Let us now, as a sequel to the foregoing, discourse respecting that anomaly of the crasis upon which tubercle is based. With a view, however, to establish a suitable groundwork for the exposition of the tubercle crasis, we would first add a few supplementary remarks concerning tubercle itself.

The tubercle crasis is, without doubt, a fibrin-crasis - jibrinosis. It is not this in respect to quantity alone - hyperinosis - but also, and this is the more important side of the anomaly, in respect to quality. This is clear even from that varied constitution of tubercle upon which we have founded our classification of fibrin-tubercle. Besides this, the fibrin must have become impaired in a particular way, in order to qualify the tubercle, which, in the one case, as simply fibrinous, cornifies; in the other case, as fibrino-croupous, does not undergo the rapid process of dissolution (puriform liquefaction) proper to croupous fibrin.

This peculiar vitiation of the fibrin may itself become somewhat modified, or admit of some accessory impairment. And this may operate as the cause of many differences in tubercle, recognized to this day only by deviating physical properties; those, for instance, of coloration and lustre, of consistence, external form, mode of aggregation of the granulations, etc. Thus, the gray tubercle-granulation is distinguished at times by its dingy bluish coloration, by a grayish lustre, by its aggregation in sharply defined spheres thinly scattered through the pulmonary texture; the yellow tubercle by a lardaceous aspect. The croupous tubercle effused into the lung during the inflammation and ichorous off-throwing of cancers, is, owing no doubt to the fundamental cancerous vitiation of the fibrin, remarkable for its whitish coloration, its softer glue-like consistency, its liquefaction to a whitish, cream-like ichor.

A point of great moment, in relation to the crasis, is the recognition of an impress upon general nutrition indicative of a predisposition to tubercle, and consisting in certain developmental proportions of textures and organs; in a word, the "tuberculous habit" Another point of equal interest is the relation of tubercle to other morbid processes, bound up with primitive or consecutive anomalies of the crasis.

There exists undeniably a habit, expressed in a delicate construction of the soft parts, in imperfect development of the muscular, with preponderance of the vascular, system, and especially in a so-called phthisical build of the thorax, commonly deemed ominous of pulmonary tubercle. It is essential, however, that this build should not, according to the vulgar notion, be imputed to smallness of the lungs within a seemingly insufficient thorax, but rather to very voluminous lungs within a thorax, the obvious narrowness of which, in its antero-posterior diameter, is amply compensated for by its length, with a relatively small abdominal cavity, and small abdominal viscera.

Nevertheless, tubercle does not always, nor exclusively, thrive upon a substructure like this. The tuberculous crasis, like the local tuberculosis of an organ, may become acquired in an individual of quite a different habit, as a consequence of surpassing external and internal mischief.

With reference to the second point, namely, the relation of the tubercle to other morbid processes, no disease offers so much that is interesting, that is corroborative of views already set forth, that is practically serviceable and inductive of ulterior research, as tubercle. It is especially distinguished by its exclusive relation towards several morbid processes.

The sum of an immense range of experience in point is to the following effect:

1. Cyst-Formation

Cyst-Formation, as a new growth, is rarely found concurrent with tubercle, either in the same organ or in the same organism generally. In this sense the proliferous cyst-formations are distinguished. Where their seat is in the abdominal cavity, as for instance in the ovary, the immunity against tubercle is augmented by an accessory circumstance, in itself most important, namely, the coarctation of the thoracic space by pressure from beneath.

Experience seems to show that it is more common for cyst-formations to succeed to the extinction of tuberculosis, than the converse.

A comparison of the occurrence of both in the various organs establishes, as the extreme points of the scale, the well-known great frequency of tubercle against the extreme rarity of cyst-formation in the lungs, and the reversed proportion of the two in the ovaries, and next to these in the salivary glands. This relation seems highly important in reference to the affinity which cyst-formation bears to sarcoma and carcinoma.

2. A Similar Antagonism

A Similar Antagonism, as shown from still more numerous observations, prevails between tubercle and carcinoma. Whenever their general correlation is susceptible of proof, cancer has seemed to succeed to tuberculosis, tubercle rarely to become developed after the extinction of cancer and its crasis. Moreover, it must be repeated that to cancer, and in particular to inflamed and ulcerating cancer, there is sometimes superadded, more especially in the lungs, a tubercle, marked by a whitish coloration, a softish glue-like consistence, and a tendency to resolve itself into a whitish cream-like ichor. It has the import of tuberculo-croupous impairment of a carcinomato-dyscrasial fibrin.

A corresponding result of much interest is afforded by a comparison of the scale of frequency of cancer and tubercle, as well as of several special local relations of both.

They are diametrically opposed to one another, as thus:

Again, the special localities present many differences of their own. Thus, in the uterus, the vaginal portion and cervix become affected with cancer, whilst tubercle fastens upon the mucous membrane of the body of the womb, and generally stops short at the internal orifice. The epididymis becomes primarily and essentially tuberculous; the testis, cancerous. In the lungs the upper section is peculiarly obnoxious to tubercle, whilst cancer occurs at every part of the lung-parenchyma. In fine, cancer and tubercle possess a different import in the most various organs according as the one or the other is primitive or secondary. Thus, cancer of the liver is not rarely a primitive, tuberculosis of this organ almost invariably a secondary affection, if not a mere participation of general tuberculosis.