Part 7

The exhalations are never all increased or diminished at the same time; I except however the state of excitement at the commencement of some fevers, when all are suppressed. In every other case, when one fluid is abundantly poured out, the others are diminished; thus the skin is dry in dropsies. There is sweating in the first stages of phthisis pulmonalis; but when in the latter, dropsical effusions are considerable, sweating ceases.

I have moreover divided into two classes the causes of increased exhalations. 1st, One of these proves an increase of life; 2d, the other, a real diminution of the vital forces; hence active and passive exhalations. How can the same phenomenon arise from two causes exactly opposite? It is difficult to determine precisely; but so many phenomena prove this distinction of exhalations as well as secretions, that we cannot refuse to admit it. It is important to recollect this in the following article.

III. _Of Preternatural Exhalations._

I call by this name those, in which the exhalants pour out a fluid different from that which is natural to them. The first which offers is that of the blood.

_Sanguineous Exhalation._

The blood frequently passes off by the exhalants instead of their own fluids; hence arise hemorrhages very different from those that take place from rupture. I shall examine these hemorrhages in each kind of exhalants.

_Hemorrhage of the Excrementitious Exhalants._

The vulgar expression which is sometimes used, to sweat blood and water, &c. indicates that under certain circumstances, though they are very rare, the cutaneous exhalants give passage to the blood. Haller has collected a number of instances of it, that may be found in his work. The first year that I came to Paris, I saw constantly with Desault, a woman with a cancer of the womb, who had at certain periods sweats that stained her clothes as much as is ordinarily done by the catamenia. This woman had had frequent hemorrhages before the beginning of her disease. After these sweats commenced, they had continued but were more rare. I regret that I neglected to collect the particulars of this singular fact.

No exhalants pour out blood more frequently than the mucous; so that hemorrhages are an affection almost characteristic of the mucous surfaces, in which they have different names, according to the portion of them that are attacked. It is not my object to present here the phenomena of these hemorrhages; I only wish to prove that they are an exhalation.

1st. I have very often opened subjects that have died during a hemorrhage; I have had occasion to examine with this view the bronchial, gastric, intestinal and uterine surfaces; I have never seen the least mark of erosion, notwithstanding the precaution of carefully washing the surfaces, of letting them macerate and even examining them with a glass. 2d. The following experiment uniformly succeeds upon the wombs of women who have died during menstruation, and often even at other times; by pressing them, there issues from the mucous surface a greater or less number of little bloody drops, which evidently correspond with vascular extremities, and being wiped off, no erosion can be seen. 3d. The analogy of all the other open surfaces that pour out blood, and which evidently do it by their exhalants, is a proof that the same phenomenon has the same seat in the mucous surfaces. 4th. The womb would be only a mass of cicatrices in females of advanced age, if there had been a rupture in it in menstruation. 5th. In active hemorrhages, in which there is evidently a congestion of blood previous to its escape, we can conceive, to a certain degree of the rupture of the small vessels; but in passive hemorrhages, in those in which the organic sensibility being annihilated, seems to allow of a simple transudation through the exhalants, how can we conceive of these ruptures? 6th. We understand with difficulty how an evacuation, which is often produced with an extreme rapidity, which ceases in one place and immediately appears in another, which is subjected to all the sympathetic influences, we understand, I say, with difficulty how it can happen from rupture. 7th. Observe menstruation, furnishing sometimes for one moment blood, and not giving it the next, renewing twenty or thirty times a day, in certain affections, these alterations of flowing and ceasing to flow; it would be necessary then, that at each time the wounds should open and be cicatrized. 8th. Besides, compare hemorrhages evidently produced by rupture upon the mucous surfaces, such as those, which in wounds of the head, take place from the nostrils, the ears, &c.; those, which by a fall upon the rectum, sometimes happen from the bladder; those which, in too great efforts in coughing, arise upon the bronchial surface; those of which the stomach is the seat from the action of different poisons, &c. &c.; compare, I say, these hemorrhages, and many analogous ones that I could mention, with those that take place spontaneously from the mucous surfaces; you will see that they do not resemble them in their phenomena and their duration; that by suppressing them, they do not give rise to others; that they are independent of all kinds of sympathetic influence; that the passions have no effect upon their cessation or their production, whilst they have so powerful an influence upon the others.

Let us conclude from all these considerations, that all mucous hemorrhages, whether active or passive, are real exhalations. Hence you see that there is not so great a difference as might be thought, between the first and inflammation. In fact, in one there is an accumulation of blood in the capillary system, then the passage of this fluid by the exhalant vessels, that are continuous with this system. In the other, there is only the first phenomenon. Undoubtedly the signs, the circumstances, &c. are wholly different, because the modifications the organic sensibility undergoes are not the same; but the state in which the small vessels and the blood are respectively found, is not less analogous. One proof that in active hemorrhages, it is the organic sensibility which, differently modified, opens or closes the passage to the blood by the exhalants, is this, that almost always there are previous symptoms which continue for some time, and which evidently declare the disturbance that the vital forces, the organic sensibility in particular, experience in the part; we know the itching, the forerunner of nasal hemorrhages, the tickling and sometimes sense of heat which precede the pectoral. Sometimes, according to the varieties of alteration it undergoes, the organic sensibility at first permits serous fluids to pass, then bloody; this is what we see in menstruation, in which the exhalants oftentimes pour out serum for some minutes, then true blood.

In passive hemorrhages, the organic sensibility is without doubt diminished, as well as the tone or insensible organic contractility. We might say, that the small vessels were not able then to contract sufficiently to retain the blood; it is as in our injections which ooze from the mucous surfaces, because life no longer opposes their passage. Observe that when these hemorrhages are produced by an organic disease, it is almost always that portion of mucous surface nearest the organ, that is influenced by it. Thus in the last stages of disease of the heart or the lungs, the patients often spit blood; they pass it by stool, towards the termination of those of the liver, or even throw it up by vomiting, &c. The whole mucous system never loses its forces so as to pour out blood everywhere; it is only in a determinate part that it is weakened.

What disposes the mucous exhalants more than all the others to pour out blood? It appears to be because the capillary system whence they arise is constantly entered by blood, and the course is very short from this fluid when present in the capillaries to the mucous surfaces. This is so true, that those portions of the mucous system that have but little of this fluid in a natural state, as those of the sinuses of the face, of the ear, &c. are less subject to hemorrhages. I am confident, that if there were exhalants upon the muscles to pour out constantly a fluid upon the exterior of these organs, hemorrhages would be very frequent in them.

Hence we see that the mucous hemorrhages have nothing in common, but the extravasation of blood, with those which are the effect of hemorrhoids, and always suppose a rupture of the veins, with those that aneurisms or varices produce, with those that are the effect of a cut, of a violent concussion, &c. They form a class by themselves, and resemble those only that the exhalants furnish upon the other surfaces where they open.

If I should class hemorrhages, I should distinguish them, 1st, into those that come from exhalation; 2d, into those that are produced by rupture. I should place among the first the bloody sweats, the mucous, serous, cellular hemorrhages, &c.; among the second, those that accompany wounds, aneurisms, &c. In order to embrace in one view all the sanguineous evacuations that can happen in the animal economy, I think it absolutely necessary to adopt this division which moreover accords with the phenomena and treatment of hemorrhages. Would you bleed to arrest a hemorrhage from rupture? undoubtedly not; but you would bleed to check an active hemorrhage by exhalation, because by diminishing the mass of blood, you diminish the excess of organic sensibility which produces the hemorrhage; it is nearly the same as when we bleed for inflammation. It is certainly necessary that the hemorrhage should be stopped as it has been produced; it is necessary that the sensibility of the exhalants should return to its natural type before the blood ceases to flow. We do not bleed to draw the blood to another place, as has been said; if it was so it should be done in passive hemorrhages. Most of those who bleed much in hemorrhages, believe that plethora is the sole cause that produces them, that the vessels containing too much blood, require a part of it to be taken away; but there are many more cases of active hemorrhage in which there are no signs of plethora, than there are of those in which these signs exist. There may be a real deficiency of this fluid in the great vessels, but if the exhalants of a part are by their peculiar sensibility in relation with it, they will pour it out in as great abundance as if there was an excess of it. It is as in the increase of natural secretions, exhalations, &c. Whether there was plethora or not in the great vessels, when the local affection has raised the peculiar sensibility of the secretories or the exhalants, they would draw abundantly from the blood. The influence of plethora upon the increase of the different fluids which are separated from the blood, is evidently one of the remains of the opinions of Boerhaave. If the heart agitated everywhere the fluids, if it propelled the blood, the serum, &c. that go out by the exhalants, the, secreted fluids that go out by their ducts, this influence would necessarily be real; but since all the fluids going from the capillary system are necessarily beyond every action of the heart, as in their circulation, they are wholly under that of the organic sensibility and tone of the capillaries, it is evident that these fluids are independent of the quantity of blood contained in the great vessels and moved by the heart; that the alterations of the vital forces of the part are the sole causes of the different phenomena that their course exhibits.

Who does not know that feeble and delicate temperaments are often subject in women to a much more copious menstruation than those that are stronger, more vigorous, more sanguineous, as it is called? You will find many results in authors, upon the quantity of blood evacuated by the catamenia, and you will observe at the same time that these results do not resemble each other; why? because each womb has, if you may so say, its own temperament, which oftentimes does not correspond with the general temperament, because each is disposed consequently to a different kind of vitality. There is more or less blood then given at each menstruation, as it is given for a greater or less time, for some women have at first only a serous fluid, while others have blood immediately. I cannot repeat it too much, that every vital phenomenon is necessarily subjected to many irregularities, which arise from those to which the vital forces are themselves exposed. On the contrary, every physical phenomenon is almost immutable, because it is the nature of physical laws to remain always the same.

Hence we see how hemorrhages of the great arteries, which are under the immediate influence of the heart, should differ essentially from those of the capillary system and of the exhalants, whose phenomena are under the influence of the forces of the part where they happen, whether they arise from rupture or exhalation. Though in fact these two classes may be essentially different in their principal phenomena, as I have already said, yet they approximate, because the modifications of the vital forces of the part have a necessary influence upon them when they are in the capillary system. Thus astringents, tonics, styptics and other medicines which evidently act upon the organic sensibility and the insensible contractility, frequently stop hemorrhages of the capillary system. The contact of the air, by modifying these properties in wounds is even sufficient to produce this effect. On the contrary, ligatures alone can, in the great vessels, resist the powerful influence of the heart. All styptics imaginable may be heaped upon an open artery, and they would not check the effect of this influence. This then is the essential difference between the hemorrhages of the capillaries and exhalants, and those of the arteries, that every medicine which acts upon the organic sensibility and tone, can be advantageously employed for the first, whereas they have no effect upon the second. I go now to the sanguineous exhalations which are made by the recrementitious exhalants.

_Hemorrhages of the Recrementitious Exhalants._

The serous membranes are the frequent seat of hemorrhages. The examination of dead bodies incontestably proves it. Nothing is more common than to find in the peritoneum, the pleura, the pericardium, &c. a serum, reddish if a little blood is effused, very red if more, and even pure blood is found under certain circumstances.

I have made these observations in two different cases, 1st. After inflammations whether acute or chronic, especially the last. The serous sac then contains a greater or less quantity of blood, sometimes alone, more frequently mixed with serum, and now and then even with whitish and albuminous flakes. The previous inflammation seems to rank these hemorrhages among the active. 2d. Often at the end of organic diseases, in which the exhalations of serum increase almost uniformly in the serous sacs so as to produce dropsies evidently passive, a greater or less quantity of blood is mixed with this serum. What anatomist has not observed these bloody effusions in the pericardium, the pleura, &c.? I have observed that the tunica vaginalis and arachnoides are infinitely less subject to them than other similar sacs; I have never seen them in the last, and twice only in the first. I of course do not speak of the hemorrhages that are the effects of wounds of the head and in which the blood is effused between the two folds of the arachnoides.

I have carefully examined the internal surface of the peritoneum, the pleura, and the pericardium, after this kind of hemorrhages, produced either in consequence of the inflammation of the membrane itself, or of an organic disease; their surface has appeared to me to be perfectly sound, so that it is very evident that the exhalants have furnished blood, instead of the serum they threw out there before.

I compare a serous surface preternaturally pouring out blood after inflammation, with the active hemorrhages of the mucous surfaces. On the other hand, when the serous exhalants throw out blood at the end of organic diseases of the heart, the womb, the lungs, &c. it is certainly the same phenomenon, as when blood brought by the mucous exhalants, under like circumstances, is thrown off by spitting, vomiting, or stool.

Are there cases during life, in which the blood, poured out by exhalation upon the serous surfaces, is afterwards taken up by absorption? I believe that it may happen after inflammation, though we are possessed of no positive facts upon the subject. Cruikshank and Mascagni have seen the blood absorbed by lymphatic vessels, after wounds of the chest; why might not that happen after hemorrhages by exhalation, which takes place after those from rupture?

The cellular exhalants frequently pour out blood in the cells. 1st. This phenomenon is often very evident in phlegmon or in other similar tumours. By cutting into them, in the dead body, we find blood extravasated in the cells; this is so true, that some authors have made the nature of inflammation consist in this extravasation. But in slight phlegmonous inflammation, the blood undoubtedly remains in the cellular capillary system; it is only in those cases where the inflammation is very great, that this passage takes place. 2d. As to the passive hemorrhages of the cellular texture, who does not know that oftentimes the water in dropsies is reddish? who does not know, that in scurvy, considerable portions of the cellular texture are infiltrated with blood, which has certainly not been poured out by erosion? I injected not long since two subjects, with very evident scorbutic spots on the legs, and there was no kind of extravasation in them; there would have been if the rupture of the vessels produced these spots. As these things did not arrest my attention particularly in former years, I did not pay much attention to many subjects that I have injected with these scorbutic spots. I do not think that they would ever have presented cellular effusions, which would undoubtedly have struck me if they were there, when I dissected bodies for the students.

As to the hemorrhages of the medullary exhalants, we are ignorant of them. I have never seen in examinations of dead bodies, blood effused in the articulations, except from wounds, &c.

As to the nutritive exhalants, it is evident that every sanguineous exhalation is foreign to them.

_Preternatural Exhalations, not Sanguineous._

The blood is not the only fluid that sometimes passes by the exhalants instead of the fluids that these small vessels naturally pour out. Who does not know how much the sweat differs? Sometimes water is almost alone transmitted by the skin; at other times the sweat is filled with many substances more or less heterogeneous; it is more or less salt; we know how very different at times is the odour of it. Observe the many substances that are thrown out upon the external surface by the exhalants, in the small pox, measles, scarlatina, &c. in herpetic affections, in different eruptions; compare the critical sweats with those that are natural, and you will see that the exhalants are, if I may so express myself, a common passage, which all the substances contained in the body can pass through, and which in fact they do pass through in certain cases, when, among the numerous modifications of which the cutaneous organic sensibility is susceptible, they find those that are in relation with them. Shall I speak of the serous exhalants? observe that the surfaces of the same name, according as they are affected, pour out many different fluids, a milky serum, and a thick substance that attaches itself to their surface in the form of a compact membrane, &c. If you have opened but little the bodies of those who have died of chronic peritonitis, you must have been astonished at the diversity of fluids then contained in the peritoneum. Grey, yellowish, fetid, without odour, thick, viscid, thin, &c. &c. these fluids are hardly twice the same. The serum appears to be always the general vehicle; but the substances that it contains, by the effect of the change that disease has produced in the vital forces of the membrane, are infinitely variable.

Thus we shall see that the glands are a common way, through which pass, according to the manner in which they are affected, many substances which differ essentially from those that compose the secreted fluids in the natural state.

IV. _Of the Preternatural Development of the Exhalants._

The exhalants are developed preternaturally in many parts; it is especially in the cysts that this development is best seen. Their internal surface, ordinarily smooth, pours out very different fluids, according to the particular sensibility they possess. When we open these cysts, the exhalants furnish new fluids, and it is often necessary to remove them to prevent exhalation. Sometimes instead of the fluid that is ordinarily exhaled there, the blood is thrown out, as happens on the serous surfaces; for example, I have found very bloody serum in the encysted dropsies of the ovarium; latterly I have seen in them coagulated blood. I would observe that this is an essential difference to be added to those mentioned above, between the fluids that are exhaled and those that are secreted. These last are never preternaturally poured out in a cyst. We never find preternaturally a quantity of bile, of urine, saliva, serum, &c. whilst we often find serum, as in encysted dropsies, fat as in steatoma and other tumours which have a fatty liquid analogous to this fluid, synovia, as in the tumours called ganglions, when they are not dilatations of the synovial glands, which have cysts preternaturally produced, &c. Whence arises this difference? it would be necessary that the glands should be preternaturally developed in our parts, in order that the secreted fluids might be preternaturally separated from the blood, now the structure of these organs is too complicated, their organization supposes too many conditions, to admit of their preternatural development. On the contrary, the simple organization of the exhalant surfaces, which have only vessels continuous with the arteries, and without an intermediate organ, requires much less for them to grow preternaturally in parts, in which they were before unknown.

Sometimes the fluids exhaled preternaturally do not collect in a cyst; they continually flow out; this is what takes place in fistulas, and other preternatural or artificial drains that are made in our organs. Then the cellular texture, constantly preserving the preternatural modification of sensibility that it has taken locally from a deposit, or any other circumstance, constantly continues to pour out a fluid different from the serum that is exhaled in a natural state.

ABSORBENT SYSTEM.

This system results from the union of a multitude of small vessels which arise from all the parts, and carry different fluids that are poured into the black blood, after having passed through certain peculiar swellings that are called lymphatic glands, and which make a part of the system with them. The whole of the absorbent system comprehends then two things, 1st, the vessels; 2d, the swellings or glands, an improper name, inasmuch as it assimilates them with organs which pour out fluids by the excretories that arise from them.

ARTICLE FIRST.

_Of the Absorbent Vessels._

We shall examine these vessels in their origin, their course and their termination.

I. _Origin of the Absorbents._