A profuse, very acid, sour-smelling perspiration is one of the striking symptoms occurring in the course of acute articular rheumatism, and {31} until very lately it has been generally held to indicate an excessive formation in, and elimination of acid from, the system, either lactic acid or some of the acids normal to the perspiration, as acetic, butyric, and formic. However, not only have chemists failed to detect lactic acid in the perspiration of acute rheumatism, but late research tends to show that the excessive acidity of the perspiration in this disease is but very partially due to the perspiration itself, and is chiefly owing to chemical changes taking place in the overheated and macerated surface of the skin and its epidermis, and to the retention of solid products accumulated on that surface. Besnier says that if in acute articular rheumatism or other disease attended with much perspiration the surface be kept well washed, the sweat will be found in the greater number of cases at the moment of its secretion to be nearly neutral as soon as actual diaphoresis occurs, more decidedly acid when the perspiration is less abundant or begins to flow, and exceptionally alkaline. Most physicians are aware that the profuse perspiration of acute rheumatism is non-alleviating; it is not a real critical discharge of noxious materials from the system, nor is it followed by prompt reduction of the temperature and other symptoms. It is but a symptom of the disease, and occurs especially in severe cases, and when it continues long after the reduction of the temperature it is a source of exhaustion, and may be checked with advantage. The blood is deficient in red globules, Malassez finding in men from 2,850,000 to 3,700,000 per cubic millimeter instead of 4,500,000 to 5,000,000, and in women 2,300,000 to 2,570,000 instead of 3,500,000 to 4,000,000. The hæmoglobin and the oxidizing power of the blood are also considerably reduced; the fibrin is largely increased (6 to 10 parts in 1000 instead of 3); the albumen and albuminates are lessened, the extractives increased; the proportion of urea is normal, and no excess of uric acid is found in the blood. Instead of that fluid being less alkaline than normal, Lepine and Conard have recently stated that its alkalinity is increased in acute rheumatism, but constantly diminished in chronic rheumatism,[43] and no excess of lactic acid has been proved to exist in the blood in either acute or chronic rheumatism. A condition of excessive coagulability of the fibrin, independently of its excessive amount (inopexia), is an habitual character of acute rheumatism; however, in very bad cases, especially those attended with hyperpyrexia and grave cerebral symptoms, the blood after death has been black and coagulated and the fluid in the serous cavities has given an acid reaction. The above alterations in the blood usually are proportionate to the intensity of the fever and the number of the joints and viscera involved.