tion not very far off. Tubercle is a disease on a quite different physiological basis. The action of mercury is as injurious to tubercular products as it is beneficial to syphilitic. If syphilis had not fortunately the natural forces of repair underlying it, mercury would presumably be of no use; its use is to suspend the habit of bad healing, so that the reparative action is resumed on the proper lines. Tubercle has not certainly that particular force ready to come to its rescue; but has it not something appropriate to its own antecedents to expect from the readiness of the bodily actions to return to the beaten track, if the opportunity be given them?

It will hardly be possible to place these indications of cure on a serious basis, unless some attempt be first made to meet the obvious objections to this transcendental view of tubercle which will have presented themselves to the practical reason.

By far the most important of the collateral considerations in the question of tubercle, is that the lungs are the organs most affected. It may well seem hopelessly paradoxical and wrong-headed to assert that the affection of the lungs in tubercle is after all a secondary or derived one, or that pulmonary consumption is not essentially a disease of the respiratory apparatus. Yet, to get the true therapeutic indications, we must go as far below the surface as that.

There are cases, it is true, where bronchial irritation is directly, if not remotely, answerable for the pulmonary consumption; such cases as the consumption of

miners, stone-masons, and other classes of workmen habitually inhaling dusty particles. But even in these cases consumption would hardly be the sequel of the irritation where there not some specific diathetic cause at work in the body. The commonness of consumption under such circumstances only shows how widely spread the specific diathesis or constitutional taint is; it does not by any means show that the dust of minerals or metals can produce consumption of the lungs as the proper effect of its irritation.

Besides these cases there are many more where a common pulmonary catarrh may have had a considerable share in determining the incidence of the disease, or its character as "infiltrated" tubercle. But it is difficult to believe that so specific an issue would ever arise unaided from a common kind of irritation, whose effects are otherwise so often self-limited and nonspecific. There is always the memory of erroneous tissue-nutrition when consumption ensues, upon what incitement soever.

The original circumstances, or at least the analogous circumstances, are revealed in the bovine species; and the significant fact meets us there, that the disease in the lungs is secondary to the disease of the serous membranes. The lungs are the seats of metastasis, just as they usually are in sarcomatous tumours. In the bovine lung the metastasis may be either in the form of nodular masses, or of diffuse chalky or gritty infiltration; but it is in all cases a metastasis in idea, even if it should overshadow the serous-membrane

disease itself, as it usually does in inherited cases. The divided interest, if not the subordination, of the lung affection in the bovine disease (or prototype of all tubercle) is farther made evident by the fact that various groups of lymphatic glands, many of them in no way connected with respiration, are subject to the same kind of textural overgrowth and degeneration. Wherever bovine tubercle occurs, whether in the lungs or elsewhere, and within that species or beyond it, we may take it that it stands for memories, more or less remote, of seriously disordered tissue-nutrition, and more particularly that it means fat-tissue gone

wrong.

I make no reference to the minute organisms found here and there in the unstable tubercular products (as well as in other granulomatous new growths): firstly, because a sufficiently close scrutiny of the experimental evidence set forth to prove the disease-producing property of the bacillus will satisfy anyone that there is a fatal flaw in it;* and secondly, because all the world knows that the therapeutic indications of the parasitic doctrine are worthless. I address myself to a kind of tubercle-pathology which has lessons for us of the most practical kind. Such of them as relate to what I think the true fons et origo mali, namely, the shortsighted maxims and unconsciously cruel practices of cow-keeping, are matter of national concern; and I have nothing farther to say on that subject at present.

*Pointed out by me in a fly-sheet on 'Dr. Koch's Method of Cultivating the Micro-Organisms in Tubercle,' 1884.

But for the more immediate indications of cure in the individual there is something to be gleaned on a nearer look at the erroneous habit of tissue-nutrition.

If that erroneous habit arises in the first instance, as I believe it does, in the fat of serous membranes, it becomes in the end a sort of idea* pervading the tissue-nutrition elsewhere; just as the erroneous healing of venereal sores becomes a pervading idea in the constitutional infection of syphilis. The archetypal error of tubercle is derived, in the last resort, from the fortunes of the adipose tissue in certain localities; and although human tubercle retains no trace of an adipose origin, the pervading idea of the disease may be said to be always and everywhere that of fat gone wrong. Are there any therapeutical indications from that pathology?

Whatever therapeutical indications there may be will come to us in the first instance from watching the natural behaviour of fat-tissue under various circumstances of malnutrition. Such behaviour is always conservative, or by way of safe retreat from a threatened position. When it falls short of its full structure and function, owing to failure of the blood-supply, it adapts itself to the circumstances; it becomes sclerosed, or semi-cartilaginous, or calcified; it becomes a kind of tissue which can subsist with little or no blood. This is seen in loose bodies of the synovial or serous surfaces, which appear to live by the imbibition of

* Idea may be read in the Aristotelian sense of "forma, vel anima, vel idea," as applied to the transmission of parental characters (see p. 14).

juices only. Next in order of safe retreat, the redundant tissue becomes coarsely fibrous, a condition in which it can maintain itself when the blood-supply is reduced in amount or present on the periphery only. This is the best of the conservative adaptations in tubercle itself. Still keeping on the line of safe retreat, it may undergo dry necrosis with or without calcareous deposition; and if the outer zones succeed in keeping up their vascularity the result may be harmless obsolescence. This is the common issue in those innumerable cases where the lungs or lymphatic glands are found after death to contain what are rightly called obsolete tubercles, usually with a cretaceous centre. Safe retreat from a dangerous position is the process of cure spontaneously instituted in very many cases of tubercle.

The administration of remedies has to be directed towards securing obsolescence; just as in syphilis it is directed to securing sound repair. But experience shows that the worst cases of tubercle are not nearly so amenable to treatment as the worst cases of syphilis. The idea of syphilis, it is contended, is an error of healing; correct the error, and the healing will proceed. On the other hand, the idea of tubercle is faulty nutrition affecting a peculiarly susceptible metabolic tissue, namely fat-tissue. If we were near enough to the fountain-head of the disease, the cure would be to make the perverted fat-tissue return to its proper metabolism. But that is, of course, a chimerical idea, for the reason that tubercle, as we