line: hence the fusion of organs and of cavities. Of the causes which produce abnormal development, the author is not disposed to treat. He merely states the most general conditions under which anomalies and monstrosities occur: for, in the midst of this apparent disorder, order still prevails; this cannot be understood but by a knowledge of the fundamental type. This may be called pathological general anatomy.

The author here lays down the general laws observed in the development of the various structural anomalies and monstrosities. Thus, 1. When two subjects become fused together, different tissues are never connected together: it is only similar organs are confounded when a monstrous juxta-position takes place. 2. In every monstrous individual there exists, between the different anomalies constituting it, a sort of organic balancing, by means of which an anomaly by defect draws on an anomaly by excess of development; as if there existed a certain amount of productive force, which, if it did not act on one side, must necessarily act on the other. 3. Anomalies are so much the more frequent, in proportion as they are less serious, and in the inverse ratio of the importance of the organ affected by them: thus, varieties are more frequent than monstrosities. In the distribution of the vascular system it has been remarked that varieties are more usual at the termination of the branches than at their origin. The anomalies most rarely met in the vascular system are those which occasion a mixture of the pulmonary blood with the blood of the body, and thus seriously affect the health. 4. Most of the defects of conformation occur on the left side; it seldom happens that the vertebral artery of the right side arises directly from the aorta, whilst this is of frequent occurrence on the left. There are, however, exceptions to this law. 5. Certain systems are more subject than others to the defects of conformation. The greatest portion of the nervous system, the osseous system, and the muscular system, present anomalies much more rarely than others, and more especially than the vascular system. 6. The more an organ is repeated in the body, the more obnoxious is it to anomalies, and the less important is the anomaly. It is observed that the anomaly by excess is more frequent in the upper half of the body than in the lower. 7. There is some analogy between the anomalies of one and the same organ; when, for instance, there are two tongues, they are superimposed, one upon the other, and not placed laterally. The perforation of the septum of the heart, the divisions of the urethra, &c., always occur in some particular point. 8. Every organ presents certain deviations rather than others. The kidneys, for instance, have a particular tendency to unite on the median line. 9. The same individual may present several anomalies at one and the same time. Sometimes they occupy organs belonging to the same apparatus; sometimes they have their seat in different regions of the body. Thus the heart is always wanting in acephalous fœtuses; the simultaneous disappearance of the brain and supra-renal capsules may be said to be constant, &c. 10. Defects of conformation are confined within certain limits to whatever degree the form of an organ or of the entire organism may deviate from the normal standard, it never becomes altogether incapable of being recognized: the heart has never been seen on the back, the lungs in the abdomen, &c. 11. However great the monstrosity may be, it will never cause the foetus to descend in the zoological No. LXXXI.

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scale. The erroneous opinions of some writers on this subject have had their origin in a supposed law, viz. that man passes through degrees of formation corresponding to constant formations in the animal series. Defects of conformation are more frequent in the female; still, various defects of conformation of the heart and bladder occur more frequently in the male than in the female. 13. Certain anomalies seem to be hereditary members of the same family having six fingers may be adduced as an instance of this.

The author next proceeds to an enumeration of the various morbid productions occurring in the various organs and parts of the body. He here adopts Müller's classification, with which our readers are already sufficiently acquainted.

In the Second Section, CHAP. I., he treats of the CELLULAR SYSTEM, which he defines to be a whitish or greyish mass, extremely soft, possessing but little resistance, moist, very elastic, diffused throughout the entire body, forming an uninterrupted whole, consisting of lamella and fibrils placed in juxta-position, the interstices of which are filled with serosity. With respect to its Physical Properties, it is very extensible; when very much distended, it at first becomes perceptibly attenuated, and at length gives way. This property of extensibility it owes to the presence of serosity. As soon as extension of the tissue ceases, retractility is produced. This is a distinct property from contractility, which is organic, and manifests itself after the employment of stimulants. The retractility in question is but a physical property, and the effect of elasticity. The cellular tissue is in general very soft; it is always moistened with serosity -it is colourless, when it occurs in thin layers; when it is thicker, it is whitish; it is semi-transparent, when distended. When dried by heat, it loses these physical properties, and acquires new ones.

Vital Properties.-Sensibility is not the attribute of the cellular tissue in the ordinary state. It may be cut, and drawn in different directions, without the individual experimented on evincing any sign of pain. The cellular tissue is endowed with organic contractility, that is, the property of shortening during life under the influence of certain irritating agents. This contractility is most perceptible in the tunic of the dartos appertaining to the scrotum; which has induced some anatomists to constitute this a separate and particular tissue. All the absorption which takes place in the cellular tissue must be attributed to the blood-vessels existing in it. We must take care to distinguish imbibition from absorption; the former is a physical phenomenon common to all the tissues; whilst absorption is an organic property, with which certain vessels only are endowed.

The Chemical Properties of cellular tissue are next considered at full length. Then the Structure; here the opinions of Bichat, Bordeu, Meckel, and others, with respect to the nature and structural peculiarities of this tissue, are freely canvassed. The author next notices the texture, distribution, and mode of development of the cellular tissue, which, as containing nothing new, we shall pass over and proceed to notice a few of the pathological relations of this system A knowledge of the physical properties of the cellular tissue accounts for several pathological phenomena. The most remarkable of these properties is its permeability. This property

will at once explain the following facts:-1. Migrations of solid bodies which readily traverse the cellular system. Pins, introduced into the stomach, or under the skin, are found to reach the fingers, toes, or other parts of the body. 2. The facility with which emphysema manifests itself after wounds of the lung, or after rupture of one of the cartilaginous rings of the trachea. Air penetrates very rapidly throughout all the cellular tissue, not only beneath the skin, but also in the interstices of the muscles, and in the substance of all the viscera. When a large aperture is made to favour its escape, it passes out only in very small quantity, owing to the filamentous structure of the cellular tissue retaining the air in its interstices. 3. The readiness with which purulent collections are removed to a distance. The matter of the abscesses developed in the upper part of the body, escapes even to the feet, through the cellular tissue which fills the interstices of the organs. 4. In general anasarca it not rarely happens that all the serosity escapes by one single aperture; in ædema we may drive the serum from one part to another; it accumulates more especially in the depending parts. Thus, the feet are observed to become infiltrated first, and it is only at a subsequent period the upper extremities become so. All these phenomena suppose, not only the permeability of the tissue, but also the great elasticity of its elements. This elasticity, however, is altered by the effect of inflammation, and of other morbid states which render the tissue fragile. Thus, the cellular tissue of the small intestine becomes so fragile in cases of chronic enteritis, that on the dead body of an individual who has died of this affection, one may draw off in one piece the whole mucous membrane of the intestine. The cellular tissue which surrounds the womb that has become cancerous, being engorged and tumefied, the least effort is sufficient to tear it.

It

Bichat was deceived in attributing to the cellular tissue an isolated power in diseases of different organs. This isolation of diseases of the organs depends chiefly on the structure proper to each tissue, and on the differences of the vital properties with which it is endowed. On the other hand, in acute diseases, which have their seat in a particular organ, in the lungs, stomach, intestines, &c., the cellular tissue is often affected by juxta-position, and by reason of continuity with the organ affected. becomes the seat of inflammation, of collections of pus, &c. Inflammation and the production of pus have not their seat in the anatomical elements exactly of the cellular tissue: inflammation is solely an affection of capillary vessels: but the great softness and extreme permeability of the cellular system allows the pus to accumulate more readily there than elsewhere. We are not to suppose that the cellular tissue is transformed into pus by inflammation; this morbid secretion only displaces this tissue, which is gradually destroyed.

The isolation of the organs in disease, is to be attributed, in general, not only to the different vital properties, but also to the difference of the blood-vessels, that is, to the existence in these organs of vessels arising from different trunks: thus, we find the nerves entirely intact, though all around them may be destroyed by suppuration. The knowledge of the degree of cohesion, different in different regions of the body, explains several phenomena in disease. The density, for instance, of the cellular tissue on the nose, especially inferiorly, and on the alæ, produces remark

able phenomena in erysipelas of this region, and acute pains, occasioned by the difficulty with which the skin of the nose becomes tumefied. Surgical operations, ligatures of vessels, are more difficult in the midst of a dense tissue; thus, they are more difficult in the subcutaneous tissue of the nucha, than in that on a level with the larynx. Serous infiltrations, and emphysema take place more readily in the general tissue, and in that which is very lax, than in cellular membranes, or in dense portions of the cellular tissue. Hence, the rarity of serous infiltrations in the palms of the hands, or soles of the feet. We rarely see serous infiltrations or emphysema in the dense cellular tissue beneath mucous membranes. Serous infiltration of the cellular tissue of the large intestine is rarely observed in chronic diarrhoea,

The author next considers the General Anatomy of the Nervous System. This system he divides into two parts; one he calls the central part, or the central nervous system; it is inclosed in the cavities of the cranium or spine. The other part of the nervous system, the peripheric part, constitutes the nerves. Of these, there are two classes; the one arises from the spinal marrow by two roots; these are the cerebro-spinal or white nerves. These, including the central part of the nervous system, are designated the cerebro-spinal system, or the nervous system of animal life. The others form a chain of soft nerves, and grayish-red ganglions; this is the ganglionic system, or the nervous system of organic life. Of the physical properties, the colour is the most important in this system. The white and gray colours are those which predominate, and serve to distinguish the different parts of the central portions of the nervous system. The gray and white substances of the nervous centre differ essentially from each other, in their structure and their texture, in some of their physical properties, and probably, also, in their functions. That the nervous substance possesses extensibility, to a certain degree, is proved in the case of dropsy of the ventricles. The other physical properties we shall not dwell on, but proceed to consider the vital properties. The essential vital property of the cerebro-spinal nervous system, and which solely appertains to it, is sensibility. The peripheric portion, which comprises the nerves properly so called, is sensible to a high degree. The seat of this property is, beyond all doubt, the medullary substance, the neurilema being composed merely of cellular tissue, and its removal not being sufficient to cause pain. These nerves are the organs of sensation and motion. With respect to the sensibility of the cerebral substance, which is considered as the seat of sensation, motion, and of the functions of the mind, opinions are divided. From experiments made by several physiologists, the author concludes that the brain, in the ordinary state, has no consciousness of the irritations addressed directly to its substance, and it appears, that the impressions, in order to be appreciated by this organ, require to be transmitted to it through the medium of the nerves. All are agreed as to the sensibility of the medulla spinalis and medulla oblongata.

We shall now pass on to the Chapter on the BLOOD, in which we find the author has collected all the more modern discoveries with respect to this important fluid. We shall first consider the physical and vital properties of the blood. The arterial blood is of a red vermilion colour, whilst venous blood is a deep dark colour. The heat of the blood, examined in

the vessels, is equal to that of the body; it is therefore 38 C.; its caloric capacity, that is to say, the rapidity with which it cools, is related to its specific gravity. Almost all observers have found that the arterial blood is from 1 to 1 C. warmer than venous blood. Its specific gravity varies between 1.050 and 1.059; the mean is 1.055; arterial is lighter than venous blood. The quantity of the blood has been determined by some at 10, by others at from 12 to 15 kilogrammes. Valentin says that it is to the weight of the entire body in the ratio of 1 to 4.25. The consistence of the blood depends on its specific gravity, heat and viscidity. When the blood is drawn from the vessels, its consistence changes; it becomes solid, that is, it coagulates: it is at first a gelatinous mass, which then contracts, and in this way forms the clot and the serum or serosity. Arterial blood coagulates more quickly than venous blood. With respect to the cause of the coagulability of the blood various opinions have been advanced. Some will have it that the blood is kept in the fluid form by its inherent vitality. Aneurysms, however, afford an instance of blood coagulating in the vessels during life. Others refer the coagulation to the loss of motion and of heat. This, however, has been disproved by repeated experiments, as also by pathological observation.

Almost all authors have thought that the external air may produce coagulation of the blood, a great many experiments go to prove that coagulation is accelerated by favouring the access of the air, and that it is retarded under the opposite circumstances. These experiments do not seem deserving of much confidence from the difficulty of completely excluding the contact of the air with the blood. The coagulation has been attributed chiefly to the oxygen, not to the azote, whilst the carbonic acid gas retards or prevents it: a proof of this has been sought in the blood of asphyxiated persons, &c. It is now ascertained that the blood contains several species of gas: venous blood more especially contains carbonic acid gas; an attempt has been made to favour the development of this gas by placing beside the blood some lime-water to see whether the coagulation would be accelerated, thus attributing to the development of the gas the cause of the coagulation. Home and Scudamore concurred in this view of the matter. Other physiologists imagine that the formation of the carbonic acid gas by oxygen should be considered as the real cause. The author considers the two last opinions the most probable. Hewson was one of the first who ascertained that the sulphates, muriates, nitrates, phosphates, acetates, borates, and the carbonates of soda and of potash, when mixed with the blood, are capable of preventing its coagulation. The carbonates are the most powerful; free alcaline solutions are long known to possess this preventive power. The author has seen similar effects produced by the presence of pus and albumen. In all these researches there are two circumstances which must not be forgotten; 1, that almost all substances mixed with the blood in very small quantity accelerate coagulation, even when in larger quantity they retard it. Soda and caustic potash form exceptions to this; the minutest quantities of these substances retard coagulation: 2, it must be remarked that large quantities of foreign substances may retard coagulation, by their preventing the particles of fibrine from approximating. The results of modern experiments on this subject may be thus summed up: 1, the alkalies, potash, soda and am