GLANDULAR SYSTEM. (continued 2)

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.