The miasmatic theory, so ably advocated by Maclagan,[24] assumes that rheumatism is due to the entrance into the system from without of a miasm closely allied to, but quite distinct from, malaria. His argument on this topic is ingenious and elaborate, yet has not been favorably received by pathologists. Opposed to it are the following amongst other considerations: Heredity exercises a marked influence upon the occurrence of rheumatism; unlike malarial disease, no climate or locality is immune from rheumatism; the many indications that a diathesis plays a chief rôle in rheumatism; the remarkable influence exerted by cold and dampness in the etiology of the disease. [Footnote 24: _Rheumatism: its Nature, Path., etc._, London, 1881, pp. 60-95.] Heuter's[25] infective-germ theory, like the miasmatic, refers rheumatism to a principle not generated in the system, but introduced from without. A micrococcus enters the dilated orifices of the sweat-glands, and, reaching the blood, first sets up an endocarditis, and then capillary emboli produce the articular inflammations. This is a reversal of what really happens, so far as the time of invasion of the endocardium and the synovial membranes is concerned; and Fleischauer's case, in which miliary abscesses were found in the heart, lungs, and kidneys, was probably one of ulcerative endocarditis, which, after all, is a rare complication of acute articular rheumatism. Moreover, it is a gratuitous assertion to say that endocarditis exists in all cases of the disease. If, however, Heuter were content to say that acute articular rheumatism was produced by a specific germ, as held by Recklinghausen and Klebs, which on entering the system acted specially upon the joints and the fibro-serous tissues, as the poison of small-pox does upon the skin, while at the same time it sets up general disturbances of the entire economy as other zymotic poisons do, there would be nothing opposed to general pathological laws. Even the existence of a diathesis capable of favoring the action of the specific germ would be analogous to the tuberculous diathesis, which favors the action of the bacillus of tubercle; and cold, its ordinary exciting cause, might be regarded simply as a condition which renders the system more susceptible to the action of the germ, and the modus operandi of cold in doing this might be variously explained. [Footnote 25: _Klinik der Gelenkkrankheiten_, Leipzig, 1871.]