which penetrate the glands. Injections made in these escape with great
ease by the first, without 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 result 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 confine 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 understand 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 having 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 penetrates these glands, since if they are dried after having
been deprived of it by repeated washing, they remain grey after their
drying. No system becomes harder or more brittle than this by this
preparation. It diminishes then less in size than most of the others.
When immersed 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 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 emanations. 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 substance, 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 many 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 subject 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 moment of the first ebullition,
and acquire the horny hardness 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 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 however 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 acquired elasticity. Draw in an opposite direction a tendon, a
serous or mucous membrane or a muscle that have undergone the horny
hardening, they stretch and afterwards suddenly contract the instant
the extension ceases; on the contrary, a slice of liver that has the
horny hardness 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 disposition 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 interior.
This phenomenon is however common to all the solids. Hence why care is
taken to expose what is roasting, whether it be muscular or glandular,
at first to the action of a very quick fire; afterwards when the horny
hardening of the surface has been produced, it is diminished, 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, 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 formation, 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
difference in a more remarkable manner.
The glands are much less digestible than many other animal substances,
especially when stewed, which produces 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,
become 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.
_Of the Excretories, of their Origin, of their Divisions, &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 ramifications 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 divided 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 considerable
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 amygdalæ, upon the tongue, &c. Sometimes
the surface 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
preceding; where the duct opens, no inequality is usually discovered,
the surface is smooth. 3d. There are glands which, before throwing
out their fluid by their excretories, 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 always two
excretories, one which goes from the gland to the reservoir, the other
from the reservoir outwards. These reservoirs 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 excretories may to a certain
extent be considered as such. In fact, these ramifications, as well as
those of the excretories 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 papillæ 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 windings 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 mammæ 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 preserve it to a certain extent from putrefaction; expose 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 excretories
is much less rapid than that of the blood in the veins and even than
that of the lymph in the absorbents; 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 flowing, 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 and 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 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 membranes, as the mucous, salivary, pancreatic, prostate and
hepatic excretories. The cutaneous and mucous surfaces are the only
ones then on which the excretories terminate, 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 considered as a kind
of general excretory added to the pancreatic, 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
destined, 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 contained in cavities with mucous surfaces,
they may be truly considered as being out of our parts. These surfaces
are really true internal integuments, destined to defend the organs
from the contact of the substances which they contain, a contact which
would inevitably be injurious to them.
_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 besides
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 infiltration 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 peritoneum 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 suspect 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, all 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.
I 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
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 black 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; 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. I do not doubt
but that in purulent reabsorptions, the pus 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 particularly affected in diseases;
but 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 diseases. 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 contact 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 foreign substances which had no
affinity with any particular 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 differing
from each other, and which cannot be always essentially the same. In
these experiments the most important 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 convince 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 injected 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 alterations 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 appear to be really decomposed.