Some months since I had an opportunity of repeating this experiment upon a human being. In acute inflammatory rheumatism it sometimes happens that the swelling and pain of the joints suddenly disappear, and the patient becomes comatose or wildly delirious. It has been customary to explain these symptoms as the result of the rheumatism leaving the joints and attacking the brain. Evidently, this being the case, the proper thing to do was to irritate the joints so as to draw the rheumatism back to them. This method was formerly practiced, and the almost invariable result was death in a few hours. In most if not all of these frightful cases of sudden accession of severe nervous symptoms in rheumatism the temperature will be found, on testing it, to be exceedingly high--108°, 109° or even 110° Fahrenheit. If the views advocated in this paper be correct, it is not the rheumatism, but the intense bodily heat, which causes the severe symptoms, and finally death. The joints lose their sensitiveness, not because the disease has left them, but because the heat so overpowers the brain that it has lost its power of perception: the patient's leg might be cut off without his feeling it. In such a case the proper treatment is to take away the heat by plunging the patient into a cold bath. But can there be anything more shocking to the universal belief and prejudices than to put a patient dying of acute rheumatism into an almost ice-cold bath? Last spring there was in my ward in the Philadelphia Hospital a stout young Irishman who had passed through an acute attack of inflammatory rheumatism, and was suffering from a sharp relapse. Entering the ward one day, I saw at once that the man was unconscious, and turning to the resident physician asked, "What is the matter with James?" "Nothing," was the reply: "I saw him an hour and a half ago, and he was doing very well, except that the fever was very high." "He is dying now, at any rate," was my rejoinder. On going to the bedside the patient was found perfectly unconscious, the skin dry and intensely hot, the affected joints pale and devoid of sensibility, the breathing irregular and jerking, the pulse 170 and scarcely perceptible, every muscle relaxed as in death, every power of perception abolished. A thermometer placed in the armpit registered 108-4/5° Fahrenheit.