to habitual alternations of increase and diminution. 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 compare the sleep of animal life
to the intermissions of intermittent 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 continues.
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 mammæ 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 substance that is remaining there, or that is only passing.
The glands then must be considered as continually separating a fluid
from the blood, and as being at certain periods in greater activity,
and consequently as furnishing more fluids.
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 locomotive 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 simultaneously raised in
the whole system._
The vital properties of the glands are never simultaneously excited
in all. When one is in action, the others are in remission. We might
say, that there is but a determinate 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. Observation proves this every day.
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 before 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 precisely 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 employment 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 excitement, 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 those of the
rectum, the urethra and stomach, on which we can in many cases apply in
diseases excitements in a more advantageous manner than is done 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 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 preceding character, and
it is one that may be likewise considered 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 reciprocally 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 descending
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, according 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 exhaled 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 increase 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 summer, 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 mammæ, 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.
ARTICLE FOURTH.
DEVELOPMENT OF THE GLANDULAR SYSTEM.
I. _State of this System in the Fœtus._
Though the secretions are not active in the fœtus, the glandular system
is in general much developed. All the salivary glands and the pancreas
are larger in proportion 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 precise 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 fœtus 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 corresponding with that
of remission in the adult; they secrete even less fluid, though they
appear however to be in constant 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 influence, and I have elsewhere
imagined it, from the circumstance that this blood is unable to support
many other functions. But the principal reason appears to me to be,
that in the fœtus the nutritive motion of composition predominates
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, digestion 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 example most of the drinks, which only pass into
the mass of blood, and go out immediately with the urine.
The glands of the fœtus 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
becomes 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 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
organ produces two effects in it, one of which is to excite it, either
by the motion it communicates, or by the contact of the principles
it contains, and the other is to furnish materials for the different
functions, as for exhalation, secretion, nutrition, &c. The first
effect is common to all the organs which the blood enters; the second
is peculiar to each.
I would observe however that many of the secretions are much 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 predominant ones
in early age. 1st. It is not the parotids that are enlarged in the
frequent swellings that take place in their neighbourhood, but it is
almost always the lymphatic 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 are absolutely nothing.
4th. In the same proportion in which the organic affections of the
liver and the kidneys 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
sarcoceles, 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 very frequently in action. The infant weeps
more often than the adult; we might say that all the passions which
agitate 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 passions 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 frequently occasioned by the passions of the adult; they do not
become pale or red as much in anger; thus the countenance 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 fœtus, neither the liver nor the kidneys
have the singular property of hardening by boiling. They remain during
this experiment 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 advance 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 finishes. 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 stronger, increase their action also; they
become stronger, and gradually lose the softness that characterized
them in infancy; they moreover grow harder.
Till then composition had predominated over decomposition in the
general nutritive motion. Then almost as many substances are constantly
thrown from each organ, 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 predominate 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 predominant;
then the passions to which the bilious temperament 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 predominate 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 excrescences 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 glands,
which resembles tabes mesenterica, the engorgement 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 Age._
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 except 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 colourless 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
systems, and is concentrated in the organs in the neighbourhood 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 mammæ 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 glands to be thrown out. An old
person decreases by a phenomenon opposite to the rapid growth of the
fœtus, 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
cutaneous 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 consequently in mucous glands,
are not withered and have not the horny hardening in old age; they
perform their functions 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 considerable 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.