And in the report from which the particulars are extracted, it is stated that in 1866, the ratio of death by these affections attained the very high range of 3:46; having done so among the troops on the line of march.

Statistics of the civil native population are difficult to obtain, and by no means to be relied upon when obtained. An attempt has, however, been made to draw a comparison between the ratios of mortality by pulmonic diseases and by affections of the heart in both these classes, the only year for which such a comparison is available being 1866; according to it the results are as follows, viz.:

from which figures it would appear that pulmonary consumption is much less frequent among our soldiers in that country than it is among the natives, but that on the other hand, diseases of the heart are considerably more numerous among the former than the latter. Among certain classes of natives also, asthma is of very frequent occurrence, and there appears reason to believe that deaths by it are sometimes attributed to affections of the heart. According to the views of Dr. Bryden also, prisoners being always more or less in an anæmic condition are thus especially liable to become the subjects of these diseases.

Summary.- -If then, we summarise the most important points in connection with diseases of the heart and other organs of circulation as they occur in the army, we find that they include the following, namely:

1. That disease of the heart is of more frequent occurrence in soldiers than among civilians.

2. That its principal causes are rheumatism, Bright's disease, and violent exertion.

3. That syphilis, in affecting both classes, produces like results in both.

4. Disease of the mitral valves is more common than of the aortic in civilians, but of the aortic than mitral in soldiers.

5. Heat and malaria of India probably conduce more to disease of the heart than the climate of Britain.

6. The functional disorders in young soldiers may be readily detected by the smygmograph.

7. The great and most generally recognised causes include contraction of the chest by uniform and accoutrements, thus producing a strain upon the heart.

(To be continued.)

II.-On the Evidence to be obtained as to the Nature of the Vital Force, from a Minute Study of Anatomy, and of the Laws which regulate the Electro-Magnetic Force. By R. C. SHETTLE, M.D., Physician to the Royal Berkshire Hospital, &c.

THE purport of the following paper is to demonstrate the analogy, if not perfect identity, which exists between the electro-magnetic and vital forces, as concisely as possible.

I shall first point out the general structural arrangement of the heart; secondly, by reference to minute anatomy as revealed to us by the highest powers of the microscope now used, show the formation and mode of growth of various tissues, and thirdly, endeavour to show that there is a physical force, and only one known force, under the influence of the laws of which bioplasmic matter must assume the form it does in the animal machine.

I shall refer first to some dissections of the ganglia and nerves of the heart made some years since by Dr. Robert Lee, by which he shows that the nerves wind more or less spirally round the heart, that they frequently more or less encircle the arteries, that ganglia of considerable size are formed on the superficial nerves, where they are crossing the arteries, and from these chains of ganglia branches are sent off to the coats of the blood-vessels, which sink deep into the substance of the heart.

I would next call especial attention to the general spiral arrangement of the nerves and the enlargements or ganglia formed upon them when they are crossing the arteries, an arrangement for which some cause must exist, as it so almost universally obtains.

The muscular fibres of the heart were admirably described by Dr. James Pettigrew in a communication to the Royal Society in 1863, and to his dissections I must also direct attentive consideration (as published in the Philosophical Transactions' for that year), but it is impossible, owing to the limited space that can be devoted to this paper, to do more than state that Dr. Pettigrew has shown these muscular fibres to consist of seven layers, that these layers, owing to the difference in the direction of the fibres, are well marked; that there is a gradual sequence in the direction of the fibres, whereby they are made to change their course from a nearly vertical to a horizontal or transverse, and from the transverse back again to the nearly vertical. Thus in dissecting these fibres from without inwards, the fibres of the first layer, which run in a spiral direction from left to right downwards, are more vertical than those of the second layer, the second than those of the third, the third than those of the fourth; the fibres of the fourth layer have a transverse direction,

running at nearly right angles to those of the first, passing the fourth layer, which occupies nearly a central position in the ventricular walls, the order of arrangement is reversed, and the fibres of the layers five, six, and seven, gradually return in an opposite direction, and in inverse order, to the same relation to the ventricular walls as that maintained by the fibres of the external layer.

The practical point to which I wish to call attention here is, that the muscular fibres of the heart, for the most part, form interminable coils or spiral turns around the cavities of the ventricles, and especially the left, and this arrangement is not only carried out with regard to the walls of the ventricles, but Dr. Pettigrew states that the musculi papillares, and even the valves, partake of this same character with regard to their fibres; moreover, this arrangement of the internal structure, together with the conical shape of the cavities, causes the blood to be arranged during the diastole of the ventricle in spiral columns, and subsequently to be driven out of the orifice of the ventricle with a spiral turn or twist given to it. These are facts upon which Dr. Pettigrew lays some stress, for he says "that without presuming dogmatically to assert that the ultimate arrangement of the ventricles of the bird and mammal is reduced to any known mathematical law, I cannot help mentioning that the arrangement in question can be thoroughly imitated, even in its details, by certain mechanical contrivances about to be explained; that I would consider the present communication incomplete were I not shortly to direct attention to them: thus if a sheet of paper or other flexible material whose length is twice that of its breadth be taken, and parallel lines be drawn on both sides of it, in the direction of its length to represent the course of the fibres, all that requires to be done in order to convert it into a literal transcript of one half of the left or typical ventricle is to lay it out lengthways across a table, and catching it by the right hand distal corner to roll or turn in towards oneself a conical shaped portion, and continue the rolling process in the direction of the opposite or oblique corner, until three and a half turns are made, and a hollow cone produced. It will be found that every turn in it is converted into a double conical spiral."

The formation and structure of the nerve-cells of the frog, as described by Dr. Lionel Beale in a communication to the Royal Society in 1863, must now be carefully considered. Dr. Beale has found that all the ganglion-cells from which nerve-fibres proceed to the vessels and other parts of the submucous areolar tissue of the palate, tongue, lungs, and neighbouring organs, those from which nerves distributed to the viscera are derived, as well as the cells connected with the pneumogastric, those forming the ganglia upon the posterior roots of the spinal nerves; and some others exhibit the same general structure, although there are many

special pecularities and differences of size in the cells of which some of these ganglia are composed.

The general form of these cells is oval or spherical, but upon closer examination it is found that the most perfectly formed ganglion-cell is pear- or balloon-shaped, and by its narrow extremity is continuous with the nerve-fibres, which may be followed into nervetrunks. The substance of the cells consists of a more or less granular material. Near the fundus or rounded end is a large circular nucleus with its nucleolus; in some cells, about the centre, are observed a number of small oval nuclei, which are arranged transversely to the long axis of the cell, and follow each other in lines, in a direction more or less obliquely downwards. The matter of which the mass of the cells consists gradually diminishes in diameter, and contracts so as to form a fibre, in which a nucleus is often seen. About the centre of the exterior of the cell the material gradually assumes the form of fibres, and these pass around the first fibre in a spiral manner. Thus a fibre comes from the centre of the cell (straight fibre), and one or many fibres (spiral) proceed from its surface. So much for the general structure. A few words more as to how these are formed :-" In very young animals these ganglioncells gradually form from nuclei, which appear to be imbedded in very soft granular matter. The fibres extend from the collection in at least two directions, and exist as granular nucleated bands. The fibres do not grow out of the cells, but are formed as two masses of germinal matter gradually separate from each other. New ganglioncells, nerve-fibres, and nuclei, are being constantly produced, not only in fully developed young animals and in the adult, but certainly for a considerable time after the animal has arrived at maturity, and I believe almost to the close of the ordinary period of life." After the ganglia have so formed they divide and subdivide into several divisions having the same structure; they then assume the balloon shape, and begin to move away from the point where they were first formed, and it is clear that the granular matter from which they were first formed may be drawn out, so as to form a fibre, but when the ganglion-cells are formed by changes occurring in what appears to be a nucleus of nerve-fibre, the process is somewhat different; here "a nucleus which cannot at first be distinguished from the ordinary nuclei in connection with the nerve-fibres, grows somewhat larger than the rest; sometimes several in different parts of a fibre enlarge to some extent, but for the most part only one in the course of a long distance will be developed into a ganglion-cell. The enlarged nucleus, when about to be developed into a ganglion cell, soon exhibits a transparent portion at its circumference; it next becomes separated more and more from the point where its formation commenced. The two opposite extremities of the cell are drawn lower, the fibres increase in length and lie parallel to each other,

and the form of the cell becomes much altered. If formed in connection with one of a bundle composed of numerous fibres, the cell seems to grow away from the bundle, and more commonly its long axis corresponds to the direction in which the fibres of the bundle run. The two fibres passing from this cell run amongst the bundle of nerve fibres to which their course is at first more or less at right angles. The two fibres may then be seen to alter their course and run with other fibres of the bundle, but in opposite directions."

Upon reference to the plates of Dr. Beales's work, it will be seen that, close to the cell, in which there is a considerable extent of spiral, the course of the fibres is almost transverse. Then the fibres pass spirally round the straight fibres away from the cell, and each turn becomes more oblique than the one above it, until at last the fibre (or fibres) lies parallel with the other fibre which leaves the cell. The spiral fibres are necessarily longer than the straight fibre. The spiral fibres can be shown to be continuous with the material with which the body of the cell is composed, as well as the straight fibre, but the former are connected with its surface, whilst the latter proceeds from the more central part; so that in the most perfect cells the straight fibre forms a stem round which the spiral fibres are coiled. As a general rule, those ganglion cells which have the longest stems, or are separated by the greatest distance from the general mass of the ganglion, are the oldest cells. Now these are the very cells in which the spiral exhibits the greatest number of coils, and Dr. Beale says that " from numerous observations I am convinced that the number of coils increases as the fibre advances in age. The age of the cell is also marked by an alteration in shape and bulk, in some cells scarcely anything is left but the large nucleus. It is also ascertained that there is only one large nucleus at any early period of development of the cell; whilst in a fully formed cell there may be from ten to twenty smaller oval nuclei, at the lower part of the cell, and some of which are connected with the spiral fibres." For the better consideration of the changes which occur during the formation of new cells Dr. Beale divides the matter from which such cells are built up into germinal matter and formed material, and he colours the germinal matter with a solution of carmine. In young specimens the germinal matter is seen to pass into formed material. No living tissue, he says, exists without there being living germinal matter in connection with it. The youngest cells consist almost entirely of germinal matter, while in the fully formed cell there is from ten to twenty times as much formed material as there is of germinal matter. In the fully formed cell the germinal matter (nucleus) exhibits a line around it, but there is no cell wall. The nuclei, the nucleoli, and the nucleoluli, are found one within the other, and the last or smallest centres are most darkly coloured. In the nucleoli the colour is not so intense, the nuclei again are