age ; they perform their func- 
tions as regularly as in youth. 
In general it is a very remarkable phenomenon that all 
the principal internal organs, the liver, the kidneys, the 
spleen, the heart, the lungs, &c. still preserve a very con- 
siderable vital force, whilst the sensitive and locomotive 
organs already almost exhausted, have broken in part 
the communications which connect the individual with 
the objects which surround him. DERMOID SYSTEM. 
ALL animals are covered with a more or less compact 
membrane, of a thickness in general proportioned to the 
size of their body, destined to defend the subjacent parts, 
to carry out a considerable portion of the residue of nutri- 
tion and digestion, and to place it in relation with ex- 
ternal bodies. It is in man a sensitive boundary, placed 
at the extremity of the domain of his mind, wThere these 
bodies continually touch, for the purpose of establishing 
the relations of his animal life, and of thus connecting 
his existence wTith that of every thing which surrounds 
him. This covering is the dermis or skin. We shall 
call the whole of it the Dermoid System. 
ARTICLE FIRST. 
FORMS OF THE DERMOID SYSTEM. 
The covering which forms this system, being propor- 
tioned to the parts that it covers, is applied to the'se parts, 
adapted to their great inequalities, and allows the largest 
external prominences to be visible, but conceals a great 254 
DERMOID SYSTEM. 
number on account of their small size ; thus the appear- 
ance of the body stripped of skin differs very much from 
that with the skin on. 
This covering everywhere continuous is reflected 
through different openings in the interior of the body 
and goes to give origin to the mucous system. The 
limits between the two systems are always marked by a 
reddish line ; within this line is the mucous system, 
without it the dermoid. Yet the demarcation is not as 
striking in the organization as in the colour. Both are 
confounded in an insensible manner. In the neighbour- 
hood of these openings, of those of the face especially, 
the dermoid becomes more delicate. At the commence- 
ment of these openings, the mucous borrows more or 
less, as I have said, the characters of the first. 
I. External Surface of the Dermoid System. 
This surface, everywhere contiguous to the epidermis, 
is remarkable for the hairs which cover it, for the oily 
fluid which constantly lubricates it, for the sweat that is 
deposited on it, for the sense of feeling of which it is the 
seat and which the internal surface does not possess. We 
shall in this article consider only the external dermoid 
forms, without regard to these different objects. 
We see upon this surface different kinds of folds. 
1st. Some are owing to the subjacent muscles which, 
being intimately connected with the dermis, forming 
almost a part of it, wrinkle it when they contract. Such 
are the wrinkles on the forehead ; those in the form of 
rays which the orbicularis produces around the eye-lids, 
&c.; those of which the cheeks are the seat, when the 
great and small zygomatic, &c. contract; those which the 
orbicularis of the lips produces around the mouth, when 
it contracts it by diminishing its opening, &c. All these 
folds are owing to this, that on the one hand tire skin 
cannot contract like the muscles, and that on the other it DERMOID SYSTEM. 
255 
is necessary that it should occupy less space in length at 
the instant these are shortened. They are of the same 
nature as those of which the mucous surfaces, that of the 
stomach in particular, become the seat in the contraction 
of the fleshy layer which is contiguous to them. Thus 
the direction of these folds is always perpendicular to 
that of* the subjacent muscles whose fibres they cut at a 
right angle. We are accustomed to attach much impor- 
tance to the existence of these wrinkles in the expression 
of the passions ; no doubt because then they are strongly 
marked. In fact the breadth of the face of man makes 
it well adapted to their development, whilst that of ani- 
mals is badly formed to produce them. Thus their eye, 
rather than the features of the face, is the moveable pic- 
ture which is differently sketched at every instant by the 
various feelings of anger, hatred, jealousy, &c. The 
wrinkles of the human face contribute very much to the 
expression of the countenance, they compose in part the 
physiognomy, and mark its different shades. 
The wrinkles of the scrotum are analogous, to these ; 
they depend upon the contraction of the subjacent cellu- 
lar texture, in which some fleshy fibres appear also to exist. 
2d. There are other Avrinkles which are owing also to 
the motions, but not to those of the subjacent muscles. 
There are those of the sole of the foot, and especially 
those of the palm of the baud. There is not there any 
sub-cutaneous muscle adhering to the skin, except the 
small palmar muscle, which has no agency in these wrin- 
kles that are formed at the places where the skin is con- 
stantly folded in flexion. Thus there are many of them 
about all the articulations of the phalanges. In the palm 
of the hand, we see three principal ones, one at the base 
of the thumb, produced by the motion of opposition, 
another at the anterior part of the palm, occasioned by 
the flexion of the four last phalanges which are bent to- 
wards the thumb, and the third is found in the middle of 256 
DERMOID SYSTEM. 
the palm. The dermis is folded between these depressed 
lines, in the motions in which the hand is hollowed. 
Many other small folds corresponding with less evident 
and less frequent motions, cut these at different angles. 
On the back of the foot and hand, there are many 
wrinkles about each articulation of the phalanges, when 
they are extended. They disappear in flexion, And are 
owing to this, that nature, on account of the motions, has 
made the skin more loose at this place, and broader in 
proportion to the parts it covers. About most of the 
articulations, there are analogous folds, but they are 
much less evident, because the skin adheres less to the 
neighbouring parts. Upon tbe whole trunk, the arm, the 
fore-arm, the thigh and the leg, we see no depressions but 
those from the muscular prominences. 
3d. There is a third species of wrinkles, or rather cu- 
taneous impressions, which are not very evident, found 
especially on the sole of the foot and the palm of the 
hand and which we easily distinguish from the preceding; 
they are those which indicate the rows of the papillae. 
The surface of the trunk presents hardly any thing similar. 
4th. Finally, there are the wrinkles of old age, which 
are of a wholly different nature. The sub-cutaneous fat 
having in part disappeared, the skin becomes too large 
for the parts it covers ; now as it has lost with age its 
contractility of texture, it does not contract, but folds in 
various directions. Thus where there was the most fat, 
as on the face, these wrinkles are the most evident, they 
resemble those that appear on the abdomen after several 
pregnancies, dropsy, &c. In young people, if emaciation 
takes place suddenly, the skin contracts, and no wrinkle 
is formed. 
II. Internal Surface of the Dermoid System. 
This surface answers everywhere to the cellular tex- 
ture which is loose upon the trunk, the thighs, the arms, DERMOID SYSTEM. 
257 
&c. and which is condensed upon the cranium, the hand, 
&c. In most animals, a fleshy layer called panniculus, 
and of a form analogous to that which is almost every- 
where subjacent to the mucous system of man, separates 
the skin from the other parts, and communicates to it 
various motions. In man, the dermoid system exhibits 
here and there traces of this internal muscle, as is ob- 
served in the platysma myoides, the occipito-frontalis and 
most of the muscles of the face. There is nothing simi- 
lar on the trunk, extremities, &c. Man is as much infe- 
rior in this respect to most animals, as he is superior by 
the arrangement of his facial muscles. Thus observe that 
whilst in him all the passions are painted as it were upon 
the face, and the whole exterior of the trunk remains 
calm in these tempests of the mind, this exterior is con- 
vulsively agitated in animals. The mane of the lion be- 
comes erect, the whole skin of the horse moves, a thou- 
sand different agitations animate the exterior of the trunk 
of animals, and make it a general picture on which is 
painted all that passes in the interior. You can deter- 
mine from behind, in many animals, by seeing only their 
bodies, that they are agitated with passion ; cover the face 
of man, the curtain is drawn over the mirror of his mind ; 
thus almost all nations leave it uncovered. The phy- 
siognomy is in this respect, if we may so say, more gene- 
rally spread over the exterior, in animals with a fleshy 
panniculus. 
Besides the cellular texture, the dermis is almost every- 
where subjacent to the muscles in the trunk ; but, foreign 
to the motions of these muscles, it receives no sensible 
influence from them. In the extremities it is found 
separated from the fleshy layers by aponeurotic expan- 
sions. Many vessels wind under it; the great veins pass 
through its texture; many arterial ramifications go upon, 
its surface, and many nerves between these ramifications. 258 
DERMOID SYSTEM. 
ARTICLE SECOND. 
ORGANIZATION OF THE DERMOID SYSTEM. 
I. Texture peculiar to this Organisation. 
This texture comprehends, 1st, the chorion; 2d, that 
which is called the reticular body ; 3d, the papillae. The 
chorion is the essential part of the dermis ; it is that 
which determines its thickness and form. The reticular 
body appears to be but little distinct from it. The papil- 
lae arise from it also, but are more evident. 
The chorion is of a very variable thickness. 1st. In 
the head, that of the cranium and that of the face exhibit 
an opposite arrangement. The first is very thick and 
also dense and compact, which is owing especially to the 
numerous hairs that go through it. The second, every- 
where fine and delicate, is particularly so upon the eye- 
lids and the lips. 2d. The chorion of the trunk is poste- 
riorly and all along the back, of a thickness almost double 
that of its anterior part, where it is nearly the same upon 
the neck, the chest and the abdomen. I would except 
however that of the penis, the scrotum, the great labia 
and the mammae, in which its delicacy is greater than any 
where else. 3d. In the superior extremities it is nearly 
uniform upon the shoulders, the arm and the fore-arm ; 
on the hand it increases a little in thickness and more in 
the palm than on the back. 4th. This thickness is gene- 
rally much more evident on the thigh and the leg, where 
Chorion. DERMOID SYSTEM. 
259 
there are more muscles, than on the arm or the fore-arm. 
On the foot, it increases as on the hand, less in the dorsal 
than in the plantar region, which is the thickest of all the 
parts of the dermoid system ; which is owing principally 
in the natural state to the arrangement of its epidermis. 
We see from this, that though everywhere continuous, 
the chorion is very different in its different parts. The 
relation of its thickness with its functions is easily per- 
ceived on the hand, the foot, the cranium, &c. Elsewhere 
we cannot so well see the reason of these differences, 
which are notwithstanding as constant. 
Woman has a chorion generally less thick than that of 
man ; compared in all the regions, it exhibits in the two 
sexes a sensible difference; on the mammae especially, it 
is much more delicate in woman. That of the great 
labia however is proportionally thicker than that of the 
scrotum. 
In order to understand perfectly the intimate structure 
of the chorion, it is necessary to examine it at first on its 
internal surface, after having carefully separated it from 
the fatty cellular texture, to which this surface adheres 
more or less intimately. We see then that it is differently 
arranged according to the regions. 
1st. On the sole of the foot and the palm of the hand, 
we observe an infinite number of white fibres, shining 
like aponeurotic fibres, which are detached from this in- 
ternal surface, form upon it a kind of new layer, cross 
each other in all directions, leave between them, especial- 
ly towards the heel many spaces of different sizes, that 
are filled with fat, separate more and more, and are finally 
lost in the sub-cutaneous texture, nearly as the fibres of 
the brachial aponeurosis insensibly disappear in the neigh- 
bouring cellular texture. Hence why when we dissect 
the palmar and plantar integuments, we experience the 
greatest difficulty in separating them entirely from the 
cellular texture which is interlaced with these fibres ; 260 
DERMOID SYSTEM. 
hence why also these surfaces have not, on the parts 
which they cover, the mobility which many others 
exhibit. 
The density of the cellular texture contributes also 
something to this arrangement which is essential to the 
functions of the foot and the hand, which are designed to 
seize and grasp external bodies. 
2d. The dermis of the superior and inferior extremi- 
ties of the back, of the neck, of the thorax, of the abdo- 
men, of the face even and consequently of almost all the 
body, is distinguished from the preceding, because the 
fibres are much less distinct, and are not lost in the cellu- 
lar texture by being as it were confounded with it, whence 
arises a remarkable laxity of the skin of these parts, and 
the very great facility with which it is dissected; in a 
word because the spaces between these fibres are much 
more narrow. These spaces appear like an infinite num- 
ber of holes irregularly placed at the side of each other, 
containing most of them small fatty parcels of the neigh- 
bouring texture, and exhibiting, when these small parcels 
have been carefully removed, very evident vacuities. The 
fibres which form them, are sufficiently near each other, 
to make you believe at first view, that it is a surface 
pierced with an infinite number of holes, that has been 
applied under the skin. On the contrary, on the hand 
and the foot, towards the heel especially, it is a true net- 
work the spaces of which are larger than the fibres that 
form them ; this is the reverse here. Be that as it may, 
these spaces in the internal surface of the chorion are 
very favourable to the action of tannin which penetrates 
the texture infinitely better from this side than from the 
opposite, because it insinuates itself into these numerous 
openings. I have had occasion to observe it in the human 
chorion which I have had tanned for the purpose. Chap- 
tal has observed that the epidermis is a real obstacle to 
the action of tannin, and that on this account scraping is DERMOID SYSTEM. 
261 
a preliminary operation essential to tanning, since it allows 
the skin to be penetrated on both sides ; but even when 
thus scraped, it receives the tannin much more easily on 
the side of the flesh than on the opposite one. 
3d. The chorion of the back of the hand and the foot, 
as well as that of the forehead does not exhibit these 
numerous openings on its internal surface; it is smooth 
and white, especially when it has been macerated a little. 
It is precisely the same as that of the scrotum, the pre- 
puce and even the great labia. The texture of it is more 
compact, no space is left in it, so that though more deli- 
cate than that of the extremities and the trunk, it con- 
tains almost as much substance. As to the chorion corres- 
ponding to the hair and the beard, we see in it only the 
openings necessary for the passage of the hairs, and which 
are wholly different from those of which I spoke just 
now, which form real culs-de-sac, and do not pierce 
through the chorion. 
Hence the internal face of the dermoid chorion exhibits 
three very distinct modifications. The first and last are 
seen to a small extent, whilst the second is almost gene- 
ral, with some differences however in the trunk, the ex- 
tremities and the head. Besides, these modifications do 
not suppose a diversity of nature, but only of forms. 
Much separated and arranged in fibres in the first, the 
dermoid texture is compact and condensed a little in the 
second, and by this condensation renders the spaces less 
distinct. But there is a means of seeing them every- 
where very well, where there is the least trace of them, 
and this is by maceration. This means also shows the 
dermoid texture best. In fact, when the skin has re- 
mained for some time in water, it softens, the fibres of 
its chorion separate, and their interstices become more 
distinct; then we see that the spaces exist not only on 
the internal surface, but that they extend into its texture 
which appears to be truly like, a sieve in its whole thick- 262 
DERMOID SYSTEM. 
ness, so numerous are the spaces arising from the inter- 
lacing of the fibres. 
These spaces do not terminate in culs-de-sac towards 
the external surface; they open upon this surface by many 
foramina which are very evident in a skin that has been 
macerated for a month or two, and which, in the ordinary 
state are almost imperceptible in some subjects, and very 
visible in others. Besides, in order to see them it is 
necessary to remove the epidermis; now as with the 
view of producing this effect immediately we commonly 
employ the action of boiling water or fire, the dermoid 
texture by this means acquires the horny hardening, and 
they become much less apparent, whereas maceration not 
only does not produce horny hardening of the skin, but 
it expands and dilates it, which renders these foramina 
very evident. In some parts of the skin and in certain 
subjects, we might then introduce the head of a pin into 
them ; in others they are less evident. These foramina 
never pierce the dermis perpendicularly, all open ob- 
liquely to its surface ; so that a perpendicular pressure 
tends to close them and bring their parietes in contact. 
I cannot compare their termination better than to that of 
the ureters in the bladder; hence why the hairs which 
go through them are never perpendicular, but oblique to 
the skin. We speak incorrectly when we say that the 
hairs are planted obliquely ; their insertion in the bulb is 
perpendicular; it is in their passage through the chorion 
that they change direction. 
Besides, these foramina are not vessels, but mere com- 
munications from the interior to the exterior through 
which pass the hairs, the exhalants, the absorbents, the 
blood-vessels and the nerves which go to the surface of 
the dermis; thus the subjacent spaces are only cells in 
which are contained the vessels of the glands and ot the 
cellular texture. The dermoid texture should then be 
considered as a real net-work, as a kind of cellular tex- DERMOID SYSTEM. 
263 
ture, the cells of which very evident within, become less 
so on the exterior surface, with which all communicate 
to transmit to it different organs. The chorion is then 
the outline, the frame, if I may so say, of the cutaneous 
organ. It serves to lodge in its spaces, all the other 
parts which enter into the structure of this organ, and 
contributes to give them the form they are to have, but 
is wholly foreign to them. 
What is the nature of this texture, which enters espe- 
cially into the composition of the cutaneous chorion ? 
I know not; but I think it has much analogy with the 
texture of the fibrous system ; the following considera- 
tions support this analogy. 1st. On the heel, where the 
dermoid texture has the fibrous form of the irregular liga- 
ments, it would be almost impossible to distinguish it from 
it, so uniform is the external appearance; it has the same 
resistance and density; the same sensation is experienced 
when it is cut with the bistoury. 2d. The dermoid tex- 
ture becomes yellow and transparent like the fibrous by 
stewing. 3d. It melts gradually like it into gelatine. 
4th. Like it, except the tendons however, it strongly 
resists maceration. 5th. Sometimes these two textures 
are identified ; for example, the annular ligaments of the 
wrist evidently send elongations to the neighbouring der- 
moid texture. 6th. This texture can serve, like the 
fibrous, for the insertion of muscles ; we see it in the face, 
where many of the fibres of the orbicularis of the lips 
and the eyelids, and almost all those of the eyebrows, 
find real tendons in the fibres of the dermoid texture. 
There is the same arrangement in the cutaneous palmar 
muscles. 
All these considerations evidently establish many rela- 
tions between the dermoid and fibrous textures. Yet they 
are far from being the same. To be convinced of this it 
is sufficient to observe how much their mode of sensibility 
differs, and how different also are their diseases ; it seems DERMOID SYSTEM. 
264 
at first as if there was no analogy between them in this 
double relation. Yet the line of demarcation is by no 
means as great as it appears to be. In fact the acute sen- 
sibility of the skin is not seated precisely in this white 
texture, which is interwoven so as to leave between its 
meshes the spaces of which we have spoken, and which 
we see especially on the surface adhering to this organ. 
The experiment mentioned in the article on the mucous 
system, and in which I irritated the cutaneous organ from 
within outwards, evidently proves it. It is the surface 
on which the papillae are found that especially exhibits 
this vital property. 
On the other hand morbid anatomy proves that the in- 
ternal surface of the dermis, in which are especially found 
the texture and the spaces of which we have spoken, is 
entirely free from most cutaneous eruptions. This is no 
doubt true as it respects the small pox, the itch and many 
species of herpes ; I have satisfied myself of it as to the 
vaccine vesicles, the miliary eruption, &c. &c. It is 
certain that in erysipelas, the external surface only of the 
chorion is coloured by the blood which enters the exha- 
lants; thus the slightest pressure, causing the blood to 
flow back, produces a sudden whiteness which soon dis- 
appears by the return of the blood into the exhalants. It 
is this which forms the essential difference between simple 
erysipelas and phlegmon, in which not only the external 
face of the chorion, but its whole texture and the sub- 
jacent cellular one are inflamed. In measles and scarla- 
tina, the redness is also very evidently superficial. These 
phenomena accord with those of injections ; for if they 
succeed at all in children, the skin of the face and less 
frequently that of the other parts, becomes almost entirely 
black. Now this blackness is much more evident on the 
external than the internal surface of the skin, no doubt be- 
cause more exhalants are found in the first than in the 
second, which the arterial trunks only traverse. DERMOID SYSTEM. 
265 
The preceding considerations evidently prove that the 
texture of the internal surface of the chorion, and even 
that of its interior, have a vital activity much less than 
that of the external surface; that this texture is disconnect- 
ed with all the great phenomena which take place upon 
the skin, with those especially which relate to the sensa- 
tions and the circulation ; that it is in the papillae that the 
first are seated and in the reticular body the second; and 
that it is almost passive in nearly all the periods of activ- 
ity of this double portion of the dermis. Its functions, 
like those of the fibrous texture, suppose it to be almost 
always in this passive state; they are only to defend the 
body and to protect it from the action of external bodies. 
It is this which forms our real covering; thus its proper- 
ties are well adapted to this use. Its resistance is ex- 
treme. It requires very considerable weight to tear very 
narrow strips of chorion, when it is suspended from them ; 
drawn in various directions, these strips are broken also 
with much difficulty. 
Yet this resistance is much less than when tannin is 
combined with the chorion. We know that when thus 
prepared, this portion of the skin affords the strongest 
strings we have in the arts. I know but two textures in 
the animal economy, which unite to such an extent sup- 
pleness and resistance; these are this and the fibrous tex- 
ture ; and this is a new character which approximates 
them. We have seen that it requires a very considerable 
weight to break a tendon, a strip of aponeurosis, or a liga- 
ment taken from a dead body. The muscular, nervous, 
arterial, venous, cellular textures, &c. yield infinitely 
more easily. If the dermoid texture had less extensi- 
bility, it might advantageously supply the place of the 
tendons, the ligaments, &e. in the structure of the body. 
Since the chorion is foreign to almost all the sensitive 
and morbid phenomena of the skin, let us inquire then 
in what part of the dermis these phenomena are seated. 266 
DERMOID SYSTEM. 
These parts exist very evidently on the external surface ; 
now we find on this surface, 1st, what is called the reticu- 
lar body ; 2d, the papillae. 
Of the Reticular Body. 
Most authors have considered the reticular body as a 
kind of layer applied to the external face of the skin be- 
tween the chorion and the epidermis, pierced with an in- 
finite number of openings through which the papillae pass. 
I do not know how we can demonstrate this layer, which 
escapes according to the opinion of most of them, when 
the epidermis is detached. In order to see it I have em- 
ployed a great many means, but no one has succeeded. 
1st. Such is the adhesion of the epidermis to the skin, 
that in a sound state we can hardly separate them without 
injuring one or the other. Yet with the greatest precau- 
tion we see nothing mucous on the chorion when it is laid 
bare. 2d. A portion of skin cut longitudinally, especially 
from the foot wrhere the epidermis is very thick, allows 
us to see very distinctly on the divided edge the boun- 
daries of this and of the chorion ; now nothing escapes 
from about the line which separates them. 3d. In ebul- 
lition in wThich the epidermis has been removed, nothing 
remains upon the internal surface, nor upon the chorion. 
4th. Maceration and putrefaction, the latter especially, 
produce upon the chorion a kind of glutinous layer the 
instant the epidermis is removed. But this layer is en- 
tirely the product of decomposition. Nothing similar is 
met with in the ordinary state. 
I believe, from all these considerations, that there is 
not a substance deposited by the vessels upon the surface 
of the chorion, extravasated, stagnant upon this surface, 
and representing there a layer in the sense in which 
Malpighi understood it. I believe that we ought to un- 
derstand by the reticular body, a net-work of extremely 
fine vessels, whose trunks already very delicate, after DERMOID SYSTEM. 
267 
having passed through the numerous pores with which 
the chorion is perforated, come and ramify upon its sur- 
face, and contain different kinds of fluids. 
The existence of this vascular net-work is placed be- 
yond a doubt by fine injections which change the colour 
of the skin entirely externally, without altering it much 
within. This is, as I have observed, the principal seat of 
the numerous eruptions most of which are really foreign 
to the cutaneous chorion. 
We may then consider the reticular body as a general 
capillary system, surrounding the cutaneous organ, and 
forming with the papillae a layer between the chorion and 
the epidermis. This system contains in most men, only 
white fluids. In negroes, these fluids are black. They 
have an intermediate tinge in the tawny nations. We 
know how much the shades vary in the human race. 
Hence the colouring of the skin resembles nearly that of 
the hairs, which evidently depends upon the substance 
existing in their capillary tubes ; it is analogous to that of 
the marks at birth, that are commonly called naevi ma- 
terni, and in which we never see a layer of fluids extra- 
vasated between the epidermis and the chorion. 
Moreover, I think we know but little as yet concern- 
ing this substance, which fills a part of the external capil- 
lary system. It does not circulate in it, but appears to 
remain there till another replaces it. When we examine 
the skin of a negro, we see a black teint, and that is all. 
In maceration I have observed that this teint is sometimes 
removed with the epidermis, and that it sometimes re- 
mains adhering to the chorion. It is very evidently 
foreign to both, since both have the same colour in whites 
as in blacks. It is never reproduced, after it has been 
removed ; for cicatrices are white in all people. 
Is there in white people a white substance which, re- 
maining in the external capillary system, corresponds to 
that of negroes, or does the colour of their skin depend 268 
DEHMOID SYSTEM. 
only upon the epidermis and chorion? I have been 
tempted to believe that they also have a colouring sub- 
stance, since the long-continued action of a powerful sun 
evidently blackens them. This circumstance has even 
made me believe that whiteness is natural to all men, and 
that there was but one primitive race which has degene- 
rated according to different climates. 
But in order to be convinced of the diversity of races, 
it is sufficient to observe, 1st, that the teint of the skin is 
but one of the characters which distinguish each race, and 
that man)’- others are always united to it. The nature and 
form of the hair, the thickness of the lips and the nose, 
the width of the forehead, the degree of inclination of 
the facial angle, the whole appearance of the face, &c. are 
constant attributes which indicate a general modification 
in the organization, and not merely a difference of the 
dermoid system. 2d. White people become tawny in 
hot countries; but they never acquire the teint of the 
people of the country. 3d. Removed to cold countries 
in early age, or even born in them, the blacks always re- 
main so ; their shade hardly changes at all from genera- 
tion to generation. 4th. Colour by no means follows 
temperature exactly ; we see many varieties in the shades 
of people who live under the same degree of latitude, &c. 
Every thing proves then that the colour of the skin is 
but an insulated attribute of the different human races, 
though it is that which is most striking to our senses, and 
that we should not attach to it a greater importance than 
to many others which are drawn from the stature, which 
is oftentimes very small, as in the Laplanders, from the 
broad and flat face, as in the Chinese, from the dimensions 
of the chest, of the pelvis, the extremities, &c. It is 
from the differences of the whole, and not from those of 
an insulated part, that the lines of demarcation should be 
made which separate the races. The European face and 
forms are in general the type with which we compare the DERMOID SYSTEM. 
269 
exterior of the other nations. The ugliness or beauty of 
the human races are, in our way of considering it, mea- 
sured by the distance which separates these races from 
ours. Such is in fact the force of habit with us, that 
we rarely judge in an absolute manner, and that every 
object which is much removed from those to which we 
are accustomed, is disagreeable to us and sometimes even 
disgusting. 
Besides, the colouring matter of the cutaneous reticu- 
lar body is more interesting to the naturalist than to the 
physician. What should particularly arrest the attention 
of the latter is the portion of the capillary system exte- 
rior to the skin in which the fluids circulate. In fact, be- 
sides the portion which is the seat of colour, there is evi- 
dently another that the white fluids constantly pervade, 
in which they are moved with more or less rapidity, and 
in wrhich they continually succeed each other. It is from 
this portion that the exhalant pores arise which furnish 
the sweat; it is this vascular net-work which is the seat 
of erysipelas and of all the cutaneous eruptions that are 
foreign to the chorion. 
The blood does not penetrate it in an ordinary state, 
but a thousand causes can at every instant fill it with this 
fluid. Rub the skin briskly, and it reddens in a moment. 
If an irritant is applied to it, whether it acts mechanically 
like nettles, the appendices of which penetrate the epi- 
dermis, or exerts a chemical action, like the frictions 
with ammonia, or the action of fire when a portion of 
skin is held too near it, instantly the sensibility of ,this 
vascular net-work is raised ; it invites into it the blood 
which it formerly repelled ; every part of a surface red- 
dens in proportion to the irritation. If passion acts pow- 
erfully upon the cheeks, immediately a sudden redness is 
evident in them. All rubefacients exhibit moreover a 
proof of the great tendency which the sensibility of the 
superficial capillary system of the dermis has to place 270 
DERMOID SYSTEM. 
itself, if it be ever so little excited, in relation with the 
blood which in the ordinary state is foreign to it. 
Vesicatories depend upon the same principle. Their 
first effect is to fill with blood the cutaneous capillary 
system, where they are applied, to produce in it a sudden 
erysipelas, and then to occasion a copious serous exhala- 
tion under the raised epidermis. They effect in a few 
hours what most cases of erysipelas do in many days; for 
we know that most of them terminate by vesicles which 
are raised above the skin. In burning, carried sufficiently 
far to be more than a rubefacient, and yet not so as to 
produce the horny hardening, there is also a sudden in- 
crease of exhalation under the raised epidermis. In gene- 
ral the production of every cutaneous bladder is always 
preceded by an inflammation of the external surface of 
the skin. This phenomenon is not exclusively confined 
to this system. We have seen the serous, as soon as it 
is laid bare and irritated considerably, redden in a short 
time by the passage of the blood into its exhalants ; which 
constitutes an inflammation to which often succeeds a 
copious exhalation of milky or other kind of serum. 
This exhalation does not remain upon the surface, and 
does not form vesicles there, because it has no epidermis ; 
this is the only difference between these phenomena, 
which at first view do not appear to be the same in the 
serous and cutaneous systems. 
It is not only the irritation of the cutaneous organ which 
makes the blood pass into the external capillary system. 
Whenever the heart is powerfully excited and it accele- 
rates the course of this fluid, it always tends to go into 
it; this is what is evidently seen, 1st, after violent run- 
ning ; 2d, in the hot period of a paroxysm of fever. 
Upon this subject I will make a remark which appears 
to me to be very important; it is that the capillary sys- 
tem of the face is, more than that of all the other parts 
of the skin, exposed to be thus penetrated with blood. DERMOID SYSTEM. 
271 
1st. This is evident in the two cases of which I have just 
spoken, and in which the action of the heart is increased. 
2d. In the passions, the skin remains the same in the 
other parts, whilst that of the face suddenly becomes pale 
or red. 3d. We know that physicians frequently ex- 
amine the state of the facial capillary system, which is 
almost always affected by the state of the internal viscera, 
and is full of blood or empty, according as it is sympa- 
thetically influenced. 4th. In various kinds of asphyxia, 
in those especially produced by submersion, by the vapour 
of charcoal, by strangulation, &c. the face is uniformly of 
a violet colour from the passage of the black blood into 
its external capillary system, into which it is brought by 
the arteries. Oftentimes the neck and the upper part of 
the chest are also livid ; but there is never a discolora- 
tion of the inferior parts. 5th. In many diseases, in which 
death takes place by a kind of asphyxia, because the lungs 
are the first interrupted, the dead bodies have a violet- 
coloured and swollen face ; this may be easily observed 
by all who frequent dissecting rooms. There are a hun- 
dred subjects in which the head has this lividity, to one 
in which it is observed in the inferior parts. 6th. Most 
cases of apoplexy produce the same lividity of the face. 
To what is this extreme susceptibility of the facial 
capillary system to admit the blood owing ? Three things, 
I think, principally contribute to it. 1st. The course is 
already opened to this fluid, since the redness of the 
cheeks necessarily supposes its presence in them, it only 
increases in quantity; whereas when another part of the 
dermoid surface becomes red, all the blood which enters 
it is almost accidendal. 2d. The anatomical arrange- 
ment of the capillary system is more favourable to this 
passage there than elsewhere ; for it appears that the com- 
munications of this system with the arteries of the chorion 
are more free. What proves this is, that in injections 
the face is coloured with great ease. There is undoubt- 272 
DERMOID SYSTEM. 
edly no anatomist who has not been struck with this phe- 
nomenon, especially in children, in whom if the coarse 
injections of our dissecting rooms succeed at all, the face 
becomes wholly black, whilst the fluid penetrates but 
very little into the other parts of the cutaneous system. 
3d. It appears that there is a greater sensibility in the 
face; in fact the same irritant brings blood there, which 
does not make it flow to any other place. For example, 
a blow equal to a box on the ear does not redden the skin 
of the arm, whilst it suddenly inflames the cheeks. 
The blood disappears from the facial capillary system 
as it enters it; in an instant the passions will successively 
produce there the bright red of a paroxysm of fever, the 
whiteness of syncope and all the intermediate shades. It is 
even the extreme ease with which this fluid penetrates this 
system, that renders the face well adapted to serve as a 
kind of picture, which the passions paint by turns with a 
thousand shades, that are effaced, altered, modified and 
return again according to the state of the mind. 
I would observe upon this subject that the passions 
have in the face three means of expression ; 1st, the capil- 
lary system, a means wholly involuntary, and which often 
betrays what we wish to conceal; 2d, the muscular mo- 
tion, which, by contracting or expanding the features, 
expresses the melancholy or gay emotions, and to which 
belongs as effects, the various wrinkles of which we have 
spoken; 3d, the state of the eye, an organ, which, as 
Buffon has remarked, not only receives the sensations, 
hut also expresses the passions. The two last means are 
to a certain extent voluntary ; we can at least disguise 
them ; whereas we cannot deceive by the first. The 
actor imitates anger, joy, &c. because we can give these 
passions by contracting the eye-brows, by dilating the 
face in laughing, &c. But it is the rouge of the actress 
that imitates modest chastity; it is by removing this 
rouge that she imitates the paleness of fear, horror, &c. DERMOID SYSTEM. 
273 
1 will add another essential observation in respect to 
the facial capillary system ; it is that it appears that its 
tendency to receive blood, disposes it to become the more 
frequent seat of many affections. We know, 1st, that 
erysipelas is much more frequent in this than in other 
parts ; 2d, that the variolous pustules are remarkably con- 
spicuous here; 3d, that many eruptions are more abun- 
dant here than elsewhere. 
From all that we have just said, it is evident that it is 
necessary to distinguish two portions in the capillary sys- 
tem exterior to the chorion. 1st. One is constantly filled 
with the colouring substance of the skin, a substance which 
appears to be stagnant like that of the hair of the head, 
and that of the hair of the body, which is subjected only 
to the slow and insensible motion of composition and 
decomposition and which never exhibits that sudden 
increase or diminution of which we have just spoken. 
2d. The second is constantly pervaded by many fluids 
which continually succeed each other there, and which 
constantly escape by transpiration, and which are replaced 
by the blood, that insinuates itself into this portion of the 
capillary system. These two portions are entirely inde- 
pendent, and have probably no kind of communication. 
It appears that at the instant of death there remains a 
certain quantity of the white fluids in the second portion 
of the exterior capillary system; the following experiment, 
which I have frequently made, proves it; by plunging a 
portion of skin into boiling water, and leaving it there an 
instant, the epidermis is raised up, not as a whole as in a 
blister, but in an infinite number of small vesicles which are 
formed suddenly on its surface, and which contain a serous 
fluid, that escapes as soon as we open these vesicles. 
Papillae. 
We call by this name those small eminences that arise 
from the external surface of the chorion, and which, 274 
DERMOID SYSTEM. 
piercing the capillary net-work of which we have just 
spoken, become by their extremities contiguous to the 
epidermis. These eminences are very evident in the 
palm of the hand and the sole of the foot, where they 
are regularly arranged, in the form of small curved striae 
in different directions. We see them through the epider- 
mis, notwithstanding its thickness in these places. But 
they are seen especially when this has been in any way 
removed, as by maceration, ebullition, &c. If we cut 
longitudinally a portion of the chorion of the foot, with 
its epidermis adhering to it, we see between them along 
the divided edge, a line in the form of a curved thread, 
which arises from these small eminences placed at the 
side of each other. 
In some other parts of the skin, we distinguish the pa- 
pillae in a very evident manner ; but in a great number, the 
epidermis being removed, we see only a surface, slightly 
uneven from some small eminences, especially towards 
the orifices through which the hairs and the vessels pass, 
but we do not discover those regularly arranged emi- 
nences, the papillae properly so called. 
We must not mistake for them the numerous and very 
evident prominences, which render the skin of some sub- 
jects extremely rough. These prominences are formed 
by small cellular, vascular or nervous bunches, by seba- 
ceous glands, &c. which are found near the small open- 
ings by which the chorion opens under the epidermis, 
and usually transmits the hairs. These bunches, lodged 
in the small oblique canals which are terminated by these 
openings, raise the external side of them and thus form 
this prominence. The following very curious experi- 
ment proves this arrangement; when the skin is mace- 
rated for two or three months, or even less, on the one 
hand these little bunches in which there is almost always 
a little fat, are changed into that white, thick, unctuous 
matter, analogous to spermaceti, into which fat kept a DERMOID SYSTEM. 
275 
long time in water is always converted ; and on the other, 
the foramina enlarging, as we have seen, and the skin 
changing into a kind of pulp, we can easily remove it all 
around these little prominences, and see that they are con- 
tinued with the fat which fills the meshes of the subjacent 
chorion, and which is also changed into a hard matter. 
Injections have evidently proved to me that there were 
vessels in these cellular bunches, and I have been con- 
vinced of it for some time past by the dissection of some 
subjects that died of scurvy, in whom the spots com- 
menced by very small ecchymoses, similar as it were to 
flea-bites, and which occupied these little eminences. The 
petechise of adynamic fevers have a different appearance; 
but they belong also to an extravasation of blood in the 
cellular texture, occupying the small pores which open on 
the exterior of the chorion to transmit the vessels, the 
hairs, &c. The more prominent these eminences are, of 
which we have spoken, the more uneven is the skin. In 
general they are more frequent on the extremities and on 
the back, than on the anterior part of the trunk. In the 
extremities there are more of them in the direction of ex- 
tension, than in that of flexion. 
We attach the idea of a beautiful skin, to that in which 
these small tubercles are not found, and in which the 
chorion is united at its external surface. Women have 
commonly this last arrangement more evident than men. 
The epidermis which covers these eminences very often 
scales oir at that place, especially from strong friction, 
which contributes still more to render the skin uneven, 
rough and harsh to the touch where they exist, which 
might induce a belief that they are formed by it, though 
it is always only accessory to them. Where it is very 
thick, as in the palm of the hand and the sole of the foot, 
it cannot be raised, and these small cutaneous tubercles 
are never seen. In the face where many vessels pass from 
within outwards, by the little pores of which we have 276 
DERMOID SYSTEM. 
spoken, we meet with hardly any more of them. The 
papillae scattered among these eminences, are in general 
very slightly apparent in the places where they exist. 
All anatomists attribute to these last a nervous struc- 
ture; they regard them as the termination of all the 
nerves that go to the skin, and which, according to them, 
are expanded to form these, after having first left their 
external covering. Some even say that they have traced 
filaments even into the papillae; I confess that I have 
never been able to do it. In the ordinary state, the den- 
sity of the chorion and the extreme delicacy of the fila- 
ments, are evidently an obstacle to it. In the state of 
long continued maceration, in which the chorion becomes 
pulpy and in which we might consequently trace these 
filaments, were it ever possible, it cannot be done. I do 
not however deny the texture attributed to the papillae. 
The acute sensibility of the skin seems even to suppose 
it; but it is only analogy and not demonstration, which 
establishes this anatomical fact; indeed all the other 
senses, whose organs are so sensible, have the portion of 
them which receives the impression of bodies continuous 
with a nerve. 
Action of different bodies upon the Dermoid Texture. 
In most of the other textures, we have only considered 
this action in the dead body, because during life, these 
textures always removed from external bodies, cannot be 
influenced by them. Here we can regard it in a double 
relation, since the skin is incessantly in contact with al- 
most all the bodies of nature. 
*fiction of Light. 
Light evidently acts upon the dermis. Removed from 
its influence, men are blanched, if we may so say, like DERMOID SYSTEM. 
277 
plants. Compare the inhabitant of a city, who is never 
exposed to the influence of the sun, with the peasant who 
constantly is, and you will see the difference. It appears 
that it is the light and not the heat which produces the 
effect of which I have already spoken; for individuals 
who live in a warm temperature, but removed from the 
solar light, become white like those of cold countries. 
Thus we know that some men who keep their chambers 
always very hot, are whiter than others who, living in a 
less hot atmosphere, are constantly exposed to the sun. 
We might remain forever in a bath of a temperature 
equal to the warmest seasons, and the skin would not 
blacken. Apartments for study which are warmed with 
stoves, and in which men remain as long as the labourer 
at his plough, are as warm as the atmosphere of summer, 
and yet the skin of those who occupy them never be- 
comes darker. Besides an irresistible proof is that the 
clothing which does not prevent the action of caloric upon 
the skin, and which offers a barrier to the rays of light 
only, prevents the cutaneous colouring that takes place 
upon the parts which the light immediately strikes, as 
upon the hands, the face, &c. 
I do not speak of the solar influence upon the vital 
forces of the skin, as in cases in which sun-strokes pro- 
duce erysipelas, or as when light is employed medici- 
nally to recall the life of a part; but it is only in rela- 
tion to the dermoid texture that I consider its action. 
Action of Caloric. 
The action of caloric upon the skin exhibits very differ- 
ent phenomena, according to the degree of it that it is 
applied. 
1st. A warm atmosphere expands the dermoid texture 
increases its action, and makes most of the fluids which 
form the residue of nutrition and digestion, pass off by 
the exhalants. 278 
DERMOID SYSTEM. 
2d. When contracted by cold, this texture refuses to 
admit those fluids, which then go off principally by the 
urine. 
3d. The insensible change from one to the other of 
these two states, does not disturb the functions. When 
this change is sudden, there are almost always alter- 
ations in different organs, because the fluids destined to 
pass out, cannot vary their direction as rapidly towards 
this or that organ, as the cutaneous excitement produced 
by the sudden changes from heat to cold. 
4th. The skin resists a temperature much greater than 
that of the body ; it opposes an insurmountable barrier to 
the external caloric, which tends to an equilibrium in ani- 
mate as well as inanimate bodies. Thus whilst these last 
are penetrated with this fluid in a medium warmer than 
themselves, and soon acquire the temperature of this me- 
dium, living bodies remain at the same degree, how much 
greater soever the surrounding heat may be to their own. 
The curious experiments of the English physicians have 
placed this truth, as it respects man, beyond a doubt. It 
is unnecessary to give the detail of these well known ex- 
periments, in which the mercury was seen to descend in 
the thermometer, when the bulb was placed in the mouth 
and in which the skin became covered, in a heated room, 
with the aqueous vapours of the air, which the greater 
cold of the body condensed upon its surface. A slight 
attention to animals with cold blood, living in warm 
climates, proves the same thing. I will make one remark- 
able observation upon this point, it is, that most reptiles, 
Avhose temperature is much less than that of the mammalia 
and of birds, and who consequently are brought much 
nearer than them to the temperature of winter, cannot 
however support it. They become torpid and sleep in 
subterraneous places, the heat of which remains nearly 
uniform like that of cellars, and do not awake till the 
milder temperature of spring stimulates them. DERMOID SYSTEM. 
279 
5th. The skin, in very cold climates, seems to be on the 
other hand an obstacle which prevents the internal caloric 
from suddenly escaping and thus placing the body in equi- 
librium with the surrounding medium. This is evident 
in countries near the pole. Upon this subject an observa- 
tion the reverse of the preceding can be made; it is that 
the cetaceous animals inhabit seas the temperature of 
which is most unlike their own. Whales are sought for 
especially in the latitudes of Greenland, Spitzbergen, &c. 
Why do fishes with warm blood delight in the frozen seas, 
whilst the amphibious animals with cold blood prefer the 
burning heat of the sun ? I know not. 
Let us observe that most of the internal organs when 
exposed in solutions of continuity, have not the faculty 
of preserving as well as the skin, a degree of independent 
temperature. They become cold or hot sooner than it as 
long as they remain healthy. The intestine brought out 
of the abdomen in the operation for hernia, a muscle laid 
bare, &c. &c. exhibit this phenomenon; thus in order to 
give them this faculty of having an independent tempera- 
ture, nature inflames them, and they thus constantly pre- 
serve their heat, whatever may be that of the surrounding 
medium. The mucous surfaces next to the skin resist the 
surrounding temperature the most, as is seen in prolapsus 
of the rectum, in inversion of the anus, &c. This differ- 
ence among the different systems is probably owing to 
that of their structure. 
6th. When the action of caloric is carried to a very 
considerable extent, it begins to act upon the skin, and its 
effects are the more evident in proportion as it is the 
more intense. 1st. The slightest of these effects is to 
produce an evident redness, a kind of erysipelas ; the 
caloric then acts like a simple rubefacient. 2d. The 
second is to redden the skin and then to produce vesicles 
on it. 3d. In the third there is a real horny hardening, a 
crisping of the fibres of the chorion which contract, like 280 
DERMOID SYSTEM. 
those of all the animal textures exposed to too strong a 
degree of heat. 4th. In the fourth and last effect, the 
dermoid texture is burnt, blackened and reduced to mere 
carbon. These different degrees of burning arise only 
from different degrees of caloric. 1 would observe that 
in the two first effects, this fluid acts upon the vital forces, 
and that these two effects cannot consequently take place 
except during life. The two last are exerted only upon 
the texture of the organ ; thus they take place after death 
precisely as before. Cooks often employ the horny hard- 
ness, to give to the skin a hardness and brittleness neces- 
sary in some kinds of cooking. 
7th. Cold carried to a gi’eat degree acts also upon the 
cutaneous organ, and produces different effects, according 
to its intensity. The first of these effects is very analo- 
gous to the first effect of a slight degree of caloric. It 
consists of a kind of local inflammation. The tip of the 
nose, the ears and the fingers, the cheeks, &c. become red 
from a slight degree of cold. I have not accurately ob- 
served the other effects between this and the last, which 
consists in a sudden privation of life. But there is this 
difference between the gangrene that then takes place, and 
that produced by a high degree of caloric, that the black- 
ness is sudden in this last, whereas it takes place only as 
a consequence in the other. Observe in fact that there is 
in gangrene two things which physicians do not suffi- 
ciently distinguish, 1st, the mortification of the part; 2d, 
its putrefaction. The mortification is always antecedent; 
it is produced by a thousand different causes; sometimes 
by the ligature of an artery, as in aneurism ; sometimes 
by that of a nerve ; often by violent inflammation ; some- 
times by a contusion, attrition, a bruise, &c. Whenever 
a part is dead in the midst of those which live, whatever 
may be the cause of its death, it becomes putrid precisely 
like a dead body, every part of which life has left. Putre- 
faction takes place then even sooner, because on the one DERMOID SYSTEM. 
281 
band the natural heat of the body, and on the other the 
moisture of the surrounding parts, favour it remarkably. 
This putrefaction varies according to the state in which 
the part was at the instant of death. If much blood in- 
filtrated it, as when inflammation destroys life, it quickly 
becomes putrid, blackens immediately and allows a fetid 
sanies to escape ; this putrefaction is called moist. If 
there is but little blood in the part at the instant of death, 
its putrefaction is less sudden ; it first putrifies, then black- 
ens, and allows but little sanies to escape ; this is the dry 
gangrene. Thus in a dead body, if one part is much 
loaded with blood, as the head of those that have died of 
apoplexy, its putrefaction is much more rapid and moist 
than that of the parts in which this fluid is less abundant. 
In the gangrene which succeeds mortification produced by 
cold, there is often dryness of the part, because there was 
but little blood in it at death. How little many physi- 
cians know of the progress of nature in the employment 
of antiseptics, which they apply in the living economy, 
as upon flesh without life. Antiseptics are applied for 
one of two purposes, either to prevent the death of the 
part, or its putrefaction. 1st. If it is with the first inten- 
tion, antiseptics should be varied. By untying the artery 
of a limb of an animal that has been tied, you will per- 
form an antiseptic operation. Bleeding and emollient ap- 
plications which lessen the violence of inflammation in a 
phlegmon, are antiseptics. A tonic as wine and all stimu- 
lants which excite the vital forces in a part in which they 
are languid after a bruise, are antiseptics. This word is 
then extremely improper when it is applied to medicines 
designed to prevent the mortification of the parts. Anti- 
septics are employed to prevent a dead part in the midst 
of living ones becoming putrid ; some effect is obtained ; 
thus by sprinkling cinchona, muriate of soda, or any neu- 
tral salt, by moistening a limb, a portion of skin, the ex> 282 
DERMOID SYSTEM. 
tremity of the nose, &c. which is dead from any cause, 
the putrefaction will be arrested, as in a dead body upon 
which the same means are employed. But what will be 
the result of it ? a little less fetor in the surrounding parts 
and less danger of their receiving the influence of the 
emanations of the dead part; but it is always necessary 
that this should come off; antiseptics will never bring it 
to life. Hence it is evident that these means should be 
considered in two points of view entirely different. The 
first prevent mortification, and vary remarkably though 
they are designed to effect the same object; thus our 
means of curing retention of urine are very variable, often- 
times opposite, according to the cause which tends to pro- 
duce this retention. The others prevent putrefaction, 
without restoring the parts to life ; now these are uni- 
formly the same, whatever may have been the cause of 
the local death. 
Action of the Air. 
The air acts incessantly upon the cutaneous organ. In 
the ordinary state, it constantly removes from its surface 
the sweat that is exhaled from it. Fourcroy, who has 
paid particular attention to the solution of the transpired 
fluid by the surrounding air, appears to me to have allow- 
ed too much influence to this solution upon transpiration. 
In fact there are two very distinct things in this function ; 
1st, the action of the exhalants which throw out the fluid ; 
2d, the action of the air which dissolves and evaporates 
it. Now the first of these is wholly independent of the 
other. Whether the fluid is dissolved or not, more is still 
furnished by the exhalants. If the solution does not 
take place, the fluid accumulates upon the skin, which re- 
mains moist; but this moisture does not obstruct the ex- 
halant pores and prevent new moisture from being added 
to it. A comparison will render this very evident. In 
the natural state, the serous fluids are constantly exhaled DERMOID SYSTEM. 
283 
and absorbed ; the absorbents perform for them the func- 
tions of the air which dissolves the sweat; now, though 
these vessels cease to act, as in dropsies, the exhalants 
continue their action ; there arises only a serous collec- 
tion, which, though applied to the orifices of the exha- 
lants, does not prevent them from pouring out more 
serum. The bladder in vain contains urine which presses 
upon the opening of the ureters, these ducts do not pour 
less into it. Though the mucous juices become stagnant 
on their respective surfaces, new juices are however pour- 
ed upon these surfaces. So though the skin remains moist 
from the want of solution of the transpiration, more 
transpiration is nevertheless exhaled. Solution is a physi- 
cal phenomenon wholly foreign to the vital phenomenon 
of exhalation. We transpire in a bath as well as in the 
air; only the fluid which arises from it is mixed with the 
water, instead of being reduced to vapour. 
The moisture of the skin is owing to two causes wholly 
foreign to each other; 1st, to the increase of the fluid 
furnished by the cutaneous exhalants ; now the action of 
these exhalants may be increased from three causes. 
First, every thing which accelerates the motion of the 
heart, as running, the paroxysm of acute fevers, &c. 
drives to the skin, as it is commonly expressed. In the 
second place, every thing which tends to relax and ex- 
pand the cutaneous organ by a direct action exerted upon 
it by the surrounding bodies, increases also the action of 
these exhalants, as in the great heat of summer, as in a 
bath and after coming out, as in a heated room, &c. In the 
third place, the action of the skin is in many cases sym- 
pathetically increased. Here may be classed the sweats 
of phthisis of which the lungs are the source ; those of 
fear, which depend upon a sudden affection of an epigas- 
tric organ ; those of many acute diseases, &c. Now in 
all these cases, however active the solution by the air may 
be, the skin will be constantly moist, because there is 284 
DERMOID SYSTEM. 
thrown out upon it more fluid than the air can dissolve. 
Thus in catarrhs of the lungs, in which more mucous 
juices are thrown into the bronchia than the air can re- 
move, it is absolutely necessary that there should be cough 
and expectoration to carry oft’ the remainder. 
2d. There are cases in which the moisture of the skin 
arises from the solution not being sufficient. This is 
what takes place in the moisture of the bed in which the 
air is not changed, in damp weather, &c. There is not 
then more fluid exhaled ; but the ordinary fluid becomes 
evident, because it is not dissolved. It is under this point 
of view that we must consider the action of the air upon 
the cutaneous organ which transpires. It carries off 
nothing in this organ ; it has no real action upon it; it 
takes only what its vessels throw off. Solution is merely 
accessory, it is always subsequent to exhalation, and has 
no relation with it. In the same in which the 
temperature has remained the same, the skin is often dry, 
moist, humid and even wet with sweat. If the air acts 
upon transpiration, it is By contracting or relaxing the ex- 
halants, and not by dissolving what they throw out. If 
the skin formed a sac without an opening, like the serous 
surfaces, transpiration would go on though it was remov- 
ed from the contact of the air, the same as if in contact 
with it. Why in fact should not that take place there, 
which does upon these surfaces ? 
If we consider the action of the air upon the skin of 
the dead body, we see that it produces two different 
effects, according to the state of the body. If the air 
penetrates the skin on all sides, it dries it, and it then 
acquires a sort of transparency, like the fibrous organs, 
unless a large quantity of blood had been accumulated in 
it at the moment of death, in which case it becomes black 
or of a deep brown. Thus dried, 1st, it is firm and re- 
sisting, but can be bent in various directions without 
breaking, as is the case with many textures thus dried, as DERMOID SYSTEM. 
285 
the cartilaginous, the muscular, &c. &c. 2d. It is much 
less easily altered than most of the other textures in a 
dried state. 3d. It absorbs moisture less easily than 
them, though however when immersed for a long time in 
water, it finally resumes nearly its original colour and 
loses its transparency. 4th. It does not exhale a very 
disagreeable odour, like many of the other textures. 
Hence why the skins of animals, merely dried, are used 
in many of the arts ; why some barbarous people make 
use of them for clothing, &c. The aponeuroses, and the 
mucous, serous and fibrous membranes could not be thus 
employed. It is to this also that must be attributed the 
little alteration that takes place in the exterior of mum- 
mies, which would never last for ages, if clothed with a 
fleshy or serous covering. 
When the skin is left upon the dead body, or exposed 
to a moist air, it becomes putrid instead of drying. Then 
it takes at first a dull colour, then a green and finally a 
black one. It exhales a very great fetor, swells and thick- 
ens, because the gases which are disengaged there fill the 
cellular texture in its little spaces. A mucous covering 
is spread upon its external surface, which is deprived of 
its epidermis. Nothing similar to this covering is seen 
on the internal surface. Finally, when all the fluids it 
contains are evaporated, there remains a black residuum, 
very different from that which is left after combustion. 
Action of Water. 
This action during life, is relative either to the sub- 
stances that are deposited on the surface of the skin, or 
to the cutaneous texture itself. 
The sweat deposits incessantly upon the epidermis 
many substances, the principal of which are taken away 
by the air, but many being slightly soluble in it, as the 
salts for example, remain on its surface, and adhere to it 286 
DERMOID SYSTEM. 
when not removed by friction. Mixed with the unctu- 
ous fluid which oozes out upon this surface, and with the 
different foreign particles that the air deposits there as 
everywhere else, these substances form upon the skin a 
deposit which cannot, like the transpiration, be carried off 
by solution. Now water removes all this deposit; hence 
why the use of baths is truly natural. All quadrupeds 
bathe themselves. All birds frequently plunge into the 
water ; I do not speak of those for whom this fluid is as 
it were the element. It is a law imposed upon all species 
of animals whose skin throws out a considerable quantity 
of fluid. All the human races hitherto observed fre- 
quenty plunge into brooks, rivers, or lakes, along which 
they take up their abode. The countries that are well 
watered are those which animals prefer. They avoid 
those where this fluid is wanting, or in which it is only 
sufficient for their drink. We oppose nature in every 
thing in society. In our own, numerous classes hardly 
ever use a bath; thus you must seek especially in these 
classes for cutaneous diseases. We have seen that the 
mucous juices, remaining too long upon their surfaces, 
irritate and stimulate them and cause there various affec- 
tions. Is it astonishing that the residuum of the cuta- 
neous exhalation which the air does not remove, should 
occasion various alterations upon the skin ? In summer, 
baths are more necessary, because as many excretions are 
taking place by the skin, more substances are deposited 
there. In winter, in which every thing passes off by 
the urine, the cutaneous surface becomes less dirty, and 
has less need of being cleansed. After severe diseases, 
in which there has been copious cutaneous evacuations, 
one or two baths terminate the treatment advantageously. 
Let us consider water then as acting as accessory to the 
air upon the skin, as removing from its surface sub- 
stances which the first cannot dissolve, substances, which 
varying remarkably like those that compose the urine, DERMOID SYSTEM. 
287 
have presented the transpiratory fluids to chemists, some- 
times as alkaline, sometimes as acid, oftentimes as con- 
taining salts, sometimes charged with odoriferous sub- 
stances, &c. Water is the general vehicle ; when it is 
evaporated, it leaves the substances that are not volati- 
lized like it. It is on this account that dry frictions are 
also advantageous ; they clean the exterior of the body. 
As to the action of the bath upon the cutaneous tex- 
ture, we know but little of it during life. They say in 
medicine that it softens, relaxes and unbends this texture; 
this is vague language to which no precise meaning is 
attached, and which is no doubt borrowed from the re- 
laxation which the skin of dead bodies undergoes, or even 
tanned leather, when exposed to water. A bath acts 
upon the vital forces of the skin, raises or diminishes 
them, as I shall say ; but it leaves its texture in the same 
state; it is only that of the epidermis which it alters, as 
we shall see. 
Macerated in water of a moderate degree of tempera- 
ture, in that of cellars for example which does not vary, 
the human skin softens, swells but little, becomes evi- 
dently whiter, and remains for a long time without ex- 
periencing any other alteration than that of a putrefaction 
infinitely less than that of the muscular, glandular, mu- 
cous textures, &c. subjected to the same experiment. 
This putrefaction, which removes the epidermis, appears 
to be much greater on the side nearest to this membrane; 
at the end of two or three months the skin loses but little 
of its consistence. It does not become pulpy as the ten- 
dons and muscles in this length of time when macerated ; 
it does not become a fetid pulp till the end of three or four 
months. I have preserved some of it for eight months, 
which has still its primitive form, but which feels liquid 
under the fingers when pressed a little. In the half putrid 
state, the skin still preserves the faculty of crisping 
from the action of caloric ; it moves about when placed 288 
DERMOID SYSTEM. 
on burning coals, or when plunged into boiling water. 
When once reduced to a really putrid state it loses this 
property. 
Exposed to ebullition, the dermoid texture when well 
separated from the cellular, furnishes less scum than the 
muscular, the glandular and the mucous ; it resembles in 
this respect the tendons, no doubt because being almost 
wholly gelatinous, it contains but little albumen. In the 
horny hardening that takes place a little before ebullition 
commences, it twists and then always becomes convex on 
the side of the epidermis, and concave on the opposite 
side; and for this reason ; the fibres of the chorion in 
contracting by the horny hardening, are pressed against 
each other ; all the spaces which exist between them are 
effaced ; now, as these spaces are very large in the second 
direction, the dermoid texture necessarily becomes more 
contracted there, whilst in the first, the spaces hardly 
existing at all, every thing being almost solid, the fibres 
have less space to contract, they remain longer, and the 
surface continues larger. In the natural state the cavity 
of these spaces, being filled with cellular texture, in- 
creases the extent of the internal surface; this space then 
disappearing, this surface becomes contracted. 
The moment this kind of twisting takes place upon the 
skin, it is covered, as I have said, with an infinite number 
of vesicles filled with serum, and which are formed by 
the epidermis. As this membrane is very thick on the 
soles of the feet and the palms of the hands, it cannot 
contribute in those places to their formation, and we see 
nothing there similar to them. Yet by removing it from 
feet that have been boiled, I have observed that it con- 
tained between its layers many small vesicles, which were 
scarcely visible. I have not analyzed the water of these 
vesicles, but presume it is analogous to that of blisters. 
Besides a greater or less quantity of it is poured out, and 
the vesicles are consequently larger or smaller, accprding DERMOID SYSTEM. 
289 
to the state of the external capillary system at the instant 
of death. 
By the horny hardening, the skin becomes hard, elastic, 
very resisting, thicker, but not so broad. It soon loses 
its semi-transparency and yellowish colour, like the boiled 
fibrous organs. Then the hardness it had acquired at the 
instant of the horny hardening is gradually lost; it softens, 
gives out much gelatine in the water in which it is boiled, 
does not lessen in size, but even increases in thickness. 
Every kind of fibre, vacant space and organization is then 
gone ; it is a membranous mass, homogeneous in appear- 
ance, semi-transparent and gelatinous. In this soft state, 
it does not lose the elasticity it had acquired in the horny 
hardening, like the mucous, serous, cellular textures, &c. 
&c. The great quantity of gelatine it contains still pre- 
serves this property in it. The least motion that is com- 
municated to it produces a general trembling, a sort of 
vibration of all its parts, exactly analogous to that of the 
various kinds of animal jellies, half coagulated, which 
vaccillate in the vessel from the least jar. 
Finally, the ebullition still continuing, the gelatine is 
almost all dissolved, and there remains only a residuum 
like membrane and which disappears with great difficulty; 
it requires even a very long time for common boiling- 
water to reduce the skin to this residuum. Such are the 
phenomena of the ebullition of the human skin as I have 
carefully observed them. Chemists have paid great atten- 
tion to the dermoid texture of many other animals ; they 
have formed different ideas of its nature; they have ad- 
mitted that there are two substances in it; one fibrous 
and the other gelatinous. I refer to their works upon this 
point, particularly to the labours of Seguin, and the 
work of Fourcroy ; for in general I do not relate what 
is detailed by others, it would be only a useless repeti- 
tion. 290 
DERMOID SYSTEM. 
Action of the Acids, the Alkalies and other Substances. 
The sulphuric, nitric and muriatic acids act upon the 
skin, when in contact with it, as upon all the other animal 
substances. I have remarked however that their action 
is much slower, especially on the side of the epidermis, 
though this membrane may have been previously taken 
off. The first of these acids reduces it easily to a blackish 
pulp; the others bring it to a pulpy state with more 
difficulty, even when they are very little weakened; the 
oxy-muriatic acid produces hardly any effect upon it. 
Some authors have said that the lapis infernalis pro- 
duces the same phenomena on the dead as on the living 
body. I wrapped up in a piece of skin, as in a rag, 
many fragments of this substance, so that they were in 
contact with the epidermis; at the end of a day they were 
reduced to a kind of pap of a yellowish red, by the mois- 
ture which they had absorbed. The dermoid texture, 
crisped and contracted, had not been penetrated ; it did 
not appear even to have been injured on the exterior. 
In general the action of the alkalies appears to be wholly 
different during life, and it varies even according to the 
different degrees of vitality. We know that flaccid and 
fungous flesh burns much less easily than that which is 
red and vigorous. It is the same with the acids. Never 
during life do they produce any thing analogous to that 
pulp of different colours according to the acids that are 
employed, which is always after death the result of their 
action. 
We know that an alkaline solution, put in contact with 
the skin, produces a kind of unctuous and slippery feel, 
which is no doubt owing to the combination of the alkali 
with the oily deposit of the skin, from which arises a sort 
of soap. 
I shall not speak of the tendency of the dermis to com- 
bine with tannin, nor of the phenomena of this combina- DERMOID SYSTEM. 
291 
tion; I should only be able to repeat what others have 
said upon this point. I will merely remark that it would 
be very important to try the effects of tannin on the large 
sub-cutaneous aponeuroses, the texture of which being 
essentially gelatinous has much analogy with that of the 
dermis, and which from their extent and delicacy might 
serve for uses to which the dermoid texture when tanned 
is less adapted. We know that the tanned skin is no 
longer what it wras in the natural state, and that the sub- 
stance with which it is then penetrated gives it an artifi- 
cial consistence. If much tannin has been combined with 
it, it loses entirely the faculty of acquiring the horny 
hardness, and becomes brittle ; whilst if but little of this 
substance is added to it, it preserves in part its supple- 
ness and the property of crisping from the action of 
caloric. I would compare tanned skin to bone penetrated 
with the phosphate of lime, and that which is not tanned, 
to the cartilaginous parenchyma from which the acids 
have removed this phosphate. 
JI. Parts common to the Organization of the Dermoid 
System. Cellular Texture. 
The whole dermis is penetrated with a large quantity 
of this texture. It is arranged in the following way; 
from the exterior of the sub-cutaneous cellular layer, an 
infinite number of elongations is detached which pene- 
trate the contiguous spaces of the chorion, enter after- 
wrards into those which are more exterior, and finally ter- 
minate in the numerous pores which transmit outwards 
the vessels, the nerves and the hairs, which have pre- 
viously passed through this cellular texture. We can 
then consider the chorion as a kind of sponge, the spaces 
of which represent the interstices, and which the cellular 
texture penetrates on all sides ; so that if it was possible 
to separate by dissection, these spaces from the cellular 292 
Cermoid system; 
texture, and the organs which are in it, there would be a 
kind of sieve pierced in all directions. Art cannot arrive 
at it but with difficulty on account of the delicacy of the 
parts; but that which is not done by dissection, nature 
often effects. In biles I have observed that all that which 
fdls the interstices of the dermoid fibres disappears by 
suppuration, and that these fibres, separated besides by 
the swelling of the parts, exhibit truly the appearance of 
a sieve of which I have just spoken, when the fluid that 
moistens them is removed. The bile differs in fact from 
many other cutaneous eruptions, in this 'that it attacks the 
cellular texture of the spaces of the chorion, whilst they 
have their seat, as I have said, in the reticular body. I 
do not know any acute affection which attacks the chorion 
itself; all have their seat either on its surface, or in the 
cellular texture of its cells. Its dense and compact tex- 
ture seems, like that of the aponeuroses, not able to be 
changed until a length of time. In elephantiasis I have 
seen this texture evidently disorganized. 
M. Thillaye showed me portions of skin taken from a 
cemetery, in which every thing that filled the dermoid 
spaces had disappeared, and in which these spaces and their 
dried fibres formed a real membranous sponge through 
which the light could everywhere be seen. In this case 
the reverse of what is seen in long continued macerations 
had taken place, in which the fatty cellular texture, 
changed into a solid, white substance, preserves, as I have 
said, the form of the spaces which it filled, whilst the 
dermoid fibres reduced to the pulpy state, are easily re- 
moved. In the first case it is the mould only which is 
left; in the second it is the substance which is contained 
in it. 
In chronic leucophlegmasia, the sub-cutaneous serum 
gradually extends along the cellular elongations of the 
spaces of the dermis, separates their fibres, consequently 
enlarges these spaces, and sometimes penetrates even to DERMOID SYSTEM. 
293 
the epidermis, which it breaks in different places, and 
through the crevices of which it escapes. In this case, 
there is not resolution of the skin into cellular texture, 
as it is called, but a separation of the dermoid fibres, 
which always remain. 
I do not presume that the cellular texture of the chorion 
extends to its external surface, under the epidermis; for 
when this has been removed, fleshy granulations are not 
formed, now, in all the parts where the cellular texture is 
found, these granulations are produced, when the parts 
are laid bare. 
Blood Vessels. 
The arteries winding in the sub-cutaneous cellular tex- 
ture, furnish an infinite number of small branches which 
are introduced with the cellular parcels into the most in- 
ternal dermoid spaces, afterwards pass into those that are 
nearer, approximate by winding and anastomosing a thou- 
sand times through the spaces of the external surface of 
the chorion, finally go through the pores of this surface, 
and give rise to that external capillary net-work of which 
we have spoken in the article upon the reticular body, 
and to which in the ordinary state but very little red 
blood comes. In this course through the dermoid spaces, 
but few small arteries remain in the fibres of the chorion 
itself, as fine injections prove. These fibres resemble in 
this respect those of the aponeuroses through which many 
vessels pass, but which have but few belonging to their 
own texture. 
The veins follow nearly the motion of the arteries, but 
in an inverse direction. After having passed through 
the dermoid spaces and the cellular texture which fills 
them, they go to the great sub-cutaneous trunks, which 
run a long course, form, as we have seen, a system wholly 
distinct by its position from that of the arteries and which 
can be often traced through the integuments. Not seen 294 
DERMOID SYSTEM. 
in the natural state, the venous ramifications of the spaces 
of the chorion are considerably dilated in the subjacent 
cancerous tumours, and make the skin which covers these 
tumours .appear to be marked with blue lines, which 
always grow larger as the tumour increases. Whenever 
there is a considerable distention of the cutaneous organ 
by an aneurism, pregnancy, dropsy, &c. this dilatation also 
takes place, provided the cause of the distention pursues 
a chronic course; for nothing similar is seen in acute 
affections, whatever swellings may have taken place, as 
in those consequent upon fractures, upon compound luxa- 
tions, &c. 
All the black blood formed in the skin goes into the 
general venous system ; no portion belongs to the abdo- 
minal. 
Nerves. 
Their distribution is nearly the same as that of the 
blood vessels. Many very considerable branches, as 
different divisions of the musculo-cutaneous, the internal 
cutaneous, the lumbar, the saphena, the anterior tibial, the 
intercostals, the cervicals, &c. form a kind of sub-cutaneous 
nervous system, from which go all the branches that enter 
the dermis. These branches, in passing through the der- 
moid spaces with the arteries and the veins, appear to 
anastomose often together, go through the pores which 
terminate the spaces on the interior, and no doubt form 
the papillae. Observe even that on the hand where the 
papillae are very evident, there is, in proportion to the 
surface, many more sub-cutaneous nerves than any where 
else. 
Absorbents. 
Many absorbents creep under the skin ; it is here that 
they can be the most easily studied. All the veins are sur- 
rounded with them ; various fasciculi are observed in their DERMOID SYSTEM. 
295 
interstices ; so that a layer of absorbents, arranged in the 
form of a continuous layer, seems to separate, in the ex- 
tremities, the aponeurosis and the skin. There is no 
doubt that the origin of the most of these vessels exists 
in the chorion, that they carry to the blood the fat and 
the cellular lymph of its spaces, and the nutritive matter 
of its fibres. But is there a particular order of branches 
opening upon the surface of the epidermis to absorb in 
certain cases foreign substances? This question cannot 
be answered by anatomical inspection. But the follow- 
ing considerations appear to me to throw great light 
upon it. 
1st. The sub-cutaneous absorbents, visible by injec- 
tions, are too numerous in proportion for the mere pur- 
pose of carrying back the fat and serum of the neigh- 
bouring parts. 
2d. There are many medicines which appear to be 
evidently absorbed ; such are mercury in the venereal dis- 
ease, various purgative and emetic substances, febrifuges 
even, as cinchona, which, when applied by friction, have 
produced their effects as well as if taken by the stomach ; 
cantharides often act upon the kidneys, when the tincture 
is used as a liniment, narcotic substances sometimes occa- 
sion a weight in the head and drowsiness when they have 
been externally applied, &c. These different effects are 
well known and many authors have given examples of 
them. 
3d. There is we know absorption of different kinds of 
virus, of that of hydrophobia, of the small-pox, of the 
venom of the viper, &c. an absorption, it is true, which 
rarely takes place when the epidermis is whole, but which 
uniformly does, when this being removed, the matter is 
found in contact with the external capillary net-work of 
which we have spoken. I would remark even that the 
different kinds of inoculation of the small-pox, of the 
vaccine disease, &c. evidently prove both the existence 296 
DERMOID SYSTEM. 
and importance of this net-work, to which heretofore suf- 
ficient attention has not been paid. There are many con- 
tagious principles which are absorbed through the epider- 
mis ; such are those of the plague which the clothes com- 
municate and those of different pestilential fevers which 
penetrate by the skin more than by respiration. I believe 
cutaneous absorptions, from which diseases arise may be 
divided in the following way: 
'1st, local, as the itch, herpes, tinea 
capitis, &c. &c. 
2d, genera], as pestilential diseases, 
putrid fevers taken in an un- 
_ healthy place, &c. &c. 
1st. Absorptions which take place 
through the epidermis, and which< 
produce an effect 
'1st, local, as the vaccine disease, 
the small-pox, &c. &c. 
2d, general, as hydrophobia, the 
venom of the viper, a wound 
with an instrument impregnated 
with putrid matter, &c. &c. 
2d. Absorptions which take place 
only when the epidermis is re- 
moved, and from which arises" 
an effect 
We see by this table that the absorbents when charged 
with injurious substances, sometimes do not transmit them 
beyond the part and sometimes carry them to the blood, 
which conveys them to the different organs of the econ- 
omy. Some authors have thought that in those cases in 
which the effects of the absorption become general, there 
is rather nervous action and sympathetic phenomena, than 
the transmission of an injurious matter into the circula- 
tion, and that consequently the solids take almost an ex- 
clusive part in these diseases. But to remove all doubt 
upon this point it is sufficient to observe, 1st, that, in the 
absorption of many contagious substances, for example, 
when from the puncture of the finger with a scalpel im- 
pregnated with putrid substances, a pain is produced, 
there is even a redness along the whole course of the 
absorbents of the arm, and the axillary glands afterwards 
swell; 2d, that by transfusing into the veins most of the 
substances that are applied in frictions, effects analogous 
to those which take place in these frictions are produced. 
Thus purgatives and emetics, transfused or absorbed, act DERMOID SYSTEM. 
297 
upon the intestines and stomach the same as if introduced 
in any other Avay. It seems to me that sufficient use has 
not been made of the experiments of the last age upon 
transfusions. By comparing their effect with that which 
takes place upon the cutaneous organ, I think that it is 
impossible not to admit a morbific principle in the blood, 
at the time of contagious diseases. 
3d. After the use of mercury taken in frictions, the 
emanations of this metal from the animal fluids, act evi- 
dently upon silver when placed in the mouth, the rectum, 
&c. I am persuaded even that the blood which in the 
natural state exerts but very little action upon this metal, 
would alter it then. Accoucheurs know that the waters 
of the amnios of those women who have made use of 
mercurial frictions exhibit the same phenomenon. 
4th. Many substances that are not medicinal can be 
transmitted to the blood by cutaneous absorption. Water 
appears to enter it in this way, in the rapid production 
of certain dropsies, in those cases related of travellers, 
who wanting fresh water on the ocean, have in part 
quenched their thirst by surrounding themselves with damp 
clothes, &c. When our garments are impregnated with 
the oil of turpentine, the urine soon acquires an odour 
that is owing to the principles transmitted to the blood by 
absorption. Many judicious philosophers have asserted 
that the weight of the body has been increased by a walk 
in the morning. 
I have observed that after remaining in the dissecting 
room some time, the intestinal flatus frequently acquires 
an odour exactly similar to that which the bodies in 
putrefaction exhale. In the following way I convinced 
myself that it was the skin as much as the lungs that 
absorbed these odorous particles. I closed my nostrils, 
and fitted a long tunnel to my mouth, which passing out 
of the window allowed me to breathe the external air. The 
flatus from my boAvels, after I had remained an hour in a 298 
DERMOID SYSTEM. 
small dissecting room, at the side of two very fetid bodies, 
acquired an odour nearly similar to theirs. I have ob- 
served also that by touching for a long time fetid sub- 
stances, the flatus acquires more of this odour, than by 
remaining only in an air loaded with cadaverous exhala- 
tions. Then the absorbents carry at first these exhala- 
tions to the blood, which afterwards throws them out by 
the mucous surface of the intestines. Thus when the 
urine is absorbed, the saliva, the mucous juices, &c. have 
an urinous odour. 
I could accumulate many other proofs of cutaneous ab- 
sorption ; but I have selected only the principal. Many 
others have been cited ; Haller in particular, to whom I 
refer, has multiplied examples of it. 
I would remark however that cutaneous absorptions 
have a character of remarkable irregularity ; that under 
the same apparent influence, they sometimes take place 
and sometimes do not. It is thus that most often we ab- 
sorb nothing in a bath, that we escape or take contagions, 
that the vaccine disease is or is not communicated, that 
the variolous inoculation is also often uncertain, &c. This 
is not astonishing. It requires a certain degree of sensi- 
bility in the skin for the absorption of this or that sub- 
stance ; above or below this degree, the absorbents repel 
this substance. Thus in the intestinal canal, if you raise 
by a purgative, the ordinary degree of sensibility of the 
lacteals, they cease immediately for a time to take up 
drinks, chyle, &c. and every thing passes oflf by the anus. 
Now a thousand causes act incessantly upon the skin ; a 
thousand irritants by turns applied to it make the degree 
of its organic sensibility vary every instant, increase, 
diminish and remove it from that which is necessary for 
absorption.. Is it astonishing then that this function 
should exhibit so many varieties ? Many modern phi- 
losophers have produced numerous negative facts against 
cutaneous absorption. What do these facts prove ? only DERMOID SYSTEM. 
299 
the varieties of sensibility which I have noticed ; but they 
do not destroy the mass of positive facts, generally ac- 
knowledged and which together form a body of proof 
which nothing can oppose. Thus we have seen the mu- 
cous surfaces variable in their vital forces on account of 
the variety of their excitants, vary also in their absorp- 
tion. If in the serous membranes, in the cellular texture, 
in the work of nutrition for the organs, this function is 
uniform, it is because being constantly in contact with the 
same bodies, the surfaces where it is going on have an 
uniform degree of organic sensibility. 
Many facts, in relation especially to contagions seem to 
prove that a state of weakness is favourable to cutaneous 
absorption. 1st. Children and women absorb more easily 
than strong and vigorous men. 2d. Many physicians 
have observed that in the night in which the cutaneous 
organ is in a state of remission in this respect, as it is not 
stimulated by external objects, contagious diseases are 
more easily taken. 3d. I have remarked that most of 
the pupils who have fallen sick during my dissections, 
had carried to their chambers portions of subjects, the 
emanations from which had been able to affect them dur- 
ing sleep. 4th. We know that practitioners recommend, 
that persons should not expose themselves to contagious 
miasmata during hunger, as the forces are then languid on 
account of the emptiness of the stomach. 
Exhalants. 
The external capillary system which surrounds the 
chorion and embraces the papillae, appears to be the origin 
of these vessels, as it is the termination of the arteries of 
the dermoid spaces. The exhalants take up their fluid 
there, which they throw out upon the epidermis. We 
have no anatomical knowledge as to their form, their 
length, their course and their direction ; but their exist- 300 
DERMOID SYSTEM. 
ence is incontestibly proved, 1st, by injections, which arc 
sometimes poured out upon the whole cutaneous surface ; 
2d, by the sanguineous exhalation which takes place in 
some diseasesin which there is a real bloody sweat; 3d, 
by the natural sweat and by transpiration, which can evi- 
dently have no other agents, though some authors have 
admitted that there were certain pretended glands for the 
secretion of these fluids. 
An infinite number of calculations has been made to 
ascertain the quantity of fluid which the cutaneous ex- 
halants usually pour out. We are dismayed when we 
read the result of the labours of many philosophers upon 
this point, when we go over the calculations, enormously 
multiplied, of Dodard, Sanctorius, Keil, Robinson, Roye, 
&c. To what do all these calculations, for which the 
life of a single man would perhaps be insufficient, tend ? 
To prove to us that when we start from a false principle, 
the whole chain of consequences drawn from it is false, 
though these consequences may be rigorously deduced 
from each other. In fact, most philosophers have consid- 
ered the skin as a kind of fountain with numerous capil- 
lary tubes, always throwing out in the same time the 
same quantity of fluids, and being able consequently to 
be subjected, like inert capillaries which pour out fluids, 
to proportions and calculations of quantity. But the re- 
sults of these calculations have soon proved how mistaken 
their authors were. Read these r@suits, and you will see 
that none of them agree, that frequently very great dif- 
ferences characterize them. Is this astonishing? A thou- 
sand causes make the transpiration vary at every instant. 
Temperament, exercise, rest, digestion, sleep, watchful- 
ness, the passions, &c. increase or diminish the action of 
the cutaneous exhalants. I do not speak of the difference 
from climate, seasons, &c. which is still more decided. 
An attempt has even been made recently to ascertain, 
what belongs to the urine, to the transpiration, to the pul- DERMOID SYSTEM. 
301 
monary perspiration and to the excrements, to calculate the 
relation which exists between the quantities thrown out 
in these four ways ; useless researches ! We might obtain 
from them results for one man, which would not be ap- 
plicable to others. Thus see if we have ever been able 
to make a single useful application to physiology or patho- 
logy of all these immense labours on transpiration. What 
would you say of a man who, during the days of the 
equinox, in which the state of the atmosphere was every 
minute changing, should try to establish proportions be- 
tween the quantities of rain which fell in every quarter 
of an hour, or of one who endeavoured to fix relations 
between the quantities of fluids which are evaporated in 
given times, from the surface of a vessel under which 
the intensity of the heat which warmed the water varied 
every instant. The comparison is just. We might be 
able to say in general, at the end of a given time, nearly 
how many pounds of substances went from the body; and 
yet this varies in every individual. But to attempt to 
say in -a general manner what, in this common quantity, 
the urine and transpiration separately furnish, is to prove 
that we do not understand the nature of the vital forces. 
We have already observed, that all our knowledge 
upon the varieties of transpiration, is reduced to some 
general data; that, for example, in cold seasons and 
climates, it is by the internal emunctories that the residue 
of nutrition and digestion principally passes off, whilst in 
warm climates and seasons, it is the cutaneous organ that 
principally throws it out. 
The skin on the one hand, and the kidneys and pul- 
monary surface on the other, are then in this respect, in 
a constantly inverse activity. Physicians very well know 
this difference in regard to the urine and swreat; they 
know that when one is increased, the other is diminished ; 
that in winter the urine contains principles of various 
kinds, and that in summer the transpiration has a salt taste 302 
DERMOID SYSTEM. 
and other peculiar characters which it owes to the sub- 
stances which are foreign to it in the first season. But 
they have not so well examined the relation of the tran- 
spiration with the sweat; this determined me to make the 
following experiments : 
I wished to know what is the state of the respiratory 
fluid in summer, in which there is much transpiration, 
and in which all the heterogeneous principles consequent- 
ly go out by the skin. To obtain this fluid which is ex- 
haled in insensible vapour, I placed a clean, empty bottle 
in a pail filled with ice and the muriate of soda, and I 
respired a long time in it, taking care not to allow any 
saliva to fall in. The parietes, chilled by the external 
ice, condensed into small icicles the vapour of my breath, 
on the internal surface of the vessel. When I had made 
a certain quantity of these, I withdrew the bottle; then 
by putting it into tepid water, the icicles immediately 
melted, and I had in a liquid state my respiration, which 
was before in vapour. Now I have been struck with twro 
things in this experiment, 1st, with the small quantity of 
fluid that I was able to obtain, though I had respired for 
an hour, and afterwards made two men respire each an 
hour ; 2d, with this, that most of the reagents have no 
action upon this fluid. Nitric, sulphuric and muriatic 
acids, lapis infernalis, and alkohol produce no effect when 
mixed with it. In evaporating a small quantity in the 
concavity of a watch chrystal, no residuum is left; placed 
in a spoon over the flame of a candle, it experiences no 
alteration from the heat. In a word, I have been almost 
tempted to believe that it was nothing but water. I con- 
fess however that this experiment ought to be carefully 
repeated. 
The little fluid obtained made me believe that the form 
of the vessel was not well adapted to the purpose, because 
it did not present sufficient surface and the vapour of the 
lungs was too little divided. I took then the spiral cylin- DERMOID SYSTEM. 
303 
der of a small alembic which I surrounded with ice in a 
pail; I made a man breathe through it, and I obtained in 
fact more fluid, but infinitely less however than I expect- 
ed, considering the great cloud that is formed in winter 
by respiration. In an hour, two ounces of fluid only 
were condensed, which I weighed comparatively with 
water, and found a little heavier, a proof that some prin- 
ciples are mixed with its aqueous portion, and with which 
I am unacquainted. 
I am convinced that in winter I should have condensed 
much more vapour; the inspection of an animal that 
breathes proves it even, as I have just said. I am per- 
suaded also, that like the urine, the respiratory fluid is 
then charged with principles which, during summer, pass 
off by the skin, though I have not however any experi- 
mental data upon this essential point, which I propose to 
clear up the approaching winter. 1 think even that many 
colds depend upon this. In fact, many of these princi- 
ples thrown out by the mucous surface of the bronchia, 
not soluble in the air, like their aqueous vehicle, stagnate 
upon this surface, irritate and excite a cough which throws 
them off. On this account, we cough much in winter, as 
we have often occasion to bathe in summer, when the 
saline substances, which are accumulated upon the skin 
by the exhalation that takes place there, cannot be evap- 
orated by the air. Hence why also in many affections of 
the lungs, in which the mucous glands and the bronchial 
exhalants do not increase the quantity of fluid they usually 
pour out, but only separate with it, on account of their 
change of organic sensibility, substances which the air 
cannot dissolve, hence, I say, why in these affections there 
is a constant cough ; for, as I have said, wThen a substance 
remains for any time upon the mucous system, it irri- 
tates, and it makes an effort to get rid of it. I believe 
that this elucidates the cause of many coughs, which have 
been considered as nervous, on account of the small quan- 304 
DERMOID SYSTEM. 
tity of expectoration, and which are only a means that 
nature employs to supply the want of the evaporation of 
the air. 
I think that physiologists have not paid sufficient atten- 
tion, either as it respects the bronchia or the skin, to the 
part which can be evaporated, and to that which cannot. 
Some animals seem to throw out more of these princi- 
ples that cannot be evaporated, than man ; hence why it 
is necessary to curry horses every day, and even to bathe 
them often, in order to cleanse their skins which the air 
would leave dirty. Fourcroy and Vauquelin have re- 
marked that there is never phosphate of lime in the urine 
of these animals ; this substance appears to pass out with 
the sweat, and to be chrystalized on the surface of the skin, 
from which it is removed by friction and water. I can 
hardly conceive how the hairs can be the emunctories of 
it; it appears to me to be more natural to think from an- 
alogy, that it is by the sweat that it escapes. I presume 
that the rain, in the natural state is as necessary to these 
animals as to plants. The first do not avoid it; many 
even expose themselves to it; it serves as a bath for them, 
removes the saline particles the air does not dissolve, and 
washes the skin. 
The cutaneous exhalants do not appear to be every- 
where equally abundant. The face and chest contain 
many of them ; we sweat easily in these places. On the 
back and the extremities they are less numerous. It is 
rare that we sweat on the palms of the hands and the soles 
of the feet. Besides this varies remarkably in different 
individuals. I know two sisters, belonging to a family in 
which phthisis has been frequent, whose chests are how- 
ever well formed, and who have never had any sign of an 
affection of the lungs, and yet when they are warm they 
always sweat from the chest. We know that in some the 
sweat appears most usually in the face, and in others on 
the cranium. DERMOID SYSTEM. 
305 
Have the nerves any influence upon the cutaneous ex- 
halation ? In many cases of paralysis, the patients sweat 
from the sound side. I have attended, for two months 
past, a man at the Hotel Dieu, who after an apoplexy, 
had hemiplegia so that the left side of the body was im- 
moveable, and who only sweats from this side, so that 
an evident line of demarcation is visible the whole length 
of the median line. On one side the skin is dry, and 
on the other it is very moist. I know cases are related 
in wrhich opposite phenomena have taken place ; but they 
do not destroy the observation that is uniformly made, 
that the sweat takes place equally upon the sound and 
the diseased side. Besides, who does not know that when 
the nervous action is annihilated in a limb, a blister acts 
upon it as usual ? Do convulsions, in which the nervous 
action is so much raised, increase cutaneous exhalation? 
Have the states of extreme sensibility, in which all the 
cutaneous nerves are so susceptible of receiving all im- 
pressions, the least known influence upon sweating? Let 
us acknowledge then that in cutaneous exhalation, as in 
secretion, we know nothing of the nature of the nervous 
influence, if it does exist. 
Sebaceous Glands. 
Besides the insensible transpiration and the sweat, 
which are thrown out by the skin, this organ is con- 
stantly lubricated by an oily fluid, which occasions, when 
coming out of a bath, the water with which it does not 
unite, to collect in small drops upon the body, which 
greases the linen when it remains too long in contact with 
the skin, catches the dust that is floating in the air, makes 
it remain, upon the skin, and retains many foreign sub- 
stances coming with the sweat from without or within. 
This fluid is in general much more abundant in negroes, 
whose skin is on this account disagreeable, than in Eu- 
ropean nations in whom it abounds especially in places 306 
DERMOID SYSTEM. 
provided with hair, particularly on the cranium. If left 
■without dressing, the hair becomes greasy, unctuous and 
shiny; it seems even that this abundance of oily fluid is 
destined to support their suppleness. Thus art imitates 
nature in the preparation of it, and greasy substances 
almost always enter into the dressings of the toilet. It 
appears that there is less of this fluid in other parts where 
there are hairs. It oozes in very small quantity from the 
soles of the feet and the palms of the hands, no doubt on 
account of the thickness of the epidermis. When we 
wash these last, the w’ater collects in small drops on the 
back of them, and not in the palms, which are easily and 
uniformly wet; there is never any of it deposited on the 
surface of the nails. This cutaneous oil, retained in cer- 
tain places, as in the axilla, the perineum, the folds of 
the scrotum, &c. becomes mixed there with certain prin- 
ciples of the transpiration, and often exhales a fetor that 
is almost insupportable. 
This oily fluid, of the nature of wdiich we know but 
little, is not like the transpiration or the fat exposed to 
evident increase and diminution ; it is always found in 
nearly the same proportion. It appears to preserve the 
suppleness of the skin, by preventing it from cracking. 
The ancients sought no doubt to imitate its action over 
the whole skin, as we imitate by pomatum its functions 
in regard to the hair, by the oily unctions which they 
made upon the body. This wre know was much prac- 
tised among the Romans. 
Whence comes this cutaneous oil ? It can be furnished 
from three sources, 1st, from transudation ; 2d, secretion ; 
3d, exhalation. 
Some have thought that the sub-cutaneous fat oozed 
through the pores to form it; but the scrotum which is 
destitute of this fat is one of the most oily parts. The 
skin of the cranium, which is so to the highest degree, 
is hardly at all fatty. That of the cheeks which covers DERMOID SYSTEM. 
307 
much fat, is scarcely lubricated with it, &c. In emacia- 
tion the skin is often as unctuous as in corpulency, though 
it is not always the case. Finally, in all the other func- 
tions, physical transudation is proved to be nothing; 
would it exist then here alone ? 
Those who admit the secretion of the cutaneous oil, 
(and they are the greatest number,) place the source of 
it in the small glands that are called sebaceous, and which 
they say are every where spread under the skin. We see 
some small tubercles upon the convexity of the ear, upon 
the nose, &c. ; but in most of the other parts it is impos- 
sible to distinguish any thing ; we see only the small 
eminences of which I have spoken and which make the 
skin rough; now they have nothing in common with 
these glands, the existence of which I do not deny, but 
which I confess I have many times in vain sought for. 
This has made me think that there is perhaps an order 
of exhalants destined to separate the cutaneous oil, and 
which is distinct from that of the exhalants which throw 
out the transpiratory matter. There is in the cellular 
texture exhalants for fat and others for serum. Certainly 
no gland presides there over the secretion of the fat. It 
is the same with the marrow which the exhalants of the 
medullary membrane furnish. There is I think as much 
probability in the supposition of the exhalation, as of that 
of the secretion of the cutaneous oil. 
Besides, we must not confound this oil, either with 
that ceruminous matter which certain glands pour out on. 
the edges of the eyelids and behind the ears, and whicli 
is forced out by pressure in the form of little worms, or 
with that whitish substance that is collected between the 
glans and the prepuce, and which is so evidently furnished 
by small glands. 308 
DERMOID SYSTEM. 
ARTICLE THIRD. 
PROPERTIES OF THE DERMOID SYSTEM. 
I. Properties of Texture. 
These properties are much developed in the skin. 
The alternations of emaciation and corpulency through 
which our organs, the limbs especially, pass sometimes 
from a determinate size to one double or even treble, and 
afterwards return to their primitive state, prove these 
properties ; and so do all the different tumours, deposits 
of pus, external aneurisms, sudden engorgements which 
accompany great contusions, aqueous collections in the 
abdomen, pregnancy, scirrhi, numerous affections which 
increase the size of the testicle, hydrocele, &c. We see 
in all these cases the skin at first extended and dilated, 
then contracting when the cause of the distension has 
ceased, and occupying the place in which it was origi- 
nally circumscribed. 
The remarkable separation which the two edges of a 
wound experience, that is made by a cutting instrument, 
is owing to the contractility of texture. This separation 
which takes place upon the dead body, proves what we 
have already often remarked, viz. that the properties of 
texture, absolutely inherent in the organic texture, are for- 
eign to the vital forces from which they only borrow an 
increase of energy ; thus the cutaneous retraction is much 
stronger during life in a longitudinal or transverse wound. 
But it is particularly in amputation that we observe this 
increase of contractility from the vital action. No part, 
not even the muscles retract so much as the skin ; hence 
the precept so much recommended in this operation of 
saving the integuments as much as possible ; hence the DERMOID SYSTEM. 
309 
essential modifications that have been made in the ancient 
methods. The muscular retraction is more sudden ; but 
this, which is more durable, ultimately prevails ; so that in 
the ancient mode of amputation, where every part was cut 
at the same level, they had a conical stump, the summit 
of which was formed by the bone, in which was next seen 
the muscles, arteries, &c. and in which the skin repre- 
senting the base, terminated on the side of the limb. 
There are however many cases in which the dermoid 
extensibility is less than it at first seems to be. For ex- 
ample, in large sarcoceles, the skin of the neighbouring 
parts of the scrotum being drawn, is applied upon the 
tumour, and makes up for the extensibility that is want- 
ing in the skin of this part; that of the penis especially 
is almost wholly employed to cover the tumour; so that 
this organ disappears. It is to the limits placed to the 
cutaneous extensibility that must also be referred the fol- 
lowing phenomenon ; in a wound with loss of substance, 
the fleshy granulations, in contracting by the evacuation 
of the white substance that filled them, draw the neigh- 
bouring skin in order to cover the wound ; now this 
drawing produces not only an extension but a real loco- 
motion. Hence why when the skin, naturally tense and 
adherent, cannot yield to this locomotion, the cicatrices 
are formed with so much difficulty, as we see upon the 
cranium, the sternum, &c. ; why on the contrary on the 
scrotum, the fold of the axilla, &c. they take place with 
so little ; why in dissecting out tumours, it is so much 
recommended to save the sound integuments, &c. 
When the skin is stretched, the fibres wffiich compose 
the spaces that have been spoken of, separate from each 
other, and these spaces become broader. Their breadth 
becomes especially evident on the internal surface of the 
dermis ; for as all the pores of the external surface pierce 
obliquely its texture, the distension of this texture only 
diminishes the length of the small canal they form, but 310 
DERMOID SYSTEM. 
does not enlarge the orifice of it; thus whilst the internal 
surface contains interstices of considerable size, this re- 
mains uniform, but allows us to see these interstices, 
which render it more transparent where they exist; hence 
that appearance like marble on the skin of the abdomen 
of women who have had many children. 
When the skin is contracted, the internal spaces are 
drawn together and even effaced. The external surface 
which has none of these, cannot diminish so much in 
breadth, so that there is a disproportion in the breadth of 
the internal and external surface; hence, as I have said, 
the convexity of the latter in the horny hardening pro- 
duced by boiling water; hence also the inequalities and 
external roughness which takes place when cold acts 
powerfully upon us, and which contracts the dermoid tex- 
ture. Besides, this phenomenon only takes place when 
the contractility is evident in the ordinary state; for if 
there has been previous distention, the cells already en- 
larged, return only in contracting to their natural state, 
and there is no disproportion in the extent of the internal 
and external surfaces of the skin. 
In most of the extensions, there is a diminution of the 
thickness of the dermoid texture. It is only when it is 
dilated by the infiltration of water in its spaces, as in leu- 
cophlegmasia, that it increases in thickness by diminish- 
ing in density. In chronic inflammation, in engorge- 
ment, and in various alterations of which the dermoid 
texture is the seat, it loses in part the faculty of stretch- 
ing; it breaks with ease when it is distended. This is 
what happens in some aneurisms, in those of the aorta 
especially that have produced an absorption of the ster- 
num. A slow inflammation seizes upon the skin that 
covers the tumour, and it breaks with a degree of disten- 
tion infinitely below what it bears in a sound state, if the 
death of the patient does not prevent this fatal rupture, 
two examples of which I have seen in the ward of lying DERMOID SYSTEM. 
311 
in women at the Hotel Dieu. In this state of inflamma- 
tion, the distention is very painful, whilst it is not so in 
the ordinary state. 
The skin loses also its contractile power in most of the 
chronic affections of which it is the seat, and which alter 
its texture. 
Are there some days in which the skin is more contract- 
ed, and others in which it is looser and more expanded ? 
I believe so, from observing the marks left after small- 
pox, which are much more apparent and deeper some days 
than others. 
II. Vital Properties. 
These are strongly marked in this system. We might 
say, that nature by giving an excess of life to this dermoid 
covering, has wished to establish a striking line of de- 
marcation, and to make us perceive the difference between 
the inorganic bodies with which its external surface is in 
contact, and the organized textures that its internal sur- 
face covers. I shall consider these vital properties as in 
all the other systems ; some belong to animal life and 
others to organic. 
Properties of Animal Life. 
The animal sensibility exists in the highest degree in 
the skin. It presides over the feeling, which is more 
acute and delicate there than in most of the other tex- 
tures. It is also the cause of touch, a double function 
which is very different. 
The feeling is the faculty of perceiving the impression 
of the surrounding bodies. It gives us the sensations of 
heat and cold, moisture and dryness, hardness and soft- 
ness, &c. It has relation then, 1st, to the existence ; 2d, 
to the general modifications of external bodies. Its ex- 
ercise precedes that of all the other senses which cannot 312 
DERMOID SYSTEM. 
be exercised until after its action. It is necessary to the 
sight, to hearing, smelling and the taste, as it is to the 
touch. It depends only upon a particular modification of 
the animal sensibility ; it is nothing but this property 
considered in exercise. Thus when the particular modi- 
fications of this sensibility which preside over the other 
senses have been destroyed, when the eye is insensible 
to light, the ear to sounds, the tongue to tastes and the 
pituitary membrane to odours, these different organs still 
preserve the faculty of feeling, both the presence of bodies 
and their general attributes. 
The touch has only relation to the particular modifica- 
tions of bodies ; it is the source of our notions upon their 
external forms, their dimensions, size, direction, &c. It 
differs essentially from the four other senses. 
1st. In this, that it does not require, like the feeling, 
any particular modification of sensibility. The hand is a 
little more sensible than the rest of the skin ; but there 
is not a great difference, and we should touch bodies 
almost as well, if that of the abdomen covered the pha- 
langes. On the contrary, each sense has a peculiar sensi- 
bility which places it exclusively in relation with a deter- 
minate body in nature. The pituitary membrane would 
be struck by light in vain, if placed at the bottom of the 
eye like the retina; the palatine membrane if it lined the 
nasal fossae, would not perceive odours, &c. 
2d. The touch is exercised only upon masses, more or 
less considerable parcels. The other senses are brought 
into action by the insensible and infinitely multiplied par- 
ticles of bodies, as the luminous, savoury particles, &c. 
3d. Most of the other senses do not require the previous 
exercise of the will. Odours, light and sounds strike 
upon their respective organs, and often produce, without 
our attending to them, their respective sensations. It is 
the same with feeling ; the will most commonly has no 
part in it. It is exercised because we live in the midst of DERMOID SYSTEM. 
313 
many excitements. We do not most often seek for the 
causes of general sensations ; they are those that come 
and act upon us. On the contrary, the touch requires to 
be produced by an act of the will. It is exerted in con- 
sequence of the exercise of the other senses; it is because 
we have seen, heard or felt an object, that we touch it. 
We confirm or correct by this sense the notions, which 
the others have given us. Hence why it is, as it were, 
dependant on them. The more they are contracted, the 
less frequently is it exercised. The blind, the deaf, &e. 
have less desire to touch than him, who has all his sensi- 
tive gates open to the impression of external bodies. 
4th. Most of the other senses require a peculiar struc- 
ture as well as a peculiar sensibility in the organs which 
compose them. On the contrary, the touch only requires 
a particular form in its organs. Provided that these have 
on the one hand animal sensibility, and on the other can 
embrace by many points external objects, they can dis- 
tinguish their tangible qualities. The touch will be ob- 
scure if we grasp bodies in one or two directions only ; 
yet it will take place. Thus we touch with the hollow 
of the axilla, the bend of the arms, hams, &c. with the 
lips and with the tongue. Thus the elephant touches with 
his trunk, reptiles by twining themselves around bodies, 
most animals with their snouts, &c. But the more the 
points of contact are multiplied, the more perfectly is the 
sense exercised. The hand of man is in this respect the 
most advantageously formed; it proves that he is better 
adapted to communicate with what surrounds him than all 
other animals; that the empire of his animal life is natu- 
rally much more extended than that of theirs ; that his 
sensations are more accurate, because they have a means 
of perfection that theirs have not; and that his intellec- 
tual faculties are destined to have an infinitely greater 
sphere, since they have an organ infinitely better than 
theirs to perfect them. 314 
DERMOID SYSTEM. 
The sensibility of the skin resides essentially, as we 
have seen, in the papillary body ; it is there that all the 
great phenomena relative to sensation take place. It is 
this portion of the skin that truly belongs to animal life, 
as the reticular body is, on account of the vascular plexus 
that forms it, the portion essentially dependant on organic 
life. The chorion being as it were passive, remains 
foreign to every kind of important function, and serves 
only for a covering. 
The extremely acute sensibility of the papillary body 
requires a covering to defend it from strong impressions. 
This covering is the epidermis. When it is removed, 
every touch is painful ; the impression of the air even is 
very much so ; it is this removal of the epidermis that 
produces the smarting that is felt when a blister is taken 
off. Observe in fact that smarting is a very frequent kind 
of pain, which the animal sensibility of the skin occa- 
sions when more raised than usual. This term * is bor- 
rowed from burns, which, when they are only to a cer- 
tain extent, acting nearly like blisters, lay the papillae 
bare ; now as it is always the skin which is exposed to 
the action of fire, we transfer to all burnt organs the ideas 
which wTe attach to the word smarting. But the pain is 
far from having the same character in the other systems; 
this peculiar one belongs only to the dermoid, in which 
it takes place from a burn, erysipelas, after a blister, &c. 
and during all inflammations that have their seat in the 
reticular body. No other system when inflamed gives us 
this sensation. The pain is throbbing in the cellular; it 
exhibits a wholly different modification in the muscular, 
when it is the seat of acute rheumatism, &c. 
There is another kind of pain which is also peculiar to 
the cutaneous system ; it is itching, which is the first 
* In order to understand this sentence it should be observed that the 
word which I have translated smarting is cuisson, which means the 
action of fire upon animal bodies, and is also used for the painful sensa- 
tion which this action produces.—Tr. DERMOID SYSTEM. 
315 
degree of smarting. We remove it by a gentle friction, 
which exciting in the papillae a different sensation, effaces 
that of which they are then the seat; but when this new 
sensation has passed off, the former one, which is occa- 
sioned by a permanent cause, is reproduced and requires 
a new friction ; there happens then in a small way, what 
we observe in a large one, when a stronger pain makes 
us forget one that is weaker. No other system in the 
economy exhibits this kind of pain, so frequent in itch, 
herpes and many other cutaneous eruptions. In their 
tubercular inflammations, the serous membranes become 
the seat of white eruptions, analogous to many of those 
of the skin ; the mucous surfaces are also often affected 
with many small pimples ; now this sensation is never 
manifested in either of them. 
There is also a sensation which appears to be the mini- 
mum of that pain of which smarting is the maximum ; 
it is tickling, a mixed sensation, an hermaphrodite, as an 
author has called it, which is agreeable when carried to 
a certain degree and painful beyond it. Carry the fingers 
lightly over a mucous or serous surface, a muscle or a 
nerve laid bare; an analogous sensation will never arise 
from the contact. 
The animal sensibility of the skin is, like that of the 
mucous surfaces, subjected to the essential influence of 
habit, which can transform successively into indifference 
or even into pleasure, what was at first painful. Every 
thing that surrounds us furnishes constant proof of this 
assertion. The air in the succession of the seasons, calo- 
ric in the numerous varieties of the atmosphere, in the 
sudden change from one temperature to another, water in 
a bath, in the moist vapours with which the medium is 
loaded in which we live, our garments of which some, as 
those of wool, are at first very painful, every thing which 
acts upon the skin by mere contact, produces sensations 
in it which habit continually modifies. Observe the mode 316 
DERMOID SYSTEM. 
of dress of different nations ; in some, all the superior 
extremities are bare; in others, the fore-arm only ap- 
pears ; the inferior extremities, either in whole or part, 
are naked in others ; in some, a more or less considerable 
portion of the trunk is left exposed to the air, and among 
the savages, nothing is covered. The portions which in 
each people remain naked, bear the contact of the air, 
without giving any painful sensation. Let them expose, on 
the contrary, parts usually covered, especially if it is cold, 
and at first pain will be the consequence of it; then the 
parts gradually becoming accustomed to this contact, will 
get to be insensible to it. There has been much said 
latterly of the danger of the Grecian costumes, of the 
nudity of females, &c. I do not speak of the morality of 
them; but every thing that is reprehensible physiologi- 
cally is, that the progress of the fashion has been more 
rapid than that of the sensibility. If they had exposed 
at first the neck, then a little of the chest, then the bosom, 
&c. habit would by degrees have given a new modifica- 
tion to this property, and no accident would have resulted 
from it. But in going suddenly from a costume in which 
every part is covered, to that in which the superior half 
of the chest, either before or behind, remains naked, is it 
astonishing that colds, catarrhs, &.c. should be the result 
of it? 
Habit extends its empire, in relation to tbe skin, even 
to our manners themselves. Decency is in this respect 
a thing of comparison. An Indian woman, with nothing 
but a narrow cloth around the pelvis, would be with us 
an object at which the public modesty would be shocked. 
The habit of mankind serves her as a veil in her own 
country. • A female savage transported entirely naked to 
the same country, would be indecent there ; she is not so 
in her own. Observe our fashions in their rapid succes- 
sion ; a woman, who by not changing her costume, would 
have had two years since, that of a courtezan, would now DERMCID SYSTEM. 
317 
find herself dressed with great modesty. Indecency in 
costume is that merely which shocks our habit. The 
female Indian, with the rag that covers only a quarter of 
her body, is more decent than the woman in whom a 
small opening separated the neck-handkerchief in our old 
fashions. The sight of the face shocks those people among 
whom females are veiled. Let us consider then habit as 
the type of the decency of costumes. Nature has wished 
in physiology, that the phenomena over which it presides, 
should be slowly connected ; it is the same in morals. 
The woman who suddenly changes her dress from one 
that is close to one that is not, exposes herself to painful 
sensations, to catarrhal diseases, &c. and shocks the eyes 
of those who had been accustomed to see her in a differ- 
ent exterior. When the change is gradually and insen- 
sibly brought about, neither health nor morals are affected. 
Habit does not modify the cutaneous sensibility which 
arises from an alteration of texture, from an inflammation, 
&c. Powerfully raised in this last state, it is much above 
its natural level. Then the least contact becomes ex- 
tremely painful ; thus the skin is no longer then in a state 
to exercise the sense of feeling. The touch itself does 
not distinguish general sensations. ’ All bodies make a 
common and uniform impression, it is that of pain. 
The animal sensibility of the skin sometimes dimin- 
ishes and even disappears; paralysis is a proof of this. 
These affections, more rare than the loss of motion, often 
however take place. In the organs of the senses, it is 
the eye which most frequently loses the sensation ; the 
ear comes next, then the skin, then the nostrils and finally 
the tongue, which is the sensitive organ that is always 
most rarely paralyzed, no doubt because it is that which 
is the most connected with the support of organic life, 
without which we could not exist. The others belong 
especially to animal life, which we can lose in part with- 
out ceasing to exist. 318 
DERMOID SYSTEM. 
The whole skin is never at the same time paralyzed ; 
there is rarely even hemiplegia in this respect; the feel- 
ing is not extinguished but in an insulated part. I would 
remark that the existence of these paralyses is also a 
proof of the want of nervous influence upon cutaneous 
exhalation and the capillary circulation, since both go on 
very well in this case as well as in paralysis of motion, as 
I have observed above. Cut the nerves of a limb of an 
animal, in order to render this limb insensible ; if after 
this you apply an irritant, the skin will inflame as usual. 
When the animal sensibility is in exercise, is there a 
kind of erection of the papillae that they may feel more 
acutely ? The same observation may here be made as was 
in regard to the mucous surfaces. This erection is an in- 
genious idea of some physicians, and not a fact which 
rests upon observation. I even think that this contra- 
dicts it; for examined with a glass the papillae appear to 
be constantly in the same state. Why should not the 
skin feel like a nerve laid bare, like the eye, the ear, &c. 
in which these sorts of erections have never been ima- 
gined ? 
Animal contractility is wholly foreign to the cutaneous 
organ, which moves voluntarily only by the influence of 
its fleshy pannicle. 
Properties of Organic Life. 
Organic sensibility and insensible contractility exist in 
the highest degree in the cutaneous organ. The external 
capillary system, which forms the reticular body, is, as I 
have said, especially the seat of these properties. They 
are in constant activity in order to preside, 1st, over the 
capillary circulation ; 2d, over exhalation ; 3d, over ab- 
sorption ; 4th, over the nutrition of the whole dermoid 
texture ; 5th, over the secretion of the cutaneous oil, if 
the sebaceous glands exist. It is not astonishing that DERMOID SYSTEM. 
319 
these properties should be so much developed in the skin, 
in which they have so many functions to support. Add 
to these considerations the constant action of external 
bodies, an action which keeps this organ in continual 
excitement, which incessantly stimulates its sensibility, 
which is to this sensibility what that of the bodies con- 
tained in the mucous surfaces is to the sensibility of these 
surfaces; the irritation is even more sensible, because the 
stimuli are oftener changed. A thousand agents of nature, 
of different density and composition continually succeed 
each other on the exterior of the body, and at the same 
time that they act upon the animal sensibility of the skin, 
to produce various sensations, they excite the organic sen- 
sibility in order to support the functions over which this 
sensibility presides. 
Is it astonishing then that the greater number of cuta- 
neous diseases supposes an alteration in this property 
and in the insensible organic contractility which is not 
separated from it? I divide these diseases into four classes, 
according to the structure we have distinguished in the 
skin. 
1st. There are diseases of the papillae; these are the 
paralyses and various kinds of increase of feeling, which 
reside only in the nerves. Women are especially subject 
to these last, which are so great in some nervous affec- 
tions, that mere contact of the skin if considerably pow- 
erful produces convulsions. To this also should be re- 
ferred the extreme susceptibility of some individuals in 
whom tickling produces a general revolution. It is 
necessary to distinguish these exaltations of animal sen- 
sibility, from those of which we have spoken above, and 
which depend upon inflammation. The organic sensi- 
bility is especially affected in these last; we might say 
that by its increase it is transformed into animal sensi- 
bility ; whereas in the other case this last property alone 
is altered. 320 
DERMOID SYSTEM. 
2d. There are diseases which have evidently their seat 
in the cellular texture which occupies the dermoid spaces; 
such are the inflammations of the cutaneous portion which 
covers a phlegmon, a bile, &c. 
3d. There are diseases of the external capillary net- 
work, front which the exhalants arise. To this must be 
referred erysipelas, many species of herpes, measles, scar- 
latina and many acute cutaneous eruptions that are daily 
met with in practice. 
4th. Finally, there are diseases in which the chorion is 
affected. Elephantiasis, and in general many chronic 
cutaneous diseases appear to me to be of this number, and 
I will even observe that the chorion never appears to be 
primarily affected in acute diseases. The obscurity of its 
vital forces, its dense and compact texture, and its com- 
parative want of vessels prevent it from accommodating 
itself except to chronic affections. In phlegmonous erysi 
pelas, in biles, &c. it is only influenced, but it is not 
essentially diseased. Thus we have seen that all the af- 
fections of the osseous, cartilaginous, fibrous, fibro-carti- 
laginous systems, &c. are really slow and chronic, on ac- 
count of the texture and the vital obscurity of these s}rs- 
tems. 
Now if we reflect on this division of cutaneous dis- 
eases, we shall see that except those of the first class, 
which are not numerous and which consist in greater or 
less alterations of animal sensibility, we shall see, I say, 
that all the others suppose a more or less considerable 
affection of the organic sensibility and of the correspond- 
ing insensible contractility. All are derived from an in- 
crease, a diminution or an alteration of these properties. 
It is also to the different changes of these properties, 
that must be referred the more or less copious sweats and 
the various exudations of which the skin is the seat. In 
fact, the exhalant vessels remain always the same in rela- 
tion to their structure. Why then do they admit a greater DERMOID SYSTEM. 
321 
or less quantity of fluids ? Why at certain times do they 
allow of the passage of substances, which they repel at 
others ? It is because the modifications of their organic 
forces are changed. These forces are often weakened in 
an evident manner in diseases ; they become languid and 
are prostrated. Then blisters are applied in vain ; the 
organic sensibility no longer answers to the excitement 
that is made upon it. This is a striking phenomenon in 
ataxic fevers, and proves the independence of the pheno- 
mena of cutaneous exhalation, capillary circulation, &c. 
in regard to the cerebral nerves. In fact, whilst during the 
paroxysm the brain is in extreme excitement, the volun- 
tary muscles are put by this excitement into a violent 
state of convulsion, and the energy of the whole of the 
animal life seems to be doubled before it ceases to exist, 
the organic is already in part exhausted ; the functions of 
the portion of the skin which belongs to this life have 
already ceased. 
The stimuli of cutaneous organic sensibility vary re- 
markably in their degree of intensity. 1st. The strong- 
est are fire, cantharides, the alkalies, the acids sufficiently 
diluted by water not to act but upon the vital forces and 
not to alter the dermoid texture by the horny hardening, 
the juices of many acrid and corrosive plants, certain 
fluids even produced in the economy, as those of cancers, 
&c. All these stimuli redden the skin when they are 
applied to it. 2d. Most of the same stimuli, diminished 
in intensity, stimulate it but slightly. 3d. Finally, aque- 
ous fluids, cataplasms and emollient fomentations seem to 
produce this excitement the least; they even rather 
weaken the cutaneous organic sensibility ; they seem to 
act upon it like sedatives and moderate the kind of excite- 
ment it produces in inflammations. The same is true of 
most of the fatty substances ; thus oils, butter, grease, &c. 
are in general not calculated to keep up the suppuration 
of blisters. It is requisite, in order to keep the skin at 322 
DERMOID SYSTEM. 
the degree of organic sensibility, necessary for the puru- 
lent exudation that then takes place, to mix cantharides 
with fatty substances. 
The skin does not appear to enjoy sensible organic con- 
tractility. Stimuli usually produce no other action upon 
it, than the contraction imperceptible to the eye, which 
composes insensible contractility, and which takes place 
especially in the small capillary vessels. There is how- 
ever one circumstance in which this contraction is, to a 
certain extent, apparent; it is when cold acts briskly 
upon the skin, which it wrinkles into goose flesh, as it is 
called. I have pointed out above the mechanism of this 
contraction, of which the chorion is the seat, and which 
holds a medium, like many motions which I have already 
had occasion to notice, between the two species of organic 
contractility. 
Sympathies. 
We shall still follow the division of the sympathies 
into active and passive, a division which is more remarka- 
ble here than in most of the other systems, because the 
sympathies are much more numerous. 
Passive Sympathies. 
The animal sensibility is very often brought into action 
in the skin, by the affections of the other, systems. We 
know that the application of cold to the sole of the foot 
frequently produces affections of the head ; that in many 
cases, the different species of itching, and even of smart- 
ing appear without an injury of the part where the pain 
is felt. It is useless to cite examples that are known to 
all physicians. I will confine myself to the sympathies of 
heat and cold alone, which have not yet been spoken of. 
I call by this name the sensation that is experienced 
upon the skin, when there is not a superabundance or 
absence of caloric there. There is evidently a material DERMOID SYSTEM. 
323 
cause for the heat in inflammation and for the cold in the 
ligature of a great artery. On the contrary, in the cases 
of which I spoke, it is but an aberration of the internal 
sensitive principle, which resembles that which takes 
place when we refer the pain to the extremity of an 
amputated limb. This is what occurs in many cases 
of shivering, in which the internal sensitive principle 
refers to the skin a sensation of which the cause does not 
exist. By approaching the fire then we do not become 
warm, because we really were not cold ; but we only de- 
stroy by a real sensation, the opposite sensation which is 
illusory that we experience, or rather wTe turn the per- 
ception from this sensation. We know that at the in- 
stant of the ejaculation of semen, a sudden and sympa- 
thetic chill often extends over the body. We know the 
cold of fear, which almost always arises, like the sweat 
produced by this passion, from the sympathetic action 
exerted upon the cutaneous organ by an epigastric organ 
affected by the passion. 
Observe what takes place in the beginning of most acute 
local diseases, as in those of the serous and mucous sur- 
faces, of the lungs, of the gastric viscera, &c. &c. The 
organ which is to be the seat of the disease is at first 
affected; immediately many sympathetic and irregular 
symptoms arise in all those which are sound; this is the 
affection that precedes. When the disease is once deve- 
loped, and it follows its periods, a new order is establish- 
ed, as it were, in the economy. The relations of the 
organs seem to change. In the preternatural irregularity 
of the functions, a kind of regular assemblage of symp- 
toms is manifested, it is this assemblage whieli character- 
izes the disease and distinguishes it from every other in 
which a different order of morbific relations is established 
between the functions ; now the passage from the natural 
to the preternatural relation of functions is marked by a 
thousand vague symptoms, which should be attributed to 324 
DERMOID SYSTEM. 
sympathies, and among which appears particularly the 
kind of shiverin of which I have spoken. 
In the beginning of digestion a kind of sympathetic 
cold is also referred to the skin, which is most often as 
warm as usual; it is an action exerted by the stomach 
upon the cutaneous sensibility, an action from which 
arises a particular sensation, different no doubt from that 
which the same viscus, when disordered, produces in the 
head, occasioning head-ache, but which is owing how- 
ever to the same principle. 
The heat is very often sympathetic in the cutaneous 
organ, less however, as I have observed, than in the mu- 
cous system. We know the flushes of heat that so often 
extend over the skin in an irregular manner, in different 
fevers, and which are not attended with a greater disen- 
gagement of caloric. 
Our modern philosophers will not perhaps be able to 
understand, how it is that whilst in the greatest number 
of cases, the application of a degree of caloric superior or 
inferior to that of our temperature, is necessary to pro- 
duce heat or cold, this sensation can arise in a part though 
it may not have experienced an increase or diminution 
of this principle. But in the greatest number of cases 
has not pain a material cause ? And yet all sympathies 
produce it without this cause. The vulgar, who stop at 
the diversity of the modifications of feeling, believe that 
an insulated principle presides over each. Let us dis- 
regard all these modifications, in order to see but a single 
principle in the irregularities as in the regular course of 
sensibility. That this property, sympathetically altered, 
gives us the sensation of heat or cold as in the skin, of 
pulling as in the nerves, of lassitude as in the muscles 
in the beginning of a disease, &.c. ; these are but varieties 
of a single cause, one, of which we are ignorant, but 
which evidently exists. In general, the sympathies of 
animal sensibility put into action in each system the sen- DERMOID SYSTEM. 
325 
sation which is usual there. The sympathy which, act- 
ing upon the skin, creates there a sensation of heat or of 
cold, would have produced that of lassitude if it had acted 
upon a muscle. 
In order to form an exact idea of heat and cold consid- 
ered as sensations, let us recollect that they may arise 
from different causes. 1st. From the increase or diminu- 
tion of the caloric of the atmosphere. 2d. From the disen- 
gagement or the want of disengagement of this fluid in a 
part of the economy, as in a phlegmon or after the liga- 
ture of an artery of a limb. 3d. Sometimes without 
previous inflammation more caloric is disengaged in the 
whole body ; there is a general increase of temperature ; 
we then feel an internal and external heat ; or caloric is 
disengaged locally in a part of the skin, and the patient 
feels a heat there as he does who applies his hand upon 
this place. 4th. Finally, there are sympathies of heat and 
cold. Some other parts, besides the mucous surfaces and 
the skin, feel these sympathies; we know the sensation 
of coldness that is felt to arise from the abdomen to the 
thorax, &c. 
The organic properties of the skin are also frequently 
put into action by sympathies. The sweat on the skin is 
suppressed in a moment, if. a cold body is taken into the 
stomach. The entrance of teas into this viscus, and an 
increased cutaneous exhalation, are two phenomena that 
take place almost at the same instant; so that we cannot 
refer the second to the absorption of the drink, then to 
its passage into the black blood through the lungs, and 
afterwards into the red blood. The production of sweat 
is then here analogous to its suppression in the preceding 
case ; it resembles that of fear, and that of phthisis in 
which the lungs being affected act upon the skin. Shall. 
I speak of the innumerable varieties of this organ in dis- 
eases, of its dryness, its moisture, its copious sweats, &c. 
phenomena for the most part sympathetic, and which 326 
DERMOID SYSTEM. 
arise from the relations which connect this sound organ 
with the diseased parts ? I have pointed out those which 
exist between it and the mucous surfaces. The membrane 
of the stomach is the one with which it especially sym- 
pathizes. The digestive phenomena are a proof of this. 
It would be necessary to treat of all diseases in order to 
speak of the sympathetic influences exerted upon the skin. 
These influences are often chronic. How in many or- 
ganic diseases, do different tumours form upon the skin ? 
Precisely as pctechiae, miliary eruptions, &c. are produced 
in acute fevers ; the difference is only in the duration of 
the sympathetic phenomena. 
Animal and sensible organic contractility cannot be 
evidently put into action in the passive sympathies of the 
skin, since it is not endowed with these properties. 
Active Sympathies. 
The four classes of cutaneous affections of which we 
have spoken, occasion many sympathetic phenomena, the 
following are some of them. 
1st. Whenever the papillae are strongly excited, as in 
the tickling of very sensitive people, various organs feel 
it sympathetically; sometimes it is the heart; hence the 
syncopes that then take place; sometimes it is the stomach; 
thus I knew two persons who could be made to vomit by 
tickling them ; sometimes it is the brain, as when in very 
irritable people, tickling is carried so far as to produce 
convulsions, which is not very rare in nervous women. 
Who is ignorant of the influence which the organs of 
generation receive from the skin, when stimulated in dif- 
ferent parts ? 
Physicians are often astonished at the extraordinary 
effects which some mountebanks produce in the economy, 
who know how to profit by their knowledge of the cuta- 
neous sympathies produced by tickling. But why should 
we be more astonished at these phenomena, than at the DERMOID SYSTEM. 
327 
vomitings produced by an affection of the womb, at the 
diseases of the liver arising from an injury of the brain, 
or at hemicrania the seat of which is in the gastric vis- 
cera ? The only difference is that we can in the first in- 
stance, produce to a certain extent those sympathetic phe- 
nomena, which we only observe in the other. Why do 
we not oftener make use in medicine of the influence 
which the skin when tickled exerts upon the other organs ? 
In hemiplegia, in adynamic, ataxic fevers, &c. who knows 
if the excitement of the sole of the foot, which is so sen- 
sible, as every one knows, if that of the hypochondrium, 
which is not less so in some people, &c. would not be 
better, if repeated ten or twenty times a day, than the 
application of a blister, the irritation of which soon passes 
off? Besides you would never obtain by a blister, rube- 
facients, &c. means which act as much and more upon 
the organic than the animal sensibility, an effect as strik- 
ing, an affection as general in the sensitive system, as by 
the tickling of certain parts, a means, which acting only 
upon this last species of sensibility, produces phenomena 
exclusively nervous; whilst the exhalant system and the 
capillary with red blood are especially affected by the 
others. Certainly there are cases in which one of these 
means is preferable to the other. I propose to ascertain 
these cases. 
We have not yet sufficiently analyzed the different 
kinds of excitement in diseases; we have not endeavour- 
ed to profit enough by what observation has taught us, 
upon the sympathies we can produce at will. Might we 
not however say, that nature has established certain rela- 
tions between very remote organs, that we may be able 
to make use of these relations in our means of cure ? 
The charlatan, wrho employs external tickling for certain 
nervous affections, is often more rational, without know- 
ing it, than the physician with all his pharmaceutical 
means. 328 
DERMOID SYSTEM. 
2d. Whenever the cutaneous exhalants or the external 
capillary system from which they arise, are affected in 
any manner, many other parts feel it, and this is a second 
order of the active sympathies of the skin. Here are re- 
ferred a great number of phenomena, of which the fol- 
lowing are a part. 
A bath which acts upon the skin during digestion, 
affects sympathetically the stomach, and disturbs this 
function. When this viscus is agitated by spasmodic 
motions, oftentimes the influence which it receives from 
it suddenly calms it, and brings it to its ordinary state. 
Not long since in my evening visit at the Hotel Dieu, I 
saw a woman who was vomiting continually from a sud- 
den suppression of her catamenia. I directed sedatives 
which were useless. The next evening she was in the 
same state ; I had her put into a bath ; every thing was 
calmed the moment she came out of it, and yet the cata- 
menia did not return. Few organs are more dependant 
on the skin than the stomach. 
The action of cold upon the cutaneous organ produces 
many sympathetic effects, especially when this action 
takes place while we are sweating. The term repercus- 
sion of transpiration is not proper to express what then 
takes place ; it gives a very inaccurate idea. Let us sup- 
pose that a pleurisy arises from cold suddenly applied, 
the following is what happens ; the organic sensibility of 
the skin being immediately altered, that of the pleura is 
sympathetically altered. By it the exhalants become in 
relation with the blood ; they adroit it instead of the 
serum which they before received, and inflammation super- 
venes. Thus this phenomenon is the same as that in 
which the application of a cold body upon the skin sud- 
denly arrests uterine, nasal hemorrhage, &c. &c.; the re- 
sult only differs. Now in this last case, no one ever sup- 
posed that there was a repercussion of fluid. The sup- 
pression of the transpiration is a thing purely accessory DERMOID SYSTEM. 
329 
and foreign to the internal inflammation which takes 
place. When the skin sweats in summer, the vital forces 
are more raised by the caloric which penetrates it; in 
this state, it is more capable of acting sympathetically 
upon the forces of the other systems. Hence why all 
strong stimulants that act upon it are more to be feared 
then. It is so true that it is not the suppression of the 
sweat which is dangerous, but the alteration of the vital 
forces of the skin which sweats, that many kinds, as the 
sweat of phthisis, are not so injurious when they cease 
for a time; they are checked even with much more diffi- 
culty, because they are not produced by a cause acting 
immediately upon the skin. Now if there was a reper- 
cussion of the transpiration, every species of sweat that 
was suppressed would be injurious. We never hear of a 
peripneumony arising from a suppression of sweat pro- 
duced by fear, rheumatism, &c. There would be then also 
a repercussion of mucous matter, when a pleurisy arises 
from swallowing a glass of cold water. Men judge only 
by that which is striking. The suppression of the sweat is 
an effect like inflammation of the pleura, but it is not the 
cause of it. If there was no sweat the instant the cold 
was applied to the skin, inflammmation would neverthe- 
less come on. In wounds of the head, with abscesses of 
the liver, &c. there is no repercussion of fluids. 
The trembling of which the voluntary muscles become 
the seat, the debility of the pulse which the weakness of 
the action of the heart produces, &c. are phenomena which 
the influence of the skin affected by cold alone causes. 
In fact, only this organ, the commencement of the mu- 
cous surfaces and all of that of the bronchia, are made 
cold by the external air; all the others remain at their 
usual temperature. 
We know the innumerable phenomena which arise from 
the disappearance of herpes, the itch, &c. imprudently 
produced ; in all these cases it does not appear that the 330 
DERMOID SYSTEM. 
morbific matter is carried to the other organs, though I 
do not pretend that this never happens. It is the vital 
forces of these which are raised and which then occasion 
different accidents ; now as these forces vary in each sys- 
tem, these accidents will he essentially different; thus the 
same morbific cause disappearing from the skin, will pro- 
duce vomiting if thrown upon the stomach, in which the 
sensible organic contractility predominates; pains, if it 
goes to the nerves which are especially characterized by 
animal sensibility ; derangements of sight, hearing and 
smell, if it affects the respective viscera of these senses; 
hemorrhage, catarrhs, phthisis, tubercular inflammation, 
&c. if it attacks the mucous surfaces, the lungs, the serous 
membranes, &c. in which the organic sensibility is much 
raised. Now, if the same morbific matter carried upon 
these different organs, produced these accidents, they 
ought to be uniform. Do not their varieties, and espe- 
cially the constant analogy which they have with the pre- 
dominant vital forces of the organs in which they appear, 
prove, that they depend upon the cause which I have 
pointed out ? 
We know that the serous surfaces and the cellular tex- 
ture on the one part, and the skin on the other, are often 
in opposition in diseases. There is no sweat when drop- 
sies are formed ; the dryness of the skin is often even 
more remarkable than the small quantity of urine, &c. 
3d. When the cellular texture contained in the dermoid 
spaces is inflamed, as in phlegmonous inflammation, in 
biles, in some malignant pustules, &c. there comes on 
many sympathies which can be referred to those of the 
general cellular system, which have been already noticed. 
4th. The affections of the chorion itself, all mark- 
ed with a chronic character, on account of the kind of 
vitality and structure of this portion of the skin, occasion 
also sympathies which have the same chronic character, 
but of which we know but little. DERMOID SYSTEM. 
331 
The organic contractility cannot be put sympathetical- 
ly in action in the skin, as it does not exist there. 
Characters of the Vital Properties. First Character. 
The Cutaneous Life varies in each organ. 
Though we have spoken in general of the vital proper- 
ties of the skin, they are far from being uniform or at the 
same degree in all the regions. 
1st. There is no doubt that the animal sensibility of the 
soles of the feet and the palms of the hands is greater 
than that of the other parts. Many persons are so sen- 
sible in the hypochondriac region, that the least tickling 
there produces convulsions. The anterior and lateral part 
of the trunk is always more sensible than the region of 
the back. 
2d. The organic properties do not vary less. The ex- 
treme susceptibility of the face to receive the blood, is a 
proof of it, as I have said. It is generally known that 
some parts are more proper than others for the applica- 
tion of blisters. Observe on this subject that the places 
where the animal sensibility predominates, are not the 
same as those in which the organic is in the greatest pro- 
portion. The soles of the feet and the palms of the hands 
hold the first rank in relation to one, and the face in re- 
lation to the other. 
In diseases we also see these varieties. Who does not 
know that some particular parts of the skin are especially 
the seat of some particular cutaneous affections, and that 
when these affections are general, they always predomi- 
nate in certain places. We ought not to be astonished at 
these varieties, since we have seen that the dermoid tex- 
ture is infinitely variable as it respects its papillae, its retio 
ular body, its chorion, &c. 332 
DERMOID SYSTEM. 
Second Charader. Intermission in one relation / 
continuity in another. 
The life of the cutaneous system is essentially inter- 
mittent in relation to animal sensibility. All the senses 
exhibit this phenomenon. Thus when the eye has for a 
long time gazed upon objects, the ear heard sounds, the 
nose received odours, and the mouth tastes, these dif- 
ferent organs become unfit to receive new sensations ; 
they become fatigued, and require rest to regain their 
forces. It is the same with regard to feeling and the 
touch ; wearied by the impression of surrounding bodies, 
the skin requires an intermission of action to regain ex- 
citability adapted to new impressions. We know that a 
short time before sleep, external bodies produce hut an 
obscure sensation upon it, and that their contact has no 
effect in this state, in which animals seem to lose half of 
their existence. The more powerfully the cutaneous 
sensibility* has been excited, the more profound is sleep ; 
hence why all painful exercises, great frictions, &c. are 
always followed by a deep sleep. Yet this sense can 
sometimes exert itself, while the others sleep ; pinch the 
leg of a man asleep ; he draws it away without waking, 
and has afterwards no remembrance of the sensation. 
Thus somnambulists often hear sounds, even eat, &c. ; 
for, as I have said elsewhere, sleep may affect but a very 
limited part of animal life, as it may the whole. 
Under the relation of organic sensibility, the life of the 
cutaneous system is essentially* continuous. Thus the 
functions over which this property presides have a charac- 
ter opposite to the preceding. The insensible transpi- 
ration takes place continually, though there may be some 
periods in which it is more active than in others. The 
oily* fluid is incessantly* carried away and renewed ; we 
might even say sometimes that it is when the animal DERMOID SYSTEM. 
333 
sensibility is interrupted, that the organic is in the great- 
est exercise. 
It is especially in diseases that they have made this 
observation, which is besides generally applicable to or- 
ganic life. All this life is as active and even more so 
during the night than during the day. Most of the dis- 
eases that attack the functions which belong to it, are 
marked by an increase of activity during the night. All 
fevers which particularly affect the circulation have their 
exacerbation towards night. In diseases of the heart, the 
patients are more oppressed at this period, &c. In phthisis 
which affects respiration, it is in the night especially that 
there is hectic fever, sweats, &c. Pneumonia and pleu- 
risy, exhibit frequent exacerbations towards night. In 
glandular diseases, either acute or chronic we make the 
same observation. It would be necessary to refer to 
almost all the affections which alter especially an organic 
function, in order to omit nothing upon this point. On 
file contrary, observe hemiplegia, epilepsy, convulsions, 
various paralysies of the different organs of sense, most 
mental alienations, apoplexy and other affections which 
exert their influence more particularly upon animal life, 
they have not, so often at least, their exacerbations to- 
wards evening and during the night, no doubt because in 
the natural state, this life is in the habit of becoming 
drowsy and not of being raised like the other which seems 
to imprint this character upon its alterations. Other 
causes no doubt have an influence upon this phenomenon : 
but I believe this to be a real one. 
Third Character. Influence of the Sexes. 
The sex has an influence upon the cutaneous life. In 
general the animal portion of this life is more raised in 
women, in whom every thing that belongs to the sensa- 
tions is proportionally more marked than in man, who pre- 
dominates by the power of his locomotive muscles. The 334 
DERMOID SYSTEM. 
effects of tickling are infinitely more powerful in females. 
All the arts which require nicety and delicacy of touch are 
advantageously cultivated by women. The peculiar tex- 
ture of the chorion, a texture generally more delicate, has 
no doubt an influence upon this phenomenon. As to the 
organic portion of the cutaneous life, the difference is 
not very great. Man appears to he superior in this re- 
spect ; he generally sweats more ; his skin is more unctu- 
ous, which proves a greater secretion. 
Fourth Character.. Influence of Temperament. 
The temperament peculiar to each individual is not a 
less real cause of differences in the skin. We know that 
the colour, roughness and pliability of this organ vary 
according as individuals are sanguineous, phlegmatic, &c. 
that these external attributes are even a character of the 
temperaments. Varieties of structure no doubt coincide 
with these. Is it then astonishing that the animal sensi- 
bility differs so much, that the touch itself should be deli- 
cate in some and dull in others, that some should be very 
ticklish, whilst others are not so at all, &c. ? Ought we 
to be astonished if the organic sensibility, which is very 
variable, should determine, according to the individuals, 
many varieties in the phenomena over which it presides ; 
if in some, it allows much blood to go to the face, and 
if it repels this fluid in others who are always pale ; if 
some men sweat much, whilst others have the skin almost 
always dry ; if the cutaneous oil varies in quantity; if 
there arc some skins much disposed to eruptions, either 
acute or chronic, to pimples of different natures, and if 
others are almost always free from them, even when the 
individuals expose themselves to the contagion of these 
diseases; if superficial wounds, of the same extent and 
made by the same instrument, are sometimes quicker and 
sometimes slower in healing; if the cure of cutaneous 
diseases is also very variable in its periods, &c. &c. ? DERMOID SYSTEM. 
335 
ARTICLE FOURTH, 
DEVELOPMENT OF THE DERMOID SYSTEM. 
I. State of this System in the Foetus. 
In the first periods after conception, the skin is but 
a kind of glutinous covering, which seems to be gradually 
condensed, forms a transparent envelope, through which 
we see in part the subjacent organs, the Vessels especially, 
and which is torn by the least jar. This state continues 
for a month and a half or two months. The consistence 
constantly increasing, soon gives to the skin an appear- 
ance more nearly like that which it has in infants after 
birth. Its delicacy is extreme at this period. It has not 
one quarter the thickness of that of the adult. The mo- 
ment in which it begins to lose its mucous state appears 
to be that in which the fibres of the chorion are formed. 
Until then the cellular texture and the vessels especially 
composed it, and as the first is abundantly filled with 
juices during the early periods, it is not astonishing that it 
should then give way under the least pressure. But when 
the fibres are formed, the cellular texture diminishes on 
the one hand, and is concentrated in the spaces that are 
developed, and on the other the dermoid fibres, more dense 
than its layers, increase the resistance. 
We do not see upon the external surface of the skin of 
the foetus most of the wrinkles of which we have spoken 
above. Those of the face in particular are not seen ; the 
kind of immobility, in which the facial muscles are, is 
evidentl}' the reason of it„ The forehead, the. eyelids, 336 
DERMOID SYSTEM. 
the edges of the lips, &c. are smooth. Besides, the 
abundance of fat which then distends the integuments of 
the cheeks, prevents every species of fold there. As the 
hands and the feet are found in part bent at their articula- 
tions, by the attitude of the foetus, different wrinkles are 
already formed about these articulations, principally on 
the hand, where however they appear less in proportion 
than afterwards. The curved, papillary lines are not very 
evident on the foot and the hand, even when the epider- 
mis is removed. 
The internal surface of the skin is remarkable for the 
slight adhesion of the subjacent cellular texture, the cells 
of which filled with fatty particles are removed with great 
ease, by scraping, this surface with the edge of a knife. 
We see then there the spaces already well formed, and as 
distinct in proportion as afterwards. By pursuing their 
dissection from within outwards, we insensibly lose sight 
of them towards the external surface where the skin is 
condensed. 
More blood enters the skin of the foetus, than at any 
other period of life. It is easy to observe this in small 
animals taken alive from the womb of their mother; for 
in the foetuses that are dead at birth, or born prematurely, 
the cause which destroys life, increasing or diminishing 
in the last moments the quantity of cutaneous blood, pre- 
vents us from drawing any conclusion as to the ordinary 
state by an inspection of them. The nerves are, as in all 
the other parts, more evident; but the papillae, though sen- 
sible, as I have said, have not a proportionable increase. 
The animal sensibility is not in exercise in the skin of 
the foetus, or at least it is very obscure there. This is 
owing to the absence of the causes of excitement. These 
are the surrounding heat, the waters of the amnios and 
the parietes of the womb, which can furnish materials for 
sensations ; but as these causes are always uniform, and 
have no varieties, the foetus can have but a very feeble DERMOID SYSTEM. 
337 
perception, because acuteness of sensation requires change 
of stimuli. We know that heat long continued at the 
same degree becomes insensible, that a long continuance 
in a bath takes away almost entirely the sensation of the 
water, because habit is every thing as it respects sensa- 
tion ; nothing but what is new affects us powerfully. 
Is the organic sensibility of the skin in activity in the 
foetus ? does it preside over the alternate exhalation and 
absorption of the waters of the amnios ? This is not the 
common opinion, it is not even a probable one ; but this 
question is far from being settled in so precise a manner 
as many other points of physiology. 
Besides, it cannot be doubted that there is a copious 
secretion of an unctuous and viscid fluid, which covers 
the whole body of the foetus, but which is more abundant 
in some places than others, as behind the ears, in the 
groin, the axilla, &c. either because it is secreted there 
in greater quantity, or accumulated on account of the 
arrangement of the parts. Accoucheurs have it wiped off 
after birth, and the females of animals remove it by the 
repeated application of their tongues to the surface of the 
body. This fluid appears to be to the skin of the foetus 
what the oily fluid is to that of the adult; it defends this 
organ from the impression of the waters of the amnios. 
If the sebaceous glands exist, it would appear that they 
furnish it, for it is certainly from a different source from 
the sweat. When care has not been taken to remove this 
covering, it irritates the skin, and may produce excoria- 
tions, and a species of erysipelas. The air cannot remove 
it by solution. Nothing similar oozes from the skin of 
the infant after birth. Is it because the black blood alone 
is capable of furnishing the materials of this substance ? 
II. State of the Dermoid System during growth. 
At the moment of birth the dermis experiences a sud- 
den revolution. Hitherto entered only by black blood, 338 
DERMOID SYSTEM. 
it is at the time the foetus is born, more or less coloured 
by it. Some foetuses come wholly livid, others are paler ; 
there is a remarkable variety in this respect. But all, 
shortly after they have respired, become more or less de- 
cidedly red. It is owing to the arterial blood which is 
formed and succeeds the venous blood that circulated in 
the cutaneous arteries. In this respect the state of the 
skin is in general an index of what goes on in the lungs. 
If an infant remains a long time of a violet colour, he 
either does not breathe or breathes with difficulty. The 
extremities of the hands and the feet in general become 
red the last. The)r are those in which the lividity con- 
sequently continues the longest, when this lividity is very 
evident. The blood which goes to the cutaneous organ, 
enters it in general in a very uniform manner ; the cheeks 
do not appear to receive more of it in proportion. The 
sudden excitement it brings to the organ, raises its vital 
forces and renders it more fit to receive the impressions, 
which are new to it, of the surrounding bodies. 
Observe in fact that a thousand different agents, the 
surrounding temperature, the air, dress, the fluid in which 
the foetus is washed, the tongues of those quadrupeds who 
lick their young, carry to the skin an excitement which 
is so much the more felt by the foetus, as it is not accus- 
tomed to it, and as there is an essential difference be- 
tween these stimuli, and those to which it had been pre- 
viously subjected. It is then that the remarkable sympa- 
thy which connects the skin with all the other organs, 
becomes especially necessary. Every thing within soon 
perceives the new excitements that are applied without. 
It is these excitements, those of the mucous surfaces at 
their origin and those of the whole of the bronchia, which 
especially bring into action many organs hitherto inactive. 
There happens then, what is observed in syncope, in which 
respiration, circulation, the cerebral action and many func- 
tions suspended by the affection, are suddenly roused up DERMOID SYSTEM. 
339 
by external friction, by the irritation of the pituitary 
membrane, &c. The phenomena are different, but the 
principles from which they are derived in both cases are 
the same. 
Then the organic sensibility is also raised. Transpi- 
ration is established. The skin begins to be an emunctory 
of different substances, which it did not before throw 
out; it becomes also capable of absorbing different prin- 
ciples applied to its surface. The skin of the foetus is 
hardly ever the seat of any kind of eruptions ; then pim- 
ples of different kinds frequently appear. 
All the parts of the cutaneous organ do not however 
appear to be raised to the same degree of organic sensi- 
bility. For a long time after birth the skin of the crani- 
um appears to be the centre of a more active life; it be- 
comes the frequent seat of many eruptions, all of which 
denote an excess of the vital forces. The different kinds 
of scurf with which it is covered do not appear elsewhere. 
In this respect, the skin of the cranium follows, like the 
bones of this part and the cerebral membranes, the early 
development of the brain, which, on this account is the 
seat of diseases in infancy more than at any other age. 
The skin of the face seems to be sometimes in less 
activity. In the first months after birth, it has not that 
bright colour which it will afterwards have upon the 
cheeks, and which does not commence until the develop- 
ment of the sinuses and dentition bring to this part more 
vital activity for the nutritive work. It is also towards 
this period that the eruptions of which this part of the 
cutaneous system is especially the seat, like those of the 
small-pox, measles, &c. begin to take place. 
For a long time after birth the skin still preserves a 
remarkable degree of softness; a very great quantity of 
gelatine enters it; this substance is obtained from it with 
great ease by ebullition, which, continued for some time, 
finally melts this organ entirely. The fibrous part noticed 340 
DEltMOID SYSTEM. 
by Seguin, is in very small quantity. I think it is this 
predominance of the gelatinous portion of the skin, which 
renders that of young animals easy of digestion. We 
know that in calves’ heads, roasted lamb, and small suck- 
ing pigs, prepared for our tables, it presents an aliment 
which the digestive juices alter with the greatest ease ; 
whilst that of animals of mature age and especially old 
ones, cannot be digested by them. The carnivorous 
species tear their prey, feed upon its internal organs, the 
muscles especially, and leave the skin. Now what is it 
that makes the skin of young animals differ from that of 
old ones ? It is because the gelatinous substance predomi- 
nates over the fibrous in the first, and the fibrous pre- 
dominates in the second. 
The skin of children is gradually thickened ; but it is 
not until the thirtieth year that it acquires the thickness 
that it is always to have afterwards. Till then the dif- 
ferent ages are marked in this respect by different degrees. 
Take a portion of skin at birth, at two, six, ten, fifteen, 
twenty years, &c. you will see these differences in a re- 
markable manner. The more its thickness increases the 
more compact it becomes ; it is because the fibrous sub- 
stance tends constantly to predominate over the gela- 
tinous. 
As we advance in age, the adhesion of the internal sur- 
face of the dermis with the subjacent cellular texture be- 
comes much greater. It is more difficult to detach one 
from the other. On the external surface the wrinkles of 
the face are gradually formed. Smiles and tears agitate 
the face of the infant the most. One is the expression of 
the happiness, the other of the uneasiness which all its 
passions produce in its mind. Now the wrinkles which 
weeping occasions on the eyelids are marked in rather a 
more permanent manner, either because weeping is more 
frequent than smiling, or because continual winking adds to 
the motion which weeping produces, or because less fat is DERMOID SYSTEM. 
341 
found in this place. As smiling is on the one hand more 
rare, and on the other much fat puffs out the cheeks of 
the infant, the perpendicular wrinkles formed by the 
muscles of the face, which in this motion separate trans- 
versely the features from within outwards, are much 
slower in forming. Besides, the nursing of the infant, 
which requires the contraction of its face from without 
inwards, opposes their formation. The wrinkles of the 
forehead are always very slow in forming, because the 
motions which contract the eyebrow, and those which 
wrinkle the forehead, are rare in the infant, who has 
hardly any of those dark passions which these motions 
serve to depict. 
The growth of the dermoid system has not remarkable 
revolutions like that of most of the others; it goes on in 
an uniform manner. At the period of the growth of the 
hairs, it does not change, because this growth is abso- 
lutely foreign to it, these productions only passing through 
it. At puberty it increases in energy like all the other sys- 
tems. Until then sweats had not been very copious ; for, 
other things being equal, we may say that children sweat 
less in general than adults, and that the residue of their 
nutrition passes rather by the urine, which is probably the 
reason why they are so remarkably disposed to calculi. 
Beyond the twentieth year we begin to sweat more, and 
until old age, especially in summer, the fluids appear to 
go out in this way. 
III. State of the Dermoid System after Growth. 
After growth, the skin continues for a long time to 
have great activity ; the excess of life which animates it, 
renders it capable of influencing with ease the other or- 
gans if it be but a little excited. Hence the disposition to 
pneumonia, pleurisy, &c. from the action of cold on the 
skin in sweat, a state in which it is more disposed to exert 
an injurious influence upon the internal organs, because 342 
DERMOID SYSTEM. 
its forces are more excited. As to the different affections 
which result from this influence, they depend upon the 
internal organs upon which it is directed ; so that the 
same sympathetic irradiations going from the skin, will 
produce sometimes an affection of the abdomen, some- 
times a disease of the thorax, according to the age in 
which the abdominal or pectoral organs, predominating 
by their vitality, are more disposed to answer to the in- 
fluence directed in general upon the whole economy. 
The skin becomes more and more firm and resisting 
as we advance in age, as the fibrous substance is constantly 
tending to a predominance over the gelatinous. Less 
blood seems to be carried to it. It becomes less and less 
disposed to eruptions, so common in youth and infancy, 
&c. I will not speak of its other differences ; for all that 
we have said of it in the preceding articles relates espe- 
cially to the adult age. 
I will only observe that if, during the greatest part of 
life, the skin be so fruitful a source of diseases, and the 
various alterations it experiences produce so frequent dis- 
orders in the internal organs, it is only owing to the 
varied causes of excitement to which it is every instant 
subjected. If the glands, the serous surfaces, &c. have 
an influence less frequently upon the other organs, it is 
because being deeply situated, and almost always in con- 
tact with the same excitants, they are not subject to so 
many revolutions in their vital forces. The secreted fluids 
and those exhaled in the serous and synovial systems are 
not, for the same reason, so much subject to those con- 
siderable increases, and those sudden suppressions which 
so frequently happen to the sweat. 
Observe that society has also multiplied to a great ex- 
tent the injurious excitements to which the skin is sub- 
jected. These excitements consist especially in the rapid 
passage from heat to cold, which makes the latter act 
very powerfully upon the cutaneous sensibility, which DERMOID SYSTEM. 
343 
like that of all the other systems, answers so much the 
more to excitements made upon it, as they are different 
from those, whose action they had previously experienced. 
In the natural state, there is only the succession of the 
seasons ; nature knows how to connect insensibly heat 
with cold, and to make the transition but rarely abrupt. 
But in society, the different garments, the artificial de- 
grees of temperature of our apartments, degrees differing 
at first from that of the atmosphere, then varying greatly 
from eaeh other, so that the same man who in winter en- 
ters thirty apartments, is often subjected to thirty different 
temperatures ; the hard labour in which most men are en- 
gaged, and which makes them sweat copiously, every 
thing incessantly presents numerous causes which make 
the vital forces of the dermoid system vary rapidly. Thus 
the bronchial mucous surface is constantly in contact in 
cities, with a thousand excitements that are continually 
renewed, and with which the air is not charged in a 
natural state. Thus the alimentary substances, continu- 
ally varying in their composition, temperature, &c. change 
the excitement of the gastric mucous surface, and are the 
source of many affections, from which most animals are 
exempt by the uniformity of their food. 
If the skin and the mucous surfaces were always kept 
at the same degree of excitement by the constant unifor- 
mity of the stimuli, they would certainly be a much less 
fruitful source of diseases, as is clearly proved by the 
foetus, which is hardly ever sick, bec'ause all the external 
causes which act upon its mucous and cutaneous sensibi- 
lity, as the heat, the waters of the amnios and the parietes 
of the womb, do not vary until birth. At this period, 
animals brought into a new medium, find many more 
varieties in the stimuli which act upon them, even in a 
natural state and far from society; thus their diseases are 
naturally much more frequent after than before birth. In 
society, in which man has increased four, six and even 344 
DERMOID SYSTEM. 
ten times the number of the stimuli which affect the sur- 
faces destined to be in contact with the external bodies, is 
it astonishing that the diseases should be so dispropor- 
tioned to those of animals ? 
IV. State of the Dermoid System in Old Jlge. 
Towards the decline of life, the dermoid system be- 
comes more and more firm and compact; it is softened 
with great difficulty by ebullition. The gelatine, which 
it yields, is less abundant and more hard and consistent. 
I think it would not be fit to make any kind of glue, 
even the strongest, unless mixed with that of adult ani- 
mals. Its yellowish tinge becomes very deep. When it 
is cooled, it requires a much stronger and more durable 
fire to melt it; the fibrous portion of the dermis which 
does not melt or at least resists for a long time, is in- 
finitely greater in proportion. It is like the bones in 
which the gelatinous portion is in an inverse ratio, and 
the earthy portion in a direct ratio to the age. 
The dermoid texture becomes then like all the others, 
dense and stiff; it is not proper for our food, the teeth 
cannot tear it. Prepared with tannin, it is more resisting 
and less pliable, and cannot on that account serve for the 
same purposes as that taken from young animals. Every 
one knows the difference of the leather of calves and oxen, 
especially when the latter are old. This difference is 
owing first to the thickness, which being much greater in 
the second than the first, does not allow it to be so easily 
bent in different directions; and then to the nature of the 
texture itself. Cut in two horizontally a piece of the 
leather of an ox ; each half will be as thin as a piece of 
calves skin, and yet it will be less pliable. I do not esti- 
mate here the varieties which may depend on the greater 
or less quantity of tannin that may be combined with it; 
I suppose the proportions to be all DERMOID SYSTEM. 
345 
Submitted to dessiccation, the human dermoid texture 
becomes much more stiff in old age than in the preceding 
ones. Maceration softens it with more difficulty. The 
hair of a child falls out much sooner by it than that of 
an old person ; thus it requires longer to clean the skins 
of old animals than those of young ones ; tanners know 
this very well. I would remark upon this subject, that 
the skins of animals, having more hairs pass through them, 
exhibit in comparison with that of man, an innumerable 
quantity of little pores on their external surface; which 
favours in them on this surface the action of tannin, which 
insinuating itself into the dermoid spaces and filling them 
completely with a new substance formed by the combina- 
tion of tannin with gelatine, occupies entirely the texture 
of the spaces. The previous maceration to which the 
skin has been exposed, favours not only the removal of 
the hairs, but facilitates also to a great degree the en- 
trance of the tannin, by separating the fibres of the spaces, 
by making them larger, and increasing the size of the ex- 
ternal pores. 
The more we advance in age, the less is the quantity of 
blood that penetrates the skin. The redness of the cheeks 
disappears in old people. We no longer see then the 
rosy complexion of the young man and even of the adult, 
and which arose from the vessels winding through the 
cellular texture of the spaces of the chorion. 
The continual pressure of external objects increases 
then remarkably the adhesion of the subjacent cellular 
texture to the dermis. They are separated from each other 
with great difficulty by carrying the edge of a scalpel 
over the internal face of the chorion; a circumstance 
which is owing also to this, that the cellular texture hav- 
ing become more dense, is less easily torn ; for this tear- 
ing is then necessary, considering the continuity of the 
sub-dermoid layer with that which enters the spaces. 346 
DERMOID SYSTEM. 
The exterior of the skin is uneven and rough. All the 
wrinkles of which we have spoken become infinitely more 
evident; many belong exclusively to this age. 
The vital forces of the dermoid system are more weak- 
ened in old age than those of most of the others, because 
it is more excited during life by external bodies. Most 
of these bodies then make no impression upon it. The 
habit of feeling has blunted the animal sensibility. The 
touch is exercised but rarely ; for, as I have observed, 
this sense requires to put it in action, the previous exer- 
cise of the will. We touch, because we have previously 
seen, heard, tasted, &c. in order to correct or confirm our 
other sensations; now the old man, to whom every thing 
around is known, to whom nothing is new, is induced 
to touch nothing. Compare in this respect the two ex- 
treme ages of life. The infant, to whom every thing that 
strikes his eyes, his ears, his nostrils, &c. is unknown, 
who finds in every thing that surrounds him new objects 
of sensation, wishes to touch and lay hold of every thing. 
Its little hands are in continual agitation. To touch is a 
pleasure to him, for every new object of sensation is 
agreeable. If in his last years, man* was transported into 
the midst of objects that never before struck his senses, 
he would oftener exercise his touch; but none of those 
things excite him among which he has always lived. 
Hence why old age is not the age of enjoyments. In 
fact all our pleasures are almost relative ; we have but 
little that is absolute ; now as habit blunts all the relative 
pleasures, which cease because they have existed, the 
more the sensations are accumulated by time, the less 
there are of new ones left to be experienced, and the more 
are the sources of happiness dried up. For a contrary 
reason, the happiest age is infancy, because it has before 
it the whole field of sensations to go over. Man at every 
step of his career leaves behind him a cause of his en- 
joyments. When arrived at the end he finds only indif- DERMOID SYSTEM. 
347 
ference, a state very suitable to his situation, since it 
diminishes the distance that separates life from death. 
The organic sensibility of the skin is not less blunted 
in old age, than its animal sensibility ; hence the follow- 
ing phenomena ; 1st, contagious miasmata are absorbed 
with difficulty at this age ; almost all pass over the cuta- 
neous surface with impunity. 2d. The exhalation of 
sweat is uniformly less ; it is hardly ever subject to those 
great increases, that are seen in the adult. 3d. The oily 
fluid is also furnished in much less quantity; hence the 
constant dryness of the exterior of the skin, the cracking 
of the epidermis in some cases, &c. 4th. All the diseases 
which suppose an increase of this organic sensibility are 
much more rare. Erysipelas and the different kinds of 
eruptions are a proof of it. When these affections take 
place, they have a character of remarkable slowness. 5th. 
The skin resists external cold much less ; it loses easily 
the caloric of the body, which always tends to escape in 
order to be in equilibrium with that of the surrounding 
medium ; thus old people are always fond of heat. 6th. 
I am well persuaded that the skin would resist also less, 
at this age, a degree of temperature greater than that of 
the body, and as it permits the internal caloric to be easily 
lost in a colder medium, it would allow the external to 
penetrate in a warmer one. It would be very curious to 
repeat, on the two extreme ages of life, the experiments 
of the English physicians. EPIDERMOID SYSTEM. 
IF we examine attentively, it is easy to perceive the 
immense difference there is between the preceding system 
and this, which physiologists have considered as one of 
its dependancies. Organization, properties, composition, 
functions, growth, &c. every thing differs in the two. By 
explaining these, the line of demarcation that separates 
them will be perceived. 
I rank in this system, 1st, the external epidermis ; 2d, 
that which is spread upon the mucous system, or at least 
upon one of its parts ; 3d, the nails. Though these last 
differ very much from the epidermis in their external 
appearance, yet they resemble it in so many respects, 
that it is difficult not to place them in the same system. 
In fact the nails serve as an epidermis for the skin which 
is subjacent to them ; they are continued with that of the 
fingers in an evident manner, are detached and regener- 
ated during life with the same phenomena. The compo- 
sition appears to be very analogous. The kind of ex- 
crescences is the same. After death, the nails are de- 
tached by the same means as the epidermis, and then 
make, as it were, a part of it. 350 
EPIDERMOID SYSTEM. 
ARTICLE FIRST. 
OF THE EXTERNAL EPIDERMIS. 
The external epidermis is a transparent membrane, 
more or less thick, according to the regions in which it 
is examined, covering everywhere the skin, and receiving 
immediately the excitement of external bodies which 
would act too powerfully upon this. 
I. Forms, Relations with the Dermis, fyc. 
We see upon the epidermis the same wrinkles as upon 
the skin, because being exactly contiguous, both wrinkle 
at the same time. Different pores open on its surface 
after having passed through it. Some transmit the hairs; 
these are the most apparent; others give passage to the 
exhalants. We do not see these in the natural state, be- 
cause their course is oblique, and they open between two 
small layers, which, being in contact with each other 
when we do not sweat, conceal their termination. But 
if, the skin being very dry, we suddenly sweat, as after 
drinking tea, then the little drops which escape from the 
whole cutaneous surface, not having had time to run 
together, but remaining separate, we see, by the places 
where they are, the orifice of the exhalants. Besides, if 
we examine against the light a considerable portion of 
epidermis, its transparency allows us to see many small 
pores separated from each other by interstices, and which 
pass through it in an oblique direction. It is only in the 
soles of the feet and the palms of the hands that we can- 
not make this observation, which is owing to the thick- 
ness in those parts. It is impossible to distinguish in EPIDERMOID SYSTEM. 
351 
these pores the absorbent orifices from those of the exha- 
lants, even when mercury enters the first by friction. 
The internal surface of the epidermis adheres very 
closely to the skin. The means of union are at first the 
exhalants, the absorbents and the hairs, which in passing 
through the first, adhere to it more or less, and thus fix 
it to the second, from which they arise. By separat- 
ing the epidermis by maceration, which is the most pro- 
per means, we see on its internal surface many small 
elongations of greater or less length, and which, when 
examined attentively, appear to be nothing but the broken 
extremities of exhalants and absorbents. In fact these 
little elongations which are easily raised up, and which 
then appear like small ends of thread when they are of 
some size, but which exhibit only inequalities when they 
are left very short, have all of them an oblique course, 
and terminate in the pores which, we have said, pass 
through the epidermis to go to its surface. Their exist- 
ence is sufficient, at the first inspection and without the 
aid of a microscope, to enable us to distinguish the inter- 
nal from the external face of this membrane. The spaces 
that separate them are more or less large. About these 
spaces, the adhesions are less. It is at this place that the 
small epidermoid vesicles are formed with which the 
skin is covered when plunged into boiling water. The 
depressed interstices, which separate these vesicles, are 
the places where the exhalants are and which have pre- 
vented the epidermis from being raised up. When ebul- 
lition is long continued, they are detached also. 
We cannot doubt then that all these vascular elongations 
serve powerfully to unite the epidermis to the chorion. 
How is the adhesion formed in their interstices ? I know 
not; but it exists, though it is less evident. The cellular 
texture, as I have said, appears to take no part in it. 
Every one knows that many causes destroy the adhe- 
sions of the epidermis, and raise it up. These causes are, 352 
EPIDERMOID SYSTEM. 
1st, every severe inflammation, whatever may be its 
species. We know that after erysipelas, phlegmon, biles, 
and cutaneous eruptions of different natures, the epidermis 
is always detached; there is then no fluid that raises it 
up. The exhalants cannot furnish it, as they are full of 
blood ; it is dry when detached. 2d. Various cutaneous 
eruptions, which have not an inflammatory character, as 
herpes, &c. also detach the epidermis at the place where 
they are. It most commonly comes off then in the form 
of dry scales ; hence no doubt the idea of some authors 
who have attributed to it a scaly structure, which neither 
observation nor experiment upon the epidermis in the 
natural state have proved. This pealing off in scales is 
owing to the same cause precisely as the formation of 
vesicles which take place the instant after the skin has 
been plunged into boiling water, viz. to the greater ad- 
hesion of the exhalant vessels which go to the epidermoid 
pores. Observe in fact that it is always in the space be- 
tween these pores that the scales are produced, which do 
not exist in nature, but which arise only from the manner 
in which the membrane is raised up. For example, when 
herpetic eruptions take place on the chin, the pores 
through which the hairs pass are not detached; it is only the 
epidermis in the space between these pores ; now as these 
are very near together, these scales are extremely small; 
they are almost like dust. 3d. Whenever the epidermis 
is raised up by cutaneous inequalities, the least friction 
detaches it from these inequalities. Hence why, after 
strong dry frictions, a rough skin becomes scaly, wdiilst 
a smooth one experiences no alteration ; it is this even, 
which in the external appearance, contributes much to 
the ugliness of the one and the beauty of the other. 4th. 
After idiopathic fevers, and even many affections of the 
internal viscera, the skin which has felt the sympathetic 
influence of the disease, becomes the seat of an alteration 
which without having any external sign, is sufficient to EPIDERMOID SYSTEM. 
353 
break the union of it with the epidermis, which is every- 
where raised up. 5th. We know that the action of a 
blister, which draws a large quantity of serum to the 
external surface of the chorion, breaks off the exhalants 
which go from it to the epidermis ; so that this serum is 
effused under it and forms a more or less considerable sac. 
The water dees not escape through the open pores, be- 
cause their oblique course through the epidermis makes 
their parietes, when brought in contact with each other 
by the pressure of the water, form an obstacle to it. It 
is for the same reason, that though these pores may be 
very evident, as I have said, in a separate portion of epi- 
dermis when examined against the light, this portion will 
support mercury, without giving passage to its particles. 
6th. Most of the preceding means, which produce their 
effect only by an alteration of the vital forces, have no 
effect in raising the epidermis in the dead body. Putre- 
faction, maceration and ebullition are those b}7 wrhich it 
is effected. All act by breaking the elongations which 
extend from the dermis to the epidermis, though the 
mechanism of this rupture is not exactly known. 
II. Organization, Composition, 
Authors have made many conjectures upon the struc- 
ture of the epidermis, which it would be useless to relate 
here. I shall only speak of what accurate observation 
demonstrates. Its thickness is in general very uniform 
in all the parts. It has not appeared to me to be in- 
creased or diminished, according to the varieties of thick- 
ness of the skin on the back, the abdomen, the extremi- 
ties, &.c. It is only on the soles of the feet, the palms of 
the hands and the corresponding face of the fingers, that 
this thickness becomes greater. It is even so great in 
these places, that there is no proportion between them 
and the other parts of the body as it respects this mem* 354 
EPIDERMOID SYSTEM. 
brane ; it is especially towards the heel that it exhibits 
this character. This excessive thickness appears to be 
owing to different layers which are applied upon each 
other, and which seem to be superadded to the layer of 
the ordinary epidermis; but there is also a real differ- 
ence, though but little known, in the organization ; for 
example, when the epidermis has been removed from 
these parts by maceration, we cannot see, as in the others, 
those small appendices or inequalities regularly scattered 
over it, and which are the remains of the broken exha- 
lants. In these places these vessels are torn smoother on 
the internal surface of the epidermis, on which are seen 
only the traces of the wrinkles of which we have spoken. 
I attribute to this excessive thickness of the epidermis 
of the soles of the feet and the palms of the hands, the 
difficulty and oftentimes impossibility of making blisters 
act in these places, on which I have often applied them 
there, because I thought that the sensibility being greater, 
they would produce more effect in some diseases. The 
failure of my attempts has compelled me to renounce them. 
This thickness takes from the epidermis the trans- 
parency it has in the other parts ; it is whitish and opake 
even on the hand and the foot. Thus the epidermis which, 
in negroes not being coloured, allows the blackness of 
the subjacent reticular texture to be seen, conceals in part 
this blackness in these places. I have observed however, 
by means of maceration, that the less deep colour of the 
soles of the feet and the palms of the hands depends also 
in this race upon this, that the reticular texture is really 
less coloured. We might say that every thing relates to 
animal sensibility in this region, the capillary net-work 
of which appears to be less, and in which all the pheno- 
mena that are derived from organic sensibility are much 
less active. 
In examining in this relation the hand and foot of a 
negro, I have been led to make upon the colour of the EPIDERMOID SYSTEM. 
355 
reticular body some other experiments, which form a 
short digression. 1st. By plunging into boiling water a 
piece of the dermis taken from any part it becomes twice 
as black, almost immediately ; which is probably owing to 
this, that the fibres in approximating by the horny hard- 
ening, bring together the colouring particles, whence 
arises a deeper black. This phenomenon is very striking, 
when the piece plunged into the water is compared with 
one that has not been. 2d. Maceration for a month or 
two, sometimes removes the epidermis without the reti- 
cular body, the seat of colour, and sometimes detaches the 
whole together. 3d. Being immersed for some days in 
cold water produces no sensible effect. 4th. Long contin- 
ued stewing hardly changes at all this colour, after the deep 
tinge that has been suddenly given to it. Only by scrap- 
ing with a scalpel the external surface of the skin which is 
then reduced to a kind of gelatinous pulp, we easily 
detach the coloured reticular body from it, which how- 
ever always remains adherent to a small portion of the 
chorion. 5th. Sulphuric acid, which reduces the skin 
like all the other organs to a kind of pulpy state, also 
enables us to remove this coloured portion easily, which 
is detached in separate pieces, but the shade of which is 
hardly altered at all. Gth. Nitric acid, though very much 
weakened, does not facilitate so much the removal of this 
coloured portion. It yellows the internal surface of the 
skin and the epidermis ; but it has appeared to me to pro- 
duce but very little effect upon the blackness of the reticu- 
lar body. 7th. A portion of the skin of a negro, im- 
mersed for twenty-four hours in a solution of caustic pot- 
ash, has not appeared to rne to have undergone any altera- 
tion in its colour. I have made the same observation 
when I used a weaker solution. Sth. Putrefaction detaches 
the coloured portion of the skin, sometimes with the epi- 
dermis, sometimes alone, but it does not alter its colour. 
I have not employed other agents to ascertain the nature 356 
EPIDERMOID SYSTEM. 
of this colour of the skin of negroes. Let us return to 
the epidermis, which we have for a moment lost sight of. 
Where it is very thick, as on the concave surface of 
the foot and the hand, we see that it is evidently formed 
by layers added to each other, and which are separated 
with difficulty, because their adhesion is so intimate. 
Everywhere except in the foot and the hand, there is but 
a single layer; no fluid penetrates the epidermoid tex- 
ture. Cut in different directions either in the living or 
dead body, it allows nothing to ooze through it. Their 
scales are always dry; no bloodvessel exists in them. 
The absorbents and exhalants only pass through it without 
anastomosing, without winding on its interior before open- 
ing on its surface, as happens in the serous membranes, 
which on this account become black by injection, though 
but little blood appears to enter them during life. The 
epidermis on the contrary is never coloured by this means, 
even when the injection, being very fine and driven with 
success, oozes out on the external surface of the skin. 
Thus, in inflammation, in which all the cutaneous exha- 
lants are full of blood which they do not contain in the 
natural state, this fluid never enters the epidermis, which 
is uniformly disconnected with all the diseases of the 
subjacent reticular body, and which, being only raised up 
by inflammation, is detached and afterwards renewed. 
The epidermis has evidently no nerves. It is also des- 
titute of cellular texture ; thus fleshy granulations, which 
are formed by this texture, never arise from this mem- 
brane ; the excrescences of which it is the seat have not 
the character of the different tumours which the cellular 
texture especially contributes to form, such as fungi, 
schirri, &c. 
From this it is evident that none of the general sys- 
tems common to all the organs, enters into the epidermoid 
system. It has not then the common base of every or- 
ganized part: it is as it were inorganic in this respect. EPIDERMOID SYSTEM. 
357 
The epidermoid texture exhibits no fibre in its interior ; 
it has in general but. little resistance, and is broken by a 
slight distention, except on the fingers and the hand where 
it resists more, on account of its thickness. 
The action of the air hardly alters it at all. Only when 
it is exposed to it after having been removed in the form 
of a large layer, it hardens a little, becomes a little more 
consistent, and is torn with less ease. It is of all the or- 
gans, next to the hair and the nails, that which drying- 
changes the least in the natural state. It also becomes a 
little more transparent by it; but resumes its ordinary 
state when again immersed in water, which proves that it 
contained a little of it in this state. The action of the 
air, which is so quickly efficacious upon the skin in putre- 
faction, leaves it then wholly untouched. It is only raised 
up, but does not itself putrify. Separated in this way and 
washed to cleanse it of the fetid substances that might 
adhere to it, it exhales no bad odour. Kept a long time 
in moist air, alone and well separated from the neighbour- 
ing parts, it does not alter. It is, next to the hair and 
the nails, the most incorruptible of the animal substances. 
I have preserved a foot found in a cemetery, the skin 
and fat of which are transformed into a fat, unctuous and 
hard substance, which burns in the candle, whilst the 
epidermis, which is very thick, is hardly changed at all 
in its nature. 
The action of water upon the epidermis can be consid- 
ered under many relations. 1st. During life it whitens 
it, when it is some time in contact with it, and at the 
same time wrinkles it at different points. We often see 
this phenomenon in the hands on coming out of a bath ; 
but it is particularly evident after ten or twelve hours ap- 
plication of an emollient cataplasm, in which the action 
of the farina is nothing, and in which it is the water that 
produces the whole effect. This whiteness of the epider- 
mis appears to be then owing to its having really imbibed 358 
EPIDERMOID SYSTEM. 
some of the fluid. It is the same phenomenon that takes 
place on the serous, fibrous, membranes, &c. which, hav- 
ing become artificially transparent by drying, whiten 
again when immersed in water. Here the epidermis, 
naturally transparent, whitens by the addition of this 
fluid. In this state it renders the sensibility of the papillae 
infinitely more obtuse ; I have often made the experiment 
upon myself, by applying a cataplasm in the evening and 
removing it the next morning. When the water is evapo- 
rated which the epidermis has imbibed, it again becomes 
transparent, wrinkles, resumes its natural state, and allows 
the sensibility of the skin to be again apparent. This 
phenomenon is especially observed upon the epidermis of 
the foot and the hand, for it is not often as sensible else- 
where. 2d. In the dead body, the epidermis separated 
from the skin, and immersed in water, whitens also, but 
does not wrinkle. Left to macerate in water, it does not 
undergo any putrid alteration. Only there rises on the 
surface of the fluid many particles, which being in juxta- 
position, form a whitish pellicle of the nature of which 
I am ignorant. At the end of two or three months, the 
epidermis thus left in water, softens, does not swell, and 
is torn with great ease ; it is not reduced to a pulp analo- 
gous to that of the other organs thus macerated. 3d. 
When stewed, the epidermis does not undergo, at the 
Instant of ebullition, a horny hardening like all the other 
organs. Hence why, whilst by this horny hardening the 
skin is much diminished in extent, the epidermis which 
remains the same is obliged to be folded in different direc- 
tions. When the ebullition is continued, this membrane 
becomes less resisting and breaks with great ease, but is 
never reduced to gelatine, does not acquire a yellowish 
colour, and does not become elastic like the organs which 
furnish much of this substance; besides, we know that 
the epidermoid texture does not combine with tannin, 
and that it is even an obstacle to it when it tends to pene- EPIDERMOID SYSTEM. 
359 
Irate the skin. After long stewing, the different layers 
which compose the epidermis of the palm of the hand, 
and especially that of the sole of the foot, are separated 
with great ease ; this is the best way of seeing this lamel- 
lated structure. Between these layers there is often 
formed on the foot small vesicles fdled with serum. 
Caloric produces upon the epidermis phenomena wholly 
different from those which the other systems experience 
from the contact of this substance. A portion of this 
membrane well dried by the action of the air, and ex- 
posed to the flame of a candle, 1st, does not undergo 
hardly at all the horny hardening, as a portion of skin 
does when thus treated ; 2d, it exhales a fetid odour analo- 
gous to that of burnt horn, and different from that of all 
the other textures when subjected to the same experi- 
ment ; 3d, it burns with great ease, which does not take 
place with any of the preceding systems when dried; it 
is often even sufficient to put the fire to it at one end to 
consume it entirely; 4th, at the place of the flame we 
see a blackish bubbling fluid, from which often escapes 
little burning drops, and which is very analogous to that 
of a feather when burnt. It is evidently an oil which sup- 
ports the combustion by its great abundance, and which 
does not appear to be found in as great quantity as in the 
hair and the nails. This oil deserves particular examina- 
tion ; it is that which gives out in burning so disagree- 
able an odour, and which forms those burning and whitish 
drops of which we have spoken. It appears to be of the 
same nature as that which Bertholet obtained from the 
hair in so great a proportion. After combustion there is 
left a blackish charcoal, which I have not analyzed. 
Light does not appear to have a great action upon the 
epidermis, which I have found of the same colour, in por- 
tions of skin blackened by it, and in those which have 
been sheltered from it. 360 
EPIDERMOID SYSTEM. 
Nitric acid yellows very sensibly the epidermis, more 
even than any other animal substance ; but it does not 
dissolve it without great difficulty. The sulphuric on the 
contrary acts very powerfully upon it, especially when it 
is a little concentrated. When it is drawn out after having 
been a short time plunged in, it is found to be very thin, 
extremely transparent, and almost similar in this respect 
to the pellicle that is taken from an onion. This curious 
phenomenon has often struck me. When left too long in 
the acid, the epidermis is finally entirely dissolved in it. 
The alkaline lies dissolve this membrane, but with dif- 
ficulty. Pure alkali has a very prompt action upon it. 
Alkohol has no influence upon the epidermis. 
III. Properties. 
The epidermis has but very little extensibility, since 
the least cutaneous tumour can tear it and raise it up in 
scales, as in herpes, or in larger pieces, as from a blister. 
Yet it is not entirely destitute of it, as the vesicle proves 
which is formed by this last. Its contractility of texture 
is nothing. We observe, that when no longer distended, 
this bladder remains flaccid and never contracts. 
Every kind of animal sensibility is foreign to the epi- 
dermis. We know that it can be pricked, cut or torn, 
without being felt. It is especially on the palms of the 
hands and the soles of the feet that these experiments are 
easily made. The thickness of this membrane is such in 
this place, that we can remove layers of it, as we see done 
by those who try the edge of an instrument, that it is 
possible even, as most cooks do, to put it in contact with 
live coals, and that it is not impossible to carry a red hot 
iron over it. It is by this insensibility that it blunts the 
action of the acids, the caustic alkalies, and of all the 
powerful stimuli, which when in contact with the dermis 
laid bare by a blister, give excessive pain. EPIDERMOID SYSTEM. 
361 
The epidermis differs from all the other organs that are 
destitute, like it, of animal sensibility, as the cartilages, 
the tendons, the ap.oneuroses, &c. in this, that it is never 
capable of acquiring it; whereas the others, if a little ex- 
cited, often take a degree of it superior to that of the 
organs which naturally possess it. Whence does this 
arise ? From the fact, that in order that the animal sensi- 
bility may arise in an organ it is necessary that the rudi- 
ments of it should be there already, and that this organ 
should enjoy organic sensibility, which, when raised by 
irritation is transformed into animal ; now the epidermis 
appears to be destitute also of this last property, as well 
as of insensible contractility. In fact, 1st, there is no 
sensible circulation in it. 2d. The exhalants and absorb- 
ents which go through it, are wholly foreign to it. 3d. 
No morbid phenomenon, that supposes organic sensibility, 
appears in the epidermis. It does not inflame ; it is pas- 
sive in all cutaneous affections, and never partakes of them 
notwithstanding its continuity. The impossibility of in- 
flaming makes it an obstacle, wherever it exists, to cuta- 
neous adhesions, which cannot take place until it is re- 
moved. Its internal surface, raised by a blister, and reap- 
plied to the dermis by the evacuation of the serum of the 
vesicle by means of a small puncture, never unites again. 
4th. The excrescences of which it is the seat, as corns, 
some indurations, &c. are inert and dry like it, and with- 
out internal circulation ; if they are painful, it is from the 
pressure upon the subjacent nerves, and not from them- 
selves. 5th. No sensible operation is performed in the epi- 
dermis ; it is worn incessantly by friction, like inorganic 
bodies, and it is afterwards reproduced. 
This continual destruction of the epidermis has not suf- 
ficiently arrested the attention of physiologists. The 
following are the proofs of its reality ; 1st, if with the 
blade of a knife, we scrape strongly its external surface, 
a large quantity of powder is removed which sulphuric 362 
EPIDERMOID SYSTEM. 
acid easily dissolves, and which is greyish. The epi- 
dermis whitens a little in this place, then resumes its 
colour, especially if it is moistened. By scraping again, 
we do not remove any more powder, it is necessary in 
order to obtain it, to wait twelve or twenty hours. 2d. 
This substance becomes superabundant, when the skin has 
not been washed for a long time. Hence why those who 
soak their feet that have not been cleaned for a long time, 
detach so great a quantity of it. It is especially on the 
sole of the foot that this substance is formed in abundance. 
We often observe in dead bodies that it forms almost a 
layer in addition to the epidermis, but which is very 
distinct from it, and can be removed with ease. I attri- 
bute this circumstance to the thickness which the epider- 
mis has in this place. We should no doubt find as much 
upon the hand, were it not for the continual friction of 
this part. We see it often on the patients in hospitals, 
after remaining a long time in bed without having been 
cleansed. 
Water naturally removes this substance, that is produced 
by the destruction of the epidermis, and, which, mixing 
with the residue of transpiration, that the air cannot carry 
off by evaporation, renders bathing, as I have observed, a 
natural want. Though it may be neither exhaled nor ab- 
sorbed, and though its production may appear to be owing 
to mechanical friction, yet we can, in its relation, consider 
the epidermis as an emunctory of the body, since it is 
renewed by a substance coming from the dermis, as fast 
as it is removed. 
It is evident, as the epidermis has no vital properties, 
that it cannot he the seat of any kind of sympathies, 
which are aberrations of these properties. Hence its life 
is extremely obscure, I doubt even if it possesses vitality. 
We might almost say that it is a semi-organized body, 
inorganic even, whicli nature has placed between ex- 
ternal inanimate bodies and the dermis, which is com- EPIDERMOID SYSTEM. 
363 
pletely organized, in order to assist their passage and 
smard against their force. 
The epidermis has a property very distinct from those 
of most of the other systems; it is that of being repro- 
duced when it has been removed. It grows anew and is 
formed again with an appearance exactly similar to what 
it first exhibited ; it is that which makes it differ from all 
the other systems, as the cellular, which throw out vege- 
tations when they are laid bare, but which are only repro- 
duced in an irregular manner, and wholly different from 
their natural state. How is the epidermis thus repro- 
duced? Is it the pressure of the atmospheric air which 
renders the external surface of the skin callous ? Is it the 
air, which, by combining with the products which escape 
from this surface, forms a new compound ? I know not. 
What is certain is, 1st, that this production is wholly dif- 
ferent from that of the internal organs ; 2d, that it cannot 
take place except upon the skin, and that the fine pellicle 
that covers all the other cicatrized parts, after a wound 
with loss of substance, does not resemble it at all and pre- 
sents even a texture wholly different. Thus this pellicle 
is not raised up by the different means which raise the 
epidermis; thus it often becomes the seat of acute sensi- 
bility which is never the case with the epidermis. This 
is what takes place especially in changes of weather, a 
time in which the cicatrices become, as we know, very 
painful; I have often observed, that not only the interior, 
but the pellicle even of the cicatrix are then sensible. 
Besides, when this pellicle is formed, red blood vessels 
evidently penetrate it, whilst nothing similar is observed 
in the formation of the epidermis. 
It is this faculty of reproduction which is put in action 
in many epidermoid excrescences, as in corns, and callosi- 
ties which have nothing in common but the name with 
those which form the edge of fistulas, &c. All these ex- 
crescences are insensible, without vessels or nerves, of the 364 
EPIDERMOID SYSTEM. 
same consistence and the same colour as the epidermis; 
they are often removed from it and afterwards formed 
again. It appears that external pressure has much influ- 
ence upon their development; too narrow shoes and the 
solid bodies which are used on the hands of smiths and 
other workmen are the frequent cause of them. 
I preserved a great part of the skin of a man who died 
at the Hotel Dieu, and his epidermis, which was treble the 
thickness from his birth and even in the womb of his 
mother, that it is in the ordinary state, had been subject 
during his life to a continual desquamation which made 
the whole of it appear as if covered writh herpes, though 
nothing similar to this affection existed upon the dermis, 
which was perfectly sound. The face alone was exempt 
from this defect of conformation. 
The epidermis is not only reproduced when the w?hole 
of it has been removed, but also when the superficial lay- 
ers alone have been taken away, especially on the foot 
and the hand on which other layers arise upon those 
which the cutting has laid bare ; which proves that they 
are not, as has been said, the juices of the reticular body 
which form it by drying. 
IV. Development. 
Those who have thought that the epidermis is formed 
by pressure, would be convinced that this is not the case 
if they would examine that of the foetus, which is very 
distinct, more even in proportion than many other sys- 
tems. We observe it when the skin begins to leave the 
pulpy state of which we have spoken. At the end of the 
fifth month, it has proportions analogous to those which 
it will afterwards exhibit. It is very thick on the soles of 
the feet and the palms of the hands, and very thin else- 
where ; it is easily detached by all the means we have 
pointed out. We know that in a foetus that has died and EPIDERMOID SYSTEM. 
365 
become putrid in the womb, it is found in great measure 
detached. At the place of the umbilical cord, it is con- 
tinued in an insensible manner with the skin. 
At birth, though it is in contact with a fluid that is new 
to it, it does not undergo a great alteration ; which proves 
that the air has little or no agency in its formation. It 
becomes thicker as we advance in age, and follows, in 
this respect, nearly the same proportions as the skin. 
Beyond the twenty-sixth or thirtieth year it increases no 
more. I have often raised up in many places the epi- 
dermis of an old person ; it has not appeared to me to dif- 
fer much from that of the adult; it is a little more sub- 
ject to scale off and it is a little thicker. In some miser- 
able objects which come to hospitals, there is often vermin 
in cracks of the epidermis, whose layers are afterwards 
separated by them and in which they live ; so that I have 
seen the epidermis in this way conceal thousands of little 
animals, which were evidently found between the layers 
of this membrane, and which were not upon the reticular 
body and the papillae. It is the only means that has shown 
to me the lamellated structure of the epidermis, in any 
other place than on the foot and the hand, in which I have 
never seen vermin. 
The cracks of the epidermis in old age appear to arise 
from its dryness owing to the want of exhalation ; it is 
that which renders the skin so rough and harsh. What 
contributes to it also is, that as it has many inequalities on 
account of its numerous folds, frictions being more felt in 
these prominent places, make the epidermis scale off; 
thus in the adult the same cause renders it scaly on a 
tubercular skin, whilst a skin that is smooth and well 
distended with fat, undergoes every kind of friction with- 
out desquamation. 366 
EPIDERMOID SYSTEM. 
ARTICLE SECOND. 
INTERNAL EPIDERMIS. 
All authors have admitted the epidermis of the mu- 
cous membranes. It appears that most have believed that 
it is only this portion of the skin which descends into the 
cavities to line them. Haller in particular is of this opin- 
ion. But the slightest inspection is sufficient to show, 
that here as upon the skin, it forms only a superficial layer 
over the papillary body and the chorion. Boiling water 
which detaches it from the palate, the tongue and the 
pharynx even, enables us to see the two other layers. 
I. Epidermis of the origin of the Mucous Surfaces. 
The epidermis is very distinct upon all the origins of 
the mucous system, upon the glans, the entrance of the 
anus, the urethra, the nasal fossse, the mouth, &c. It is 
demonstrated in these places by the excoriations that take 
place there, upon the lips especially, by dissection with 
a very fine lancet, by the action of boiling water, macera- 
tion, putrefaction and even epispastics, as is proved by the 
fact that the ancients employed this method to make the 
edges of a hare-lip raw. The delicacy of this epidermis 
is much greater than on the skin ; and as it is more in 
the interior this delicacy increases. It is to this circum- 
stance that must be attributed the ease with which different 
remarkable modifications are produced through this mem- 
brane, when in galvanic processes, we arm with zinc the 
surface of the tongue and with another metal the mucous 
surface of the conjunctiva, the pituitary membrane, the 
surface of the rectum, the gums, &c. and bring in mediate 
or immediate contact these different metals. EPIDERMOID SYSTEM. 
367 
The mucous epidermis is quickly reproduced when it 
has been removed. Destitute of every kind of animal 
and organic sensibility, it is in this respect, destined like 
the skin, to defend the very sensitive papillary body that 
is subjacent to it. It is to its presence upon the mucous 
membranes, that should be in part attributed the faculty 
they have of being exposed to the air, and even to the 
contact of external bodies, without exfoliating or inflaming 
as in preternatural anus, prolapsus of the rectum, &c. ; 
whilst the serous membranes cannot bear this contact 
with impunity. 
Besides, the nature of the mucous epidermis is the same 
as that of the cutaneous. Submitted to the action of the 
same agents, it gives the same results. The excrescences 
formed on its surface are also analogous, though much 
more rare. It becomes callous by pressure. Chopart re- 
lates the case of a shepherd, whose urethra became so, from 
frequently introducing a small stick to procure pleasure’ 
We know the density that this covering has in the stomach 
of the gallinaceous animals, and in certain cases in which 
the mucous membranes come out of the body as in pro- 
lapsus of the rectum, the vagina, the womb, &c. Some- 
times in those cases the pressure of the clothes produces in 
this epidermis a thickness evidently greater than what is 
natural to it; it is this which then makes these membranes 
lose in part the bright red that characterizes them in 
the interior. 
II. Epidermis of the deep seated mucous surfaces. 
The epidermis gradually becomes more delicate, and is 
soon almost insensible, on the internal mucous mem- 
branes. 1st. In the stomach, the intestines, the bladder, 
the gall-bladder, the vesiculse seminales, in all the excre- 
tories, &c. the most delicate instrument cannot raise it up. 
2d. In the maceration and ebullition of the mucous sys- 368 
EPIDERMOID SYSTEM. 
tem of these parts, I have never seen the epidermis raised 
up on its surface. 3d. I have drawn out of the abdomen 
of a doe; a portion of intestine ; its mucous coat has been 
laid bare by an incision, and I have applied an epispastic 
to it; more redness was seen upon the free surface of this 
coat, but no pellicle was raised up from it. 4th. We do 
not see in preternatural anuses, complicated with inver- 
sion, excoriations analogous to those of which the surface 
of the lips, that of the glans, &c. are the seat. 5th. I have 
already had frequent occasion to open bodies affected with 
acute or chronic catarrhs of the intestines, the stomach, 
the bladder, &c.; now I have never seen the epidermis 
separated by inflammation, as happens after erysipelas, 
phlegmon, &c. upon the cutaneous organ. 6th. We do 
not see upon the deep seated mucous surfaces those exfo- 
liations, desquamations, &c. so frequent upon this after 
many affections. 
From all these considerations it would appear, that the 
epidermis does not exist upon the deep seated mucous 
surfaces, and the great quantity of mucous juices con- 
stantly poured out by the subjacent glands, supplies its 
place in defending the papillae and the chorion from the 
impression of substances heterogeneous to the economy, 
contained in the internal cavities. Yet there is a circum- 
stance that would seem to demonstrate the existence of 
the epidermis upon the deep seated mucous surfaces ; it 
is the separatiomof preternatural membranes, which are 
often detached from these surfaces, and which may be 
considered as a kind of epidermoid exfoliation. Many 
authors give examples of these membranes formed either 
upon the bladder and voided by the urethra, or upon the 
stomach and oesophagus and thrown up by vomiting, or 
upon the intestines and expelled with the alvine evacua- 
tions ; Haller has collected many cases. Dr. Montaigu 
informed me that he saw a membrane vomited up, which 
formed a sac without a rent, exactly analogous to that EPIDERMOID SYSTEM. 
369 
of the stomach whose internal surface it lined. Desault 
saw a sac almost analogous to the bladder, voided by a 
patient who was affected with retention of urine. 
I confess that I have made no observation on this point, 
so that I cannot say what is the nature of these mem- 
branes. But authors in general agree in attributing to 
them a soft and pulpy nature, which does not appear to 
me to accord with that of the epidermis. I have many 
times seen at the Hotel Dieu white membranes detached 
from the oesophagus after poisoning with the nitric acid. 
But these membranes are evidently the superficial portion 
of the mucous organ, which is disorganized, and thrown 
off by suppuration which takes place below. It is thus 
that cutaneous eschars fall off in the form of membranes 
from large burns; in this way the osseous lavers are 
formed in necrosis, which are only the superficies of the 
bone that dies and is detached in a lamellated form. 
From this, the existence of the epidermis of the deep 
seated mucous surfaces appears to me to be very uncer- 
tain, and cannot be admitted till a new examination, 
which will, I think, prove rather against than in favour 
of its existence. What is the place in which the epider- 
mis terminates that lines the origin of the mucous sur- 
faces, or if it exists everywhere, where does it begin to 
become no longer apparent from the action of our differ- 
ent reagents ? We cannot, I think, determine with pre- 
cision ; it diminishes in an insensible manner, and is lost 
as it were by degrees. 
ARTICLE THIRD. 
OF THE NAILS. 
All the fingers have at their extremity, on the outer 
side or that of extension, hard, transparent and elastic lay- 370 
EPIDERMOID SYSTEM. 
ers, of the nature of the horns of many animals, and 
which are called nails. 
I. Forms, Extent, Relations, fyc. 
The nails of man differ from those of most other ani- 
mals, in their breadth and want of thickness. The first 
makes them better adapted to support the extremity of 
the fingers, which is broader than in most animals for the 
perfection of touch; the second renders them less fit to 
serve for defence or as a means of aggression. 
Most people cut their nails even with their fingers, so 
that the length of these bodies which is seen is not what 
is natural to them. When allowed to grow, they lengthen 
and turn over on the side of flexion, and cover entirely 
the lower end of the fingers. This growth has a certain 
limit which the nail cannot pass, and which it attains 
when it exhibits at its extremity a cutting and sharp edge. 
As long as this edge has the appearance of having a part 
cut off, the nail continues to grow. 
We usually think that the habit of cutting our nails is 
a thing of mere decorum. But if we reflect a little upon 
society and the numerous arts to which it gives rise, upon 
the perfection, delicacy, precision and rapidity of the mo- 
tions which the fingers are oftei> forced to execute, upon 
the necessity of approximating them, crossing them in a 
thousand different ways, &c. we shall soon see that this 
habit is almost inevitably the result of the social state, and 
what appears to us the effect of fashion is that of neces- 
sity. The sense of touch in man in a natural state is 
coarse and obscure ; it is only necessary that he should 
seize objects destined for his nourishment, his defence, 
his aggressions, &c. that he should climb especially and 
attach himself to trees to keep himself upon them ; now 
his nails are for this purpose of great use. What he loses 
in this respect in society, he seems to gain by the pre- EPIDERMOID SYSTEM. 
371 
eision and extent which are added to his touch, and by the 
faculty which the fingers acquire of distinguishing the 
most delicate tangible qualities. In the first state, his 
hands are of great assistance to him in locomotion. In 
the second, they contribute hardly at all to this use, and 
they gain in the partial motions of their fingers what they 
lose in their motions as a whole, which become of less 
urgent necessity. 
The nail has three distinct parts in the natural state ; 
one posterior, concealed on both sides by the integuments ; 
another middle, free only on one side, and the third an- 
terior, without adhesion at either side. 
The posterior portion of the nail is nearly a sixth part 
of its extent. Its convex surface adheres very intimately 
to the epidermis, which goes in the following manner to 
fix it. After having covered over the portion of the 
finger corresponding with flexion, it is reflected upon the 
concave edge where the skin terminates and where the 
nail begins to become external ; it commonly forms all 
around this edge a kind of small string that is very dis- 
tinct and has a small groove in the top of it, and which 
is evidently composed entirely of epidermis, since we can 
cut the whole of it without giving any pain, and which is 
afterwards easily reproduced. After having formed this 
string, which is in the form of a parabola, the epidermis 
is again reflected, passes between the skin and the nail, 
and is glued, if we may so say, to the concave surface of 
the latter, without being intermixed with it; for we can 
remove it with ease by scraping with a scalpel. So that 
the dermis which covers the superior portion is really be- 
tween two layers of epidermis. After having thus fixed 
the nail, and having arrived at its posterior edge, the epi- 
dermis is continued and identified as it were with this 
edge, whose evident delicacy and softness approximate it 
in nature to this membranous layer. Hence it follows 
that without the adhesion of the epidermis to the nail, 372 
EPIDERMOID SYSTEM. 
there would be between them, a kind of cul-de-sac. Some 
authors have thought that the extensor tendon is extended 
as far; but it is easy to see that it does not go beyond the 
tubercle which terminates behind the phalanx. The nail 
does not reach this tubercle, there is a space of three lines 
between them. The concave surface of the posterior 
portion of the nail corresponds with the same substance 
as the middle portion. 
This middle portion is bare on its convex surface, which 
is smooth, whitish behind where this colour forms a kind 
of half moon, reddish in the greater part of its extent, a 
colour which is foreign to it and which it derives from 
the subjacent texture. Upon the sides, the skin covers 
this surface a little, and terminates afterwards by continu- 
ing the concave and free edge of which we have spoken. 
The epidermis forms also in this place a small string 
which is continued on each side with that pointed out 
above; then it unites to the nail and adheres to its lateral 
edges with which it is identified. The concave surface 
of this middle portion is fixed in front by the epidermis, 
which, after having covered the extremity of the fingers, 
and having arrived at the place where the nail ceases to 
be free, is separated from the dermis, and adheres to the 
whole length of the nail in a curved line ; then by mix- 
ing with it, it seems to form its internal lamina. The 
dermis on the contrary is continued on the convexity of 
the last phalanx, has there a remarkable consistence, a 
reddish appearance, and a texture like pulp and wTholly 
different from what is observed elsewhere ; more vessels 
run through it; there is no distinct space in it, and no 
elongation goes from it to the surface of the nail of which 
the epidermis forms a part. We do not see on this sur- 
face, as on those of the other parts of the epidermis, those 
threads, which are the remains of the broken exhalants 
and of which we have spoken ; thus the sweat never 
passes through the nail. There is neither any oily oozing EPIDERMOID SYSTEM. 
373 
upon its surface; whence it follows that water is not form- 
ed into little drops on the exterior of its horny laminae. 
Hence the nail is evidently insulated from all the other 
organs except the epidermis, with which it is continued 
on its concave face and especially on its posterior and 
lateral edges. Thus observe that when collections of pus 
or other affections have broken this continuity behind or 
on the sides, the whole of the nail, though unaffected in 
the middle falls off. 
The free or anterior portion of the nail is of a length 
which it is difficult to determine. I have never seen it 
allowed to take its natural growth. I have only observed 
that if it is permitted to grow to a considerable size, we 
see evidently that it has a greater thickness than the pos- 
terior and middle portion. In general, the thickness, 
resistance and hardness of the nail increase in a gradual 
manner from the posterior to the anterior part; we shall 
now examine to what this is owing. 
II. Organization ; Properties, fyc. 
In order to observe the organization of the nails advan- 
tageously, it is necessary to take those that are very dis- 
tinct, as those of the great toe, the thumb, &c. We then 
see evidently that a single lamina occupies the whole of 
their convex surface. Behind, this lamina exists alone ; 
hence the extreme thickness of the nails at this place. 
But as we examine towards the front, we see new laminae 
successively added to it, on the concave surface ; so that 
the nail becomes successively thicker. These laminae can 
he easily raised up layer by layer. The most anterior 
are the shortest. They often exhibit upon the concave 
surface of the nail an infinite number of very evident 
small striae, all longitudinal and parallel, and which make 
us attribute to it a fibrous texture. At other times this 
arrangement is less evident. 374 
EPIDERMOII) SYSTEM. 
What-is the nature of the laminae which form the nails? 
I believe that they are almost precisely the same as the 
epidermis. What proves it is, 1st, that the most super- 
ficial is evidently continued with it by its edges ; there is 
no intermediate agent between them. 2d. I have already 
observed that the nails are detached, and then regene- 
rated exactly like the epidermis. They have two modes 
of increase; one in length, when we cut their extremi- 
ties; the other in thickness, when we detach only a lami- 
na, which is soon formed again. When the whole of 
the nail comes off, all the portion of the dermis which 
covers the back of the last phalanx, contributes at the 
same time to form it anew by its external surface. 3d. 
There is the same obscurity in the vitality of the nails as 
in that of the epidermis. No trace of animal sensibility 
is discoverable in them. The excruciating pain that is 
experienced when they are pulled out arises solely from 
the sensibility of the subjacent pulpy texture ; it is from 
the same cause as in pulling out the hair. There is no 
organic sensibility, no internal circulation and conse- 
quently no heat inherent in the texture of the nails ; thus 
the horns of animals are nearly of the same degree of 
temperature as the atmosphere, whilst some external pro- 
ductions with evident vital forces, though raised up like 
horns, have a temperature equal to that of the body. 
Such are the combs of the cock of our country, and those 
which are more striking of the cock-turkey. Compare 
these excrescences with those on the feet of these animals, 
which are horny, and the difference of temperature is 
evident, dth. The nails give out when burning a dis- 
agreeable odour, analogous to that of the epidermis under 
the same circumstances ; they exhibit then the same phe- 
nomena. Their combustion is supported, like that of the 
epidermis, by an oil of which they contain a great quan- 
tity. 5th. If maceration and stewing do not produce 
upon the nails that want of consistence, that kind of brit- EPIDERMOID SYSTEM. 
375 
tleness, if I may so express myself, which they produce 
upon the epidermis, it appears to be owing only to their 
greater solidity. 6th. The action of the nitric, sulphuric 
acids, &c. has exhibited to me nearly the same phenomena 
as upon the epidermis. 
Every thing then appears to establish the most exact 
analogy in the composition, organization and properties 
of the nails and the epidermis. There is no doubt a dif- 
ference of principles between them, since the appearance 
is not the same, and since, though many epidermoid 
layers may be in juxta position as on the soles of the feet 
and the palms of the hands, they do not exhibit the form 
and texture of the nails ; so that we cannot consider these 
as mere layers of epidermis applied to each other. Chemists 
must ascertain what these differences are, which are cer- 
tainly very slight. Thus nature often employs indif- 
ferently the two organs for the same uses; it is thus that 
on the sole of the foot of man and many analogous species, 
there is a thick epidermis; whilst on the feet of animals 
with hoofs, we see a horny substance of the nature of the 
human nail. 
An evident proof of the slight degree of internal motion 
which is going on in the epidermis and the nails, of the 
kind of inertia in which they are in relation to the con- 
stant motion of composition and decomposition, which 
constitutes nutrition, and of the insensibility which they 
exhibit to various excitants, is the ease with which they 
are penetrated by different colouring substances, and the 
very long time they retain them. We know this effect 
with regard to the nails of dyers. Many savage people 
who paint the face, various parts of the body, and often 
even the whole of the external surface of the body, pre- 
serve for a long time, without a new coat, the colour 
which they have artificially given themselves. I have 
removed the epidermis of a portion of skin of the arm of 
a dead body, which was coloured blue during life; this 376 
EPIDERMOID SYSTEM. 
colour was not only on the surface of the membrane, but 
penetrated the whole of it, like a piece of cloth that had 
been soaked in it. Yet the pores were as evident as be- 
fore, and the sweat could pass through them; I presume 
this secretion goes on as usual in savages who paint the 
skin. Thus the cloth which is immersed in a dye, has 
not its pores closed by it. I may make use of this com- 
parison, as the epidermis and the nails are really species 
of inorganic bodies. Lay any organ bare and paint it in 
this way ; the colour, together with the contact of the 
air will irritate and inflame it, and the suppuration arising 
from this inflammation will soon throw out the colouring 
particles, which nutrition would have done, if inflamma- 
tion had not. There is a means however which can per- 
petuate the colour, even upon organs, which, very sensi- 
ble like the skin, are constantly subject to the double nu- 
tritive motion ; it is that of using the colours with a red 
hot iron. It is in this way I am convinced that the letters 
or coloured figures which most soldiers mark upon them- 
selves, with a red hot pin, have their seat not only in the 
epidermis, but also in the chorion itself. 
Development. 
The nails have in the foetus a very considerable con- 
sistence, whilst the skin is still pulpy ; but their tenuity 
is then extreme. But they thicken and acquire greater 
consistence as the foetus increases in size. They have 
not at birth a length proportionable to what they are after- 
wards to have. They do not extend beyond the ends of 
the fingers which are often much the longest; so that it is 
not till after birth that they are bent over and exceed the 
fingers in length, for both of these would be useless in 
the womb of the mother, as there is nothing there for the 
foetus to seize upon. Their transparency allows us evi- 
dently to see, at the moment of birth, first the black colour 
of the blood which before circulated in the arteries, and EPIDERMOID SYSTEM. 
377 
then the vermilion colour which respiration suddenly im- 
parts to it. As we advance in age, the nails grow in the 
same proportions as the epidermis, but they have nothing 
peculiar in their growth. In old people they become ex- 
tremely thick. 
These organs experience during life those diseases only 
which are analogous to those of the epidermis. These 
are excrescences, augmentations of size, &c. and other 
productions, the texture of which is precisely the same as 
that of the nail, and in which there is neither more sen- 
sibility, nor more circulation, nor more heat, nor more 
life ; a remarkable character which distinguishes them 
from those tumours which arise upon the other organs 
with very active vitality, as upon the skin, the muscles, 
&c. tumours the texture of which is very different from 
that of the organs which have produced them, and which 
most usually have properties entirely different. But the 
epidermoid excrescences are in every respect analogous 
to the epidermis. PILOUS SYSTEM. 
THE adjective by which I characterize this system, is 
derived from the latin substantive which signifies the or- 
gans of which it is composed. Hair is found less gene- 
rally upon man than upon most other animals. It forms 
upon them a kind of covering external to the skin, which, 
lessening in part the contact of external bodies, makes the 
cutaneous animal sensibility perform a less important part, 
and establishes less numerous relations between these 
bodies and them. External life is then, in this respect, 
more limited in them than in man, in whom a delicate 
epidermis and a few hairs thinly scattered over it, sepa- 
rate the organ of feeling from surrounding objects, the 
least impression of which is felt, and which, owing to 
this, keep the animal sensibility in permanent activity; 
thus man is designed to live more without than within 
himself. The pleasures of reproduction and digestion 
constitute exclusively the happiness of animals. That of 
man is in part the result of them; hut an order of plea- 
sures wholly different, purety intellectual and in relation 
only with external sensations, enlarges immensely by its 
presence, and contracts by its absence, the fieid of this 
happiness. 380 
PILOUS SYSTEM. 
The hair of man covers especially the cranium, some 
parts of the face, the front of the trunk, the genital or- 
gans, the extremities, &c. The quantity varies remarka- 
bly, as well as the form, length, &c. In order to form an 
accurate idea of it, wTe shall now consider it separately in 
the different organs, we shall then treat of its general or- 
ganization, properties and development. 
ARTiCLE FIRST. 
EXAMINATION OF THE PILOUS SYSTEM IN THE DIFFER- 
ENT REGIONS. 
This system must be considered on the head, the trunk 
and the extremities. 
I. Pilous System of the Head. 
The head is the part of the body in which this system 
predominates; it covers the whole cranium and defends 
it against the impression of external bodies, as the hairy 
coat of quadrupeds defends them. Thus this part is the 
least capable of exercising the sense of touch, either from 
the obscurity of the animal sensibility arising from this 
hairy covering, or because its convex form allows it to be 
in contact with external bodies only by a small surface. 
The face is less generally covered with hairs, though 
many are found upon it, especially in men. This part, 
in which in a very small space are collected the greatest 
number of our means of communication with external 
objects, viz. the organs of taste, smell, sight and even PILOUS SYSTEM. 
381 
hearing, has but very little to do with the sense of touch, 
on account of its villous arrangement. Its form is also 
badly adapted to this sense. The mouth which is flat- 
tened cannot be applied to external bodies. Thus whilst 
the snout which is elongated in most quadrupeds, per- 
forms the double function of first feeling all bodies, turn- 
ing them in various directions in order to ascertain their 
tangible qualities, and then of seizing them for nourish- 
ment, the mouth of man serves only for this last use ; it is 
the hands which are destined for the first. Thus observe 
that all animals, even the most of those with clavicles, 
almost uniformly direct their snout towards the earth, 
whilst the mouth of man is naturally destined to an op- 
posite position. 
Of the Hairs of the Head. 
They occupy upon the cranium all the space which 
corresponds with the occipital, parietal, the squamous 
portion of the temporal and a small portion of the frontal 
bones. Their limits do not vary on the sides ; they 
always correspond above the ear. Behind, they some- 
times go down upon the superior part of the neck; at 
others, they do not extend beyond the head. In apply- 
ing blisters on the ligamentum nuchae, we observe in this 
respect, almost as many varieties as there are subjects. 
We know how variable these limits are in front. Some- 
times extended lower down, sometimes carried higher up, 
sometimes describing a curved line, and at others forming 
a real triangle the anterior point of which corresponds 
with the median line, they have really nothing constant. 
These inequalities alone determine the breadth or nar- 
rowness of the forehead, whilst its degrees of inclination 
depend solely upon the bone which forms it. It is in this 
way that the hair contributes a little to the expression of 
the face ; I say a little, for it is less to the breadth of the 
forehead than to its approximation to a perpendicular, 382 
PILOUS SYSTEM. 
that we attach the ideas of majesty and greatness which 
characterize heroes and gods. The poets, as we know, 
have particularly celebrated the forehead of the god of 
thunder. Observe in relation to this subject that there is 
a great difference between that which expresses majesty 
or abjectness in the face, from that which serves there 
to express the passions. It is the osseous structure of 
this region and the degree of inclination resulting from 
this structure, which serve for the first use, and it is espe- 
cially the muscular motions which contribute to the 
second. Why ? Because majesty, grandeur, &c. are espe- 
cially connected with the extent of the understanding, and 
the understanding has its seat in the brain, and because 
the various capacities of the cranium, which contain this 
organ, and which correspond with its various degrees of 
development, have inevitably an influence the dif- 
ferent dimensions of the face. Now as the bony struc- 
ture is a thing constant and invariable, the air of majesty 
or abjectness remains always imprinted upon the face. 
On the contrary, the passions which especially affect the 
epigastric organs, which afterwards excite the facial mus- 
cles, have necessarily a transitory expression. 
The number of hairs is very variable on the same sur- 
face. In some people they are very close together and 
even all touch ; in others more thinly scattered, they 
allow in part the skin of the cranium to be seen in their 
interstices, a circumstance which is either owing to origi- 
nal conformation, or to a disease which makes them fall 
out in part. They have, like the nails, a determinate 
growth which they do not exceed. We know but 
little of the limit of this growth. Yet we have seen them 
reach to the waist, the thighs, and the legs even. It ap- 
pears that in women they have a greater grow’th ; we 
might say, that nature has compensated this sex in this 
way for the want of hair in many other parts. Floating 
upon the shoulders, the breast, the trunk, &c. they form PILOUS SYSTEM. 
383 
in the natural state a sort of protection from the injuries 
of the air and the light. Their extent evidently proves 
that man was destined to an erect attitude. In fact, in 
the attitude of quadrupeds, they would trail much upon 
the earth, and form an obstacle to motion. The hair of 
no animal, I believe, in a natural attitude retards his pro- 
gress so much, as the hair of man then would. 
Man, who opposes nature in every thing, has made it 
a habit in most societies to cut the hair, the beard, &c. 
By common people, it is considered merely a thing of 
fashion; by the physician, as a practice which has per- 
haps a greater influence than is thought upon the func- 
tions. In fact, in the natural state when the pilous sys- 
tem has once acquired its growth, it no longer exhibits the 
constant motion of composition and decomposition. On 
the contrary, in man who cuts it, it is constantly the seat 
of this motion and of that of growth. This practice per- 
petuates then the phenomena which take place m them 
in infancy, and consequently keeps up there a more active 
work, which perhaps is performed at the expense of that 
of many other parts. 
The natural difference of the hair has much influ- 
ence upon its length ; that which is smooth and curls but 
little is in general the longest. The more it has the oppo- 
site characters, the shorter it is, as is proved by that of 
negroes and those white people whose hair curls like 
theirs. 
The tenuity of the hair is very great, yet its resistance 
is in proportion very considerable. There is no part in 
the economy, not even those of the fibrous system, which 
can support so great a weight in proportion to its size 
Thus woven strings of hair would have an enormous 
resistance, if they were sufficiently long to be employed 
for different uses. 
The colour of the hair varies remarkably according to 
country, latitude, climate, temperature, &c. This colour 384 
PILOUS SYSTEM. 
is even, like that of the skin, a characteristic attribute of 
the different human races. Naturalists have been much 
occupied with this subject, and I refer to their works. 
In our climate the principal colours are black, flaxen 
and bright red. They are, as it were, the three general 
types to which may be referred many particular shades. 
The black has under it the brown, the chesnut, &c. The 
flaxen is connected on the one hand with the bright 
red and on the other with the chesnut. The bright red 
which touches the flaxen by one of its extreme shades, 
goes by an opposite shade to the natural colour of certain 
flames. 
All physicians have considered the colour of the hair 
as among the characters of the temperaments. Black in- 
dicates strength and vigour. The figure of a wrestler 
with flaxen hair would be almost ridiculous. This colour 
is the attribute of weakness and delicacy ; it floats upon 
the head of figures which painters have made strangers 
to the great passions, to powerful and heroic deeds ; it is 
found upon the figures of young people, in pictures where 
laughter, sport, grace and pleasure preside over the sub- 
jects. These two colours, black and flaxen, as well as 
their secondary shades, are found distributed among 
women in nearly equal proportion ; now reflect upon the 
kind of sentiment this sex inspires according to the colour 
of the hair, without, regard to any other consideration, 
and you will see that a woman with flaxen hair creates a 
sentiment which beauty and weakness united seem to 
dictate. The epithets that we employ express this double 
attribute. On the contrary, the term brunette announces 
in her that it designates, a mixture of force and beauty. 
Beauty is then a common gift which attracts us, but 
which, differently modified by external forms, attracts us 
by touching, interesting and exciting us. Eyes in which 
langour is depicted, are frequently associated with flaxen 
hair; whilst black hair is almost always met with, in PILOUS SYSTEM. 
385 
those whose vivacity and sparkling seem to proclaim an 
excess of life which seeks to be diffused. 
Habit which accustoms us to every thing, changes our 
taste in regard to the colour of the hair, as it does to 
that of our dress. Black, flaxen and their numerous shades 
are in turns fashionable in France ; and as the organiza- 
tion does not change with our taste, we have contrived 
artificial hair; a happy means, which seems to subject to 
our inconstancy the invariable course of nature, and which, 
changing at our will the expression which the physiog- 
nomy borrows from the hair, can at every instant exhibit 
man under forms which fashion extols to day, and which 
ridicule pursues tomorrow. Now among these number- 
less variations which succeed each other among us in the 
fashion of the hair, bright red and its various shades never 
find a place. Most people have a decided aversion to it. 
It is almost, in our eyes, a mal-formation to be born with 
it. This opinion is too general not to have some real 
foundation. The principle appears to me to be the usual 
connexion between the hair and the temperament and of 
course the character which results from this ; now the 
kind of character connected with this kind of hair is not 
commonly the happiest, though there are many exceptions 
to this principle, which is proverbial. Another reason 
for the aversion to hair of a bright red, is that the oily 
fluid which lubricates it often exhales a fetid odour foreign 
to the other kinds of hair. 
What is the relation that can exist between the hair 
and the character ? Has the first an influence upon the 
second ? No; the following is the way in which it should 
be considered. Every man has his peculiar kind of organ- 
ization and constitution. This forms the temperament; 
now, to each kind is attached on the one hand this or that 
species of hair, and on the other the predominance of 
some internal viscera, which though less apparent is not 
less real. This predominance disposes evidently to certain 386 
PILOUS SYSTEM. 
passions, which are the principal attributes of character; 
then the colour of the hair and character are two differ- 
ent results from the same cause, viz. constitution ; but one 
has no influence upon the other. 
The hair coming out of the cutaneous pores has such a 
direction, that that of the anterior part of the cranium is 
almost always oblique in front, and tends to fall over the 
forehead ; that of the middle and posterior part pierces 
the skin perpendicularly, and that of the posterior and in- 
ferior part traverses it obliquely, so as to fall naturally 
down the length of the posterior part of the neck. It is 
the same with that of the sides, which its direction as 
well as its weight, carries upon the region of the ear which 
it covers. 
Upon the arch which borders the orbit above, is found 
a collection of hairs forming a portion of a circle more or 
less evident, which shades the eye and defends it from the 
too powerful impression of the rays of light. The hairs 
of the eyebrows are thicker together in persons of dark 
complexion, than in those of light. More numerous 
within, they sometimes unite together the two eyebrows 
upon the nasal prominence, and thus shade the root of the 
nose. Fewer without, they there cause the eyebrow to 
terminate in a point. All are obliquely directed from 
within outwards. Sometimes towards the internal side, 
they go perpendicularly forwards. Their length is scarcely 
more than half an inch ; they do not exceed this except in 
some extraordinary cases. Their colour is usually, though 
not invariably, the same as that of the hair. They are 
firmer, more resisting and larger than the hairs of the head. 
If they were longer they would curl like the hairs on the 
genital parts, of the nature of which they partake. 
The eyebrows enjoy two evident motions. 1st. They 
are depressed and carried inwards, by forming over the 
Eyebrows. PILOUS SYSTEM. 
387 
eye a very evident arch. 2d. They are raised up and 
separated from each other, by expanding the parts around 
the orbit. The length between the extremes of these two 
motions is nearly an inch. The first motion takes place 
to defend the eye from a very bright light. It expresses 
also the melancholy and gloomy passions; hence the rea- 
son no doubt why the same word is applied to the moral 
state of the mind, and to the row of hairs of which we 
are treating. Observe on this subject that the sanguineous 
and choleric temperaments, which are the most disposed 
to the passions which make the eyebrows contract, are 
precisely those in which the hairs that compose them are 
found in general the most evident. The second motion 
enables us to receive upon the region of the orbit a great 
quantity of the rays of light; it allows us to raise the 
upper eyelid to a great extent in order to open the eye 
wide, which the first evidently prevents. It expresses 
also the gay passions, those which dilate the face. Paint- 
ers have studied more than anatomists, the different de- 
grees of elevation and depression of the eyebrows. 
Upon both eyelids there exists a small row of hairs, a 
little longer than those of the eyebrows, of the same 
nature as them, directed obliquely forwards, crossing each 
other when the two eyelids are brought together, and 
serving to defend the eye from the small particles floating 
in the air. In general they do not curl; when they do 
and turn towards the eye, an irritation ensues, and they 
must be cut off. Sometimes a bad direction is the cause 
of this irritation. 
I would remark on the subject of the eyelashes, that all 
the openings of communication with the interior, as those 
of the meatus auditorius externus, the nose and the anus, 
and oftentimes also the orifices of the lactiferous tubes, 
are surrounded with a great number of hairs which defend 
Eyelashes. 388 
PILOUS SYSTEM. 
these openings from external bodies. Around the mouth 
the beard takes the place of these hairs; the urethra has 
none, but the prepuce at its orifice is instead oi them. 
Beard. 
The males of most animals are distinguished from the 
females by some external productions. The comb of the 
cock, the mane of the lion, the horns of the stag, &c. are 
examples of these distinctive characters. In man, the 
beard is the principal attribute of the male. It occupies 
all the chin, the sides of the face, both lips and the supe- 
rior part of the neck. It leaves the cheeks bare as well 
as the parts around the eyes ; thus observe that it is there 
that the passions are principally depicted, the expression 
of which would be concealed by the hairs, if the Lower 
part of the face was the seat of them. 
The beard, not so long in general as the hair of the 
bead, is longer than that of every other part of the body. 
It is very commonly of the colour of the first, though 
more rarely flaxen and is more frequently of a bright red, 
which it often is in persons with flaxen hair. The nature 
of the hairs of the heard is the same as that of the hairs 
of the genital parts, the eyebrows, &c. They curl, are 
stifl'er, more resisting and uniformly less oily than the 
hair of the head. 
The quantity of beard varies remarkably in different 
men. Those in whom it is abundant and of a deep black 
are in general strong and vigorous. Observe also that 
the strongest males in the different species of animals are 
those, in whom the external production which distin- 
guishes them from the females, is the most conspicuous 
We might say that this characteristic production is the in- 
dex of the strength or weakness of their constitution. A 
small lion has not a noble mane; great horns belong to a 
well made stag, and long, twisted ones to a good formed 
ram. Observe that it is not the same with the other hairs PILOUS SYSTEM. 
389 
common to the two sexes. Often in a weak man, those 
of the arms, the thighs, &c. are as evident and even more 
numerous, than in the most muscular. 
The habit of cutting the beard as most Europeans do, 
of preserving it like the Asiatics and of dressing it in dif- 
ferent ways like the Chinese, gives a different expression 
to the face which characterizes the people. A masculine, 
vigorous physiogomy which expresses strength and ener- 
gy, cannot be deprived of this external attribute without 
losing a part of its character. That of the Orientals ex- 
hibits an appearance which coincides with the strength of 
their bodies, and forms a contrast with the effeminacy of 
their manners. I do not know if, in consulting the his- 
tory of the different people who allow their beard to 
grow, and that of nations who cut it, we might not be 
tempted to believe that muscular force is to a certain ex- 
tent connected with its existence, and that this force is 
always diminished a little when we are constantly de- 
prived of it. Every one knows the vigour of the an- 
cients, that of the people with long beards, and that even 
of certain men who, among us, allow their beards to grow 
in conformity with the laws of monkish institutions. No 
doubt many causes may make weakness exist with a 
beard ; but in a general view I think we can admit that 
there is a certain relation between it and strength. Take 
from a cock his comb, which is the characteristic of the 
male, as the beard is that of man, and he will lose strength. 
I am persuaded that we might take from the lion a part 
of his power by taking away his mane. We know the 
result of the experiments of Russel upon the castration 
of stags ; their horns, after this operation have grown in 
an irregular manner, or have not even grown at all. This 
external attribute of the male in this species, appears as 
we know at the period of virility, when the vital forces 
are increased. It is the same with the human beard. 
This coincidence would alone prove that the use of this 390 
PILOUS SYSTEM. 
last is to serve for an external character to the male sex. 
The eunuch, whose powers are feeble, loses also often- 
times much of his beard. 
Such are our prejudices in regard to the idea we form 
of beauty, that we ridicule what is really and absolutely 
so, for that is certainly so which indicates organic perfec- 
tion. A peacock without his tail of emeralds, a ram 
or a stag without their horns, displease us ; why does 
not man without his beard ? 
II. Of the Pilous System of the Trunk. 
The hairs on the trank are very variable. Some men 
appear as it were shaggy, whilst others are almost with- 
out hairs. There are more of them generally on the an- 
terior than on the posterior part of the trunk. It is prin- 
cipally along the linea alba and upon the chest, that they 
are found in man. This last part is in general destitute 
of them in woman, who has usually very few on the 
trunk. 
Both sexes have a very considerable quantity on the 
genital parts. They are there, as I have said, of the 
nature of the beard. Less frequently flaxen than the 
hair of the head, as frequently of a bright red, they are 
most usually black. They are, next to the beard, the 
longest hairs. They have generally no determinate direc- 
tion; each hair almost has a different one. Few animals, 
like man, exhibit this excess of hair upon the genital parts. 
There is a great difference in individuals as to its quantity. 
The blackness and abundance coincide in general with 
strength. 
III. Pilous System of the Extremities. 
Man has many hairs upon the whole surface of his ex- 
tremities. The proportion of number is nearly the same PILOUS SYSTEM. 
391 
in all ; but the length varies very much ; in some, they 
form only a down ; in others, they are a little longer; 
whilst in others, they are nearly of an inch in length, 
reach over each other, and give the extremities a shaggy 
appearance. 
At the top of the superior extremities, there is in the 
hollow of the axilla a collection of hairs which are longer 
than the others, and are nearly of the nature of those of 
the genital parts. Nothing similar is seen on the inferior 
extremities. 
The pilous system does not exist on the internal part of 
the arm and fore-arm in many men, in whom we see it 
only behind and on the sides. It is more uniform on the 
inferior extremities. The back of the foot and hand 
always have hairs. They are never seen on the sole of 
the one or the palm of the other; a circumstance of essen- 
tial advantage to the perfection of touch. 
ARTICLE SECOND. 
ORGANIZATION OP THE PILOUS SYSTEM. 
Whatever varieties exist in the form, size and arrange- 
ment of the hairs, their organization is nearly the same in 
all. We shall now examine this organization in a general 
manner. Chirac, Malpighi and all anatomists since them, 
have explained very well in some respects, and very badly 
in others, the structure of the hairs of the head, which is 
nearly the same as that of all the other hairs. The follow- 
ing is what careful dissection has shown me concerning it. 392 
PILOUS SYSTEM. 
I. Origin of the Hairs. 
The hairs of the head, and in general all the hairs, arise 
from a sub-cutaneous fat, or the cellular texture of the 
parts which are destitute of this fluid. Each is contained 
at its origin, in a kind of small membranous canal, the 
nature of which is perfectly unknown to me, and whose 
transparent parietes allow the hair to be plainly seen, 
when we have separated them with a delicate scalpel from 
the surrounding parts. This small cylindrical canal ac- 
companies the hair to the corresponding pore of the skin, 
insinuates itself into this pore, passes through it, extends 
to the epidermis and is intermixed there with the texture 
of this membrane, but goes no further. The length of 
this canal, and consequently of the course which the hair 
runs under and in the skin, is nearly five lines in the 
hairs of the head. There is no adhesion between the hair 
and the internal surface of this small canal, except at the 
enlarged base of the first where, it receives its nourish- 
ment. Thus, by opening the canal at this place, and 
destroying its adhesions there, the hair becomes free, and 
is drawn from without inwards with great ease, by taking 
hold of its enlarged end with small forceps. In this way, 
the canal is insulated. I have thus dissected and sepa- 
rated, upon a surface of two inches, a very great number 
of these canals which appear, when nothing but them is 
left on the internal surface of the skin, like so many small 
elongations of it. 
Are there vessels and nerves in this small cylindrical 
sac which contains the origin of the hairs ? We see dis- 
tinctly" elongations going to its external surface, especially 
towards its extremity opposite to the skin ; but dissec- 
tion does not teach us the nature of these elongations. I 
have never been able to trace them to a neighbouring 
vessel or nerve. Haller has not been more successful. PILOUS SYSTEM. 
393 
though he speaks of authors who have traced nerves to 
the origin of the hairs. I presume however that these 
elongations are especially vascular. Is there a fluid be- 
tween the origin of the hair and its covering? By open- 
ing the latter, nothing escapes, though some authors have 
pretended the contrary. Besides, if this fluid is in the 
form of dew, a6 upon the serous surfaces, it cannot be 
distinguished. 
It is in the middle of this small cylindrical sac, of 
which I have just spoken, that the origin of the hair is 
found. We see at its extremity an enlargement often- 
times almost insensible, at others very evident, though 
always less than has been said. This enlargement is of 
the same colour and nature as the hair itself. It adheres 
to the canal very probably by the vessels and perhaps the 
nerves it receives from it. The hair which arises from 
it goes through its canal without adhering, as I have said, 
to its parietes, passes with it through the oblique pore 
of the dermis, leaves it at the epidermis, and goes out- 
ward. 
All authors say that the hair does not pierce the epi- 
dermis, but only raises it up, and that this forms a sheath 
which accompanies it to its extremity. This assertion is 
incorrect; in fact, 1st, the hair is as thick in its canal of 
origin as it is out of it. 2d. This canal being opened at 
its extremity opposite to the skin, we can draw out of it, 
as I have said, the whole hair with great ease, and with- 
out the least resistance ; which would not be the case 
however if the covering of the epidermis was to be 
broken. It appears that from the enlargement of its ex- 
tremity, the hair has no adhesion either in the subcuta- 
neous canal, or in its passage through the skin, or the epi- 
dermis. 3d. If the cutaneous epidermis was raised up to 
cover the hair, this would have a treble thickness, unless 
this epidermis became wonderfully thin upon it. 4th. 
We do not see this pretended rising up by drawing out a 394 
PILOUS SYSTEM. 
hair of the head ; on the contrary a depression exists at 
the place where this comes out. The cutaneous epider- 
mis furnishes nothing then to the hairs, though the nature 
of them may be in part the same as its own, and it is 
proper to consider them as uniform in their structure from 
one extremity to the other. 
Under the skin, through it and out of it, the hair is 
composed of two distinct parts. One external, forms a 
canal which extends from the enlargement of the dermoid 
extremity to the opposite one ; the other internal, which 
composes as it were the medulla of it, is of an unknown 
nature. 
II. External Covering of the Hairs. 
The external covering of the hair appears to be of the 
nature of the epidermis. It has in fact almost all the- 
attributes of it. 1st. The hairs of the head burn exactly 
like this membrane, give out when burning an analogous 
odour, and leave after combustion a similar kind of coal ; 
now it is principally to the external portion that these 
phenomena are owing. 2d. Water penetrates the hairs 
with great ease ; hence very useful hygrometers can be 
constructed with them ; now the same is true of the epi- 
dermis •, and moistened hairs in foggy weather present in 
this respect a phenomenon analogous to that of the epider- 
mis softened, wrinkled and whitened by the contact of a 
cataplasm. 3d. It is by means of the epidermoid cover- 
ing that the hairs are foreign to life, that they are insen- 
sible and never become the seat of any acute or chronic 
affection. 4th. This covering is white, whatever may he 
the colour of the hairs. The cause of the colour resides 
in the internal medulla ; thus the epidermis of negroes 
and that of white people differ but very little. Hence 
why when the internal substance of the hair has dis- 
appeared, the canal remaining alone exhibits a more or PILOUS SYSTEM. 
395 
less evident whiteness. 5th. In this state, though the in- 
terior of the hair may be dead, the epidermoid exterior, 
which is independent of it, preserves most commonly the 
faculty of growing when it is cut; thus the cutaneous 
epidermis is truly foreign to all the subjacent diseases of 
the skin. 6th. I presume that it is this covering which 
gives to the hairs of the head the property of remaining 
so long uninjured. When removed far from the access of 
the air, they remain unaltered for ages ; they have not in 
them the principle of decomposition of the other animal 
substances. They never become putrid either in air or 
water. Thus we have seen that the cutaneous epidermis 
never undergoes putrefaction, which seizes upon the sub- 
jacent parts. 
It appears however that the hairs are more unalterable 
than the epidermis, and that there is even a difference of 
nature between them. In fact, 1st, maceration and ebulli- 
tion, which make the epidermis very easy to be broken, 
though they soften it but little, leave the hairs with their 
usual resistance, unless carried to degrees that I have not 
tried. By boiling and macerating them comparatively 
with the epidermis, we easily make this observation. 2d. 
The acids act less efficaciously upon the hairs than upon 
this membrane ; but the alkalies dissolve them with as 
much and even more ease. 3d. A thread of epidermis 
of equal thickness would be incomparably less resisting 
than a hair. 4th. The hairs can, like the epidermis, be 
painted of different colours ; but they do not retain them 
so long, and on this account the colour must be renewed 
oftener. 
Some modern authors have said that there is detached 
from the external covering of the hairs a kind of scales 
which form as it were little branches to them. We do 
not see these elongations. However the experiment men- 
tioned by Fourcroy, and which consists in this, that by 
rubbing a hair between the fingers, it is raised like the 396 
PILOUS SYSTEM. 
heads of some species of grain in the direction from its 
base to its point, this experiment, I say, appears to prove 
the existence of these insensible elongations, which per- 
form also an essential part in the adhesion of the hairs of 
the head to each other, an adhesion that is such that when 
they have remained a long time without being separated, 
as in long diseases, it is only done with the greatest 
difficulty. 
Sometimes the hairs are bifurcated in a very evident 
manner at their extremity. 
It is the greater or less thickness of the epidermoid 
covering of the hairs, which constitutes the different nature 
of them. Thick and compact on the genital parts, the 
chin, &c. it is less easily penetrated with water, and ren- 
ders the hairs more elastic there and more capable of 
curling. Loose and thin in the hairs of the head, it makes 
them more smooth, and gives them more sensibly the pro- 
perty of the hygrometer. It. is the peculiar nature of this 
external covering, which gives to the hairs of the head 
and the hair of negroes the character which distinguishes 
them. 
From what we have just said it is evident that the ex- 
ternal covering of the hairs of the head is the part of them 
which is essentially inert and foreign to life. It is not 
the same with their internal substance. 
III. Internal Substance of the Hairs. 
This substance is the most important; it is this which 
essentially characterizes the hairs, which I should have 
ranked in the epidermoid system, if they had nothing but 
their external covering, as is the case when they become 
white. 
We are entirely ignorant of the nature of this internal 
substance. It can only be presumed that there are ex- 
tremely delicate vessels inclosed in the common epider- PILOUS SYSTEM. 
397 
moid covering containing a colouring substance, which 
stagnates in these vessels, or at least is subjected in them 
to a very slow nutritive motion. Among these vessels, 
do any of them as on the skin, open outwards to throw 
off fluids? Many physiologists have thought so, and on 
this account they have considered the hairs as real emunc- 
tories. I do not believe that we have any anatomical 
data upon this point; but the plica polonica, a singular 
disease in which the hair when cut pours out blood, evi- 
dently proves that they have exhalants in a natural state, 
which then becoming enlarged and dilated, pour out a 
fluid that they before refused to admit. Besides, there 
is no doubt that the pilous exhalants, infinitely less active 
than the cutaneous, are a much less copious emunctory. 
As to the absorptions which some have pretended are 
made by the vessels of the hairs, I think that nothing can 
prove them. 
From what we have just said upon the internal sub- 
stance of the hairs, it appears that it has a true analogy 
with the reticular body of the skin, and that, like it, it 
arises from two sorts of vessels, one in which the colour- 
ing matter stagnates, the other which gives passage, in 
some cases at least, to fluids, and in which there is con- 
sequently a kind of circulation. 
The colouring substance of the hairs has some analogy 
with that of the skin. Thus we observe that the first, 
like the second, is blacker in warm climates and nearer 
the equator than in colder ones ; thus red hair is fre- 
quently found with freckles which are more or less abun- 
dantly spread upon the skin of some people, and which 
are evidently seated in the reticular body, as I have ascer- 
tained in many patients who had these marks, and in 
whom the epidermis was raised up either by erysipelas 
or a blister. The acids however change the colour of the 
hair more than they do that of the skin of negroes. The 
muriatic whitens at first the hairs of the head which 398 
PILOUS SYSTEM. 
become yellow in drying ; the nitric yellows, and the 
sulphuric leaves them black. 
That which especially interests us in the internal sub- 
stance of the hail’s, is the real vitality which it enjoys, 
and which essentially distinguishes it from the external 
covering. It is to this character that must be referred 
the following phenomena. 
1st. The different passions of the mind have a remark- 
able influence upon the internal substance of the hairs. 
Often, in a very short time, grief has changed the colour 
of it, and whitened it by occasioning no doubt the re- 
absorption of the fluid contained in the small capillary 
vessels. Many authors have related facts of this kind. 
Some, even Haller, have doubted them. But I know at 
least five or six instances in which a discoloration has 
taken place in less than eight days. The hair of a person 
of my acquaintance became almost entirely white in the 
course of a night upon the receipt of melancholy intelli- 
gence. In these changes, the epidermoid covering re- 
mains the same, preserves its texture, its nature and its 
properties; the internal substance only is altered. It is 
said that terror can make the hair stand an end ; painters 
express it even by this external attribute ; I know not to 
what extent we should give belief to this phenomenon 
which I have never seen ; but it is an opinion too gene- 
rally received not to have some real foundation. Now if 
fear acts so powerfully upon the hair, if it can give it a 
real motion, is it astonishing that grief and pain should 
suddenly change the fluids that are found in it, and de- 
prive it even of these fluids ? 
2d. The plica polonica, of which I spoke just now, in 
which the hairs of the head become, when they are cut or 
even when they are not, the seat of a bloody exhalation, 
and in which they have a remarkable excess of life, evi- 
dently resides in the internal substance ; the epidermoid 
covering has no connexion with it. Some authors even PILOUS SYSTEM. 
399 
say that this internal substance acquires sometimes a fleshy 
nature ; then their covering is raised up in scales. 
3d. We know the danger of cutting the hair after many 
acute diseases. I have already seen a melancholy in- 
stance of it. Many physicians, Lanoix in particular, have 
related others. Now, to what are these accidents owing? 
It is certainly not to the contact of the air, from which 
the hair defends the head ; for these accidents take place, 
though the head may be covered. It can only be owing 
to this, that the growth of the hairs that are cut, calls to 
these organs a vital activity which the internal viscera 
soon sympathetically feel ; hence the pains of the head, 
the affections of the eyes, &c. observed in these cases. 
It is a species of active sympathy exerted by the hair 
upon the viscera ; now, every organ which sympathizes 
has a real vitality, and enjoys very distinct vital proper- 
ties. The epidermis never takes part in sympathies, be- 
cause it is almost completely inert, is hardly organized, 
is not at the level of the other organs, and cannot conse- 
quently correspond with them. The danger of cutting 
the hair after severe sickness, gives me opportunity to 
observe that it is often as dangerous to remove suddenly 
the vermin from the heads of children during these dis- 
eases. I have seen three or four instances of accidents 
from this cause. 
4th. The hairs not only influence other systems, but 
are also influenced by them. This is what we often see- 
after acute diseases, in which the roots sympathetically 
affected, repel the fluids that come to nourish them, die, 
and the hairs fall out. Observe that this falling out of 
the hair very rarely takes place at the same time with the 
desquamation of the epidermis ; which proves, that the 
generally admitted opinion of the origin of the external 
covering of the hairs is entirely false, and that, though 
very analogous to the epidermis, this covering does not 
arise from it, as I have said. 400 
PILOUS SYSTEM. 
5th. Many animals lose at one season of the year their 
hairy covering, which is afterwards reproduced; now the 
period of its regeneration is often that of many diseases, 
and almost always that of a greater weakness than at other 
times. We might say that the nutritive work which then 
calls to the exterior much vital force, diminishes this 
force in the other regions. Man is not subject to these 
annual renewals of the external productions which cover 
his body, like birds, many quadrupeds, reptiles, &c. It 
is a cause of less diseases. In fact, a thousand different 
causes would no doubt have frequently deranged these 
renewals in society, as a thousand causes disturb the men- 
strual evacuation, &c. ; hence the various diseases we 
escape by the want of this renewal. Man is in general 
subjected to fewer causes of natural revolutions, than most 
animals. 
6th. Heat and cold have also oftentimes an influence 
upon the internal substance of the hairs. We know that 
in some animals, as rabbits, hares, &c. they become white 
in the winter and resume their original colour in the sum- 
mer. 
7th. A short time after painting the hairs of the head 
black, a fashion now more common in France than at the 
period in which they powdered them, there is often ex- 
perienced pains in the head and a swelling of the hairy 
scalp, though the skin has been in no way concerned, 
has not been pulled, and the hair only has been affected. 
It follows from all we have just said, that the hairs 
analogous, by their external covering, to the epidermis; 
foreign by means of it, if we may so say, to life, belong to 
it much more particularly by their internal substance, a 
substance whose nature is yet but little known, as I have 
already said. What moreover evidently proves this asser- 
tion, is that the phenomena of which I have just spoken, 
and to which I could add many others, cease to be evi- 
dent in persons, in whom the hairs having become white, PILOUS SYSTEM. 
401 
have no longer any thing but the epidermoid covering, 
the internal substance having in part disappeared ; parti- 
cular observation proves this. It may be however that 
in this case that portion alone of this internal substance, 
corresponding to the colour, is destroyed, whilst that which 
is the seat of the exhalations continues to live as usual; 
and, in this respect, white hairs may experience vital 
phenomena, of which, I believe, there are a few examples. 
But all this is subordinate to the future experiments, 
which will elucidate the pilous structure more than it 
now is. 
ARTICLE THIRD. 
PROPERTIES OF THE PILOUS SYSTEM. 
The hairs experience but a slight degree of the horny 
hardening when exposed to the action of caloric. They 
then turn in various directions, curl and twist; but this 
arises from a cause entirely different from that of the 
horny hardening of the other organs. The caloric then 
removes the moisture with which the hairs are constantly 
penetrated, and thus approximates their particles. Thus 
when the hair is moistened by fog, a bath, &c. the curls 
disappear. The oily substances that are used at the toilet, 
give a coat that is insoluble in water, and preserve the 
curling, by preventing it from penetrating the hairs. 
Some time after the head has been washed, they curl 
more, as we have had occasion to observe since the Gre- 
cian head dresses have been in fashion among us. This 402 
FILOUS SYSTEM. 
at first appears to be contradictory, but it is not so. In 
fact by then rubbing the hairs much, the unctuous sub- 
stance is removed, which always surrounds them, or this 
substance combines with the soap, if the water contains 
it, as is often the case; by this means it easily penetrates 
the hairs, the pores of which remain open, and by after- 
wards evaporating with the fluids that were already there, 
and which the unctuous substance retained, it leaves these 
organs more dry than they were, and consequently more 
disposed to curl. 
A proof, that it is the epidermoid covering which thus 
imbibes the moisture that it afterwards loses in the state 
which succeeds the curling, is, that the detached epider- 
mis can be curled with a hot iron, and afterwards render- 
ed supple by soaking it in water. 
The contractility and extensibility of texture are very 
indistinct in the hairs ; it is their resistance which pre- 
vents their rupture ; they can hardly be stretched at all. 
They have no animal sensibility when pulled ; the pain 
that arises from it has its seat especially in the skin 
through which they pass. Thus when drawn opposite to 
their direction, we suffer much more than by stretching 
them in the direction of their pores. I do not deny how- 
ever that these elongations, which fix their origin to the 
neighbouring parts, may be also the seat of pain when 
the hairs are pulled. These organs have no animal con- 
tractility. 
The organic properties certainly exist in their internal 
substance. The changes which this substance undergoes 
can only depend on the different alterations which affect 
these properties. The organic sensibility and the insen- 
sible contractility especially are raised in it in a remark- 
able degree in the plica polonica ; now in order to have 
the degree of energy which they then do, they must have 
existed there in a natural state. It is these two proper- 
ties, that, the sympathies of which we have spoken. PILOUS SYSTEM. 
403 
put into action. The organic contractility is nothing in 
the hairs. 
Yet we cannot deny that in the natural state, these 
organs are, next to the epidermis and the nails, those in 
which life is the least active, those which have the least 
numerous relations with the other organs. Whilst every 
thing is destroyed in most of the other systems by dis- 
eases, this is most often unaffected by them ; it grows as 
usual, and appears to be in no wise disturbed; it has then 
a manner of being, of existing, wholly different from the 
others. 
In general, the external productions of animals, as the 
feathers, the hair, the scales, &c. seem to form a separate 
class of organs, foreign to the life of the internal organs ; 
it is almost like the different species of mosses that grow 
upon trees, without making essentially a part of them. 
ARTICLE FOURTH. 
DEVELOPMENT OF THE PILOUS SYSTEM. 
1. State of this System in the First Age. 
In the first months of the foetus there are no hairs on 
the skin which is then gelatinous. It is when the fibres 
of the dermoid texture are formed, that there begins to 
appear on the head a light down, an indication of the 
hairs which are afterwards to arise. This down is whitish 
and concealed by that fatty and unctuous substance, which 404 
PILOUS SYSTEM. 
we have said is deposited on the external surface of the 
skin at this age. Soon this down, which appears to be 
but the external covering of the hairs, which is then of 
extreme tenuity, begins to be coloured black or flaxen, 
according to the tint that is afterwards to predominate; 
it is the internal substance that forms it. The colour re- 
mains faint until after birth. At this period the hairs are 
often more than half an inch long. Upon all the rest of 
the body there is only the down, the precursor of the 
hairs; the face especially has much of it. The hairs of 
the head are then in advance at one period of the other 
hairs, in their growth. 
After birth the hairs grow much more rapidly than be- 
fore. It is precisely the reverse of most of the other 
parts, whose growth is more rapid in the womb of the 
mother. During the whole of youth this system has a 
tint less deep, than it is afterwards to have. The flaxen 
becomes nearer the chesnut, and this nearer black, and 
the first tints of the bright red grow many degrees darker 
towards the period from the twenty-sixth to the thirtieth 
year. The light tints are to the pilous system in youth, 
what the imperfectly developed forms are to the muscu- 
lar, cellular, &c. Oftentimes that which is to be after- 
wards flaxen, approaches a whitish tint, which is owing 
only to the nature of the internal substance, and not to its 
absence in old age. Thus the white of the Albinoes de- 
pends also upon the peculiar species of this internal sub- 
stance. Many hairs are wanting upon the body of the 
young man. 
II. State of the Pilous System in the following Jiges. 
At puberty there is a remarkable revolution in this 
system which becomes almost double. The hairs of the 
genital parts are formed; the beard which is, as I have 
said, the characteristic attribute of the male in the human 
species, is also then developed. We might say that there PILOUS SYSTEM. 
405 
was the same relation between the hairs of the neigh- 
bourhood of the testicles and those of the beard, as be- 
tween the testicles themselves and the organs of the 
voice, between the womb and the mammse. The beard 
is, in this respect, the external sign of virility. Some 
time before it comes out, we see under the skin the sac 
which contains the origin of the hairs ; it is already very 
evidently formed, and permits the principle of the organ 
to be seen which it is to contain, as I have oftentimes as- 
certained ; thus the sac of the tooth exists a long time be- 
fore the tooth is cut. 
At the same time the hairs of the axilla grow also; 
those of the trunk and extremities, which were then al- 
most in a state of down, become larger, assume a deter- 
minate colour, and increase even much in number. 
Why does puberty occasion this general growth in the 
pilous system ? This is asking the reason of all the other 
phenomena which appear at this period. I would only 
observe that the hairs of the head, the eyebrows, the eye- 
lashes and the hairs at the openings of the body, are those 
which are the least affected by this revolution. Besides, 
this growth is gradual; it requires at least two or three 
years for the beard to become what it is always to be. 
In the following ages the hairs undergo but few changes: 
they grow in proportion as they are cut in different parts, 
and are the seat of a constant external work ; now, observe 
that this work is more prompt, and the growth of the 
hairs consequently more rapid, in summer in which the 
cutaneous organ is especially in action, than in winter in 
which it is contracted ; an additional proof of the real 
vitality of the organic forces of the internal substance of 
the hairs. 
III. State of the Pilous System in Old Jlge. 
Towards the end of life, the pilous system is affected 
by the general obliteration which takes place in almost all 406 
PILOUS SYSTEM. 
the external vessels; it ceases at first to receive the col- 
ouring substance. The internal substance dies, the epi- 
dermoid covering remains alone ; the hairs become white. 
The hairs of the head appear the first, and are the first to 
die. The heard, the hairs of the genital parts and then 
those of all the parts of the body afterwards die. Be- 
sides, there is a great variety among men as it respects 
the period in which the hairs whiten ; in some, this phe- 
nomenon begins about the thirtieth year, and even sooner, 
in others it is towards the fortieth, fiftieth or sixtieth. A 
thousand causes arising from the passions of the mind, 
from diseases, aliments, &c. can have an influence in so- 
ciety upon this premature death, so common in many 
men, but which does not take place in animals, who are 
not exposed from their kind of life, to the same revolu- 
tions, until the last years. 
The hairs, after remaining white for a longer or shorter 
time, finally fall out; then the sac which covered the 
origin of them flattens down and entirely disappears. I 
have examined many bald heads ; the skin of the cranium 
was perfectly smooth on its internal surface, though it 
had been separated from the cellular texture. No trace 
is discoverable there of the innumerable appendices which 
the canals form, after the hairs they contain have been 
drawn inwards. I have also dissected a man who after a 
putrid fever had become almost entirely bald. There 
were all these little canals entire, and in the bottom of 
them could already be seen the rudiments of new hairs. 
There is then this difference between the falling out of 
the hairs of old people, and that which is the consequence 
of diseases, that every thing dies in the first, because the 
vessels which go to the root cease to transmit fluids to it; 
whereas in the second case the hair alone falls out, and 
its sac remains. 
It is a pretty generally received opinion that the hair, 
the nails and the epidermis continue to grow after death. PILOUS SYSTEM. 
407 
We have, I think, but few data respecting this singular 
phenomenon. I am however certain that I observed a 
real elongation of the hairs of a chin of a head that had 
been carefully shaved, and which I macerated eight days 
in a cellar. An attendant of the dissecting room, who 
prepares many heads for the bones, informed me that he 
had often made the same remark, when putrefaction is 
prevented for some time. What is certain also is, that the 
growth of the beard is not in the direct ratio of the vital 
forces ; in the diseases which affect these forces with 
a general prostration, it grows as much as in those in 
which there is a general exaltation of these forces. We 
remark this in hospitals where at the side of an inflam- 
matory fever, there is often found a putrid or slow nerv- 
ous one. Besides, why should there not be sufficient 
tonic forces left in the hairs to grow some time after 
general death, as there is in the lymphatics to absorb, &c. ? 
The different phenomena which the hair, the epider- 
mis, the skin, and in general all the external organs ex- 
perience in the successive ages, are wholly owing, like 
those of the internal organs, to the laws of nutrition, and 
not to the action of surrounding bodies. This is an essen- 
tial difference between organic and inorganic bodies. The 
latter are gradually altered in two ways by the contact of 
external bodies which act upon them, 1st, mechanically 
by friction, tearing, &c. &c. ; 2d, chemically, by combin- 
ing with them, as for example, the air whose different 
principles undergo many combinations which change its 
nature and that of the bodies with wrhich it is in contact. 
In this respect all inorganic bodies grow old. At the end 
of some time, they have no longer the exterior which 
characterized them in the beginning. Observe monuments, 
pictures, engravings, earths, metals, stones, &c. &c. every 
thing which in the arts, commerce, sciences, in the uses of 
life or in the phenomena of nature is formed of any inert 
bodies, whether these bodies have never lived, or having 408 
PILOUS SYSTEM. 
lived, have not been able to preserve themselves after death, 
as the solid portions of vegetables, the bones, the horns, the 
hair of animals, &c. every thing finally has the indelible 
stamp of time ; every thing grows old ; every thing loses 
its freshness, every thing changes on the exterior of inert, 
as well as on that of organic bodies ; but as in the first sur- 
rounding bodies alone have acted, the internal partis still 
young, whilst the external is old, if I may be allowed to 
use two very improper words. Thus the rock whose sur- 
face is blackened by the lapse of years, is the same in the 
interior as when it was created. On the contrary in ani- 
mals and vegetables, the internal organs are worn out, as 
well as the exterior. Time is marked upon the viscera, as 
well as upon the forehead of the aged. Surrounding 
bodies act upon us, wear out life, if we may so say ; but 
it is as stimuli that they exert their action; it is by ex- 
hausting the sensibility and contractility, and not by com- 
bination, mechanical contact or friction. Language ought 
to express this difference. We do not use the term 
young when viewing the exterior of a new building, a 
new garment, or a picture recently painted ; why do we 
say an old monument, an old piece of cloth, &c. ? if it is 
a metaphor, very well; but this word cannot express a 
state analogous in its nature, to that of an old animal, an 
old plant, &c. 
IV. Preternatural Development. 
There are three principal cases in which the hairs are 
preternaturally developed in the economy. 
1st. Sometimes they are formed on the internal sur- 
face of the mucous membranes; they have been seen in 
the bladder, the stomach and the intestines ; many authors 
have given cases of them. I have found them upon the 
calculi of the kidney. I have seen in the gall-bladder at 
one time a dozen of nearly an inch in length, and which 
were evidently implanted in its surface. PILOUS SYSTEM. 
409 
2d. There is often seen on the skin preternatural col- 
lections of them, which are usually a defect from birth. 
These collections are particularly observed upon some of 
those productions or irregular excrescences, that are called 
naevi materni. There was exhibited at Paris, six years 
since, an unfortunate person, who had from his birth his 
face covered with hairs almost like those of a wild boar ; 
and to whom there came on at the age of thirty-six years, 
that particular species of elephantiasis, in which the skin of 
the face increased in size, exhibits, if we may so say, the 
features of the lion, a species which I have since had 
occasion to observe upon a natural skin. This double 
circumstance gave to the face of this man an air of fero- 
city which it is impossible to describe. Many of the 
stories circulated by the vulgar concerning men with the 
heads of wild boars, bears, &c. are nothing but these naevi 
in the face, with a growth of hair upon them. 
3d. Hairs are often preternaturally developed in cysts, 
in those of the ovaria especially. A great many instances 
have been related. Haller in particular has collected 
many ; I have seen two. The following is what they ex- 
hibit ; a considerable large sac contained many very dis- 
tinct small balls, analogous to those of the dung of sheep, 
formed by a fat, unctuous, whitish substance, very differ- 
ent in its appearance from ordinary fat. On the internal 
surface of this sac were implanted many hairs, which the 
least force could remove, because they hardly penetrated 
below the surface. These hairs were black. Many 
already detached were found crossed in different direc- 
tions, in the small balls of fatty matter, which was like 
spermaceti; for it very much resembled the substance 
into which the fat is changed by maceration. 
END OP THE LAST VOLUME. .lv.ilytic.il table of contents. 
VOLUME FIRST. 
PAGE. 
Preface by the Translator. 5 
Preface by the Author. ib. 
GENERAL OBSERVATIONS. 
Of Animate and Inanimate Beings.—Of their Laws.—Of 
the Sciences which treat of their Phenomena. 9 
I. General Remarks upon the Physiological and Physical Sciences. 
The differences between these sciences are derived from 
the properties which preside over the phenomena.— 
The necessity of always connecting the second with the 
first.—Periods at which this progress commenced in 
the physical sciences. False applications made to the 
physiological sciences.—The necessity of following in 
these the same course as in the others. 9 
II. Of the Vital Properties. and their influence upon the pheno- 
mena of the Physiological and Physical Sciences. 
Vital properties considered in the series of living beings. 
—Of those which animate plants.—Consequences in re- 
gard to their diseases.—Of those which belong to ani- 
mals.—Consequences in regard to their diseases.—Ex- 
amination of each vital property under the relation of 
the diseases over which it presides.—Necessity of re- 
ferring to these properties the action of medicines. 
—Uncertainty of the Materia Medica.—Each vital pro- 
perty has a particular class of medicines which act upon 
it.—Proofs.—Inconveniences of describing morbid phe- 
nomena and those of medicines in too general a man- 
ner.—Consequences of the preceding remarks. 13 412 
ANALYTICAL TABLE 
P^GE 
III. Characters of the Vital Properties, compared with the charac- 
ters of the Physical Properties. 
Extreme variableness of the first, invariableness of the 
second.—Consequences of this principle as it regards 
the phenomena.—There can only be diseases where 
there are vital properties.—Why.—The progress of 
the physiological and physical sciences wholly different 
in this respect.—Differences between animate and in- 
animate solids and fluids.—The vital properties become 
exhausted, the physical do not—Consequences.—The 
latter are inherent in matter, the others are not.— 
General remarks upon the enumeration of the differ- 
ences of animate and inanimate bodies.—Particular re- 
mark relative to sympathies.—Their general pheno- 
mena. 23 
IV. Of the Vital Properties and their Phenomena considered in 
relation to the Solids and the Fluids. 
Division of the fluids into those of composition and 
those of decomposition.—The vital properties are 
seated essentially in the solids.—These are the seat of 
almost all the morbid symptoms.—The fluids however 
may be affected.—Different attributes of the fluids of 
composition and of those of decomposition in diseases. 
—How the alterations of the first may take place.—Of 
those of the second.—Of the cases in which the solids 
and the fluids are primarily affected.—Division of dis- 
eases in this view.—The question must necessarily be 
considered in many points of view.—What is true on 
one side is not so on another.—Of the vitality of the 
fluids.—What it is.—Their alterations affect their vi- 
tality.—New proofs of these alterations.—How the 
fluids are assimilated and altered. 29 
V. Of the Properties Independent of Life. 
Properties of texture.—Of contractility by the horny 
hardening.—Of the agents which put it into action.— 
It is of two kinds.—Characters of each.—Their differ- 
ences.—Almost all the solids undergo the horny hard- 
ening.—Condition which it requires.—Of the horny 
hardening during life and after death.—Difference of 
this contractility from the others.—General remarks. 33 OF CONTENTS. 
413 
PAGE 
VI. General Observations upon the Organization of Animals. 
Of the simple systems.—Necessity of considering- them ab- 
stractedly.—Their difference of forms.—Their variety 
of organization, 1st, in the peculiar texture ; 2d, in the 
common parts.—Manner of knowing these differences. 
—Differences of the vital properties and of texture.— 
Of the peculiar life.—It cannot be understood of the 
compound organs, but of the simple systems.—Exam- 
ples which prove this assertion in the different organs. 44 
VII. Consequences of the preceding Principles relative to Diseases. 
Each texture can be separately affected in an organ.— 
This even almost always happens.—Various proofs of 
this assertion.—Observations upon different diseases. 
—Sympathies do not take place in an organ as a w hole, 
but in some one texture of this organ.—Why.—Of sym- 
pathetic fevers.—The different inflammations vary in 
each texture.—Phenomena of the different kinds of 
virus variable from the same cause.—Yet the different 
textures of the same organ have a certain dependance 
upon each other.—Proofs.—Diseases chronic and acute. 
—Differences of diseases in each simple system.—Two 
classes of symptoms in the local affections.—Their dif- 
ference.—Varieties of the pain, heat, &c. according to 
the systems.—What should be understood by acute and 
chronic affections in the simple systems.— Influence of 
these considerations upon morbid anatomy.—Defects of 
the old divisions.—New manner of considering morbid 
anatomy. 4© 
VIII. Remarks upon the Classification of the Functions. 
Table of this classification. 6© 
SYSTEMS COMMON TO ALL THE APPARATUS. 
General Observations. 
Division of the systems.—Systems common to all the ap- 
paratus.—Their characters.—They form the nutritive 
parenchyma of the organs.—Remarks upon nutrition.— 
Diversity of the nutritive substances. 77 414 
ANALYTICAL TABLE 
CELLULAR SYSTEM. 
PAGE 
General Remarks.—Division. 87 
ARTICLE FIRST. 
OF THE CELLULAR SYSTEM CONSIDERED IN RELATION TO THE 
ORGANS. 
I. Of the Cellular System exterior to each Organ. 
Division of the organs in relation to the neighbouring 
texture. 88 
Of the Cellular System which adheres only to one side of the 
organs. 
Sub-cutaneous cellular texture.—Arrangement of this tex- 
ture, 1st, upon the median line; 2d, in the different 
regions of the body.—Varieties of density and laxity. 
Uses of the sub cutaneous texture.—Its fluids. 88 
Sub-mucous cellular texture.—Difference of this texture 
from the preceding.—The density of that.—Conse- 
quences. 
Sub-serous cellular texture.—It is in general loose and 
abundant.—Why.—Place where it is dense. 92 
Cellular texture exterior to the arteries.—Its peculiar nature 
is analogous to that of the sub-mucous texture.—Its re- 
lations with the arterial fibres. 
Cellular texture exterior to the veins.—It is analogous to the 
preceding, only less thick.—Remarks. 
Cellular texture exterior to the excretory ducts.—The same 
structure and arrangement as in the preceding. 96 
Of the cellular system considered in relation to the organs 
that it surrounds on all sides.—Cellular atmosphere.— 
Fluids of this atmosphere.—Insulation of the vitality of 
the organs.—Of this atmosphere considered as a means 
for the propagation of diseases.—It favours the mo- 
tion of the parts. 96 
II. Of the Internal Cellular System of each Organ. 
Arrangement of this texture.—Its uses.—Its different pro- 
portions. 102 OF CONTENTS. 
415 
ARTICLE SECOND. 
OF THE CELLULAR SYSTEM CONSIDERED INDEPENDENTLY OF THE 
ORGANS. 
PAGE 
I. Of the Cellular System of the Head. 
Cellular texture of the cranium.—It is almost nothing within. 
—Its communications.—Consequences of these com- 
munications —It is more abundant without. 
Cellular texture of the fac .—It is very abundant.—Its 
uses.—Its communications, &c. 104 
II. Of the Cellular System of the Trunk. 
Vertebral cellular texture.—It is not abundant in the cavity 
of the canal.—On the exterior, there is but little be- 
hind, and more in front.—Consequences. 
Cervical cellular texture.—It is abundant.—Its communica- 
tions.—Consequences. 
Pectoral cellular texture.—It is found especially upon the 
median line.—Its communications.—External texture. 
Abdominal cellular texture.—Of the parts in which it is 
most abundant.—Its communications. 
Cellular texture of the pelvis.—It is very abundant.—Why. 
—Consequences.—Its communications. 108 
III. Of the Cellular System of the Extremities. 
Its different proportions in the superior and the inferior. 112 
ARTICLE THIRD. 
OF THE FORMS OF THE CELLULAR SYSTEM, AND THE FLUIDS IT 
CONTAINS. 
I. Of the Cells. 
Their form.—Their capacity.—Their communication — 
Experiments.—Of the cellular permeability.—In what 
sense it should be understood. 114 
II. Of the Serum of the Cellular Membrane. 
Proof of its existence.—Its evaporation.—It varies in 
the different regions.—Method of ascertaining the pro- 416 
ANALYTICAL TABLE 
PAGE 
portions of it.—Experiments.—Nature of this fluid.— 
Experiments. 117 
III. Of the Cellular Fat. 
Natural proportions of the fat.—Varieties of its propor- 
tions according to the regions, organs, systems, &c.— Its 
peculiar arrangement in childhood.—Varieties accord- 
ing to the other ages. 119 
Unnatural proportions of fat.—Its preternatural abundance 
indicates weakness.—Different proofs.—Of the causes 
of the diminution of fat.—Remark upon this diminu- 
tion. 121 
Different states of the fat.—Its degree of fluidity is not 
during life in proportion to temperature.—Its consist- 
ence in young animals.—Consequences.—Its alterations 
by age, diseases, &c. 125 
Exhalation of fat.—Different opinions.—The fat is ex- 
haled.—Proofs.—Nature of this fluid.—Relation of its 
uses with the places where it exists and with those in 
which it is wanting. 127 
ARTICLE FOURTH. 
ORGANIZATION OF THE CELLULAR SYSTEM. 
I. Texture peculiar to the organization of the Cellular System. 
Filaments and layers from which it results.—Method of 
seeing them to advantage.—Their nature.—Essential 
difference in the cellular organization.—There are two 
species of cellular texture. 129 
Composition of the cellular texture.—Experiments upon 
this texture.—Action of the air, water, caloric and the 
gastric juices.—Experiments.—Of the gases sometimes 
extricated in the cellular texture. 132 
II. Parts common to the Organization of the Cellular Texture. 
Blood vessels.—The inaccuracy of injections in demon- 
strating them. 
Exhalants.—Of the cellular exhalations.—Proofs and phe- 
nomena of these exhalations. 
Absorbents.—Cellular absorptions.—Proofs.—The cellular 
texture is not wholly formed of absorbents. 
Nerves. 136 
•# OF CONTENTS. 
417 
ARTICLE FIFTH. 
PROPERTIES OF THE CELLULAR SYSTEM. 
I. Properties of Texture. 
PAGE 
Extensibility.—Examples of the different distensions.— 
Distinctive character of the cellular extensibility.—Its 
phenomena.—It becomes nothing in inflammation, chro- 
nic engorgements, &c. 
Contractility.—Different examples of this property brought 
into action.—Its varieties according to the ages.—Gene- 
ral remarks. 140 
II. Vital Properties. 
The animal ones are inconsiderable.—The organic are 
greater, except sensible contractility, which however 
exists to a certain extent. 
Sympathies.—It is necessary to distinguish them from the 
phenomena of juxta-position.—Various examples.— 
General observations.—Vital properties put in action 
by the sympathies. 
Character of the vital properties.—The vital activity is very 
considerable in the cellular texture.—Various proofs.— 
Remarks upon the species.—Difference of vitality in 
the two species of cellular texture. 143 
III. Properties of Re-production. 
Influence of the cellular texture upon the formation of cica- 
trices.—Division of the periods of the cicatrices. 
First, period.—Inflammation.—How it takes place.—Its ad- 
vantages. 
Second period.—Fleshy granulations.— Experiments.— 
Provisional membrane of the cicatrices.—Its uses.— 
General phenomena of the internal cicatrices.—Cellu- 
lar nature of this membrane and of the granulations. 
—Different opinions. 
Third period.—Suppuration.—What corresponds to it in 
the internal cicatrices.—Analogy of these cicatrices 
with the external. 
Fourth period.—Contraction of the fleshy granulations.— 
Adhesions.—Consequences of the preceding principles. 
—Of union by the first intention. 148 418 
ANALYTICAL TABLE 
PAGE 
Influence of the cellular texture in the formation of tumours. 
—Cellular nature of all tumours which grow and in- 
crease.—Proofs.—Mode of development of these tu- 
mours.—How they differ from various engorgements, 
acute and chronic. 157 
Influence of the cellular texture in the formation of cysts.— 
What is a cyst.—Its analogy with the serous surfaces. 
—Its cellular structure.—Mode of its development. 160 
ARTICLE SIXTH. 
DEVELOPMENT OF THE CELLULAR TEXTURE. 
I. State of the Cellular System, in the First -Age. 
Mucous mass represented by the cellular texture of the 
foetus.—Superabundance of fluid.—This is then the 
cellular fluid.—Difficulty of emphysema in the foetus.— 
State of the cellular texture in infancy and youth.—Its 
vital energy.—Consequences. 164 
II. State of the Cellular System in the After Ages. 
Arrangement of the cellular texture in the adult.— 
Differences arising from sex.—Degeneracy of this tex- 
ture in old age.—Withering that it experiences.—Con- 
sequences. 167 
NERVOUS SYSTEM OF ANIMAL LIFE. 
Division of the nerves into two systems.—Differences of 
these two systems.—General arrangement of that of 
animal life.—Its symmetry.—Relation of size between 
the nerves and the brain. 169 
ARTICLE FIRST. 
EXTERNAL FORMS OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
I. Origin of the Cerebral Nerves. 
In what sense this origin must be understood.—It takes 
place, 1st, in the brain; 2d, in the tuber annulare and OF CONTENTS. 
419 
PAGE 
its dependancies; 3d, in the spinal marrow.—Manner of 
this triple origin.—Of the crossing of the nerves.— 
Phenomena of paralysis in regard to this.—Peculiar 
arrangement of the cerebral membranes at the origin 
of the nerves.—Extent, direction and form of the nerves 
at this origin. 171 
II. Course of the Cerebral Nerves. 
Communications of the cerebral nerves at their exit from their 
osseous cavity.—There are none between the nerves of 
the brain properly called—The communications begin 
in those of the tuber annulare.—They are very nume- 
rous in those of the spinal marrow.—Arrangement of 
the plexuses which result from them.—Consequences 
as it regards descriptive neurology. 
internal communications of the nervous cords.—Manner of 
these communications.—Internal plexus to each nerve. 
—Consequences.—Difference from anastomoses. 
Nervous Trunks.—Their course.—Their form.—Their 
length, &c. 
Nervous branches, smaller branches, ramifications, <§-c.— 
Mode of origin.—Length.—Course, &c. 176 
III. Termination of the Nerves. 
What is to be understood by it.—Triple mode of termina- 
tion. 
Anastomoses with the same system.—What is to be under- 
stood by anastomoses.—They are rare in this system. 
—They can be referred to three classes. 
Anastomoses with the system of organic life.—Termination 
in the organs.—Manner of this termination.—Division 
of the organs in this respect. 182 
ARTICLE SECOND. 
ORGANIZATION OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
I. Texture peculiar to this Organization. 
Arrangement of the nervous cords.—Their varieties.— 
Each nerve has its peculiar organization.—Of the struc- 
ture of the nervous filaments. 420 
ANALYTICAL TABLE 
PAGE 
Of the nervous coat and its origin.—How this origin may be 
seen.—Its triple arrangement at the brain, the tuber 
annulare and the spinal marrow.—Particular arrange- 
ment of the optic nerve.—Remarks upon the pia mater. 
—Course of the nervous coat. 185 
Action of certain substances upon the nervous coat ; its resist- 
ance, &rc.—Action of the acids, water, caloric, and the 
alkalies.—Resistance of the nervous coat. 
Medullary substance ; its origin, arrangement and propor- 
tions. 
Comparison between the medullary substance of the brain and 
the nerves.—Etfect of desiccation upon each.—Putrefac- 
tion audits phenomena.—Absence of the horny harden- 
ing in both.—Action of water upon both.—Action of 
the acids, the alkalies, neutral salts and the digestive 
juices.—Difference of the nervous pulp in each part. 190 
II. Parts common to the Organization of the Nervous System of 
Animal Life. 
Cellular texture.—It is wanting in the nerves, in the cra- 
nium and the spine. Elsewhere it is found between 
their filaments and cords.—Cellular fat. 
Blood vessels.—Their arrangement.—Remarks upon the 
veins.—Of the blood.—Of the nerves.—Action of this 
fluid upon them. 
Exhalants and Absorbents.—Examination of the opinion 
upon the exhalation of the nervous coat.—Different 
observations. 
Nerves. 199 
ARTICLE THIRD. 
PROPERTIES OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
I. Properties of Texture. 
They are but xery slightly marked.—Remarks upon the 
nervous distensions. 204 
II. Vital Properties.—Properties of Animal Life. 
Animal sensibility inherent in the nerves.—Various experi- 
ments upon this sensibility.—Remarks upon that of 
the brain.—Phenomena of the experiments upon the 
nerves.—Character of the animal nervous sensibility. OF CONTENTS. 
421 
I'AGF. 
—Of neuralgias.—Another character of this sensibility. 
—Experiments.—Consequences. 206 
Influence of the nerves upon thehniinal sensibility of all the 
organs.—Distinction of the sensations, in tins respect, 
into external and internal.—Subdivision of the external 
into general and particular.—Part which the nerves 
perform in each.—Internal sensations.—Uncertainty 
respecting the nervous influence in sensations.—Differ- 
ences between animal sensibility and contractility.—Of 
the nervous atmosphere.—Uncertainty of this opinion. 211 
Animal contractility.—Influence of the nerves upon that of 
the other parts.—How the nerves are the agents of this 
property.—Different opinions upon the action of the 
nerves.—Uncertainty of these opinions.—General ob- 
servations. 
Properties of organic lif , considered in the nerves.—They 
are slightly marked.—Increase of the size of the nerves 
in the affections of some parts.—Various experiments 
and observations. 
Influence of the cerebral nerves upon the organic properties 
of the other parts.—They are foreign to these pro- 
perties.—They have not there any known influence, 1st, 
upon the capillary circulation; 2d, upon exhalation; 
3d, upon secretion; 4th, upon absorption; 5th, upon 
nutrition.—Different proofs of these assertions.—Re- 
marks on the diseases which affect animal life and 
those which affect organic.—Uncertainty of the term 
nervous influence. 216 
Sympathies.—Sympathies peculiar to the nerves.—Different 
phenomena of these sympathies.—Sympathies, 1st, be- 
tween two nerves of the same pair; 2d, between two 
nerves of the same side ; 3d, between the branches of 
the same pair; 4th, between the nerves and different 
organs.—Different examples of these sympathies. 224 
Influence of the nerves upon the sympathies of the other 
organs—Different opinions upon sympathies.—Uncer- 
tainty of these opinions.- Division of sympathies founded 
upon that of the vital properties.—Different influence 
of the nerves upon each species of sympathy.—Cases 
in which it is real and those in which it is nothing. 226 
III. Properties of Reproduction. 
Phenomena of nervous cicatrizations.—Their analogy 
with other cicatrizations. 233 422 
ANALYTICAL TABLE 
ARTICLE FOURTH. 
DEVELOPMENT OF THE NERVOUS SYSTEM OF ANIMAL LIFE. 
I. State of this System in the Foetus. 
PAGE 
It is much developed.—-General remarks.—Inactivity of 
the brain,notwithstanding its development.—Its softness. 
—Action of the alkalies upon this organ.—The cerebral 
nerves are developed in proportion.— Peculiar phe- 
nomenon of their development.—This phenomenon is 
opposite to that of the arteries.—Consequence which 
results from it. 235 
II. State of the Nervous System during Growth. 
Phenomena at birth.—Influence of the red blood.—Pre- 
dominance of the nervous system during childhood.— 
Consequences relative to the sensations, motions and 
various affections. 240 
III. Slate of the Nervous System after Growth. 
Phenomenon of puberty.—Phenomena of the following 
ages. 244 
IV. State of the Nervous System in Old Age. 
Its action is slight.—State of the brain at this period.—In- 
fluence of this state upon sensibility.—Phenomena of 
sensation and motion in old age. 244 
NERVOUS SYSTEM OF ORGANIC LIFE. 
GENERAL REMARKS. 
How this system should be understood.—The great sym- 
pathetic does not exist.—Each ganglion forms an in- 
sulated system.—This system belongs to organic life.— 
It exhibits many irregularities.—The mode of describ- 
ing it. 249 OP’ CONTENTS. 
423 
ARTICLE FIRST. 
OF THE GANGLIONS. 
1. Situation, Forms, Relations, 4'C. 
PAGE 
Ganglions that are constant.—Those that are accidental. 253 
II. Organization. 
Colour.—Difference of the texture of the ganglions from 
that of the brain.—Comparative experiments.—This 
texture is not fibrous.—It differs essentially from that 
of the nerves.—Its organic lesions are rare.—Common 
parts of this texture. 255 
III. Properties. 
The ganglions have the organic ones.—The animal ap- 
pear to be slightly marked in them.— Experiments.— 
Sympathies.—Nervous affections of the ganglions.— 
The kind of pain of this system.—General remarks. 260 
IV. Development. 
It does not follow that of the brain.—Influence of this 
fact upon the diseases of childhood.—Another difference 
between the ganglions and the brain. 263 
V. Remarks upon the Vertebral Ganglions. 
Their arrangement.—Obscurity which they throw upon 
the functions of this system. 264 
ARTICLE SECOND. 
OF THE NERVES OF ORGANIC LIFE. 
I. Origin. 
Manner of this origin.—Method of seeing it. 265 
II. Course, Termination, Plexuses. 
Of the branches which go to the cerebral nerves.—Of 
those which go to the neighbouring ganglions.—Of 424 
ANALYTICAL TABLE 
PAGE 
those which go the muscles.—Of those which form the 
plexuses.—Arrangement of these last.—Of the tilaments 
which go from them.—Their double arrangement upon 
the arteries. 267 
III. Structure, Properties, $*c. 
Analogy with the preceding nerves as to texture.—Ani- 
mal sensibility appears to be less in them.—Experi- 
ments.—Sympathies of these nerves.—General re- 
marks. 271 
VASCULAR SYSTEM WITH RED BLOOD. 
ARTICLE FIRST. 
GENERAL REMARKS-fPON THE CIRCULATION. 
1. Division of the Circulation. 
Circulation of red blood.—General organs.—Direction. 
Circulation of black blood.— General organs.—Direction. 
Difference of the two circulations.—Their separation is com- 
plete.—Opposition of the lungs to all the parts. 
General mechanical phenomena of the two circulations.—Coni- 
cal form of the circulatory apparatus.—There are two 
cones for each circulation.—The heart is placed at 
their union as a double agent of impulse.—Its inequality 
in this respect. 275 
II. Reflections upon the General Uses of the Circulation. 
General uses of the circulation of the red blood.—It furnishes 
the materials of secretion, exhalation, absorption, &c. 
—AH the great phenomena of the economy are de- 
rived from it. 
General uses of the circulation of black blood.—It repairs the 
losses made by the preceding, by the substances which 
it receives.—General and opposite attributes of the two 
sanguineous systems. 282. OF CONTENTS. 
425 
ARTICLE SECOND. 
SITUATION, FORMS, AND GENERAL ARRANGEMENT OF THE VASCULAR 
SYSTEM WITH RED BLOOD. 
PAGE 
Of the two portions of this system.—Of their union.— 
Position of the agent of impulse compared to the whole 
body. 285 
I. Origin of the Arteries. 
Origin of the aorta.—Peculiar anatomical arrangement of 
this origin. 287 
Origin of the trunks, branches, smaller branches, <Vc.—Num- 
ber of the arterial divisions.—Angles of origin.—Pro- 
portion of the divisions. 288 
II. Course of the Arteries. 
Course of the trunks and branches.—Their position, rela- 
tion an»l direction.—Motions which they communicate. 291 
Course of the smaller branches, ramifications, &rc.—Position. 
—Relations.—Curvatures.—These curvatures have no 
influence upon the motion of the blood.—Proofs.— 
Uses of these curvatures. 293 
Anastomoses of the arteries in their course.—Of the two 
modes of anastomoses.—Triple mode of those in which 
two equal trunks terminate.—Anastomoses with un- 
equal trunks.—General remarks upon anastomoses. 296 
Forms of the arteries in their course.—In what direction they 
are conical.—Relation of capacities. 299 
III. Termination of the Arteries. 
It takes place in the capillary system.—Its varieties ac- 
cording to the organs. 300 
ARTICLE THIRD. 
ORGANIZATION OF THE VASCULAR SYSTEM WITH RED BLOOD. 
I. Texture peculiar to this Organization. 
Two principal membranes form it. 301 
Peculiar membrane of the arteries.—Thickness.—Colour.— 
Experiments.—Varieties in the cerebral arteries,— 426 
ANALYTICAL TABLE 
PAGE 
Arterial fibres.—Arrangement of these fibres at the 
origin of the branches.—Their nature is not muscular. 
Their brittleness.—Their resistance.—General con- 
sequences. 302 
Action of different agents upon the arterial texture.—Desic- 
cation.—Putrefaction.—Maceration.—Stewing.—Action 
of the acids, the alkalies, &c. 308 
Membrane- common to the system with red blood.—Its differ- 
ences in the different regions.—Of the fluid which mois- 
tens it.—Its relations.—Its nature.—Its singular dispo- 
sition to ossification.—Peculiar phenomena and laws of 
this ossification.—Pathological consequences. 311 
II. Parts common to the Organization of the Vascular System 
with lied Blood. 
Blood vessels.—Their arrangement.—They do not appear 
to go to the internal membrane. 317 
Cellular texture.—There are two species of it.—Of that 
which unites the artery to the neighbouring organs.— 
Of that which is peculiar to it, and which lias a pecu- 
liar nature.—The arterial fibres are remarkable for 
having none of this texture between them.—Conse- 
quences. 318 
Exhalants and absorbents.—There does not appear to be 
absorption in the arteries.—Experiments. 321 
Nerves.—Of the cerebral ones.—Of the organie ones.— 
Their proportion.—Their course, &c. 324 
ARTICLE FOURTH. 
PROPERTIES OF THE VASCULAR SYSTEM WITH RED BLOOD. 
1. Physical Properties. 
Remarkable elasticity.—Its use.—Its differences from con- 
tractility of texture. 322 
II. Properties of Texture. 
Extensibility•—1st, of that in the axis; 2d, of that in the 
diameter. 324 
Contractility.— Of that in the axis.—Of that in the diame- 
ter.—Its differences from irritability.—Remarks upon 
this contractility.—Practical consequences. 326 OF CONTENTS. 
427 
PACE 
III. Vital Properties. Properties of Animal Life. 
Sensibility.—Experiments upon this property. 329 
Contractility.—It is nothing. ib. 
Properties of organic life.— Sensible organic Contractility.— 
It is nothing.—Different experiments to prove it.— 
Mistakes concerning this property. 330 
Insensible organic contractility.—How its influence must be 
understood.—Vital activity is but slightly marked in the 
arteries.—General consequences. 332 
Remarks upon the causes of the motion of the red blood.— 
These causes appear to be foreign to the arteries. 335 
Influence of the heart in the motion of red blood.—Different 
proofs of this influence.—Morbid phenomena.—Dif- 
ferent experiments.—Observations.—General Conse- 
quences. 336 
Of the limits of the action of the heart.—They appear to 
be at the place of the change of the red blood into 
black.—Increasing influence of the arteries upon the 
red blood in the neighbourhood of the capillaries. 342 
Phenomena of the impulse of the heart.—The motion of the 
red blood is sudden and instantaneous.—Proofs.—The 
contraction of the arteries does not push the blood.— 
From what it arises.—The causes of delay are nothing. 
—General remarks. 334 
Remarks upon the pulse.—The arterial locomotion has a 
great part in it.—Of the accessory causes.—Of the 
varieties of the pulse.—General reflections. 348 
Sympathies.—They are in general rare in the arteries.— 
Why. 352 
ARTICLE FIFTH. 
DEVELOPMENT OF THE VASCULAR SYSTEM AVITH RED BLOOD. 
I. State of this System in the Foetus. 
The two systems are then confounded.—There is hut one 
species of hlood.—How the foetus can live with black 
blood alone.—Peculiar mode of circulation in the feel us. 
Consequences which result from it. Insensible 
change of this mode of circulation.—How it takes place. 
—Great development of the arteries in the foetus. 354 428 
ANALYTICAL TABLE 
PAGE 
II. Stale of the Vascular System with Red Blood during Growth. 
Sudden formation of the red blood at birth.—Changes in 
the course of this fluid.—Phenomena and causes of 
these changes.—Predominance of the arteries during 
youth, " 384 
ill. State of the Vascular System with Red Blood after Growth. 
Influence of the genital organs.—Varieties of the influ- 
ence of the red blood according to the ages. 371 
IV. State of the k ascular System with Red Blood during old .dge. 
Diminution of the arterial ramifications.—The red blood 
is less abundant.—The arteries are condensed.—Pheno- 
mena of the pulse.—Of the pulse in the last moments 
of life.—Experiments upon this subject. 373 
V. Jlccidental Development of the System with Red Blood. 
There are two kinds of it; 1st, Dilatation from an obstacle. 
2d, Dilatation from any tumour. 377 
VASCULAR SYSTEM WITH BLACK BLOOD. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
SITUATION, FORMS, DIVISION AND GENERAL ARRANGEMENT OF THE 
VASCULAR SYSTEM WITH BLACK BLOOD.- 
I. Origin of the Veins. 
Manner of this origin.—Two orders of veins. 380 
II. Course of the Veins. 
Examination of this course on the exterior and the interior. 381 
III. Proportion of the capacity of the two systems with Black 
and Red Blood. 
Remarks upon the varieties of venous capacity.—Parallel 
between the two vascular apparatus with red and black OF CONTENTS. 
429 
ILAGE 
blood in this respect.—General consequences.—The 
velocity is in an inverse ratio of the capacity, &c. 382 
Ramifications, small branches, branches, angles of union, <Vc. 
—Forms of the Veins.—In what direction these vessels 
are conical.—Relations between the branches and their 
divisions. 388 
Anastomoses.—They are very frequent.—Why.—Commu- 
nication between the external and the internal order.— 
Consequences.—Different modes of anastomoses.—Their 
necessity from the numerous obstacles to the course of 
the blood.—Of these obstacles. 392 
IV. Termination of the Veins. 
Mode of termination in the heart.—Of the two venous 
cones, the superior and the inferior.—Of their commu- 
nication by the azygos. 396 
ARTICLE SECOND. 
ORGANIZATION OF THE VASCULAR SYSTEM WITH BLACK BLOOD. 
I. Texture peculiar to this Organization. 
Membrane peculiar to the reins.—Manner of seeing it.—Its 
longitudinal fibres.—Varieties of these fibres.—Their 
nature.—Peculiar arrangement of the cerebral sinuses. 3 9 
Common membrane of the black blood.—Its differences from 
that of the red blood.—More extensibility.—Less thick- 
ness.—No disposition to ossify.—Consequences. 403 
Of the valves of the veins.—Their form.—Their situation. 
—Veins which they occupy.—Their size.—Remarks 
upon their relations with the caliber of the veins.— 
Their variety.—Their number. 404 
Action of reagents upon the venous texture.—Action of the 
air, water, caloric, the acids, &c. 407 
II. Parts common to the Organization of the Vascular System 
with Black. Blood. 
Blood vessels. Cellular texture.—Of that which unites the 
veins to the neighbouring parts.—Of that which is 
peculiar to them. 408 430 
ANALYTICAL TABLE 
PAGE 
Exhalants and Absorbents.—Experiments upon venous ab- 
sorption. 
Nerves.—There are but very few of them. 409 
ARTICLE THIRD. 
PROPERTIES OF THE VASCULAR SYSTEM WITH BLACK BLOOD. 
I. Properties of Texture. 
Extensibility.—It is very evident.—Venous ruptures how- 
ever take place.—Various examples.—Their causes 
are but obscurely known. 411 
Contractility.—Of this property in the longitudinal and 
the transverse direction. 413 
II. Vital Properties. 
Properties of Animal Life.—Result of the experiments 
upon sensibility.—There is no contractility. 414 
Properties of organic life. Sensible Contractility.—It ap- 
pears to be but slight.—General remarks. 415 
Of the venous pulse.—Of its cause.—It is a reflux.—Double 
cause which produces it. 416 
Insensible Contractility.—It appears to exist.—The vital 
activity is greater in the veins than in the arteries.— 
Consequences. 419 
Observations on the motion of the black blood in the veins.— 
There is no pulse analogous to that of the arteries.— 
Agent of impulse of the venous blood.—Causes of de- 
lay —Accessory causes of motion.—Resemblance be- 
tween the motion of the veins and that of the arteries. 420 
Sympathies of the veins.—They are very obscure. 424 
ARTICLE FOURTH. 
DEVELOPMENT OF THE VASCULAR SYSTEM WITH BLACK BLOOD. 
I. State of this System, in the Foetus. 
The veins are less developed in proportion than the arte- 
ries.—Why.—Remarks. 425 OF CONTENTS. 
431 
PAGE 
II. State of this System during Growth and afterwards. 
Various phenomena of childhood, adult age, &c. 427 
III. State of this System in Old Age. 
The veins are much developed in old age.—This deve- 
lopment is only a dilatation.—its varieties according to 
different circumstances. 428 
IV. Accidental Development of the Veins. 
It must be considered, 1st, in tumours; 2d, in the disten- 
sions of the different parts. 430 
ARTICLE FIFTH. 
REMARKS UPON THE PULMONARY ARTERY AND VEINS. 
Though the two kinds of blood are separate, yet the 
mechanical phenomena of their courses are analogous 
in the aorta and the pulmonary artery, and in the 
general and the pulmonary veins. ib. 
ARTICLE SIXTH. 
ABDOMINAL VASCULAR SYSTEM WITH BLACK BLOOD. 
Situation, forms, general arrangement, anastomoses, $-c.— 
Origin and termination in the capillaries.—Abdominal 
portion —Hepatic portion.—Differences between them. 433 
Organization, properties, fyc.—Analogy with the veins in 
this respect.—Peculiar arrangement in the hepatic 
portion.—Absence of valves.—Why. 436 
Remarks upon the motion of the black abdominal blood.— 
Comparison between the liver and the lungs.—Their 
difference as it regards the blood that goes to them.— 
Mechanism of the circulation of this system.—Induence 
of the accessory causes. 438 
Remarks upon the liver.—It performs another function be- 
sides the secretion of bile.—Proofs.—We are ignorant 
of this function.—It must be extremely important.— 
Various proofs.—The liver exhibits phenomena that no 432 
ANALYTICAL TABLE OF CONTENTS. 
PAGE 
other gland does.—It is not certain that the black ab- 
dominal blood serves for the secretion of bile.—Proofs. 
—General observations.—Experiments. 440 
Remarks upon the course of the bile.—Course of this fluid 
during abstinence and during digestion.—Cystic bile.— 
Hepatic bile.—Reflux towards the stomach during va- 
cuity and fulness.—Experiments. 446 
Development.—There is only one vascular system in the 
foetus.—It is divided into three at birth.—State of the 
umbilical vein and the vena porta in the foetus.—Rela- 
tive size of the liver at this period.—Phenomena at 
birth.—Different influences of this system in the follow- 
ing ages. 450 
END OF CONTENTS TO VOL. I. VOLUME SECOND. 
CAPILLARY SYSTEMS. 
PAGE. 
There are two of them.—Their general arrangement.— 
Their opposition. 3 
ARTICLE FIRST. 
OF THE GENERAL CAPILLARY SYSTEM. 
General arrangement of this system. 4 
I. General division of the Capillaries. 
Of the organs in which the capillaries contain only blood. 6 
Of the organs in which the capillaries contain blood andfluids 
differing from it.—Serous system taken for an example. 
—Experiments by injections.—Various other systems 
present analogous facts.—Proportion of the blood and 
the fluids differing from it. ib. 
Of the organs in which the capillaries do not contain blood. 8 
II. Difference of Organs in respect to the number of their 
Capillaries. 
There are many classes of organs in (his respect.—Why 
the capillaries are very much developed in some.— 
Consequences as it regards diseases. 9 
Remarks upon injections.—Their insufficiency in making 
us acquainted with the small vessels. 10 
III. Of the proportions which exist in the Capillaries between the 
Blood and the Fluids that differ from it. 
Continual varieties in the proportion.— Cause of these 
varieties.—They are very numerous. 12 434 
ANALYTICAL TABLE 
PAGE 
Different proportions of blood in the capillaries, according as 
the secretions and exhalations are active or passive.—Of 
active and passive exhalations.—Of secretions of the 
same nature.—Examination of each.—Proofs that 
wherever there is activity,blood enters the capillaries. 
.—Opposite arrangement in the pas ive phenomena. 13 
Consequences of the preceding Remarks. 17 
IV. Of the Anastomoses of the Ceneral Capillary System. 
Mode of these anastomoses.—The capillaries considered in 
relation to the vessels with which they communicate.— 
Influence of these communications.—Important ob- 
servation in regard to the examination of dead bodies. 
—IIow acute inflammations disappear at death. 17 
V. How, notwithstanding the general communication of the Capil- 
lary System, the Blood and the Fluids differing from it, remain 
separate. 
This depends on the different modifications of the organic 
sensibility.—Proofs.—General remarks. 21 
VI. Consequences of the preceding principles, in relation to In- 
flammation. 
Every thing arises, in this affection, from the alteration 
of the organic sensibility.—Proofs.—Varieties of inten- 
sity and nature in inflammations.—Terminations of in- 
flammations.—Of putrefaction.—Of death.—Of indura- 
tion.—Of the blood which stops in inflamed parts. 24 
jDifferences of inflammation according to the different sys- 
tems.—Each has a peculiar one.—Of those which are 
the most disposed 1o it.—It has peculiar modifications 
in each.—Same observation in regard to its termina- 
tions. 30 
VII. Structure and Properties of the Capillaries. 
We cannot ascertain completely the structure.—It has 
however varieties. 33 
VIII. Of tiie Circulation of the Capillaries. 
Motions of the fluids in the Capillary System.—The blood is 
independent of the action of the heart in the capilla- 
ries.—Various proofs of this assertion.—The blood 
circulates by the influence of the forces of tiie part.— 
Varieties of the motions.—Causes of these varieties — 
Influence of the atmosphere upon the capillary circuia- OF CONTENTS. 
435 
PAGE 
tion.—Of the two kinds of bleeding iq relation to the 
capillaries and to the trunks.—Circulation of other 
fluids than the blood in the capillaries. 34 
Phenomena af the alteration of the fluids in the Capillary 
System.—Change of the red blood to black.—Phenom- 
ena of this change. 41 
IX. Of the Capillaries considered as the seat of the production of 
Heat. 
Different hypotheses.—Phenomena of animal heat.—How 
it is produced.—Analogy of the production of heat 
with exhalation, secretion, &.c.—Influence of the differ- 
ent vital forces.—Explanation of the phenomena of 
animal heat in the state of health and disease.—Sym- 
pathetic heat.—Sympathies of heat.—Difference be- 
tween the two. 43 
ARTICLE SECOND. 
PULMONARY CAPILLARY SYSTEM. 
I. Relation of the two Capillary Systems, Pulmonary and General. 
How all the blood of the general system can go through 
the pulmonary.—Difference of one from the other as it 
respects the course of this fluid. 55 
II. Remarks upon the Circulation of the Pulmonary Capillaries. 
Peculiar character of pulmonary inflammations.—Phe- 
nomena to which they give rise.—Of the pulmonary 
circulation in various other diseases. 58 
III. Alteration of the Blood in the Pulmonary Capillaries. 63 
IV. Remarks upon the state of the Lungs in Dead Bodies. 
Their proportions very various from engorgement.—They 
are hardly ever in the natural state.—Why.—Conse- 
quences. 64 436 
ANALYTICAL TABLE 
EXHALANT SYSTEM. 
PAGE 
deneral Remarks upon the differences of exhalations and 
absorptions. 67 
ARTICLE FIRST. 
GENERAL ARRANGEMENT OF THE EXHALANTS. 
I. Origin, Course and Termination. 
Different hypotheses respecting these vessels.—What ob- 
servation shows us concerning them. 69 
II. Division of the Exhalants. 
They can be referred to three classes.—Table of these 
classes and their division. 71 
III. Difference of the Exhalations. 73 
ARTICLE SECOND. 
PROPERTIES, FUNCTIONS AND DEVELOPMENT OF THE EXHALANT 
SYSTEM. 
I. Properties. 
We are ignorant of those of texture.—The organic are 
very evident in it. 74 
Characters of the Vital Properties.—They vary in each sys- 
tem.—Consequences as it regards functions. ib. 
II. Of Natural Exhalations. 
They are all derived from the vital properties.—They 
vary consequently like these properties.—Proofs.—Of 
sympathetic exhalations. 75 OF CONTENTS. 
437 
PAGE 
III. Of Preternatural Exhalations. 
Sanguineous exhalation.—Hemorrhage of the excrementitious 
exhalants.—Hemorrhage from the skin.—Hemorrhages 
from the mucous surfaces.—They take place by exha- 
lation.—Proofs.—Experiments.—Of active and passive 
hemorrhages.—Differences between hemorrhages by 
rupture and by exhalation, between those of the capil- 
laries and those of the great vessels. 78 
Hemorrhages of the recrernentitious exhalants.—Hemorrhages 
of the serous surfaces.—Observations concerning dead 
bodies.—Cellular hemorrhages.—Other hemorrhages 
of the exhalants. 85 
Preternatural exhalations, not sanguineous.—Varieties of the 
exhaled fluids, according to the state of the vital forces 
of the exhalants.—Different examples of these varie- 
ties. 87 
IV. Of the preternatural development of the exhalants. 
It is especially in cysts that it takes place.—The secreted 
fluids are never preternaturally poured out like the ex- 
haled.—Why.—Of the natural emunctories. 88 
ABSORBENT SYSTEM. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
OF THE ABSORBENT VESSELS. 
I. Origin of the Absorbents. 
Table of absorptions.—Of external absorptions.—Of in- 
terna! absorptions.—Of the nutritive absorptions.—It is 
impossible to know the mode of origin of the absorb- 
ents.—Interlacing of the branches. 9! 
II. Course of the Absorbents. 
Their division into two layers, superficial and deep-seated. 
—Their arrangement in the extremities and the trunk. 95 438 
ANALYTICAL TABLE 
PAGE 
Forms of the absorbents in their course.—They are cylindri- 
cal, full of knots, &.c.—Consequences of these forms.— 
The absorbents have not as great capacity during life 
as in the dead body. 97 
Of the capacity of the absorbents in their course.—Manner 
of ascertaining it.—Extreme varieties which it exhib- 
its.—Capacity of the absorbents compared with that of 
the veins. 99 
Anastomoses of the absorbents in their course.—Different 
modes of these anastomoses.—Remarks upon the lym- 
phatic circulation. 102 
Remarks upon the difference of dropsies that are produced 
by the increase of exhalation, and those that are the effect 
of a diminution of absorption.—Cases that may be re- 
ferred to one or the other cause. 104 
III. Termination of the Absorbents. 
Trunks of termination.—Their disproportion with the 
branches.—Consequences.—Difficulties in regard to the 
motion of the lymph.—Remarks upon venous absorp- 
tion. 105 
IV. Structure of the Absorbents. 
Exterior texture.—Vessels.—Peculiar membrane.— 
Valves.—Uses of these last. 109 
ARTICLE SECOND. 
LYMPHATIC GLANDS. 
I. Situation, Size, Forms, c^c. 
Varieties of their number and situation in the different 
regions.—Relation with the cellular texture.—Varieties 
from age, sex, &c. Ill 
II. Organization. 
Colour.—Its varieties.—Particular arrangement about the 
bronchia. 114 
Common parts.—External cellular texture.—Cellular mem- 
brane.—Vessels. 115 
Peculiar texture.—Density.—Cells.—Contained fluid.— 
Properties and phenomena of this texture.—Interlacing 
of the absorbents. 116 OF CONTENTS. 
439 
ARTICLE THIRD. 
r 
PROPERTIES OF THE ABSORBENT SYSTEM. 
PAGE 
I. Properties of Texture. 118 
II. Vital Properties. 
Animal sensibility.—Its phenomena in the vessels and the 
glands.—Organic properties.—Their duration after 
death.—Remarks upon the absorbent faculty of dead 
bodies. 119 
Characters of the vital properties.—Life is very evident in 
this system.—Its disposition to inflammation.—Charac- 
ter which this affection has in it. 122 
Differences of the vital properties in the absorbent vessels 
and their glands.—These differences are remarkable.— 
Their influence upon diseases. 123 
Sympathies.—Sympathies of the glaidi.—Sympathies of 
the vessels.—Remarks upon the engorgements of the 
lymphatic glands. 124 
ARTICLE FOURTH. 
OF ABSORPTION. 
I. Influence of the Vital Forces upon this Function. 
All depends on the organic properties. 128 
II. Varieties of Absorption. 
Different examples.—Of resolution.—Of the absorption 
of morbific principles. 129 
111. Motion of the Fluids in the Absorbents. * 
Laws of this motion.—It is not subject to any reflux.— 
Why. 132 
IV. Of Absorption in the different Ages. 
It appears that the internal and external absorptions are 
opposite at the two extreme ages.—Remarks. 131 440 
ANALYTICAL TABLE 
V. Preternatural Absorption. 
Absorption of certain fluids different from those naturally 
absorbed.—Absorption in the cysts. 138 
PAGE 
SYSTEMS PECULIAR TO CERTAIN APPA- 
RATUS. 
GENERAL OBSERVATIONS. 
Differences of the systems peculiar to certain apparatus, 
from those common to all.—Characters of the first.— 
Their distribution in the apparatus. 139 
OSSEOUS SYSTEM. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
OF THE FORMS OF THE OSSEOUS SYSTEM. DIVISION OF THE BONES. 
I. Of the Long Bones. 
Relation of their position with their general uses.—Ex- 
ternal forms of the body and the extremities.—Internal 
forms.—Medullary canal.—Its situation, extent and 
form.—Its use.—It disappears in the first periods of 
callus.—It is shorter in proportion in childhood. 144 
II. Of the Flat Bones. 
Relations of their situation and external forms with the 
general use of forming the cavities.—Internal forms. 147 OF CONTENTS. 
441 
PAGE 
III. Of the Short Bones. 
Position.—Internal and external forms.—General uses. 149 
IV. Of the Bony Eminences. 
Their division into those, 1st, of articulation ; 2d, of inser- 
tion ; 3d, of reflection; 4th, of impression.—Remarks 
upon each of these divisions.—Relations of the second 
with the muscular force.—How these last are formed. 150 
V. Of the Osseous Cavities. 
Their division into those, 1st, of insertion ; 2d, of recep- 
tion ; 3d, of sliding; 4th, of impression; 5th, of trans- 
mission ; 6th, of nutrition.—Particular remarks upon 
each division.—Of the three kinds of canals of nutrition. 153 
ARTICLE SECOND. 
ORGANIZATION OF THE OSSEOUS SYSTEM. 
I. Texture Peculiar to the Osseous System. 
Common division of this texture. 
Texture with cells.—How it is formed.—When it is formed. 
—Of the cells and their communications.—Experi- 
ments. 156 
Compact texture.—Arrangement of its fibres.—Their for- 
mation.—Experiments to ascertain their direction.— 
The osseous layers do not exist.—Proofs.—Influence 
of rickets upon the compact texture. 158 
Arrangement of the two osseous textures in the three kinds of 
Bones.—Arrangement of the compact texture.—Two 
kinds of texture with cells in the long bones.—Propor- 
tion of the common texture with cells and the compact 
texture in the short and broad bones.—The same pro- 
portion examined in the cavities and the osseous emi- 
nences. 161 
Of the composition of the osseous texture.—There are two 
principal bases.—Of the saline calcareous substance.— 
Experiments.—Nature of this substance.—Experiments 
to ascertain the gelatinous substance.—Different rela- 
tions of each of these substances with vitality. 164 442 
ANALYTICAL TABLE 
PACJK 
II. Common Parts which enter into the organization of the 
Osseous System. 
Three orders of blood vessels.—Arrangement of each.— 
according to age.—Com- 
munication.—Proofs of the existence of the cellular 
texture. 167 
ARTICLE THIRD. 
PROPERTIES OF THE OSSEOUS SYSTEM. 
I. Physical Properties. 
Elasticity.—It is in the inverse ratio of the age. 171 
II. Properties of Texture. 
Different examples of contractility and extensibility.— 
Characters of these properties. 171 
III. Vital Properties. 
They are obscure. 173 
Characters of these properties.—Slowness of their develop- 
ment.—Their influence upon diseases. 174 
Sympathies.—Their character is always chronic.—Gene- 
ral remark upon sympathies. 175 
Seat of the. vital properties—They are not seated in the cal- 
careous substance.—They exist oniy in the gelatinous. 
—Experiment which proves it. 177 
ARTICLE FOURTH. 
OF THE ARTICULATIONS OF THE OSSEOUS SYSTEM. 
I. Division of the Articulations. 
Moveable Articulations.—Observations upon their Motions.— 
1st. Opposition ; it is extensive or confined.—2d. Cir- 
cumduction ; a motion composed of all those of oppo- 
sition.—3d. Rotation; a motion upon the axis.—4th. 
Sliding. 180 OF CONTENTS. 
443 
PAGE 
Immoveable articulations.—They are on surfaces in juxta- 
position, inserted into each other or implanted. 182 
Table of the Articulations. 183 
II. Observations upon the Moveable Articulations. 
First genus-—Situation.—Form of the surfaces.—Rotation 
and circumduction are inversely in the humerus and 
the femur.—Why. 184 
Second genus.—Form of the surfaces.—Motions. 186 
Third genus.—Diminution of the motions.—Direction in 
which they take place. 187 
Fourth genus.—Motions still less. 189 
Fifth genus.—Remarkable obscurity of the motions. 190 
III. Observations upon the Immoveable Articulations. 
Situation, forms of each order.—Relation of the structure 191 
to the uses. 
IY. Of the means of Union betvwen the Articular Surfaces. 
Union of the immoveable Articulations.—Cartilages of union. 193 
Union of moveable articulations.—Ligaments and muscles 
considered as articular bands. 194 
ARTICLE FIFTH. 
DEVELOPMENT OF THE OSSEOUS SYSTEM. 
Remarks. 195 
I. State, of the Osseous System during Growth. 
Mucous State.— What should be understood by it. 196 
Cartilaginous State.—Period and mode of its development. 
—Of this state in the broad bones. 197 
Osseous Stale.—Its phenomena.—Its period. 198 
Progress of the osseous state in the long bones ; 1st, in the 
middle ; 2d, in the extremities. 200 
Progress of the osseous state in the broad bones.—Varieties 
according to the bones. Formation of the ossa w;ormi- 
ana. ih. 
Progress of the osseous state in the short bones. 202 444 
ANALYTICAL TABLE 
PAGE 
II. Slale of the Osseous System after its Growth. 
Increase in thickness.—Composition and decomposition 
after the termination of growth in thickness.—Experi- 
ments.—State of the bones in old age. 203 
III. Peculiar Phenomena of the Development of the Callus. 
1st. Fleshy granulations.—2d. Adhesions of these granu- 
lations.—3d. Exhalation of gelatine and then of phos- 
phate of lime. 206 
IV. Peculiar Phenomena of the Development of the Teeth. 
Organization of the teeth.—Hard portion of the teeth.— 
Enamel.—Experiment which distinguishes it from 
bone.—Its thickness.—Its nature.—Reflections upon 
its organization.—Osseous portion.—Its form.—Cavity 
of the tooth. 209 
Soft portion of the tooth.—Its spongy nature.—Its acute 
sensibility.—Remarks upon its different sympathies. 211 
First dentition considered before cutting.—Follicle.—Mem- 
brane of this follicle analogous to the serous mem- 
branes.—Albuminous nature of the fluid which lubri- 
cates it.—Mode of development of the osseous tooth 
upon the follicle.—Number of the first teeth. 213 
First dentition considered at the period of cutting.—Mode 
of cutting.—Accidents.—Their causes. 216 
Second dentition considered before cutting.—Formation of 
the second follicle. 217 
Second dentition considered at the period of cutting.—Fall 
of the first teeth.—Appearance of the second. 
Phenomena subsequent to the cutting of the second teeth.— 
Growth in length and thickness.—Fall of the teeth 
earlier than the death of the bones.—Why.—State of 
the jaws after the fall of the teeth. 219 
V. Particular Phenomena of the Development of the Sesa- 
moid Bones. 
General arrangement of the sesamoid bones.—Situation.— 
Forms. 221 
Fibro-cartilaginous state.—Osseous state.—Phenomena of 
the patella.—Use of the sesamoid bones. 222 OF CONTENTS, 
445 
MEDULLARY SYSTEM. 
RAGE 
Division of this system. 223 
ARTICLE FIRST. 
MEDULLARY SYSTEM OF THE FLAT AND SHORT BONES, AND THE 
EXTREMITIES OF THE LONG ONES. 
I. Origin and Conformation. 
It is an expansion of the vessels of the second order. 225 
II. Organization. 
There is no medullary membrane.—Vascular interlacing. 226 
III. Properties. 
There are only organic ones.—Experiments. 227 
IV. Development. 
There is no medullary oil in infancy.—Proofs.—Experi- 
ments. 227 
ARTICLE SECOND. 
MEDULLARY SYSTEM OF THE MIDDLE OF THE LONG BONES. 
I. Conformation. 
It is like the cellular. 229 
II. Organization. 
The medullary membrane is not an expansion of the peri- 
osteum.—Its vessels. 230 
* III. Properties. 
Properties of texture.—Vital properties.—Animal sensi- 
bility.—Vitality more active than in the bones. 231 446 
ANALYTICAL TABLE 
PAGE 
IY. Development. 
How the medullary membrane is formed.—The marrow 
of the infant is wholly different from that of the adult. 
—Proofs. 233 
Functions.—The marrow is exhaled.—Its alterations.—Its 
relations with the nutrition of the bone.—Necrosis.— 
The marrow is foreign to the synovia. 234 
CARTILAGINOUS SYSTEM. 
What must be understood by cartilage. 237 
ARTICLE FIRST. 
OF THE FORMS OF THE CARTILAGINOUS SYSTEM. 
I. Forms of the Cartilages of the Moveable Articulations. 
Internal and external surfaces.—Relations of the two cor- 
responding cartilages.—Peculiar characters of these 
cartilages in each kind of moveable articulations. 238 
II. Forms of the Cartilages of the Immoveable Articula- 
tions. 241 
III. Forms of the Cartilages of the Cavities. 242 
ARTICLE SECOND. 
ORGANIZATION OF THE CARTILAGINOUS SYSTEM. 
I. Texture, pecicliar to the Cartilaginous System. 
Fibres.—Remarkable resistance of the cartilaginous tex- 
ture to putrefaction, maceration, &c.—Stewing and de- 
siccation of this texture.—Its various alterations. 243 OF CONTENTS. 
447 
PAGE 
II. Parts common to the Organization of the Cartilaginous 
Texture. 
Cellular texture.—Means of seeing it.—Absence of blood 
vessels.—White vessels.—Their colour in jaundice. 245 
ARTICLE THIRD. 
PROPERTIES OF THE CARTILAGINOUS SYSTEM. 
I. Physical Properties. 
Elasticity.—It appears to be owing to the superabundance 
of gelatine.—Proofs. 247 
II. Properties of Texture. 
They are very obscure. 248 
III. Vital Properties. 
They are inconsiderable, as well as the sympathies. 249 
Character of the Vital Properties.—All the phenomena over 
which they preside have a chronic progress.—General 
observations upon tne reunion of the parts. 250 
ARTICLE FOURTH. 
DEVELOPMENT OF THE CARTILAGINOUS SYSTEM. 
I. State of the Cartilaginous System in the First Age, 
Predominance of gelatine in the early periods.—Property 
which the cartilages then have of becoming red by 
maceration.—Vascular layers between the cartilage 
and the bone.—Cause which limits ossification in the 
cartilage.—Development of the cartilages of the cav- 
ities. 252 
II. State of the Cartilaginous System in the after Ages. 
Different character which the gelatine assumes.—Ossifi- 
cation of the cartilages in old age,—-Those of the cavi- 
ties are the soonest ossified. 25r 448 
ANALYTICAL TABLE 
PAGE 
III. Preternatural Development of the Cartilaginous System. 
Tendency of the membrane of the spleen to become the 
seat of it.—Preternatural cartilages of the articula- 
tions. 257 
FIBROUS SYSTEM. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
OF TIIE FORMS AND DIVISIONS OF THE FIBROUS SYSTEM. 
The fibrous forms are either membranous or in fasciae. 259 
I. Of the Fibrous Organs of a Membranous Form. 
Fibrous membranes.—Fibrous capsules.—Fibrous sheaths. 
—Aponeuroses. 260 
II. Of the Fibrous Organs in the form of Fasciae. 
1st. Tendons.—2d. Ligaments. 262 
III. Table of the Fibrous System. 
Analogy of the different organs of this system.—The 
periosteum is the common centre of these organs. 262 
ARTICLE SECOND. 
ORGANIZATION OF THE FIBROUS SYSTEM. 
I. Of the Texture peculiar to the Organization of the Fibrous 
System. 
Peculiar nature of the fibrous texture.—Its extreme re- 
sistance.—Phenomena of this resistance.—It can be OF CONTENTS. 
449 
PAGE 
overcome.—Difference of the fibrous and muscular tex- 
tures.—Experiments upon the fibrous texture subject- 
ed to maceration, ebullition, putrefaction, the action of 
the acids, the digestive juices, &c. 264 
II. Of the Common Parts zohich enter into the Organization 
of the Fibrous System. 
Cellular texture.—Blood vessels.—Their varieties accord- 
ing to the organs. 270 
ARTICLE THIRD. 
PROPERTIES OF THE FIBROUS SYSTEM. 
I. Physical Properties. 
II. Properties of Texture. 
Extensibility.—Peculiar law to which it is subjected there. 
Contractility.—It is almost nothing.—When it is mani- 
fested. 272 
III. Vital Properties. 
Animal sensibility.—Singular mode of putting it in action 
by distension.—Consequence of this peculiar phenome- 
non to the fibrous texture. 274 
Character of the vital properties.—The vital activity is more 
evident in this system than in the preceding.—It ap- 
pears that the fibrous texture does not suppurate. 277 
Sympathies.—Examples of those of the animal and the or- 
ganic properties. 279 
ARTICLE FOURTH. 
DEVELOPMENT OP THE FIBROUS SYSTEM. 
I. Stale of the Fibrous System in the First Jige. 
The fibres are wanting in most of the fibrous organs of 
the foetus.—Softness of these organs at this age.— 
Varieties of development.—Remarks upon rheumatism. 281 ANALYTICAL TABLE 
450 
PAGE 
II. State of the Fibrous System in the After Ages. 
Phenomena of the adult.—General stiffness in old age. 283 
III. Preternatural Development of the Fibrous System. 
Various tumours exhibit fibres analogous to those of this 
system. 284 
ARTICLE FIFTH. 
OF THE FIBROUS MEMBRANES IN GENERAL. 
I. Forms of the Fibrous Membranes. 
Their double surface.—These membranes are like moulds 
of their respective organs.—Researches respecting that 
of the corpus cavernosum.—Experiments which show 
that it differs essentially from the subjacent spongy tex- 
ture.—Other researches upon that of the testicle. 285 
II. Organization of the Fibrous Membranes. 288 
III. Of the Periosteum. Of its Form. 
Its two surfaces.—Their adhesion to the bones. 289 
Organization of the periosteum.—Preternatural develop- 
ment of its fibres in elephantiasis.—Its connexions with 
the fibrous bodies in infancy. 291 
Development of the periosteum. 
Functions of the Periosteum.—In what way it assists ossifi- 
cation.—It relates as much to the fibrous organs as to 
the bones. 292 
IV. Perichondrium. 
Experiments upon this membrane. 294 
ARTICLE SIXTH. 
OF THE FIBROUS CAPSULES. 
I. Forms of the Fibrous Capsules. 
They are very few.—Arrangement of (he two principal 
ones.—Canal between them and the synovial capsule. 295 
II. Functions of the Fibrous Capsules. 296 OF CONTENTS. 
451 
ARTICLE SEVENTH. 
OP THE FIBROUS SHEATHS. 
PAGE 
Their division. 297 
I. Partial Fibrous Sheaths. 
Their form.—Their arrangement.—Why the flexor ten- 
donsare alone provided with them. 297 
II. General Fibrous Sheaths. 299 
ARTICLE EIGHTH. 
OP THE APONEUROSES. 
I. Of the Aponeuroses for Covering. 
Their division 299 
Aponeuroses for general covering. 300 
Forms.—They are accommodated to the extremities, &c. ib. 
Tensor muscles.—Organization.—Examples of the tensor 
muscles.—Their uses relative to the aponeuroses.— 
Analogy with the tendons and difference from them. 
—Arrangement of the fibres. 301 
Functions. 302 
Aponeuroses for partial covering.—Examples.—General 
uses of these aponeuroses. 303 
II. Of the Aponeuroses of Insertion. 
Aponeuroses of insertion with a broad surface.—Their ori- 
gin.—Their uses.—The identity of their nature with 
that of the tendons.—Experiments. 304 
Aponeuroses of insertion in the form of an arch.—They are 
rare.—They exist where vessels pass through.—They 
do not compress them. 305 
Aponeuroses of insertion with separate fibres. 306 452 
ANALYTICAL TABLE 
ARTICLE NINTH. 
OF THE TENDONS. 
I. Form of the Tendons. 
PAGE 
Relation of the uses with the forms.—Union with the 
fleshy fibres. 307 
II. Organization of the Tendons. 
Method of seeing their fibres advantageously.—They ap- 
pear to be destitute of blood vessels.—Their tendency 
to be penetrated with the phosphate of lime. 309 
ARTICLE TENTH. 
OF THE LIGAMENTS. 
I. Ligaments with Regular Fascia. 
General arrangement. 311 
II. Ligaments with Irregular Fascia. 312 
FIBRO CARTILAGINOUS SYSTEM. 
Organs which compose it. 315 
ARTICLE FIRST. 
OF THE FORMS OF TltE FIBRO-CARTILAGINOUS SYSTEM. 
Division into three classes of the organs of this system. 
—Characters of each class. 314 OF CONTENTS. 
453 
ARTICLE SECOND. 
ORGANIZATION OF THE FIBRO-CARTILAGINOUS SYSTEM. 
I. Texture peculiar to the Organization of the Fibro- 
Cartilaginous System. 
PAGE 
It arises, 1st, from a fibrous substance ; 2d, from a cartila- 
ginous one.—It owes its resistance to the first and its 
elasticity to the second.—Action of caloric, air and 
water upon the fibro-cartilaginous texture.—It reddens 
by maceration.—Absence of the perichondrium upon 
most of the fibro-cartilages. 317 
II. Parts common to the Organization of the Fibro- 
cartilaginous System. 320 
ARTICLE THIRD. 
PROPERTIES OF THE FIBRO-CARTILAGINOUS SYSTEM. 
I. Physical Properties. 
Elasticity and suppleness united. 320 
II. Properties of Texture. 
Extensibility.—It is quite evident in it.—Contractility.— 
Difference from elasticity. 321 
III. Vital Properties. 
They are inconsiderable.—Influence of the obscurity of 
these forces upon the properties of the fibro-cartilages. 322 
ARTICLE FOURTH. 
DEVELOPMENT OF THE FIBRO-CARTILAGINOUS SYSTEM. 
I. State of this System in the First Age. 
Mode of development of the three classes. 323 ANALYTICAL TABLE 
454 
PA»E. 
II. Slate of this System in the after Ages. 
General rigidity of these organs.—Consequences.—Ossifi- 
cation of the fibro-cartilages rare. 325 
MUSCULAR SYSTEM OF ANIMAL LIFE. 
Difference between the muscles of the two lives.—Ob- 
servations upon those of animal life. 327 
ARTICLE FIRST. 
Ofr THE FORMS OF THE MUSCULAR SYSTEM OF ANIMAL LIFE. 
Division of these muscles into long, broad and short. 327 
I. Forms of the Long Muscles. 
Place which they occupy.—Their division.—Their sep- 
aration and reunion.—Peculiar forms of the long mus- 
cles of the spine. 328 
II. Forms of the Broad Muscles. 
Where they are situated.—Thickness.—Peculiar forms 
of the broad pectoral muscles. 330 
III. Forms of the Short Muscles. 
Where they are found.—Their arrangement.—Remarks 
upon the three species of muscles. 331 
ARTICLE SECOND. 
ORGANIZATION OF THE MUSCULAR SYSTEM OF ANIMAL LIFE. 
I. Texture peculiar to this Organization. 
Arrangement of this texture into fasciculi.—Its division 
into fibres.—Length of the fleshy fibres compared with OF CONTENTS. 
455 
PAGE 
that of the muscle.—Their direction.—Their figure.— 
Their softness.—Ease of their rupture in the dead 
body.—Difficulty in the living. 332 
Composition of the muscular texture.—Action of the air in 
desiccation and putrefaction.—Action of cold water.— 
Maceration and its products.—Ease with which the 
colouring substance is removed.—Analogy of the re- 
maining texture with the fibrin of the blood.—Relation 
of the forces with this texture.—Action of boiling 
water.—Some peculiar phenomena of common boiled 
flesh.—Roasting of the fleshy texture.—Singular affinity 
of the digestive juices to this sort of texture.—General 
observations.—Influence of sex and the genital organs 
upon the fleshy texture. 336 
II. Parts common to the Organization of this System. 
Cellular texture.—Manner in which it envelops the fibres. 
—Its uses for muscular motion.—Experiment.—Fatty 
muscles. 343 
Blood vessels.—Arteries.—Of the blood of the muscles.— 
Of their colour.—Free and combined state of the colour- 
ing substance.—Veins—Remarks upon the injection of 
them. 346 
Nerves.—There are hardly any but those of animal life.— 
Their difference in the extensors and the flexors.— 
Manner in which the nerves penetrate the muscles. 348 
ARTICLE THIRD. 
PROPERTIES OF THE MUSCULAR SYSTEM OF ANIMAL LIFE. 
I. Properties of Texture. Extensibility. 
This property is continually in action.—It is in proportion 
to the length of the fibres.—Its exercise in diseases. 350 
Contractility of texture.—Phenomena of the antagonists.— 
Distinction in these phenomena of that which belongs 
to the vital properties from that which belongs to 
those of texture.—Of the contractility of texture in 
diseases.—Extent and quickness of the contractions.— 
They continue after death.—Essential differences be- 
tween the contractility of texture and horny hardening. 
Their parallel. 352 456 
ANALYTICAL TABLE 
PAGE 
II. Vital Properties. 
Properties of animal life.—Sensibility.—Most of the ordi- 
nary agents do not develop it.—It is put into action by 
repeated contractions.—Of the sensation of lassitude.— 
Sensibility of the muscles in their affections. 359 
Animal Contractility.—It should be considered in three re- 
lations. 361 
Animal co7itractility considered in the brain.—The principle 
of this property exists in this organ.—Proofs drawn 
from observation.—Proofs derived from diseases.— 
Proofs borrowed from experiments- upon animals.— 
Cases in which the brain is foreign to the muscles. 362 
Animal contractility considered in the nerves.—Influence of 
the spinal marrow upon this property.—Observations 
and experiments.—Influence of the nerves.—Observa- 
tions and experiments.—All the nerves do not transmit 
equally the different irradiations of the brain.—Direc- 
tion of the propagation of the nervous influence. 367 
Animal contractility considered in the muscles.—Necessary 
conditions in the muscle for it to contract.—Obstacles 
to contraction.—Various experiments. 374 
Causes which bring into action animal contractility.—Divi- 
sion of these causes.—Of the will.—Of the involuntary 
causes.—Direct excitement.—Sympathetic excitement. 
—Influence of the passions.—Remarks upon the mo- 
tion of the foetus. 374 
Duration of the animal contractility after death.—Various 
experiments.—Consequences relative to respiration.— 
Variety of the duration of this property.—How it is 
extinguished. 379 
Organic Properties.—Organic sensibility and insensible 
organic contractility.—Sensible organic contractility.— 
Various experiments upon this last property.—Phenom- 
ena of irritations.—In order to study this contractility 
the animal contractility must be destroyed.—How this 
is done.—Various modes of contraction. 382 
Sympathies.—The animal sensibility is the property espe- 
cially brought into action by them.—General Remarks. 
—Sympathies of animal sensibility.—The organic pro- 
perties are rarely brought into action. 386 
Characters of the vital properties.—Different remarks upon 
these characters. 388 OF CONTENTS. 
457 
ARTICLE FOURTH. 
PHENOMENA OF THE ACTION OF THE MUSCULAR SYSTEM OF ANIMAL 
LIFE. 
I. Force of the Muscular Contraction. 
PAGE 
Difference according as it is put into action by stimuli or 
by the cerebral intluence.—Experiments.—Influence of 
muscular organization upon contraction.—The laws of 
nature the reverse of those of mechanics in the pro- 
duction of motions,—Multiplication of forces.—Uncer- 
tainty of calculations upon this point. 390 
II. Quickness of the Contractions. 
Varieties according as the contractions are, 1st, from 
stimuli; 2d, from nervous action.—Different degrees of 
quickness in different individuals.—Influence of habit 
upon this degree. 396 
III. Duration of the Contractions. 397 
IV. Slate of the Muscles in Contraction. 
Different phenomena which they then experience.—Es- 
sential remark upon the different modes of contraction. 398 
V. Motions imparted bp the Muscles. 
Simple Motions.— 1st. In the muscles with a straight di- 
rection.—How we determine the uses of these muscles. 
—2d. In the muscles with a reflected direction.—3d. 
In those with a circular direction. 400 
Compound Motions.—Almost every motion is compound.— 
How.—Different examples of compound motions.— 
Antagonist muscles. 403 
VI. Phenomena of the Relaxation of the Muscles. 
They are opposite to the preceding. 406 458 
ANALYTICAL TABLE OF CONTENTS. 
ARTICLE FIFTH. 
DEVELOPMENT OF THE MUSCULAR SYSTEM OF ANIMAL LIFE. 
I. Slate of this System in the Foetus. 
PAGE 
It contains but little blood.—Slight contractility at this 
age.—Influence upon these phenomena, of the blood 
which then penetrates the muscles.—These organs are 
then slender and weak. 407 
II. Slate of this System during Growth. 
Sudden effect of the red blood which penetrates the mus- 
cles, and of the other irritations which are connected 
with it.—Colour of the Muscles.—Period of the bright- 
est colour.—Varieties of the action of reagents on the 
fleshy texture of youDg animals. 410 
III. State of this System after Growth. 
The thickness constantly increases.—The external forms 
are more evident.—Colour in the adult.—Innumerable 
variety. 4IS 
IV. Slate of this System in Old Age. 
Increase of density.—Diminution of cohesion.—Phenom- 
ena of the vacillation of the muscles.—Atrophous mus- 
cles. 416 
V. State of the System at Death. 
Relaxation or stiffness of the muscles. 419 
END OF CONTENTS TO VOL. II. VOLUME THIRD. 
MUSCULAR SYSTEM OF ORGANIC LIFE. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
FORMS OF THE MUSCULAR SYSTEM OF ORGANIC LIFE. 
PAGE 
Curved direction of the fibres.—They do not arise from 
the fibrous system.—Varieties of the muscular forms, 
according to the organs. 4 
ARTICLE SECOND. 
ORGANIZATION OF THE MUSCULAR SYSTEM OF ORGANIC LIFE. 
General difference of organization from the preceding 
muscles. 5 
I. Peculiar Texture. 
General arrangement of the muscular fibre.—Analogy 
with the preceding and difference. 6 
II. Common Parts. 
Cellular Texture.—Blood vessels.—Nerves of the gan- 
glions and of the brain.—Proportion of each class. 8 460 
ANALYTICAL TABLE 
ARTICLE THIRD. 
PROPERTIES OF THE MUSCULAR SYSTEM OF ORGANIC LIFE. 
]. Properties of Texture. 
PAGE 
Extensibility.—Particular character of this property in 
the organic muscles.—In aneurisms of the heart and in 
pregnancy, it is not the extensibility that is brought into 
action.—Remarks upon this subject. 10 
Contractility.—It is in proportion to extensibility.—The 
substances contained in the hollow muscles are their 
antagonists.—Remarks. 14 
II. Vital Properties. 
Sensibility.—Of the lassitude of the organic muscles.— 
Remarks upon hunger. 15 
Animal Contractility.—It is nothing in these muscles.— 
Different experiments.—Observations.—Of the muscles 
in part voluntary and in part organic.—Experiments.— 
Remarks upon the bladder, rectum, kc.—Absence of 
the nervous influence upon the organic muscles. 17 
Organic Properties.—General Remarks. 24 
Of sensible organic contractility considered under the relation 
of the stimuli. 25 
Natural stimuli.—Different observations.—Remarks upon 
the fluids and solids.—Influence of the quality and 
quantity of the fluids upon the hollow muscles. ib. 
Artificial stimuli.—Action of these stimuli.—Different 
modes of action.—Limits of the horny hardening and 
vital contraction. 28 
Of sensible organic contractility, considered in relation to 
the organs. 31 
First variety. Diversity of the muscular texture.—Each 
muscle is particularly in relation with some determin- 
ate substance.—Application of this principle to the 
natural and foreign fluids. ib. 
Second variety. Age.—Vivacity of the contractility in in- 
fancy.—Consequences.—Opposite phenomenon in old 
age. 33 
Third Variety. Temperament.—Difference of individuals 
in regard to organic muscular force.—This force is not 
always in relation to the animal muscular force.—It 
cannot he increased like it by habit. 34 OF CONTENTS. 
461 
TAGF, 
Fourth Variety. Sex. 35 
Fifth Variety. Season and climate. 36 
Sensible organic contractility considered in relation to the ac- 
tion of stimulants upon the organs.—The constant exist- 
ence of an intermediate organ for this action.—Nature 
of this intermediate organ. ib. 
Sensible organic contractility considered in relation to its du- 
ration after death.—Difference of this duration according 
to the kind of death.—Remarks. 38 
Sympathies.—Sympathies of the heart.—Sympathies of 
the stomach.—Remarks upon bilious vomitings.—Gene- 
ral observations.—Sympathies of the intestines, the 
bladder, &c. 40 
Character of the vital 'properties.—Vital energy very con- 
siderable in this system.—Its affections act upon its 
predominant vital force.—The infrequency of the af- 
fections which suppose a derangement of the organic 
properties. 44 
ARTICLE FOURTH. 
PHENOMENA OF THE ACTION OF THE MUSCULAR SYSTEM OF ORGANIC 
LIFE. 
I. Force of Contractions. 
Difference from the force of contraction of the preceding 
system.—It is greater in the vital phenomena than in 
experiments.—Inaccuracy of calculations. 46 
II. Quickness of the Contractions. 
In experiments.—During life.—Comparison with the 
quickness of the preceding muscles. 49 
III. Duration of the Contractions. 50 
IV. State of the Muscles in Contraction. 
Difference in this respect between the heart and thegastric 
muscles. ib. 
V. Motions imparted by the Organic Muscles. 51 
VI. Phenomena of the Relaxation of the Organic Muscles. 
Differences of this relaxation from the active dilatation of 
the muscles.—Proofs of the phenomena of this dilata- 
tion. 52 462 
ANALYTICAL TABLE 
ARTICLE FIFTH. 
DEVELOPMENT OF THE MUSCULAR SYSTEM OF ORGANIC LIFE. 
I. State of this System in the Foetus. 
PAGE 
Predominance of the heart.—State of the other muscles. 
—Weakness of the organic contractility at this age. 55 
II. Stale of the Organic Muscular System during Growth. 
General increase of action at birth.—Of the growth in 
thickness and of that in length.—Their differences. 58 
III. State of the OrganicMuscular System after Growth. 61 
IV. State of the Organic Muscular System in Old Age. 
This system outlives, if we may so say, the preceding.— 
Phenomenon resulting from its weakness. 62 
MUCOUS SYSTEM. 
ARTICLE FIRST. 
OF TrfE DIVISIONS AND FORMS OF THE MUCOUS SYSTEM. 
]. 0/ the two general Mucous Membranes, the Gastro-pul- 
monary and the Genilo-urinary. 
Difference of these two membranes.—Their relation. 66 
II. Adhering Surface of the Mucous Membranes. 
Its relations.—It is everywhere subjacent to the muscles. 
—Sub-mucous texture.—Experiments. 69 
III. Free surface of the Mucous Membranes. 
Of the folds it exhibits.—1st. Of those which comprehend 
all the membranes.—2d. Of those w'hich are permanent OF CONTENTS. 
463 
PAGE 
upon the mucous surface.—3d. Of those which are 
owing to a state of vacuity of the hollow organs.—Dif- 
ferent experiments.—The extent of the mucous sur- 
faces is always nearly the same, whatever may be the 
state of their organs.—Relation of their free surface 
with external bodies.—Their sensibility is accommo- 
dated to this relation.—The term foreign body is mere- 
ly comparative. 70 
ARTICLE SECOND. 
ORGANIZATION OF THE MUCOUS SYSTEM. 
I. Texture peculiar to this Organization. 
What it presents for consideration. 
Mucous Corion.—Its variable thickness.—Mucous nature 
of the membrane of the ear.—Pathological conse- 
quences.—Softness of the mucous texture.—Action of 
the air, water, caloric, the acids and the digestive juices 
upon the mucous texture. 76 
Mucous papilla.—Their varieties of form.—Their nervous 
nature.—Proofs of this nervous nature.—Their influ- 
ence upon the sensibility of the mucous organs. 83 
If. Common Parts. 
Of the mucous glands and the fluids which they secrete.— 
Situation.—Forms.—Size.—Texture. 86 
Mucous fluids.—Physical properties.—Action of different 
agents upon them.—Their functions.—Parts in which 
they are most abundant and those in which they are 
less so.—Susceptibility of being increased by any irri- 
tation made upon their excretories.—Consequences.— 
Remarks upon the excitement of the mucous surfaces 
in diseases.-—Uses of the mucous membranes in rela- 
tion to the habitual evacuation of their fluids.—Gene- 
ral remarks upon the secreted fluids.—Singular sensa- 
tion arising from the continuance of the mucous fluids 
upon their respective surfaces. 88 
Blood vesseIs. —Their varieties of proportion.—Their 
superficial position.—Consequence.—Redness of the 
mucous system.—It often loses it.—Experiments upon 
the state of the mucous vessels in the fulness and vacui- 464 
ANALYTICAL TABLE 
PAGE 
ty of their hollow organs.—Other experiments upon 
the influence of the gases upon the colour of the mu- 
cous system.—Causes of its redness.—Colouring sub- 
stance combined and free. 96 
Exhalants.—Is there exhalation upon the mucous system? 
—Pulmonary exhalation.—A great part of the pulmo- 
nary perspiration arises from the solution of the mu- 
cous juices.—Other mucous exhalations.—Hemorrhages. 105 
Absorbents.—Proofs of the mucous absorption.—Irregu- 
larity of this absorption.—Cause of this irregularity. 107 
Nerves.—Those of the brain.—Those of the ganglions.— 
Their respective distribution upon this system. 108 
ARTICLE THIRD. 
PROPERTIES OF THE MUCOUS SYSTEM. 
I. Properties of Texture. 
They are less than they at first seem to be.—They are 
however real.—Their variety.—The mucous ducts are 
not obliterated by the contractility of texture when 
they are empty. 109 
II. Vital properties. 
Properties of animal life.—Acute sensibility of the mucous 
system.—Influence of habit upon this property.—Con- 
sequences of this remark.—Mucous sensibility in inflam- 
mations. 111 
Properties of organic life.—Organic sensibility and insen- 
sible contractility are very evident here.—Why.—Con- 
sequences as it respects diseases.—Varieties of these 
properties.—Species of sensible organic contractilitj' in 
the mucous texture. 114 
Sympathies.—How we shall divide them. 117 
Active Sympathies.—Example of these sympathies for 
each vital property. 118 
Passive Sympathies.—The predominant ones are those of 
insensible organic contractility.—Why. 120 
Character of the vital properties.—Vital activity of this sys- 
tem.—Its varieties.—Consequences as it regards dis- 
eases.—Remarks upon the stomachic sympathies. 123 OF CONTENTS. 
465 
ARTICLE FOURTH. 
DEVELOPMENT OF THE MUCOUS SYSTEM. 
I. State of the Mucous System in the First Age. 
PAGE 
It follows the state of the organs to which it belongs.— 
Delicacy of the papillae.—The mucous redness is then 
deeper.—Sudden change at birth.—Why.—Phenome- 
non of puberty. 125 
II. State of the Mucous System in the After Ages. 
Its phenomena in the adult.—Its phenomena in old age. 129 
SEROUS SYSTEM. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
OF THE EXTENT, FORMS AND FLUIDS OF THE SEROUS SYSTEM. 
General arrangement of its membranes.—Of the serous 
surface considered in general.—Every serous mem- 
brane is a sac without an opening. 131 
I. Free Surface of the Serous Membranes. 
It is smooth and polished.—This attribute is foreign to 
compression. This surface insulates the organs to 
which the serous surfaces belong.—Its influence upon 
the motion of these organs.—Adhesions of the serous 
surfaces.—Their division. 134 
II. Adhering Surface of the Serous System. 
Means of union.—The serous membranes often change re- 
lations with their organs.—This is owing to the laxity 
of the adhesions.—Adhesions more close. 140 466 
ANALYTICAL TABLE 
III. Serous Fluids. 
PAGE 
Their quantity.—Varieties of this quantity.—Experi- 
ments.—Morbid varieties.—Nature of these fluids. 142 
ARTICLE SECOND. 
ORGANIZATION OF THE SEROUS SYSTEM. 
% 
The serous membranes have but one layer.—Its colour. 
—Its thickness. 144 
I. Cellular nature of the Serous Texture. 
Proofs of this cellular nature.—Experiments by macera- 
tion, ebullition, desiccation, stewing and putrefaction.— 
Differences between the cellular and serous textures. 145 
II. Parts common to the organization of the Serous System. 
Exhalants.—Various proofs of serous exhalation. 149 
Absorbents.—Proofs of serous absorption.—Experiments. 
—Mode of origin of the absorbents. 150 
Blood vessels.—The serous membranes have but very few 
of them.—Those which are subjacent do not belong to 
them.—Proofs. 151 
III. Varieties of Organization of the Serous System. 
Different examples of these varieties.—Consequences in 
regard to diseases.—Remarks upon the pericardium.— 
Common characters. 153 
ARTICLE THIRD. 
PROPERTIES OF THE SEROUS SYSTEM. 
I. Properties of Texture. 
Extensibility.—It is less than it at first seems to be.—Why. 
—Use of the folds of the serous membranes.—Of their OF CONTENTS. 
467 
PAGE 
displacement.—Pain from these displacements in inflam- 
mation. 155 
Contractility.—Less than it appears to be.—It is however 
real. 156 
II. Vital Properties. 
They enjoy but little animal sensibility.—Why.—Experi- 
ments.—The organic properties are very sensible.— 
Consequences. 157 
Sympathies.—Various examples.—Remarks upon sympa- 
thetic exhalations.—Remark upon the serum of dead 
bodies. 158 
ARTICLE FOURTH. 
DEVELOPMENT OF THE SEROUS SYSTEM. 
I. State of this System in the First Age. 
Extreme tenuity of the surfaces.—Quantity of the fluids. 
—Quality.—Changes at birth.—Experiments. 161 
II. State of the Serous System in the After Ages. 
The serous surfaces obey the laws of their respective 
organs.—Increased density in old age.—Ossification 
rare. 162 
III. Preternatural Development of the Serous System. 
Various observations. 164 
SYNOVIAL SYSTEM. 
Points of resemblance between this system and the pre- 
ceding.—Its division. 165 468 
ANALYTICAL TABLE 
ARTICLE FIRST. 
ARTICULAR SYNOVIAL SYSTEM. 
I. Iiozo the Synovia is separated f rom the muss of blood. 
rage. 
There are three ways in which fluids may be separated 
from the blood. 
Is the Synovia transmitted by secretion to the articular sur- 
faces ?—Negative proofs.—Of the pretended synovial 
glands.—Experiments. 
Is the Synovia transmitted by transudation to the articular sur- 
faces ?—Negative proofs.—Another opinion. 
Is the Synovia transmitted by exhalation to the articular sur- 
faces ?—Positive proofs.—Analogy between the ex- 
haled fluids and the synovia.—Consequences. 167 
II. Remarks upon the Synovia. 
Its quantity.—It varies a little.—Rare alterations of this 
fluid.—Its difference from the serous fluids. 173 
III. Of the Synovial Membranes. 
Forms.—They represent sacs without an opening.—Dif- 
ference from the fibrous capsules.—These capsules 
are wanting in the greatest number of articulations.— 
Experiments.—Proofs of the synovial membrane where 
it adheres. 175 
Organization.—Analogy with the serous surfaces.—Struc- 
ture of the pretended synovial glands. 180 
Properties.—Properties of texture.—Vital properties.— 
Experiments.—The s}'novial system is foreign to most 
diseases. 182 
Functions.—They are foreign to the solidity of the articu- 
lation.—They have relation only to the synovia. 183 
Natural Development.—State of the synovial membrane in 
infancy, adult and old age. 184 
Preternatural Development.—Remarks upon this develop- 
ment. 185 
ARTICLE SECOND. 
SYNOVIAL SYSTEM OF THE TENDONS. 
It is oftea confounded with the preceding. 186 
Forms; relations; synovial fluid.—Forms of sacs without 
an opening.—Varieties of these forms.—Smooth and OF CONTENTS. 
469 
PAGE 
adhering surface.—Relation with the tendon.—Preter- 
natural increase of the fluid. 186 
Organization, properties, development.—Their phenomena 
are analogous to those of the preceding system.—Re- 
marks upon the affections of this kind of synovial mem- 
branes. 189 
GLANDULAR SYSTEM. 
General observations.—What a gland is. 193 
ARTICLE FIRST. 
SITUATION, FORMS, DIVISION, &C. OF THE GLANDULAR SYSTEM. 
Sub-cutaneous and deep position.—Relation of the position 
of the glands with their excretion.—Varieties of the 
glandular forms.—Distinction of these varieties.—Ex- 
ternal surface of the glands. 194 
ARTICLE SECOND. 
ORGANIZATION OF THE GLANDULAR SYSTEM. 
I. Texture 'peculiar to the Organization of this System. 
The fibrous arrangement is foreign to the glands.—There 
is but little resistance in the glandular texture.—Triple 
arrangement of this texture.—Uncertainty of the re- 
searches upon its nature.—Different experiments upon 
this texture.—Desiccation.—Peculiar effect of stew- 
ing.—Roasting.—Maceration.—Action of the acids, 
gastric juice, &c. 198 
Of the excretories, their origin, divisions, 4'C- of the glandu- 
lar reservoirs,—Origin.—Course.—Division of the glands 470 
ANALYTICAL TABLE 
PAGE 
into three classes, in regard to the termination of their 
excretories.—Of the reservoirs.—What supplies their 
place when they are wanting.—Motion of the fluids in 
the excretories. 204 
Size, direction and termination of the excretories.—All the 
excretories open upon the mucous or cutaneous sys- 
tems.—Observations upon the intestinal canal. 206 
Remarks upon the secreted fluids.—They can re-enter the 
circulation.—Various experiments on this subject.— 
Consequences. 203 
Structure of the excretories.—Internal membrane.—Exter- 
nal texture. 213 
II. Parts common to the Organization of the Glandular 
System. 
Cellular Texture.—Division of the glands into two classes, 
in regard to this texture.—Serum and fat of this tex- 
ture.—Fatty livers. 214 
Blood vessels.—Different ways in which they enter the 
glands, according as they are or are not surrounded 
with membranes.—Course of the arteries in the glands. 
—Veins.—They pour their blood into the general black 
blood.—Reflux from the heart to the glands. 216 
Of the blood of the glands.—Division of the glands into 
three classes, as it regards the fluid which penetrates 
them.—Great quantity of blood contained in the liver 
and the kidney.—Variety as it respects secretion. 219 
Nerves.—Of those of the ganglions and of the cerebral 
ones.—Their proportion.—How they enter the glands. 
—Secretion is independent of nervous influence. 221 
Exhalants and absorbents. 223 
ARTICLE THIRD. 
PROPERTIES OF THE GLANDULAR SYSTEM. 
]. Proper lies of Texture. 
They are inconsiderable.—Proofs.—New remarks upon 
the reflux of the black blood in the glands. 224 
II. Vital Properties. 
Properties of animal life.—Experiments upon animal sen- 
sibility.—Varieties of the results. 226 OF CONTENTS. 
471 
PAGE 
Properties of organic life.—The insensible contractility 
and the corresponding sensibility are the predominant 
ones.—Their influence upon secretion.—Varieties of 
the secreted fluids.—Organic affections of the glands.— 
Remarks. 227 
Sympathies. 230 
Passive sympathies.—Various examples.—Sympathies the 
causes of which act at the extremity of the excreto- 
ries.—Influence of the passive sympathies of the glands 
in diseases.—Remark upon that of each gland. 
Active Sympathies.—Various remarks. 
Characters of the vital properties. 235 
First character.—Life peculiar to each gland.—Proofs of 
this peculiar life.—Of its influence in a state of health 
and disease. 
Second character.—Remission of the glandular life.—The 
glands have a species of sleep.—Various examples. 238 
Third character.—The glandular life is never simidtaneously 
raised in the whole system.—Application of this remark 
to the digestive order.—Advantage of the artificial ex- 
citement of the glands in diseases. 239 
Fourth character.—Influence of climate and season upon 
the glandular life.—The sweat and many secreted fluids 
are opposite to each other in this respect. 241 
Fifth character. — Influence of sex upon the glandular 
life. 242 
ARTICLE FOURTH. 
DEVELOPMENT OF THE GLANDULAR SYSTEM. 
I. State of this System in the Foetus. 
The glands are very conspicuous at this age.—Yet the 
secretions are not great. 243 
II. Slate of this System during Growth. 
Suddenly increased activity at birth.—Yet it is not the 
glandular system which predominates in the first age. 
—Remarks upon its diseases,—The mucous and lachry- 
mal glands are the most frequently in action in infancy. 244 472 
ANALYTICAL TABLE 
III. State of this System after Growth. 
PAGE 
Period of puberty.—Its influence upon the glands.—In- 
fluence of the glands of digestion at the adult age. 247 
IY. State of this System in old Age. 
Of the change in the texture of the glands from the 
effect of age.—Many glands still secrete much fluid in 
old age.—Relation of this phenomenon with nutrition. 249 
DERMOID SYSTEM. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
FORMS OF THE DERMOID SYSTEM. 
I. External Surface of the Dermoid System. 
Various folds of this surface.—Their different nature. 254 
II. Internal Surface of the Dermoid System. 
Its relations.—Absence of the fleshy pannicle in man.— 
Consequences. 256 
ARTICLE SECOND. 
ORGANIZATION OF THE DERMOID SYSTEM. 
I. Texture, peculiar to the Organization. 
Chorion.—Its thickness in the different regions.—Its struc- 
ture.—Method of seeing it.—Variety of this structure 
according to the regions.—Small spaces of the chorion. 
—Fibres.—Their nature.—It approximates that of the OF CONTENTS. 
473 
PAGE 
fibrous texture.—Yet it differs from it.—The chorion is 
foreign to the functions of the skin relative to animal 
and organic life. 258 
Of the reticular body.—Idea that has been formed of it.— 
What it is.—Vascular net-work.—Colouring substance. 
—Analogy among the diversity of races.—How this 
diversity should be considered.—Of the cases in which 
the blood enters the reticular body.—Singular property 
of the vessels of the face of receiving more than the 
others.—Cause of this phenomenon.—Triple means of 
expression of the passions.—Relation between the 
tendency of the facial capillary system to receive blood 
and diseases.—Double state of the reticular body.— 
Phenomena at the instant of death.—Experiments. 266 
Papillce.—Situations.—The cutaneous prominences must 
not be taken for them.—Experiments to prove the na- 
ture of these prominences.—Their varieties.—Forms 
and nervous structure of the papillae. 273 
diction of different bodies upon the dermoid texture. 276 
diction of light.—Men whiten like plants.—Examples. ib. 
diction of caloric.—Effects which it produces on the skin 
during life according to its different degrees.—Effect of 
cold.—General remarks upon gangrene and antiseptics. 
—False opinions of authors. 277 
Action of the air.—Remarks upon the influence of this 
fluid upon the evaporation of the transpiration.—It is 
foreign to this function itself.—Desiccation of the skin 
by the air.—Its putrefaction. 282 
Action of 'water.—General uses of baths.—Their use is 
natural.—Maceration of the skin.—Pulpy state.—Stew- 
ing of the skin.—Mode of horny hardening.—Vesicles 
that arise the instant it takes place.—Other phenomena 
of stewing. 285 
Action of the acids, alkalies, and other substances.—Various 
experiments with reagents.—Remarks. 290 
II. Parts common to the Organization of the Dermoid 
System. 
Cellular texture.—Manner in which it is distributed.—Re- 
marks upon biles.—Sometimes it is wholly destroyed.— 
Appearance which the skin then has.—Remarks upon 
leucophlegmasia. 291 
Blood vessels.—Manner in which they are distributed.— 
Dilatation of the veins in some cases. 293 
.Xerves.—Mode of their distribution. 294 474 
ANALYTICAL TABLE 
PAG£ 
Absorbents.—Proofs of cutaneous absorption.—Absorption 
of virus.—Table of this absorption.—Varieties it ex- 
periences.—Absorption of medicines.—Experiments.— 
Character of irregularity of the cutaneous absorptions. 
—To what this character is owing.—Influence of weak- 
ness on this absorption. 294 
Exhalants.--Mode of distribution.—Cutaneous exhalations. 
—Uncertainty of calculations upon this point.—Rela- 
tion of this exhalation with the 
with the pulmonary exhalation.—Experiment upon this 
last exhalation.—Remarks upon the causes of many 
coughs.—Defect of evaporation of the fluid deposited 
upon the bronchia.—The cutaneous exhalants vary.— 
Are they under the nervous influence?—This does not 
appear probable. 299 
Sebaceous Glands.—Oily fluid of the skin.—Its quantity.— 
Its varieties.—Its sources.—We have but few data as it 
regards the sebaceous glands. 305 
ARTICLE THIRD. 
PROPERTIES OF THE DERMOID SYSTEM. 
I. Properties of Texture. 
They are very evident.—They are often less than they 
seem to be.—Phenomena of extensibility and contrac- 
tility. 308 
II. Vital Properties. 
Properties of animal life.—Sensibility.—Of the feeling.— 
Of the touch.—Its Characters.—Its differences from the 
other senses.—Seat of cutaneous sensibility.—The mode. 
—Pain peculiar to the skin.—Influence of habit upon 
this sensibility.—Various reflections.—Diminution of 
the cutaneous sensibility. 311 
Properties of organic life.—They are especially organic 
sensibility and insensible contractility.—Phenomena 
over which they preside.—Division of cutaneous dis- 
eases.—Excitants of the cutaneous organic sensibility.— 
Sensible organic contractility is but slightly apparent. 318 
Sympathies.—Passive Sympathies.—Different examples and 
remarks upon the sympathies of heat.—General re- OF CONTENTS. 
475 
PAGE 
marks upon the sensations of heat and cold.—Influence 
of sympathies upon the sweat. 322 
Active Sympathies.—These sympathies are relative to each 
of the classes of diseases pointed out above.—Various 
examples.—General remarks. 326 
Characters of the vital properties.—First chardcter.—The 
cutaneous life varies in each region.—Varieties of animal 
sensibility.—Varieties in the yrganic properties. 331 
Second character.—Intermission in one relation, continuity in 
another.—The peculiar life of the skin is intermittent 
as it respects the functions of relation.—Its continuity 
as it respects its organic functions. 332 
Third character.—Influence of sex. 333 
Fourth character.—Influence of temperament. 334 
ARTICLE FOURTH. 
DEVELOPMENT OF THE DERMOID SYSTEM. 
I. Stale of this System in the Foetus. 
A gluey covering in the first periods.—Absence of certain 
wrinkles in the foetus.—Laxity of adhesion.—State of 
the vital properties of the skin of the foetus.—Its func- 
tions at this age. 335 
II. State of this System during Growth. 
Sudden revolution at birth.—Entrance of the red blood 
into the skin.—Consequences.—State of the cutaneous 
vital forces in infancy.—State of the cutaneous texture. 337 
III. State of the Dermoid System after Growth. 
Increasing proportion of the fibrous substance, and de- 
creasing proportion of the gelatinous.—Remark upon 
the diseases and affections of the skin. 341 
IV. Stale of the Dermoid System in Old Age. 
State of the cutaneous texture.—Phenomena which arise 
from it.—State of the vital forces.—’State of the func- 
tions. 344 ANALYTICAL TABLE 
476 
EPIDERMOID SYSTEM. 
PAGE 
General Observations.—Division. 349 
ARTICLE FIRST. 
OP' THE EXTERNAL EPIDERMIS. 
I. Forms, Relations with the Dermis, fyc. 
Wrinkles.—Pores.—Adhesion to the skin.—Means of de- 
stroying this adhesion.—Arrangement. 350 
II. Organization, Composition, <&c. 
Uniform thickness in most parts.—Remarkable thickness 
on the foot and the hand.—Consequences of this thick- 
ness.—Experiments upon the colour of negroes.—Epi- 
dermoid texture.—Its peculiar nature.—Action of the 
air, water, caloric, the acids, the alkalies, &c. upon the 
epidermoid texture. 353 
III. Properties. 
Extensibility.—The animal properties are foreign to the 
epidermis.—It appears to be destitute also of organic 
properties.—Continual destruction of the epidermis.— 
Its reproduction when it is removed. 360 
IV. Development. 
State of the epidermis in the foetus, the adult and the old 
person. 364 
ARTICLE SECOND. 
INTERNAL EPIDERMIS. GENERAL OBSERVATIONS UPON THIS EPI- 
DERMIS. 
I. Epidermis of the origin of the Mucous Surfaces. 
It is very distinct.—Proofs of its existence.—Its reproduc- 
tion.—Its nature. 366 OF CONTENTS. 
477 
II. Epidermis of the deep Surfaces. 
PAGE 
Uncertainty of its existence.—Experiments.—Membranes 
that are sometimes thrown off.—It appears that it is not 
the epidermis. 367 
ARTICLE THIRD. 
OF THE NAILS. 
I. Form, Extent, Relations, &c. 
Of the habit of cutting the nails.—Anterior, middle and 
posterior portions of the nail.—Superior and inferior 
surfaces.—Of the texture which supports the nail. 869 
II. Organization, Properties, fyc. 
Of the laminae which form the nails.—Of their arrange- 
ment.—Their analogy with the epidermis.—Obscurity 
of the vital properties.—Facility with which the nails, 
epidermis, &c. are coloured. 373 
Development.—State of the nails in the foetus, the adult, 
and the old person. 376 
PILOUS SYSTEM. 
GENERAL OBSERVATIONS. 
ARTICLE FIRST. 
EXAMINATION OF THE PILOUS SYSTEM IN THE DIFFERENT REGIONS. 
I. Pilous System of the Head. 
General observations. 379 
OJ the Hair.—Its length, situation, limits, influence on 
physiognomy, variety according to sex, uses, thickness, 478 
ANALYTICAL TABLE 
PAGE 
fundamental colours, shades, and influence on tempera- 
ment. 381 
Eyebrows.—Their general arrangement.—Their motions. 386 
Eyelashes.—Their form, arrangement, &c. 387 
Beard.—It is the attribute of the male.—Its relations with 
strength.—Of our habits in relation to the beard. 388 
II. Of the Pilous System of the Trunk. 
Its varieties according to the regions. 390 
III. Pilous System of the Extremities. 
Its varieties.—It is wanting on the palms of the hands and 
the soles of the feet. ib. 
ARTICLE SECOND. 
ORGANIZATION OF THE PILOUS SYSTEM. 
I. Origin of the Hairs. 
Of the membranous canal which encloses this origin.— 
Relation of the hair with this canal.—Organization of 
this.—Swelling of the hair and its origin.—Its course 
to the exterior. 391 
II. External Covering of the Hairs. 
Analogy of this covering with the epidermis.—Its differ- 
ences.—Action of the different agents upon this cover- 
ing.—Its external arrangement. 394 
III. Internal Substance of the Hairs. 
We are ignorant of its nature.—Capillaries of the hairs of 
the head.—Their colouring substance.—The internal 
substance of the hairs of the head is essentially subject- 
ed to the influence of the vital phenomena.—Proof of 
this assertion.—This distinguishes it from the external 
covering, 396 OF CONTENTS. 
479 
ARTICLE THIRD. 
PROPERTIES OF THE PILOUS SYSTEM. 
PAGE 
It undergoes but little horny hardening.—Of curling.— 
The properties of texture slightly marked.—The ani- 
mal ones are nothing.—The organic are a little more 
evident. 401 
ARTICLE FOURTH. 
DEVELOPMENT OF THE PILOUS SYSTEM. 
I. State of this System in the First Age. 
Of the down of the foetus—The growth of the hairs is 
then the reverse of that of the other parts.—Their 
growth after birth.—Their colours are a little deeper 
in infancy. 403 
II. State of the Pilous System in the following Ages. 
Revolution at puberty.—Of the hairs which then appear. 
—There are but few changes in the following ages. 404 
III. Stale of the Pilous System in Old Age. 
Of the hairs which die first.—Of the whiteness which 
they then assume.—They grow in this state.—Why.— 
Do they grow after death.—General differences of ani- 
mate and inanimate bodies in their decay. 405 
IV. Preternatural Development.' 
Development upon the mucous surfaces, upon the skin 
and in cysts. 408 
END OF THE THIRD AND LAST VOLUME.