Xavier Bichat

“ The alterations of organic sensibility can diminish, increase, or variously modify this property. Let us cease to wonder then at the extreme variety of the absorptions; let us not be astonished, if many fluids, besides those ordinarily taken up, can pass into the blood by the absorbents; if the bile, the urine, the mucous fluids, which are usually rejected, can enter the circulation; if the blood effused in the cellular texture is taken up by these vessels. The forces of life impress, by their extreme variety, the same character on all the functions over which they preside. ”

“ How can an animal, breathing a very cold air, eating aliments almost deprived of caloric, &c. in northern latitudes, have as much heat as in hot climates? It is not the free caloric contained in the parts, but the combined, which, being introduced into the blood with the foreign substances, furnishes the materials of that which is disengaged in the general capillary system. Now the combined caloric is absolutely independent of temperature. As much fire is elicited from the same stone by the steel, in the coldest as in the warmest countries. ”

“ No system as a whole, is of more considerable size; no one occupies more space in the economy. Besides the numerous regions that the muscles fill, they are generally spread out under the skin, and partake, as it were, of the functions of this organ, protect like it the subjacent parts, like it bear with impunity the action of external bodies, and can even be divided in a more or less considerable extent, without the general functions of life suffering from it; which renders them very fit to defend the deep-seated organs, whose lesion would be very injurious. ”

“ Acute diseases, whatever may be their nature, change it but little. Fevers with the greatest prostration, if they suddenly produce death, leave it untouched, because this colour can only change by nutrition; now as this function is slow in its phenomena, it is but little affected by acute diseases; it is only at the end of some time that it feels the affections reigning in the economy.
I would observe that the varieties of colour that are seen in the muscles of adults, even in the healthy state, distinguish them especially from those of the fœtus, which have in general an uniform paleness. ”

“ The state of the animal muscular system is truly the thermometer of the state of the brain; the degree of its movements indicates the degree of energy of this organ. Those who attend in a lunatic hospital have often occasion to consult this thermometer. At the side of a furious patient, whose muscular power is doubled, or even trebled, you see a man all whose motions languish in a remarkable inertia. ”

“ If chemists apply their theories to these morbid changes of heat, instead of considering them as a necessary consequence of the state in which the vital forces are then found, they will necessarily find in them an insurmountable obstacle.
When we run swiftly, when the blood is violently agitated in the paroxysm of fever, more caloric is disengaged than at any other time. Does this prove that it is the general circulation which contributes to the disengagement of caloric, and that it takes place in the great vessels? No more than a copious sweat proves that the heart drives it out. ”

“ The difference of the causes which act upon the brain in the animal contractility, in order to determine it to excite the muscles, appears particularly in a remarkable manner at the instant of death. Whatever may be the way in which this happens, the intellectual functions are always the first to cease; it is even to this that we especially attach the idea of the absence of life. ”

“ Why has nature given to the life of the teeth a shorter term than to that of the other bones, which do not cease to exist but with the other organs, whilst the teeth die a long time before? Is it because the stomach becoming weak with age, the animals are thence compelled to nourish themselves in their old age, with soft substances, adapted to the languid state of the gastric forces? ”

“ Each body is by its nature capable of irritating the muscles differently, as according to individuals, ages, temperaments, seasons, climates, &c. the muscles are capable of answering differently to excitements made upon them.
It is not necessary to irritate the whole of a muscle to produce its contraction; two or three fibres only being pricked bring into action all the others. Often even when we make these experiments on a living animal, the contraction is communicated from one muscle to another. ”

“ The general muscular system very evidently forms two great divisions, differing essentially from each other, by the vital forces that animate them, by their external forms, by their mode of organization, and especially by the parts they perform, the one in animal life, and the other in organic. We shall not then consider them together. Let us begin by the examination of the muscles of animal life; these are spread out in great number in the human body. ”

“ We cannot deny that in the natural state the sensibility of the absorbents has a particular type, to which certain substances are alone accommodated, and which alone on this account can be absorbed. The exercise of the organic sensibility then always pre-exists in absorption, as it does in secretion, nutrition, &c. Thus in the physical phenomena, the exercise of gravity always precedes the fall of heavy bodies. ”

“ In other circumstances the brain is only affected sympathetically. In many acute affections what is called translation to the brain, does not arise from more blood being carried to it; the pulse is not fuller, the face is not more flushed; there are often even signs of languor in the action of the vascular system. The brain is affected, like all the other organs by sympathy, a happy word, which serves to veil our ignorance in respect to the relations of organs to each other; the brain is affected then like the heart, the liver, &c. ”

“ If the brain is wholly engrossed in its relations with the senses, or in its intellectual functions, it, if we may so say, forgets the muscles; these remain inactive; the man who looks or hears with attention, does not move; neither does he who contemplates, meditates and reflects. The phenomena of ecstasy, the history of the studies of philosophers, often present us with this important fact, this muscular inertia, the principle of which is in the distraction of the cerebral influence, which does not increase in other functions, only by diminishing in locomotion. ”

“ In order to estimate correctly the sensible organic contractility, it is necessary to destroy the animal contractility. So long as these two clash, interrupt and counterbalance each other, we cannot properly estimate them, and determine what belongs to each and what is common to both. Now we destroy animal contractility in the living subject, by cutting all the nerves of a muscle or an extremity, which then become paralyzed. ”

“ From all that I have said, it is evident that in the organs whose capillary system contains in part blood, and in part different fluids, the proportion of the first to the others is infinitely variable; that a thousand causes in a state of health, as in that of disease, by bringing to the organ more or less blood, can fill more or less its capillary system. ”

“ Observe in regard to the use of the muscles in digestion, that it is the portion of the fibrous system which adheres to them, and forms, as it were, a part of them, I refer to the tendons, which is the most easily altered by maceration, by ebullition and by the digestive juices. Observe also that the great mass which the muscles form in the body of all animals, of which they are more than one third, presents to the carnivorous species ample materials for their nutrition ”

“ In the femur the length of the neck which is the lever of rotation, gives much extent to this motion, which supplies the pronation and supination that are wanting in the leg; so that every rotation of the foot is a motion of the whole of the limb. In the humerus on the contrary, the neck being very short and bringing the axis of the bone near the centre of the motion, limits rotation, which is less necessary on account of that of the fore-arm; the motion of the hand without or within is never communicated but by a part of the limb. ”

“ Who does not know that oftentimes when the extremities are frozen, the patient feels an extraordinary internal heat? It is sufficient that the forces of the capillary system be differently modified, that the heat may be so also.
Observe, in fact, that the alterations of heat in diseases are as frequent as those of the exhalations and secretions, and that they always present, like the first, a previous derangement in the vital forces. ”

“ Many animals with red and cold blood, frogs in particular, have muscles almost white, and yet many red vessels run through this white texture. 3d. I have observed that in animals destroyed by asphyxia, the colouring substance does not change colour, no doubt because it is slowly combined with the muscle by nutrition; that on the contrary, if we cut a muscle of these animals in the last moments of life, whilst the venous blood still circulates in the arterial system, this blood flows out by black jets from the muscular arteries, the muscular texture itself remaining red. ”

“ The muscles become more and more susceptible of moving thus, as we approach old age, a period in which the least motion makes the whole muscular system vacillate. Why? Because the muscle is no longer in sufficient contraction; it is as it were too long for the space it fills. This appears to be owing to the circumstance that the contractility of texture has diminished in the last age; we can be convinced of this by cutting transversely for comparison a muscle in an old man and a young one; it retracts more in fact in an opposite direction in the second than in the first. ”

“ 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 ”

“ All that we can know upon the nature of the muscular fibre, is that it is peculiar, that it is not the same as that of the nerves, nor as that of the vessels, nor as that of the tendons or the cellular texture; for where there is identity of nature, there ought to be identity of vital properties and of texture. ”

“ If instead of blowing gas into the cellular texture of an animal, we force in different fluid substances, they produce different effects upon the muscles, according to their nature, and to their acrid, soft, or styptic qualities. No injection produces a more sudden and striking effect than that of opium dissolved in water, or than that of its various preparations; when the muscles feel it in contact, their motions cease, they fall as in paralysis. ”

“ We find on all the non-articular cartilages a membrane exactly analogous to the periosteum, and which is called perichondrium. The larynx, the ribs, &c. exhibit it in a very evident manner; it is delicate, with fibres interlaced in all directions, less closely united to the organs it covers, than the periosteum is to the bones, because the cartilages having on their surface less numerous foramina, it does not send to them as many fibrous elongations; hence a less intimate relation between the life of the perichondrium and that of the cartilage, than between that of the bone and its periosteum. ”

“ Undoubtedly in man, a thousand causes, arising especially from the nature of the aliments, their degree of heat and cold, the manner in which they are cooked, their infinitely various qualities, hasten the natural period of the death and the fall of the teeth, because by incessantly exciting and stimulating these organs, they keep them in a state of constant activity, which exhausts their life sooner than it otherwise would have been. ”

“ Every one knows the innumerable hypotheses that were made upon the production of animal heat by the mechanical physicians. Modern chemists, in showing the insufficiency of these theories, have substituted one that has not less difficulties. The lungs are considered by them as the place in which the caloric is extricated, and the arteries, a kind of tubes, that carry the heat to all parts of the body. The production of this great phenomenon belongs then wholly, according to them, to the pulmonary capillary system. ”

“ Death weakens the contractility of texture but does not annihilate it; a muscle being cut retracts a long time after life has left it. Putrefaction alone puts a limit to the existence of this property. It is the same with regard to extensibility. I would observe however that while the muscles retain the vital heat, they have more power of retraction, than when the chill of death has seized them. ”

“ But in a morbid state, the sensibility is developed to the greatest extent; we know the horrible pains that attend spina-ventosa, and those not less severe that caries produces in certain cases. If a bone is inflamed, as for example the sawed extremity of a stump after amputation, this bone which in a natural state had borne, without transmitting any painful impression, the action of the saw, becomes as it were a new sensitive organ, to which the least touch is painful. The animal contractility is nothing in the osseous system. ”

“ Not only the cavity of the cells is full, but the organ is also much dilated. I have often had occasion to open those who have died of pneumonia, in whom one of the lungs was entirely sound; now, the disproportion of weight between it and the affected one, was incomparably greater than that between an inflamed kidney and a sound one.
This phenomenon evidently arises from the fact, that the lungs alone receive as much blood as the whole body, so that when an inflammation of this viscus interrupts the course of the fluids, a very great quantity of them can accumulate there in a given time. ”

“ In the short bones, the texture of the cells always predominates; the bone is almost wholly formed of it, a delicate layer of compact texture forms only its covering, and in this respect, the organization of these bones is the same as that of the long bones at their extremities; thus the resistance of the bone depends on the whole of its mass, and no part makes a greater resistance than another against fractures. ”

“ If a fine injection but partially succeeds, it almost always shows vessels that really exist, but which were not sanguineous during life. Even the coarse injections of our dissecting rooms frequently exhibit these phenomena, especially in the face, the neck, &c.; and much more so, if the matter injected is very delicate, and managed with much address. I cannot conceive why physiologists have always taken as an indication of the blood vessels, the state of injected organs; by opening any part of a living animal, they may clearly see how deceptive this method is. ”