There is some basis for the opinion that residence in damp, cold dwellings predisposes somewhat to acute articular rheumatism, although not at all to the same degree that it does to the chronic articular and muscular forms. Chomel and Jaccoud especially have insisted that it will gradually create a predisposition to the disease, even if it has not been inherited. All pathologists agree that cold is the most frequent exciting cause of acute articular rheumatism, and that it is especially effective when applied while the body is perspiring freely or is overheated or fatigued by exercise. There is no necessary ratio between the degree of cold or its duration and the severity of the resulting rheumatism. A slight chilling or a momentary exposure to a current of cold air will in some act as powerfully and as certainly as a prolonged immersion in cold water or a night spent sleeping on the damp grass. This circumstance, together with the fact that cold applied in the same way may also produce a pharyngitis or a bronchitis, a pneumonia or a nephritis, etc., is held to indicate that the cold acts according to individual predisposition; and Jaccoud, Flint, and others maintain that unless a rheumatic proclivity exists cold will not produce an attack of the disease under consideration. I doubt that we are yet in a position to assert that absolutely, although the weight of argument is in its favor. Let it suffice to say, that while a prolonged residence in a cold, damp dwelling may gradually develop a predisposition to rheumatism, a short exposure to cold will be likely to induce an attack of rheumatism if the predisposition exist. There are other influences which may be regarded as auxiliaries to cold in exciting an attack, as they seem to increase the susceptibility of the patient to its operation: they establish what has been felicitously called a state of morbid opportunity. Such are all influences that reduce the resisting powers of the organs and organism, as bodily fatigue, mental exhaustion, the depressing passions, excessive venery, prolonged lactation, losses of blood, etc. It is probably in such a manner that local injuries (traumatism) sometimes appear to induce an attack of rheumatism. A blow on a finger (Cotain), the extraction of a tooth (Homolle), a hypodermic injection (ibid.), etc., may act powerfully in some persons upon and through the nervous system, and by lessening their resisting power {23} may favor the overt manifestation of the rheumatic predisposition. But doubtless some such cases have been examples of mere coincidence.