local disorder of a secreting or epitheliated surface or organ; the acquired local disorder is the fountain whence the infection issues, first to the immediate tissues around and afterwards to discontinuous centres, in ever-increasing strength and quantity. So long as the local growth remains undestroyed, there is always a source of infection; and there is no reason to expect, from the circumstances of the case, that constitutional treatment will be of any avail to eradicate the primary disease.

The salient point of difference between syphilis and cancer is that the former is always the tradition of bad healing, or of repair gone wrong; a tradition, therefore, which has a great element of hopefulness in it, inasmuch as the disease has still the reparative force behind it. Unfortunately there is no such reassuring fact to be found in the circumstances amidst which cancer arises. The difference will be at once apparent on comparing a lupus with a true cancerous sore or nodule: lupus has just enough of the granulomatous type in its structure to be capable of sound healing under an alterative action; but in cancer the safe issue of cicatrization or repair has no tendency to come in. The evil repute of a cancer is on the whole well founded; the disease has been hitherto mostly of the incurable sort, and there is only a glimmer of hope to be got from the pathological analysis.

The disease is the peculiar Nemesis of secretion or other epithelial action gone wrong-of long standing catarrhs, repeated congestions, or habitual irritations

of epitheliated surfaces, or of the peculiar liabilities of women in respect to the early obsolescence of their primary and secondary sexual structures and functions. The reason why cancers arise from such functional irregularities in some persons and not in others would appear to consist in the peculiar facility of the supporting connective tissues to be acted upon by the waste products of the epithelium, the induced action in the supporting tissue being in the first instance a return to embryonic characters. The great bindingtissue of the body, the chief residue of the original mesoblast, is therefore the peculiar seat of cancerous predisposition. It has a proclivity in some persons more than in others to fall into that disastrous infection, although never without repeated provocation.

Whatever precaution of living diminishes the number of fluxions, catarrhs, mechanical excitements, or reflex emotional excitements in the organs and epitheliated parts of known liability, diminishes naturally the risk of cancer. But such prevention is much too remote from the after-effects to be seriously thought of. Functional disorder is hardly ever viewed as a possible antecedent of cancer, even if the family history be disquieting. The treatment begins for the most part at a time when epithelial infection of the supporting connective tissue is already an accomplished fact; and there is hardly a hint, among the various alterative actions of the metals or other toxic substances, of any "oblivious antidote" for such a rooted memory as that.

CHAPTER XII.

THE DIATHETIC ANTECEDENTS OF TUBERCLE, AND THEIR SIGNIFICANCE FOR TREATING THE INFECTIVE DISEASE.

SYPHILIS we have considered to be the memory of bad healing communicable from sex to sex, or of granulation-tissue gone wrong. Cancer, on the other hand, is an infection arising always within the individual body, a persisting disorder of certain epithelial regions, driven at length to overstep the bounds of mere quantitative error, and to sum itself up in structural infectiveness. The examples of chronic ill-health in the chapter on Diatheses are summations on still another line; they implicate the nervous system pre-eminently, being as universal or constitutional in their extent as that system; but not even leprosy, for all its nodular formations, is an infection in the same sense as syphilis on the one hand or as cancer on the other. Chronicity, repeated provocation, habit, store of memories, come into account equally in the communicable infection (syphilis), the auto-infection (cancer) and the diatheses (leprosy, pellagra, beriberi). We have now to consider still another instance of chronic ill-health, where the

provocation and acquired morbid habit produce a result that amounts to a communicable infection on one side, an auto-infection on another, and a diathesis on a third. This kind of combination of effects is best exemplified in certain of the domesticated animals, and the particular instance in view is bovine tubercle.

For the sake of brevity, I must presume upon the evidence, and upon a view of it that I have stated elsewhere.* Bovine tubercle is, in the last analysis, a mutiple tumour-disease of the serous membranes, with the property of auto-infection as shown in the secondary invasion of the lymph-glands, lungs, abdominal and pelvic viscera, bones, joints and the like, and with the property of infectiveness beyond the individual organism, as shown in the communicability of bovine tubercle, both experimentally and accidentally, by the ingestion of the morbid products and of the milk, by inoculation, and probably also by air-borne contagion. It is a summation of morbid memories of a very complete kind, in every possible direction, including that of heredity. What is there in the primary type of chronic ill-health to bring consequences so comprehensive in their range?

The multiple nodules or tumours of the serous membranes in cows and oxen are a peculiar kind of tissue, not altogether like anything else in the body. The tissue is partly sarcomatous, partly coarse fibrous,

*"The Autonomous Life of the Specific Infections," Brit. Med. Journ.,' Aug. 4th, 1883.

with great tendency towards caseous, cretaceous, or other dry molecular degeneration. It has no resemblance of fat; but it grows to a very significant extent in the proper seats of fat in the stalled bovines, and it assumes the peculiar shapes of the subserous masses of that tissue. It certainly looks as if these multiple tumours, nodules, and deposits on the serous membranes, owed their existence to some errors of nutrition, which had caused the fat in its favourite internal seats to lose the property of a metabolic tissue and to assume an activity more decidedly structural and formative.

The distinctive mark of the serous-membrane nodules in the pearl disease is redundant growth of tissue without adequate provision of blood. Fat is the physiological type of it, and fat is a tissue in which the blood is naturally abundant. Under certain circumstances, where the blood-supply is for some reason restricted, one may observe the adaptation of the fat to a smaller amount of blood; it becomes sclerosed or semicartilaginous, or calcified; and its lobules so transformed may lead a safe existence for a considerable time, either in sitû or as loose bodies of the abdominal cavity or of the joints. I have seen a typical pearly hardness in an isolated lobule of the abdominal fat in the carcass of a perfectly healthy ox; and one may see the same kind of sclerosis sometimes in deposits of fat in the human subject.

The common pearly diathesis of the bovines has affinities to such occasional changes in the fat; but it conforms to a well-marked type of its own, the con