Chapter XV: Part 15

7th. A short time after painting the hairs of the head black, a fashion now more common in France than at the period in which they powdered them, there is often experienced pains in the head and a swelling of the hairy scalp, though the skin has been in no way concerned, has not been pulled, and the hair only has been affected.

It follows from all we have just said, that the hairs analogous, by their external covering, to the epidermis; foreign by means of it, if we may so say, to life, belong to it much more particularly by their internal substance, a substance whose nature is yet but little known, as I have already said. What moreover evidently proves this assertion, is that the phenomena of which I have just spoken, and to which I could add many others, cease to be evident in persons, in whom the hairs having become white, have no longer any thing but the epidermoid covering, the internal substance having in part disappeared; particular observation proves this. It may be however that in this case that portion alone of this internal substance, corresponding to the colour, is destroyed, whilst that which is the seat of the exhalations continues to live as usual; and, in this respect, white hairs may experience vital phenomena, of which, I believe, there are a few examples. But all this is subordinate to the future experiments, which will elucidate the pilous structure more than it now is.

ARTICLE THIRD.

PROPERTIES OF THE PILOUS SYSTEM.

The hairs experience but a slight degree of the horny hardening when exposed to the action of caloric. They then turn in various directions, curl and twist; but this arises from a cause entirely different from that of the horny hardening of the other organs. The caloric then removes the moisture with which the hairs are constantly penetrated, and thus approximates their particles. Thus when the hair is moistened by fog, a bath, &c. the curls disappear. The oily substances that are used at the toilet, give a coat that is insoluble in water, and preserve the curling, by preventing it from penetrating the hairs. Some time after the head has been washed, they curl more, as we have had occasion to observe since the Grecian head dresses have been in fashion among us. This at first appears to be contradictory, but it is not so. In fact by then rubbing the hairs much, the unctuous substance is removed, which always surrounds them, or this substance combines with the soap, if the water contains it, as is often the case; by this means it easily penetrates the hairs, the pores of which remain open, and by afterwards evaporating with the fluids that were already there, and which the unctuous substance retained, it leaves these organs more dry than they were, and consequently more disposed to curl.

A proof, that it is the epidermoid covering which thus imbibes the moisture that it afterwards loses in the state which succeeds the curling, is, that the detached epidermis can be curled with a hot iron, and afterwards rendered supple by soaking it in water.

The contractility and extensibility of texture are very indistinct in the hairs; it is their resistance which prevents their rupture; they can hardly be stretched at all.

They have no animal sensibility when pulled; the pain that arises from it has its seat especially in the skin through which they pass. Thus when drawn opposite to their direction, we suffer much more than by stretching them in the direction of their pores. I do not deny however that these elongations, which fix their origin to the neighbouring parts, may be also the seat of pain when the hairs are pulled. These organs have no animal contractility.

The organic properties certainly exist in their internal substance. The changes which this substance undergoes can only depend on the different alterations which affect these properties. The organic sensibility and the insensible contractility especially are raised in it in a remarkable degree in the plica polonica; now in order to have the degree of energy which they then do, they must have existed there in a natural state. It is these two properties, that, the sympathies of which we have spoken, put into action. The organic contractility is nothing in the hairs.

Yet we cannot deny that in the natural state, these organs are, next to the epidermis and the nails, those in which life is the least active, those which have the least numerous relations with the other organs. Whilst every thing is destroyed in most of the other systems by diseases, this is most often unaffected by them; it grows as usual, and appears to be in no wise disturbed; it has then a manner of being, of existing, wholly different from the others.

In general, the external productions of animals, as the feathers, the hair, the scales, &c. seem to form a separate class of organs, foreign to the life of the internal organs; it is almost like the different species of mosses that grow upon trees, without making essentially a part of them.

ARTICLE FOURTH.

DEVELOPMENT OF THE PILOUS SYSTEM.

I. _State of this System in the First Age._

In the first months of the fœtus there are no hairs on the skin which is then gelatinous. It is when the fibres of the dermoid texture are formed, that there begins to appear on the head a light down, an indication of the hairs which are afterwards to arise. This down is whitish and concealed by that fatty and unctuous substance, which we have said is deposited on the external surface of the skin at this age. Soon this down, which appears to be but the external covering of the hairs, which is then of extreme tenuity, begins to be coloured black or flaxen, according to the tint that is afterwards to predominate; it is the internal substance that forms it. The colour remains faint until after birth. At this period the hairs are often more than half an inch long. Upon all the rest of the body there is only the down, the precursor of the hairs; the face especially has much of it. The hairs of the head are then in advance at one period of the other hairs, in their growth.

After birth the hairs grow much more rapidly than before. It is precisely the reverse of most of the other parts, whose growth is more rapid in the womb of the mother. During the whole of youth this system has a tint less deep, than it is afterwards to have. The flaxen becomes nearer the chesnut, and this nearer black, and the first tints of the bright red grow many degrees darker towards the period from the twenty-sixth to the thirtieth year. The light tints are to the pilous system in youth, what the imperfectly developed forms are to the muscular, cellular, &c. Oftentimes that which is to be afterwards flaxen, approaches a whitish tint, which is owing only to the nature of the internal substance, and not to its absence in old age. Thus the white of the Albinos depends also upon the peculiar species of this internal substance. Many hairs are wanting upon the body of the young man.

II. _State of the Pilous System in the following Ages._

At puberty there is a remarkable revolution in this system which becomes almost double. The hairs of the genital parts are formed; the beard which is, as I have said, the characteristic attribute of the male in the human species, is also then developed. We might say that there was the same relation between the hairs of the neighbourhood of the testicles and those of the beard, as between the testicles themselves and the organs of the voice, between the womb and the mammæ. The beard is, in this respect, the external sign of virility. Some time before it comes out, we see under the skin the sac which contains the origin of the hairs; it is already very evidently formed, and permits the principle of the organ to be seen which it is to contain, as I have oftentimes ascertained; thus the sac of the tooth exists a long time before the tooth is cut.

At the same time the hairs of the axilla grow also; those of the trunk and extremities, which were then almost in a state of down, become larger, assume a determinate colour, and increase even much in number.

Why does puberty occasion this general growth in the pilous system? This is asking the reason of all the other phenomena which appear at this period. I would only observe that the hairs of the head, the eyebrows, the eyelashes and the hairs at the openings of the body, are those which are the least affected by this revolution. Besides, this growth is gradual; it requires at least two or three years for the beard to become what it is always to be.

In the following ages the hairs undergo but few changes; they grow in proportion as they are cut in different parts, and are the seat of a constant external work; now, observe that this work is more prompt, and the growth of the hairs consequently more rapid, in summer in which the cutaneous organ is especially in action, than in winter in which it is contracted; an additional proof of the real vitality of the organic forces of the internal substance of the hairs.

III. _State of the Pilous System in Old Age._

Towards the end of life, the pilous system is affected by the general obliteration which takes place in almost all the external vessels; it ceases at first to receive the colouring substance. The internal substance dies, the epidermoid covering remains alone; the hairs become white. The hairs of the head appear the first, and are the first to die. The beard, the hairs of the genital parts and then those of all the parts of the body afterwards die. Besides, there is a great variety among men as it respects the period in which the hairs whiten; in some, this phenomenon begins about the thirtieth year, and even sooner, in others it is towards the fortieth, fiftieth or sixtieth. A thousand causes arising from the passions of the mind, from diseases, aliments, &c. can have an influence in society upon this premature death, so common in many men, but which does not take place in animals, who are not exposed from their kind of life, to the same revolutions, until the last years.

The hairs, after remaining white for a longer or shorter time, finally fall out; then the sac which covered the origin of them flattens down and entirely disappears. I have examined many bald heads; the skin of the cranium was perfectly smooth on its internal surface, though it had been separated from the cellular texture. No trace is discoverable there of the innumerable appendices which the canals form, after the hairs they contain have been drawn inwards. I have also dissected a man who after a putrid fever had become almost entirely bald. There were all these little canals entire, and in the bottom of them could already be seen the rudiments of new hairs. There is then this difference between the falling out of the hairs of old people, and that which is the consequence of diseases, that every thing dies in the first, because the vessels which go to the root cease to transmit fluids to it; whereas in the second case the hair alone falls out, and its sac remains.

It is a pretty generally received opinion that the hair, the nails and the epidermis continue to grow after death. We have, I think, but few data respecting this singular phenomenon. I am however certain that I observed a real elongation of the hairs of a chin of a head that had been carefully shaved, and which I macerated eight days in a cellar. An attendant of the dissecting room, who prepares many heads for the bones, informed me that he had often made the same remark, when putrefaction is prevented for some time. What is certain also is, that the growth of the beard is not in the direct ratio of the vital forces; in the diseases which affect these forces with a general prostration, it grows as much as in those in which there is a general exaltation of these forces. We remark this in hospitals where at the side of an inflammatory fever, there is often found a putrid or slow nervous one. Besides, why should there not be sufficient tonic forces left in the hairs to grow some time after general death, as there is in the lymphatics to absorb, &c.?

The different phenomena which the hair, the epidermis, the skin, and in general all the external organs experience in the successive ages, are wholly owing, like those of the internal organs, to the laws of nutrition, and not to the action of surrounding bodies. This is an essential difference between organic and inorganic bodies. The latter are gradually altered in two ways by the contact of external bodies which act upon them, 1st, mechanically by friction, tearing, &c. &c.; 2d, chemically, by combining with them, as for example, the air whose different principles undergo many combinations which change its nature and that of the bodies with which it is in contact. In this respect all inorganic bodies grow old. At the end of some time, they have no longer the exterior which characterized them in the beginning. Observe monuments, pictures, engravings, earths, metals, stones, &c. &c. every thing which in the arts, commerce, sciences, in the uses of life or in the phenomena of nature is formed of any inert bodies, whether these bodies have never lived, or having lived, have not been able to preserve themselves after death, as the solid portions of vegetables, the bones, the horns, the hair of animals, &c. every thing finally has the indelible stamp of time; every thing grows old; every thing loses its freshness, every thing changes on the exterior of inert, as well as on that of organic bodies; but as in the first surrounding bodies alone have acted, the internal part is still young, whilst the external is old, if I may be allowed to use two very improper words. Thus the rock whose surface is blackened by the lapse of years, is the same in the interior as when it was created. On the contrary in animals and vegetables, the internal organs are worn out, as well as the exterior. Time is marked upon the viscera, as well as upon the forehead of the aged. Surrounding bodies act upon us, wear out life, if we may so say; but it is as stimuli that they exert their action; it is by exhausting the sensibility and contractility, and not by combination, mechanical contact or friction. Language ought to express this difference. We do not use the term _young_ when viewing the exterior of a new building, a new garment, or a picture recently painted; why do we say an _old_ monument, an _old_ piece of cloth, &c.? if it is a metaphor, very well; but this word cannot express a state analogous in its nature, to that of an old animal, an old plant, &c.

IV. _Preternatural Development._

There are three principal cases in which the hairs are preternaturally developed in the economy.

1st. Sometimes they are formed on the internal surface of the mucous membranes; they have been seen in the bladder, the stomach and the intestines; many authors have given cases of them. I have found them upon the calculi of the kidney. I have seen in the gall-bladder at one time a dozen of nearly an inch in length, and which were evidently implanted in its surface.

2d. There is often seen on the skin preternatural collections of them, which are usually a defect from birth. These collections are particularly observed upon some of those productions or irregular excrescences, that are called nævi materni. There was exhibited at Paris, six years since, an unfortunate person, who had from his birth his face covered with hairs almost like those of a wild boar; and to whom there came on at the age of thirty-six years, that particular species of elephantiasis, in which the skin of the face increased in size, exhibits, if we may so say, the features of the lion, a species which I have since had occasion to observe upon a natural skin. This double circumstance gave to the face of this man an air of ferocity which it is impossible to describe. Many of the stories circulated by the vulgar concerning men with the heads of wild boars, bears, &c. are nothing but these nævi in the face, with a growth of hair upon them.

3d. Hairs are often preternaturally developed in cysts, in those of the ovaria especially. A great many instances have been related. Haller in particular has collected many; I have seen two. The following is what they exhibit; a considerable large sac contained many very distinct small balls, analogous to those of the dung of sheep, formed by a fat, unctuous, whitish substance, very different in its appearance from ordinary fat. On the internal surface of this sac were implanted many hairs, which the least force could remove, because they hardly penetrated below the surface. These hairs were black. Many already detached were found crossed in different directions, in the small balls of fatty matter, which was like spermaceti; for it very much resembled the substance into which the fat is changed by maceration.

END OF THE LAST VOLUME.

ANALYTICAL TABLE OF CONTENTS.

VOLUME FIRST.
PAGE.

Preface by the Translator. 5

Preface by the Author. _ib._

GENERAL OBSERVATIONS.

Of Animate and Inanimate Beings.—Of their Laws.—Of the Sciences which treat of their Phenomena. 9

I. _General Remarks upon the Physiological and Physical Sciences._

The differences between these sciences are derived from the properties which preside over the phenomena.—The necessity of always connecting the second with the first.—Periods at which this progress commenced in the physical sciences. False applications made to the physiological sciences.—The necessity of following in these the same course as in the others. 9

II. _Of the Vital Properties, and their influence upon the phenomena of the Physiological and Physical Sciences._

Vital properties considered in the series of living beings.—Of those which animate plants.—Consequences in regard to their diseases.—Of those which belong to animals.—Consequences in regard to their diseases.—Examination of each vital property under the relation of the diseases over which it presides.—Necessity of referring to these properties the action of medicines.—Uncertainty of the Materia Medica.—Each vital property has a particular class of medicines which act upon it.—Proofs.—Inconveniences of describing morbid phenomena and those of medicines in too general a manner.—Consequences of the preceding remarks. 13

III. _Characters of the Vital Properties, compared with the characters of the Physical Properties._

Extreme variableness of the first, invariableness of the second.—Consequences of this principle as it regards the phenomena.—There can only be diseases where there are vital properties.—Why.—The progress of the physiological and physical sciences wholly different in this respect.—Differences between animate and inanimate solids and fluids.—The vital properties become exhausted, the physical do not.—Consequences.—The latter are inherent in matter, the others are not.—General remarks upon the enumeration of the differences of animate and inanimate bodies.—Particular remark relative to sympathies.—Their general phenomena. 23

IV. _Of the Vital Properties and their Phenomena considered in relation to the Solids and the Fluids._

Division of the fluids into those of composition and those of decomposition.—The vital properties are seated essentially in the solids.—These are the seat of almost all the morbid symptoms.—The fluids however may be affected.—Different attributes of the fluids of composition and of those of decomposition in diseases.—How the alterations of the first may take place.—Of those of the second.—Of the cases in which the solids and the fluids are primarily affected.—Division of diseases in this view.—The question must necessarily be considered in many points of view.—What is true on one side is not so on another.—Of the vitality of the fluids.—What it is.—Their alterations affect their vitality.—New proofs of these alterations.—How the fluids are assimilated and altered. 29

V. _Of the Properties Independent of Life._

Properties of texture.—Of contractility by the horny hardening.—Of the agents which put it into action.—It is of two kinds.—Characters of each.—Their differences.—Almost all the solids undergo the horny hardening.—Condition which it requires.—Of the horny hardening during life and after death.—Difference of this contractility from the others.—General remarks. 38

VI. _General Observations upon the Organization of Animals._

Of the simple systems.—Necessity of considering them abstractedly.—Their difference of forms.—Their variety of organization, 1st, in the peculiar texture; 2d, in the common parts.—Manner of knowing these differences.—Differences of the vital properties and of texture.—Of the peculiar life.—It cannot be understood of the compound organs, but of the simple systems.—Examples which prove this assertion in the different organs. 44

VII. _Consequences of the preceding Principles relative to Diseases._

Each texture can be separately affected in an organ.—This even almost always happens.—Various proofs of this assertion.—Observations upon different diseases.—Sympathies do not take place in an organ as a whole, but in some one texture of this organ.—Why.—Of sympathetic fevers.—The different inflammations vary in each texture.—Phenomena of the different kinds of virus variable from the same cause.—Yet the different textures of the same organ have a certain dependance upon each other.—Proofs.—Diseases chronic and acute.—Differences of diseases in each simple system.—Two classes of symptoms in the local affections.—Their difference.—Varieties of the pain, heat, &c. according to the systems.—What should be understood by acute and chronic affections in the simple systems.—Influence of these considerations upon morbid anatomy.—Defects of the old divisions.—New manner of considering morbid anatomy. 49

VIII. _Remarks upon the Classification of the Functions._

Table of this classification. 60

SYSTEMS COMMON TO ALL THE APPARATUS.

_General Observations._

Division of the systems.—Systems common to all the apparatus.—Their characters.—They form the nutritive parenchyma of the organs.—Remarks upon nutrition.—Diversity of the nutritive substances. 77

CELLULAR SYSTEM.

General Remarks.—Division. 87

ARTICLE FIRST.

OF THE CELLULAR SYSTEM CONSIDERED IN RELATION TO THE ORGANS.

I. _Of the Cellular System exterior to each Organ._

Division of the organs in relation to the neighbouring texture. 88

_Of the Cellular System which adheres only to one side of the organs._

_Sub-cutaneous cellular texture._—Arrangement of this texture, 1st, upon the median line; 2d, in the different regions of the body.—Varieties of density and laxity. Uses of the sub-cutaneous texture.—Its fluids. 88

_Sub-mucous cellular texture._—Difference of this texture from the preceding.—The density of that.—Consequences.

_Sub-serous cellular texture._—It is in general loose and abundant.—Why.—Place where it is dense. 92

_Cellular texture exterior to the arteries._—Its peculiar nature is analogous to that of the sub-mucous texture.—Its relations with the arterial fibres.

_Cellular texture exterior to the veins._—It is analogous to the preceding, only less thick.—Remarks.

_Cellular texture exterior to the excretory ducts._—The same structure and arrangement as in the preceding. 96

_Of the cellular system considered in relation to the organs that it surrounds on all sides._—Cellular atmosphere.—Fluids of this atmosphere.—Insulation of the vitality of the organs.—Of this atmosphere considered as a means for the propagation of diseases.—It favours the motion of the parts. 96

II. _Of the Internal Cellular System of each Organ._

Arrangement of this texture.—Its uses.—Its different proportions. 102

ARTICLE SECOND.

OF THE CELLULAR SYSTEM CONSIDERED INDEPENDENTLY OF THE ORGANS.

I. _Of the Cellular System of the Head._

_Cellular texture of the cranium._—It is almost nothing within.—Its communications.—Consequences of these communications.—It is more abundant without.

_Cellular texture of the face._—It is very abundant.—Its uses.—Its communications, &c. 104

II. _Of the Cellular System of the Trunk._

_Vertebral cellular texture._—It is not abundant in the cavity of the canal.—On the exterior, there is but little behind, and more in front.—Consequences.

_Cervical cellular texture._—It is abundant.—Its communications.—Consequences.

_Pectoral cellular texture._—It is found especially upon the median line.—Its communications.—External texture.

_Abdominal cellular texture._—Of the parts in which it is most abundant.—Its communications.

_Cellular texture of the pelvis._—It is very abundant.—Why.—Consequences.—Its communications. 108

III. _Of the Cellular System of the Extremities._

Its different proportions in the superior and the inferior. 112

ARTICLE THIRD.

OF THE FORMS OF THE CELLULAR SYSTEM, AND THE FLUIDS IT CONTAINS.

I. _Of the Cells._

Their form.—Their capacity.—Their communication.—-Experiments.—Of the cellular permeability.—In what sense it should be understood. 114

II. _Of the Serum of the Cellular Membrane._

Proof of its existence.—Its evaporation.—It varies in the different regions.—Method of ascertaining the proportions of it.—Experiments.—Nature of this fluid.—Experiments. 117

III. _Of the Cellular Fat._

_Natural proportions of the fat._—Varieties of its proportions according to the regions, organs, systems, &c—Its peculiar arrangement in childhood.—Varieties according to the other ages. 119

_Unnatural proportions of fat._—Its preternatural abundance indicates weakness.—Different proofs.—Of the causes of the diminution of fat.—Remark upon this diminution. 121

_Different states of the fat._—Its degree of fluidity is not during life in proportion to temperature.—Its consistence in young animals.—Consequences.—Its alterations by age, diseases, &c. 125

_Exhalation of fat._—Different opinions.—The fat is exhaled.—Proofs.—Nature of this fluid.—Relation of its uses with the places where it exists and with those in which it is wanting. 127

ARTICLE FOURTH.

ORGANIZATION OF THE CELLULAR SYSTEM.

I. _Texture peculiar to the organization of the Cellular System._

Filaments and layers from which it results.—Method of seeing them to advantage.—Their nature.—Essential difference in the cellular organization.—There are two species of cellular texture. 129

_Composition of the cellular texture._—Experiments upon this texture.—Action of the air, water, caloric and the gastric juices.—Experiments.—Of the gases sometimes extricated in the cellular texture. 132

II. _Parts common to the Organization of the Cellular Texture._

_Blood vessels._—The inaccuracy of injections in demonstrating them.

_Exhalants._—Of the cellular exhalations.—Proofs and phenomena of these exhalations.

_Absorbents._—Cellular absorptions.—Proofs.—The cellular texture is not wholly formed of absorbents.

_Nerves._ 136

ARTICLE FIFTH.

PROPERTIES OF THE CELLULAR SYSTEM.

I. _Properties of Texture._

_Extensibility._—Examples of the different distensions.—Distinctive character of the cellular extensibility.—Its phenomena.—It becomes nothing in inflammation, chronic engorgements, &c.

_Contractility._—Different examples of this property brought into action.—Its varieties according to the ages.—General remarks. 140

II. _Vital Properties._

The animal ones are inconsiderable.—The organic are greater, except sensible contractility, which however exists to a certain extent.

_Sympathies._—It is necessary to distinguish them from the phenomena of juxta-position.—Various examples.—General observations.—Vital properties put in action by the sympathies.

_Character of the vital properties._—The vital activity is very considerable in the cellular texture.—Various proofs.—Remarks upon the species.—Difference of vitality in the two species of cellular texture. 143

III. _Properties of Reproduction._

_Influence of the cellular texture upon the formation of cicatrices._—Division of the periods of the cicatrices.

_First period._—Inflammation.—How it takes place.—Its advantages.

_Second period._—Fleshy granulations.—Experiments.—Provisional membrane of the cicatrices.—Its uses.—General phenomena of the internal cicatrices.—Cellular nature of this membrane and of the granulations.—Different opinions.

_Third period._—Suppuration.—What corresponds to it in the internal cicatrices.—Analogy of these cicatrices with the external.

_Fourth period._—Contraction of the fleshy granulations.—Adhesions.—Consequences of the preceding principles.—Of union by the first intention. 148

_Influence of the cellular texture in the formation of tumours._—Cellular nature of all tumours which grow and increase.—Proofs.—Mode of development of these tumours.—How they differ from various engorgements, acute and chronic. 157

_Influence of the cellular texture in the formation of cysts._—What is a cyst.—Its analogy with the serous surfaces.—Its cellular structure.—Mode of its development. 160

ARTICLE SIXTH.

DEVELOPMENT OF THE CELLULAR TEXTURE.

I. _State of the Cellular System in the First Age._

Mucous mass represented by the cellular texture of the fœtus.—Superabundance of fluid.—This is then the cellular fluid.—Difficulty of emphysema in the fœtus.—State of the cellular texture in infancy and youth.—Its vital energy.—Consequences. 164

II. _State of the Cellular System in the After Ages._

Arrangement of the cellular texture in the adult.—Differences arising from sex.—Degeneracy of this texture in old age.—Withering that it experiences.—Consequences. 167

NERVOUS SYSTEM OF ANIMAL LIFE.

Division of the nerves into two systems.—Differences of these two systems.—General arrangement of that of animal life.—Its symmetry.—Relation of size between the nerves and the brain. 169

ARTICLE FIRST.

EXTERNAL FORMS OF THE NERVOUS SYSTEM OF ANIMAL LIFE.

I. _Origin of the Cerebral Nerves._

In what sense this origin must be understood.—It takes place, 1st, in the brain; 2d, in the tuber annulare and its dependancies; 3d, in the spinal marrow.—Manner of this triple origin.—Of the crossing of the nerves.—Phenomena of paralysis in regard to this.—Peculiar arrangement of the cerebral membranes at the origin of the nerves.—Extent, direction and form of the nerves at this origin. 171

II. _Course of the Cerebral Nerves._

_Communications of the cerebral nerves at their exit from their osseous cavity._—There are none between the nerves of the brain properly called.—The communications begin in those of the tuber annulare.—They are very numerous in those of the spinal marrow.—Arrangement of the plexuses which result from them.—Consequences as it regards descriptive neurology.

_Internal communications of the nervous cords._—Manner of these communications.—Internal plexus to each nerve.—Consequences.—Difference from anastomoses.

_Nervous Trunks._—Their course.—Their form.—Their length, &c.

_Nervous branches, smaller branches, ramifications, &c._—Mode of origin.—Length.—Course, &c. 176

III. _Termination of the Nerves._

What is to be understood by it.—Triple mode of termination.

_Anastomoses with the same system._—What is to be understood by anastomoses.—They are rare in this system.—They can be referred to three classes.

_Anastomoses with the system of organic life.—Termination in the organs._—Manner of this termination.—Division of the organs in this respect. 182

ARTICLE SECOND.

ORGANIZATION OF THE NERVOUS SYSTEM OF ANIMAL LIFE.

I. _Texture peculiar to this Organization._

Arrangement of the nervous cords.—Their varieties.—Each nerve has its peculiar organization.—Of the structure of the nervous filaments.

_Of the nervous coat and its origin._—How this origin may be seen.—Its triple arrangement at the brain, the tuber annulare and the spinal marrow.—Particular arrangement of the optic nerve.—Remarks upon the pia mater.—Course of the nervous coat. 185

_Action of certain substances upon the nervous coat; its resistance, &c._—Action of the acids, water, caloric, and the alkalies.—Resistance of the nervous coat.

_Medullary substance_; its origin, arrangement and proportions.

_Comparison between the medullary substance of the brain and the nerves._—Effect of desiccation upon each.—Putrefaction and its phenomena.—Absence of the horny hardening in both.—Action of water upon both.—Action of the acids, the alkalies, neutral salts and the digestive juices.—Difference of the nervous pulp in each part. 190

II. _Parts common to the Organization of the Nervous System of Animal Life._

_Cellular texture._—It is wanting in the nerves, in the cranium and the spine. Elsewhere it is found between their filaments and cords.—Cellular fat.

_Blood vessels._—Their arrangement.—Remarks upon the veins.—Of the blood.—Of the nerves.—Action of this fluid upon them.

_Exhalants and Absorbents._—Examination of the opinion upon the exhalation of the nervous coat.—Different observations.

_Nerves._ 199

ARTICLE THIRD.

PROPERTIES OF THE NERVOUS SYSTEM OF ANIMAL LIFE.

I. _Properties of Texture._

They are but very slightly marked.—Remarks upon the nervous distensions. 204

II. _Vital Properties.—Properties of Animal Life._

_Animal sensibility inherent in the nerves._—Various experiments upon this sensibility.—Remarks upon that of the brain.—Phenomena of the experiments upon the nerves.—Character of the animal nervous sensibility. —Of neuralgias.—Another character of this sensibility.—Experiments.—Consequences. 206

_Influence of the nerves upon the animal sensibility of all the organs._—Distinction of the sensations, in this respect, into external and internal.—Subdivision of the external into general and particular.—Part which the nerves perform in each.—Internal sensations.—Uncertainty respecting the nervous influence in sensations.—Differences between animal sensibility and contractility.—Of the nervous atmosphere.—Uncertainty of this opinion. 211

_Animal contractility.—Influence of the nerves upon that of the other parts._—How the nerves are the agents of this property.—Different opinions upon the action of the nerves.—Uncertainty of these opinions.—General observations.

_Properties of organic life, considered in the nerves._—They are slightly marked.—Increase of the size of the nerves in the affections of some parts.—Various experiments and observations.

_Influence of the cerebral nerves upon the organic properties of the other parts._—They are foreign to these properties.—They have not there any known influence, 1st, upon the capillary circulation; 2d, upon exhalation; 3d, upon secretion; 4th, upon absorption; 5th, upon nutrition.—Different proofs of these assertions.—Remarks on the diseases which affect animal life and those which affect organic.—Uncertainty of the term _nervous influence_. 216

_Sympathies.—Sympathies peculiar to the nerves._—Different phenomena of these sympathies.—Sympathies, 1st, between two nerves of the same pair; 2d, between two nerves of the same side; 3d, between the branches of the same pair; 4th, between the nerves and different organs.—Different examples of these sympathies. 224

_Influence of the nerves upon the sympathies of the other organs._—Different opinions upon sympathies.—Uncertainty of these opinions.—Division of sympathies founded upon that of the vital properties.—Different influence of the nerves upon each species of sympathy.—Cases in which it is real and those in which it is nothing. 226

III. _Properties of Reproduction._

Phenomena of nervous cicatrizations.—Their analogy with other cicatrizations. 233

ARTICLE FOURTH.

DEVELOPMENT OF THE NERVOUS SYSTEM OF ANIMAL LIFE.

I. _State of this System in the Fœtus._

It is much developed.—General remarks.—Inactivity of the brain, notwithstanding its development.—Its softness.—Action of the alkalies upon this organ.—The cerebral nerves are developed in proportion.—Peculiar phenomenon of their development.—This phenomenon is opposite to that of the arteries.—Consequence which results from it. 235

II. _State of the Nervous System during Growth._

Phenomena at birth.—Influence of the red blood.—Predominance of the nervous system during childhood.—Consequences relative to the sensations, motions and various affections. 240

III. _State of the Nervous System after Growth._

Phenomenon of puberty.—Phenomena of the following ages. 244

IV. _State of the Nervous System in Old Age._

Its action is slight.—State of the brain at this period.—Influence of this state upon sensibility.—Phenomena of sensation and motion in old age. 244

NERVOUS SYSTEM OF ORGANIC LIFE.

GENERAL REMARKS.

How this system should be understood.—The great sympathetic does not exist.—Each ganglion forms an insulated system.—This system belongs to organic life.—It exhibits many irregularities.—The mode of describing it. 249

ARTICLE FIRST.

OF THE GANGLIONS.

I. _Situation, Forms, Relations, &c._

Ganglions that are constant.—Those that are accidental. 253

II. _Organization._

Colour.—Difference of the texture of the ganglions from that of the brain.—Comparative experiments.—This texture is not fibrous.—It differs essentially from that of the nerves.—Its organic lesions are rare.—Common parts of this texture. 255

III. _Properties._

The ganglions have the organic ones.—The animal appear to be slightly marked in them.—Experiments.—Sympathies.—Nervous affections of the ganglions.—The kind of pain of this system.—General remarks. 260

IV. _Development._

It does not follow that of the brain.—Influence of this fact upon the diseases of childhood.—Another difference between the ganglions and the brain. 263

V. _Remarks upon the Vertebral Ganglions._

Their arrangement.—Obscurity which they throw upon the functions of this system. 264

ARTICLE SECOND.

OF THE NERVES OF ORGANIC LIFE.

I. _Origin._

Manner of this origin.—Method of seeing it. 265

II. _Course, Termination, Plexuses._

Of the branches which go to the cerebral nerves.—Of those which go to the neighbouring ganglions.—Of those which go the muscles.—Of those which form the plexuses.—Arrangement of these last.—Of the filaments which go from them.—Their double arrangement upon the arteries. 267

III. _Structure, Properties, &c._

Analogy with the preceding nerves as to texture.—Animal sensibility appears to be less in them.—Experiments.—Sympathies of these nerves.—General remarks. 271

VASCULAR SYSTEM WITH RED BLOOD.

ARTICLE FIRST.

GENERAL REMARKS UPON THE CIRCULATION.

I. _Division of the Circulation._

_Circulation of red blood._—General organs.—Direction.

_Circulation of black blood._—General organs.—Direction.

_Difference of the two circulations._—Their separation is complete.—Opposition of the lungs to all the parts.

_General mechanical phenomena of the two circulations._—Conical form of the circulatory apparatus.—There are two cones for each circulation.—The heart is placed at their union as a double agent of impulse.—Its inequality in this respect. 275

II. _Reflections upon the General Uses of the Circulation._

_General uses of the circulation of the red blood._—It furnishes the materials of secretion, exhalation, absorption, &c.—All the great phenomena of the economy are derived from it.

_General uses of the circulation of black blood._—It repairs the losses made by the preceding, by the substances which it receives.—General and opposite attributes of the two—sanguineous systems. 282

ARTICLE SECOND.

SITUATION, FORMS, AND GENERAL ARRANGEMENT OF THE VASCULAR SYSTEM WITH RED BLOOD.

Of the two portions of this system.—Of their union.—Position of the agent of impulse compared to the whole body. 285

I. _Origin of the Arteries._

_Origin of the aorta._—Peculiar anatomical arrangement of this origin. 287

_Origin of the trunks, branches, smaller branches, &c._—Number of the arterial divisions.—Angles of origin.—Proportion of the divisions. 288

II. _Course of the Arteries._

_Course of the trunks and branches._—Their position, relation and direction.—Motions which they communicate. 291

_Course of the smaller branches, ramifications, &c._—Position.—Relations.—Curvatures.—These curvatures have no influence upon the motion of the blood.—Proofs.—Uses of these curvatures. 293

_Anastomoses of the arteries in their course._—Of the two modes of anastomoses.—Triple mode of those in which two equal trunks terminate.—Anastomoses with unequal trunks.—General remarks upon anastomoses. 296

_Forms of the arteries in their course._—In what direction they are conical.—Relation of capacities. 299

III. _Termination of the Arteries._

It takes place in the capillary system.—Its varieties according to the organs. 300

ARTICLE THIRD.

ORGANIZATION OF THE VASCULAR SYSTEM WITH RED BLOOD.

I. _Texture peculiar to this Organization._

Two principal membranes form it. 301

_Peculiar membrane of the arteries._—Thickness.—Colour.—Experiments.—Varieties in the cerebral arteries.—Arterial fibres.—Arrangement of these fibres at the origin of the branches.—Their nature is not muscular.— Their brittleness.—Their resistance.—General consequences. 302

_Action of different agents upon the arterial texture._—Desiccation.—Putrefaction.—Maceration.—Stewing.—Action of the acids, the alkalies, &c. 308

_Membrane common to the system with red blood._—Its differences in the different regions.—Of the fluid which moistens it.—Its relations.—Its nature.—Its singular disposition to ossification.—Peculiar phenomena and laws of this ossification.—Pathological consequences. 311

II. _Parts common to the Organization of the Vascular System with Red Blood._

_Blood vessels._—Their arrangement.—They do not appear to go to the internal membrane. 317

_Cellular texture._—There are two species of it.—Of that which unites the artery to the neighbouring organs.—Of that which is peculiar to it, and which has a peculiar nature.—The arterial fibres are remarkable for having none of this texture between them.—Consequences. 318

_Exhalants and absorbents._—There does not appear to be absorption in the arteries.—Experiments. 321

_Nerves._—Of the cerebral ones.—Of the organic ones.—Their proportion.—Their course, &c. 324

ARTICLE FOURTH.

PROPERTIES OF THE VASCULAR SYSTEM WITH RED BLOOD.

I. _Physical Properties._

Remarkable elasticity.—Its use.—Its differences from contractility of texture. 322

II. _Properties of Texture._

_Extensibility._—1st, of that in the axis; 2d, of that in the diameter. 324

_Contractility._—Of that in the axis.—Of that in the diameter.—Its differences from irritability.—Remarks upon this contractility.—Practical consequences. 326

III. _Vital Properties. Properties of Animal Life._

_Sensibility._—Experiments upon this property. 329

_Contractility._—It is nothing. _ib._

_Properties of organic life.—Sensible organic Contractility._—It is nothing.—Different experiments to prove it.—Mistakes concerning this property. 330

_Insensible organic contractility._—How its influence must be understood.—Vital activity is but slightly marked in the arteries.—General consequences. 332

_Remarks upon the causes of the motion of the red blood._—These causes appear to be foreign to the arteries. 335

_Influence of the heart in the motion of red blood._—Different proofs of this influence.—Morbid phenomena.—Different experiments.—Observations.—General Consequences. 336

_Of the limits of the action of the heart._—They appear to be at the place of the change of the red blood into black.—Increasing influence of the arteries upon the red blood in the neighbourhood of the capillaries. 342

_Phenomena of the impulse of the heart._—The motion of the red blood is sudden and instantaneous.—Proofs.—The contraction of the arteries does not push the blood.—From what it arises.—The causes of delay are nothing.—General remarks. 334

_Remarks upon the pulse._—The arterial locomotion has a great part in it.—Of the accessory causes.—Of the varieties of the pulse.—General reflections. 348

_Sympathies._—They are in general rare in the arteries.—Why. 352

ARTICLE FIFTH.

DEVELOPMENT OF THE VASCULAR SYSTEM WITH RED BLOOD.

I. _State of this System in the Fœtus._

The two systems are then confounded.—There is but one species of blood.—How the fœtus can live with black blood alone.—Peculiar mode of circulation in the fœtus.—Consequences which result from it.—Insensible change of this mode of circulation.—How it takes place.—Great development of the arteries in the fœtus. 354

II. _State of the Vascular System with Red Blood during Growth._

Sudden formation of the red blood at birth.—Changes in the course of this fluid.—Phenomena and causes of these changes.—Predominance of the arteries during youth. 364

III. _State of the Vascular System with Red Blood after Growth._

Influence of the genital organs.—Varieties of the influence of the red blood according to the ages. 371

IV. _State of the Vascular System with Red Blood during old Age._

Diminution of the arterial ramifications.—The red blood is less abundant.—The arteries are condensed.—Phenomena of the pulse.—Of the pulse in the last moments of life.—Experiments upon this subject. 373

V. _Accidental Development of the System with Red Blood._

There are two kinds of it; 1st, Dilatation from an obstacle. 2d, Dilatation from any tumour. 377

VASCULAR SYSTEM WITH BLACK BLOOD.

GENERAL OBSERVATIONS.

ARTICLE FIRST.

SITUATION, FORMS, DIVISION AND GENERAL ARRANGEMENT OF THE VASCULAR SYSTEM WITH BLACK BLOOD.

I. _Origin of the Veins._

Manner of this origin.—Two orders of veins. 380

II. _Course of the Veins._

Examination of this course on the exterior and the interior. 381

III. _Proportion of the capacity of the two systems with Black and Red Blood._

Remarks upon the varieties of venous capacity.—Parallel between the two vascular apparatus with red and black blood in this respect.—General consequences.—The velocity is in an inverse ratio of the capacity, &c. 382

_Ramifications, small branches, branches, angles of union, &c.—Forms of the Veins._—In what direction these vessels are conical.—Relations between the branches and their divisions. 388

_Anastomoses._—They are very frequent.—Why.—Communication between the external and the internal order.—Consequences.—Different modes of anastomoses.—Their necessity from the numerous obstacles to the course of the blood.—Of these obstacles. 392

IV. _Termination of the Veins._

Mode of termination in the heart.—Of the two venous cones, the superior and the inferior.—Of their communication by the azygos. 396

ARTICLE SECOND.

ORGANIZATION OF THE VASCULAR SYSTEM WITH BLACK BLOOD.

I. _Texture peculiar to this Organization._

_Membrane peculiar to the veins._—Manner of seeing it.—Its longitudinal fibres.—Varieties of these fibres.—Their nature.—Peculiar arrangement of the cerebral sinuses. 399

_Common membrane of the black blood._—Its differences from that of the red blood.—More extensibility.—Less thickness.—No disposition to ossify.—Consequences. 403

_Of the valves of the veins._—Their form.—Their situation.—Veins which they occupy.—Their size.—Remarks upon their relations with the caliber of the veins.—Their variety.—Their number. 404

_Action of reagents upon the venous texture._—Action of the air, water, caloric, the acids, &c. 407

II. _Parts common to the Organization of the Vascular System with Black Blood._

_Blood vessels. Cellular texture._—Of that which unites the veins to the neighbouring parts.—Of that which is peculiar to them. 408

_Exhalants and Absorbents._—Experiments upon venous absorption.

_Nerves._—There are but very few of them. 409

ARTICLE THIRD.

PROPERTIES OF THE VASCULAR SYSTEM WITH BLACK BLOOD.

I. _Properties of Texture._

_Extensibility._—It is very evident.—Venous ruptures however take place.—Various examples.—Their causes are but obscurely known. 411

_Contractility_—Of this property in the longitudinal and the transverse direction. 413

II. _Vital Properties._

_Properties of Animal Life._—Result of the experiments upon sensibility.—There is no contractility. 414

_Properties of organic life. Sensible Contractility._—It appears to be but slight.—General remarks. 415

_Of the venous pulse._—Of its cause.—It is a reflux.—Double cause which produces it. 416

_Insensible Contractility._—It appears to exist.—The vital activity is greater in the veins than in the arteries.—Consequences. 419

_Observations on the motion of the black blood in the veins._—There is no pulse analogous to that of the arteries.—Agent of impulse of the venous blood.—Causes of delay—Accessory causes of motion.—Resemblance between the motion of the veins and that of the arteries. 420

_Sympathies_ of the veins.—They are very obscure. 424

ARTICLE FOURTH.

DEVELOPMENT OF THE VASCULAR SYSTEM WITH BLACK BLOOD.

I. _State of this System in the Fœtus._

The veins are less developed in proportion than the arteries.—Why.—Remarks. 425

II. _State of this System during Growth and afterwards._

Various phenomena of childhood, adult age, &c. 427

III. _State of this System in Old Age._

The veins are much developed in old age.—This development is only a dilatation.—Its varieties according to different circumstances. 428

IV. _Accidental Development of the Veins._

It must be considered, 1st, in tumours; 2d, in the distensions of the different parts. 430

ARTICLE FIFTH.

REMARKS UPON THE PULMONARY ARTERY AND VEINS.

Though the two kinds of blood are separate, yet the mechanical phenomena of their courses are analogous in the aorta and the pulmonary artery, and in the general and the pulmonary veins. _ib._

ARTICLE SIXTH.

ABDOMINAL VASCULAR SYSTEM WITH BLACK BLOOD.

_Situation, forms, general arrangement, anastomoses, &c._—Origin and termination in the capillaries.—Abdominal portion.—Hepatic portion.—Differences between them. 433

_Organization, properties, &c._—Analogy with the veins in this respect.—Peculiar arrangement in the hepatic portion.—Absence of valves.—Why. 436

_Remarks upon the motion of the black abdominal blood._—Comparison between the liver and the lungs.—Their difference as it regards the blood that goes to them.—Mechanism of the circulation of this system.—Influence of the accessory causes. 438

_Remarks upon the liver._—It performs another function besides the secretion of bile.—Proofs.—We are ignorant of this function.—It must be extremely important.—Various proofs.—The liver exhibits phenomena that no other gland does.—It is not certain that the black abdominal blood serves for the secretion of bile.—Proofs.—General observations.—Experiments. 440

_Remarks upon the course of the bile._—Course of this fluid during abstinence and during digestion.—Cystic bile.—Hepatic bile.—Reflux towards the stomach during vacuity and fulness.—Experiments. 446

_Development._—There is only one vascular system in the fœtus.—It is divided into three at birth.—State of the umbilical vein and the vena porta in the fœtus.—Relative size of the liver at this period.—Phenomena at birth.—Different influences of this system in the following ages. 450

END OF CONTENTS TO VOL. I.

VOLUME SECOND.

CAPILLARY SYSTEMS.

PAGE.

There are two of them.—Their general arrangement.—Their opposition. 3

ARTICLE FIRST.

OF THE GENERAL CAPILLARY SYSTEM.

General arrangement of this system. 4

I. _General division of the Capillaries._

_Of the organs in which the capillaries contain only blood._ 6

_Of the organs in which the capillaries contain blood and fluids differing from it._—Serous system taken for an example.—Experiments by injections.—Various other systems present analogous facts.—Proportion of the blood and the fluids differing from it. _ib._

_Of the organs in which the capillaries do not contain blood._ 8

II. _Difference of Organs in respect to the number of their Capillaries._

There are many classes of organs in this respect.—Why the capillaries are very much developed in some.—Consequences as it regards diseases. 9

_Remarks upon injections._—Their insufficiency in making us acquainted with the small vessels. 10

III. _Of the proportions which exist in the Capillaries between the Blood and the Fluids that differ from it._

Continual varieties in the proportion.—Cause of these varieties.—They are very numerous. 12

_Different proportions of blood in the capillaries, according as the secretions and exhalations are active or passive._—Of active and passive exhalations.—Of secretions of the same nature.—Examination of each.—Proofs that wherever there is activity, blood enters the capillaries.—Opposite arrangement in the passive phenomena. 13

_Consequences of the preceding Remarks._ 17

IV. _Of the Anastomoses of the General Capillary System._

Mode of these anastomoses.—The capillaries considered in relation to the vessels with which they communicate.—Influence of these communications.—Important observation in regard to the examination of dead bodies.—How acute inflammations disappear at death. 17

V. _How, notwithstanding the general communication of the Capillary System, the Blood and the Fluids differing from it, remain separate._

This depends on the different modifications of the organic sensibility.—Proofs.—General remarks. 21

VI. _Consequences of the preceding principles, in relation to Inflammation._

Every thing arises, in this affection, from the alteration of the organic sensibility.—Proofs.—Varieties of intensity and nature in inflammations.—Terminations of inflammations.—Of putrefaction.—Of death.—Of induration.—Of the blood which stops in inflamed parts. 24

_Differences of inflammation according to the different systems._—Each has a peculiar one.—Of those which are the most disposed to it.—It has peculiar modifications in each.—Same observation in regard to its terminations. 30

VII. _Structure and Properties of the Capillaries._

We cannot ascertain completely the structure.—It has however varieties. 33

VIII. _Of the Circulation of the Capillaries._

_Motions of the fluids in the Capillary System._—The blood is independent of the action of the heart in the capillaries.—Various proofs of this assertion.—The blood circulates by the influence of the forces of the part.—Varieties of the motions.—Causes of these varieties.—Influence of the atmosphere upon the capillary circulation.—Of the two kinds of bleeding in relation to the capillaries and to the trunks.—Circulation of other fluids than the blood in the capillaries. 34

_Phenomena of the alteration of the fluids in the Capillary System._—Change of the red blood to black.—Phenomena of this change. 41

IX. _Of the Capillaries considered as the seat of the production of Heat._

Different hypotheses.—Phenomena of animal heat.—How it is produced.—Analogy of the production of heat with exhalation, secretion, &c.—Influence of the different vital forces.—Explanation of the phenomena of animal heat in the state of health and disease.—Sympathetic heat.—Sympathies of heat.—Difference between the two. 43

ARTICLE SECOND.

PULMONARY CAPILLARY SYSTEM.

I. _Relation of the two Capillary Systems, Pulmonary and General._

How all the blood of the general system can go through the pulmonary.—Difference of one from the other as it respects the course of this fluid. 55

II. _Remarks upon the Circulation of the Pulmonary Capillaries._

Peculiar character of pulmonary inflammations.—Phenomena to which they give rise.—Of the pulmonary circulation in various other diseases. 58

III. _Alteration of the Blood in the Pulmonary Capillaries._ 63

IV. _Remarks upon the state of the Lungs in Dead Bodies._

Their proportions very various from engorgement.—They are hardly ever in the natural state.—Why.—Consequences. 64

EXHALANT SYSTEM.

General Remarks upon the differences of exhalations and absorptions. 67

ARTICLE FIRST.

GENERAL ARRANGEMENT OF THE EXHALANTS.

I. _Origin, Course and Termination._

Different hypotheses respecting these vessels.—What observation shows us concerning them. 69

II. _Division of the Exhalants._

They can be referred to three classes.—Table of these classes and their division. 71

III. _Difference of the Exhalations._ 73

ARTICLE SECOND.

PROPERTIES, FUNCTIONS AND DEVELOPMENT OF THE EXHALANT SYSTEM.

I. _Properties._

We are ignorant of those of texture.—The organic are very evident in it. 74

_Characters of the Vital Properties._—They vary in each system.—Consequences as it regards functions. _ib._

II. _Of Natural Exhalations._

They are all derived from the vital properties.—They vary consequently like these properties.—Proofs.—Of sympathetic exhalations. 75

III. _Of Preternatural Exhalations._

_Sanguineous exhalation.—Hemorrhage of the excrementitious exhalants._—Hemorrhage from the skin.—Hemorrhages from the mucous surfaces.—They take place by exhalation.—Proofs.—Experiments.—Of active and passive hemorrhages.—Differences between hemorrhages by rupture and by exhalation, between those of the capillaries and those of the great vessels. 78

_Hemorrhages of the recrementitious exhalants._—Hemorrhages of the serous surfaces.—Observations concerning dead bodies.—Cellular hemorrhages.—Other hemorrhages of the exhalants. 85

_Preternatural exhalations, not sanguineous._—Varieties of the exhaled fluids, according to the state of the vital forces of the exhalants.—Different examples of these varieties. 87

IV. _Of the preternatural development of the exhalants._

It is especially in cysts that it takes place.—The secreted fluids are never preternaturally poured out like the exhaled.—Why.—Of the natural emunctories. 88

ABSORBENT SYSTEM.

GENERAL OBSERVATIONS.

ARTICLE FIRST.

OF THE ABSORBENT VESSELS.

I. _Origin of the Absorbents._

Table of absorptions.—Of external absorptions.—Of internal absorptions.—Of the nutritive absorptions.—It is impossible to know the mode of origin of the absorbents.—Interlacing of the branches. 91

II. _Course of the Absorbents._

Their division into two layers, superficial and deep-seated.—Their arrangement in the extremities and the trunk. 95

_Forms of the absorbents in their course._—They are cylindrical, full of knots, &c.—Consequences of these forms.—The absorbents have not as great capacity during life as in the dead body. 97

_Of the capacity of the absorbents in their course._—Manner of ascertaining it.—Extreme varieties which it exhibits.—Capacity of the absorbents compared with that of the veins. 99

_Anastomoses of the absorbents in their course._—Different modes of these anastomoses.—Remarks upon the lymphatic circulation. 102

_Remarks upon the difference of dropsies that are produced by the increase of exhalation, and those that are the effect of a diminution of absorption._—Cases that may be referred to one or the other cause. 104

III. _Termination of the Absorbents._

Trunks of termination.—Their disproportion with the branches.—Consequences.—Difficulties in regard to the motion of the lymph.—Remarks upon venous absorption. 105

IV. _Structure of the Absorbents._

Exterior texture.—Vessels.—Peculiar membrane.—Valves.—Uses of these last. 109

ARTICLE SECOND.

LYMPHATIC GLANDS.

I. _Situation, Size, Forms, &c._

Varieties of their number and situation in the different regions.—Relation with the cellular texture.—Varieties from age, sex, &c. 111

II. _Organization._

_Colour._—Its varieties.—Particular arrangement about the bronchia. 114

_Common parts._—External cellular texture.—Cellular membrane.—Vessels. 115

_Peculiar texture._—Density.—Cells.—Contained fluid.—Properties and phenomena of this texture.—Interlacing of the absorbents. 116

ARTICLE THIRD.

PROPERTIES OF THE ABSORBENT SYSTEM.

I. _Properties of Texture._ 118

II. _Vital Properties._

Animal sensibility.—Its phenomena in the vessels and the glands.—Organic properties.—Their duration after death.—Remarks upon the absorbent faculty of dead bodies. 119

_Characters of the vital properties._—Life is very evident in this system.—Its disposition to inflammation.—Character which this affection has in it. 122

_Differences of the vital properties in the absorbent vessels and their glands._—These differences are remarkable.—Their influence upon diseases. 123

_Sympathies._—Sympathies of the glands.—Sympathies of the vessels.—Remarks upon the engorgements of the lymphatic glands. 124

ARTICLE FOURTH.

OF ABSORPTION.

I. _Influence of the Vital Forces upon this Function._

All depends on the organic properties. 128

II. _Varieties of Absorption._

Different examples.—Of resolution.—Of the absorption of morbific principles. 129

III. _Motion of the Fluids in the Absorbents._

Laws of this motion.—It is not subject to any reflux.—Why. 132

IV. _Of Absorption in the different Ages._

It appears that the internal and external absorptions are opposite at the two extreme ages.—Remarks. 134

V. _Preternatural Absorption._

Absorption of certain fluids different from those naturally absorbed.—Absorption in the cysts. 138

SYSTEMS PECULIAR TO CERTAIN APPARATUS.

GENERAL OBSERVATIONS.

Differences of the systems peculiar to certain apparatus, from those common to all.—Characters of the first.—Their distribution in the apparatus. 139

OSSEOUS SYSTEM.

GENERAL OBSERVATIONS.

ARTICLE FIRST.

OF THE FORMS OF THE OSSEOUS SYSTEM. DIVISION OF THE BONES.

I. _Of the Long Bones._