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DIFFUSION BY MEANS OF CONTAGIOUS JUICES. 219

matters are frequently diffused by their means, and for the simple reason that the metastases of cancer very frequently do not correspond with those with which we have become acquainted as occurring in embolia. The usual form of metastatic diffusion in cancer follows rather the direction of the secreting organs. The lungs, as is well known, are much more rarely invaded by cancerous disease than the liver, not only after gastric and uterine, but also after mammary cancer which would necessarily rather produce cancer in the lungs, if it were anything corpuscular which was conveyed away, became stagnant and gave rise to a new eruption of the disease. The manner in which the metastatic diffusion takes place seems, on the contrary, to render it probable that the transference takes place by means of certain fluids, and that these possess the power of producing an infection which disposes different parts to a reproduction of a mass of the same nature as the one which originally existed. We need only imagine a process similar to that which we see upon a large scale in small pox. The pus of small pox when directly inoculated does indeed induce the disease, but the contagium1 is also volatile, and a person may have pustules over his skin after merely breathing air of a certain character. A similar state of things seems to prevail in cases, in which, in the course of heteroplastic processes, dyscrasiae occurwhich do not burst out afresh at pointswhich, according to the direction of the current of blood or lymph, would be most directly exposed to them, but at remote spots. As the salts of silver do not deposit themselves in the lungs, but pass through them to be precipitated only when they reach the kidneys or the skin, so an ichorous juice may pass from a cancerous tumour through the lungs without producing any change in them, and yet at a more remote point, as for example in the bones of a far distant part, excite changes of a malignant nature.

1 i. E., Contagious matter.—Transl.

LECTURE XI.

MARCH 27, 1858. PIGMENTARY ELEMENTS IN THE BLOOD. NERVES.

Melanaemia.—Its relation to melanotic tumours and colorations of the spleen.

Red blood-corpuscles. — Origin.—Melanie forms.—Chlorosis.—Paralysis of the respiratory substance.—Toxicaemia.

The nervous system.—Its pretended unity.

Nerve-fibres.—Peripheral nerves: their fasciculi, primitive fibres, and perineurium. — Axis-cylinder (electrical substance).—Medullary substance (Myeline).—Non-medullated and medullatecUfibres.—Transition from the one kind to the other: hypertrophy of the optic nerve. — Different breadth of the fibres.—Their terminations.—Pacinian and tactile bodies.

Gentlemen,—I have still some observations to make to you in reference to the changes of the blood, more for the sake of completeness than because I am able to offer to you in doing so any decisive points of view.

In the first place I wish to mention one other condition which has recently been a great deal talked about and might, when occasion offered, present increased interest to you, the so-called melancemia. This is a condition most nearly connected with leukaemia, inasmuch we have in it to deal with elements, which, like the colourless corpuscles in leukaemia, make their way from definite organs into the blood and circulate with it. The number of recorded observations concerning this matter is already tolerably large, indeed I might almost say, larger than perhaps is necessary, for it seems indeed that here and there mistakes have slipped in, which should, I think, be again removed from the history of the affection. But unquestionably there is a state in which coloured elements are met with in the blood that do not belong to it. Isolated observations in support of this fact have already

MEL ANEMIA. 221

for a considerable length of time * been upon record, and indeed first occur in the history of melanotic tumours, concerning which it has frequently been declared that in their neighbourhood minute black particles are met with in the vessels, and the opinion put forward that from this source the melanotic dyscrasia arose. But this is not quite the condition which is meant when melanaemia is now-a-days spoken of. In the last ten years not a single observation has been made known which in any way adds to our knowledge concerning the passage of the particles of melanotic tumours into the blood.

The first observation concerning that class of diseases which in a narrower sense of the word is designated melanaemia, was made by Heinrich Meckel in the case of a lunatic a short time after I had published my description of leukaemia. Meckel found that here too the spleen was enlarged in a very considerable degree and pervaded by black pigment, and he therefore ascribed the change in the blood to an absorption of coloured particles from the spleen. The next observation I made myself (and that too in a class of cases which afterwards proved very fruitful) in the case of an ague-patient, who had long been afflicted with a considerable enlargement of the spleen; for I found in the blood of his heart cells containing pigment. Meckel had only observed free granules and flakes (Schollen) containing pigment. The cells which I discovered in many respects bore a resemblance to colourless blood-corpuscles; they were spherical, but frequently also rather oblong, nucleated cells, within which a greater or less number of large black granules were to be seen. In this case also the occurrence of a large black spleen was again verified. Since that time attention has been continually more and more drawn to these conditions by Meckel himself and by a number of other observers in Germany, and last of all by Frerichs, and in Italy by Tigri. Tigri has not scrupled to designate the disease milza nera, from the blackness of the spleen in it, whilst according to the view of Meckel which has been expanded by Frerichs, it is rather one of the more severe forms of intermittent fever which is to be explained in this way.

1 Dr. Stiebel, sen., of Frankforc-on-the-Maine, calls my attention to the fact that he had already in a review of Schonlein's Clinical Lectures (in Haser's «Archive '), mentioned the occurrence of pigment-cells in the blood.

Note to the Second Edition.

[graphic]

It has been attempted to explain the serious import of these affections by supposing that the elements, which find their way into the blood, accumulate at certain points in the more minute capillary districts, and there produce stagnation and obstruction. This was especially held to be the case in the capillaries of the brain, in which they were said to attach themselves after the manner of emboli to the points of division, and so occasion sometimes capillary apoplexies, sometimes the comatose and apoplectic forms of severe intermittent fever. Frerichs has added a new and important kind of obstruction, namely, that of the minute hepatic vessels, which is said ultimately to give rise to atrophy of the parenchyma of the liver.

If all this be the case, there would seem to existan extremely important series of conditions directly dependent upon the dyscrasia. Unfortunately I can myself say but little concerning the matter, inasmuch as I have not since my first case again been in a position to observe anything similar, I cannot therefore form a decided opinion with regard to the value of the relations which have been laid down with respect to the connection of the secondary changes with the con

Fig. 76. Melanaemia. Blood from the right heart (Cf.' Archiv f. pathol. Anatomie und Physiologie,' vol. ii, fig. 8, p. 594). Colourless cells of various shapes filled with black, and in part angular, pigment-granules. 300 diameters. RED BLOOD-CORPUSCLES. THEIR OBIGIN. 223

tamination of the blood. I only wish to remark that all the facts with which we are acquainted concerning these conditions, indicate that the contamination of the blood has its rise in a definite organ, and that this organ, as in the case of the colourless blood-corpuscles, is generally the spleen.

In the course of my description of the blood I have hitherto scarcely made any mention of the changes which take place in the red corpuscles, not by any means because I regarded them as unimportant constituents of that fluid, but because as yet remarkably little is known concerning their changes. The whole history of the red blood-corpuscles is still invested with a mysterious obscurity, inasmuch as no positive information has even at the present time been obtained with regard to the origin of these elements. We only know this much with certainty, as I have already (p. 157) had occasion to remark, that a part of the original corpuscular elements of the blood proceed just as directly from the embryonic formative cells of the ovum, as all the other tissues which build themselves up out of them. We know moreover that in the first months of the existence even of the human embryo divisions take place in the cells, whereby an increase in the number of them present in the blood itself is produced. But after this time all is obscure, and this obscurity indeed corresponds pretty exactly with the period at which the corpuscles in the blood of man and the mammalia cease to exhibit nuclei. We can only say that we are acquainted with no fact whatever which speaks in favour of a further independent development, or of a cell-division, in the blood, but that everything points to the probability of a supply from without. The only hypothesis which has in more recent times been advanced with regard to the independent development of the blood-corpuscles in the blood itself, is that

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