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secretion does not proceed in a regular manner, the immediate result is an accumulation of urates in the blood, as has been shown in a very able manner by Garrod. Then at last deposits begin to form at other points, not throughout the whole body, nor uniformly in all parts, but at certain definite points and in accordance with certain rules.

Here we have to do with very different forms of metastasis from those with which we became acquainted whilst considering the nature of embolia. That the changes which ensue in the substance of the kidney, in consequence of the absorption of silver from the stomach, accord with what has in pathology since times of old been termed metastasis is unquestionable. This consists in a transference of matter from one spot to another, so that the same substance which had previously been present in the first comes and lodges in the second, and the secreting organ takes up minute particles of the matter into its own tissue. This is what we find constantly recurring in the history of all metastatic deposits of this kind, in which only matters in solution and not particles of a visible and mechanical nature are present in the blood. The urate of soda cannot be directly seen in the blood of the gouty person, unless it have previously been collected by the help of chemical processes; and just as little the salts of silver.

I have moreover described a new form of metastasis which is certainly more rare but yet belongs to the same category. When calcareous salts are reabsorbed from the bones in large quantity, the bone-earth is generally excreted by the kidneys, likewise in large quantity, so that sediments form in the urine, the knowledge of which has straggled down to us in the history of osteomalacia [mollities ossium], from the notorious Mme. Supiot in the last century. But this regular excretion of the calcareous salts is not unfrequently impaired by disturbances in the functions of the


kidneys, in the same way as in arthritis the excretion of urate of soda; then there also arise metastatic deposits of bone-earth, but at other points, namely the lungs and the stomach. Considerable portions of the lungs sometimes become calcified without any injury to the permeability of the respiratory passages; the diseased parts look like fine bathing sponge. The mucous membrane of the stomach becomes filled in like manner with calcareous salts, so that it feels like a rasp and grates under the knife without the glands of the stomach becoming directly implicated; they are merely imbedded in a stiffened mass, and possibly even thus secretion might take place from them.

To these kinds of metastasis in which definite substances, though not in a palpable form, but in solution, find their way into the mass of the blood, careful attention must at all events be paid when we endeavour to unravel the complex mass of conditions which are comprehended under the term pyaemia. I see at least no other possible way of explaining certain more diffuse processes, which do not present themselves in the form of the ordinary circumscribed metastatic deposits. To this class belongs that metastatic pleurisy which develops itself without any metastatic abscesses in the lungs—that seemingly rheumatic articular affection, in which no distinct deposit is found in the joints— that diffuse gangrenous inflammation of the subcutaneous connective tissue which cannot well be accounted for unless we suppose a more chemical mode of infection. Here we have, as may be seen in cases of variolous and cadaveric infection, to deal with a transference of corrupted, ichorous juices into the body; and we must admit the existence of a dyscrasia {ichorous infection) in which this ichorous substance which has made its way into the body, displays its effects in an acute form in the organs which have a special predilection for such matters.

Now it may possibly happen that in the course of the

same case of illness the three different changes which we have considered may coexist. An increase in the number of the colourless corpuscles (leucocytosis) may take place to such an extent as to tempt one to believe in the presence of a morphological pyaemia. This will at all events always be the case when the process has been connected with extensive irritation of the lymphatic glands. The formation of thrombi, moreover, and embolia with metastatic deposits may occur. And finally there may at the same time be taking place an absorption of ichorous or putrid juices (ichorrhaemia, septhaemia). These three different conditions may present themselves as complications one of the other, but do not necessarily coincide. If it be wished therefore to retain the term pyaemia, let it be reserved for such complications as these, only we must not seek for a common central point in a purulent infection of the blood, but the term must be regarded as a collective name for several processes dissimilar in their nature.

I hope, gentlemen, that what I have now imparted to you will be sufficient to put you in possession of the chief bearings of the subject. Of course no real demonstration can be afforded without reference to distinct cases. You will, however, yourselves have sufficient opportunity for testing the exactitude of this description of mine, and I shall be glad if you find that important data have thereby also been furnished, by which clearer conceptions with regard to the really practical, and especially the therapeutical, questions arising out of the subject, may be obtained.

Now that we have become acquainted not only with corporeal particles, but also with certain chemical substances as the originators of dyscrasiae, lasting for a longer or shorter time according as the supply of these particles and substances continues for a longer or shorter period, we may CANCEROUS DYSCRASIA. 217

briefly revert to the question, whether, in addition to these forms, a kind of dyscrasia can be shewn to exist in which the blood is the permanent seat of definite changes. We must answer this question in the negative. The more marked a really demonstrable contamination of the blood with certain matters is, the more manifest is the relatively acute course of the process. Just the very forms1 in which medical men are the most apt to console themselves—especially for the shortcomings of the therapeutical results, with the reflection that they have to do with a deeply rooted and incurable chronic dyscrasia—just these forms depend, I imagine, least of all upon an original change in the blood; for these are precisely the cases, in the majority of which extensive alterations are discovered in certain organs or in individual parts. I cannot assert that investigation has in this matter in any way been pushed to its utmost limits, I can only say that every resource afforded by microscopical or chemical analysis has hitherto been fruitlessly employed in investigating the part played by the blood in these processes; and that, on the other hand, we are in most of them able to demonstrate important changes in larger or smaller groups of the ultimate constituents of organs; and that on the whole the probability that the dyscrasia should in these instances also be regarded as secondary, and as derived from definite points in organs, becomes stronger every day. I shall have to examine this question a little more closely when I come to consider the theory of the propagation of malignant tumours, in the case of which recourse is, you know, so often had to the supposition that the malignancy has its root in the blood which gives rise to the local affections. And yet it is precisely in the course of these processes that it is comparatively

1 Tubercle, cancer, purpura, syphilis, &c.

most easy to shew the mode of propagation, both in the immediate neighbourhood of the diseased part, and in remote organs; and it is in them we find, that there is one circumstance which especially favours the extension of such processes, namely the abundance of parenchymatous juices in the pathological formation. The drier a new formation is, the less in general are its powers of infecting, both nearer and more distant parts. The mode of propagation itself commonly entirely agrees with what we have already said; first of all, a conveyance of the morbid matter through the lymphatic channels, and then an affection of the lymphatic glands, takes place, and it is only by degrees that processes of a similar nature declare themselves in more remote organs. Or the process may here too in the first instance encroach upon the walls of the veins, so that they become really cancerous, and after a certain time the cancer either grows directly through the walls into the vessel and there continues its course, or a thrombus forms at the point, which invests the cancerous plug in a greater or less degree and into which the mass of cancer grows. Here, therefore, we see a diffusion of the disease may possibly take place in two different manners, but the diffusion of corpuscular elements only in one, when, namely, an irruption ensues into the veins. An absorption of cancercells by means of the lymphatics cannot indeed in itself be ranked amongst impossibilities, but at all events this much is certain, that no propagation of the disease can take place until the lymphatic glands have in their turn undergone a complete cancerous transformation, and similar masses of cancer push on their growth from them into their efferent vessels. In no case can a peripheral lymphatic vessel sweep along into the blood the cells of the cancer so simply as it does the fluid parts; this is only conceivable and possible in the case of the veins. But even in that case there is not the slightest probability that noxious

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