In cases of chronic intoxication and such like diseases of metabolism, such as gout, and in cases of old age, perspiration induced by very hot baths, providing the circulatory system is in good condition, should be tried and given often if the results prove satisfactory, as we thus obtain the benefit of the bath and also of the perspiration. The sweat baths should not exceed 15 to 20 minutes in duration unless they are well borne, when a few more minutes may be added. In old people cold douches should not be resorted to, but directly after the bath they should be put to bed, which should have been previously warmed by hot-water bottles. In persons where the processes of oxidation are diminished and the skin very inactive, as is the case with many aged people, such baths give very excellent results. Sweating improves the functions of the kidneys in a much greater degree than those of the skin. By insensible perspiration water is eliminated, together with certain harmful solid products which otherwise would make their way through the kidneys; this occurs much more so when the perspiration is greatly increased by sweating processes. In such cases about a liter of water can pass through the skin daily, and in addition a considerable part of the nitrogenous end-products of metabolism and of common salt. It has been discovered by Professor Hermann Strauss[238] that in a liter of sweat, under favorable circumstances, fully six grammes of common salt can be removed from the body. Leube once found 2.31 grammes of chlorides in 800 grammes of sweat. Footnote 238: Deutsche Med. Wochenschrift, p. 34, 1904. Of nitrogenous bodies, according to Strauss, about 2 grammes can be removed through the skin daily, and according to Professor von Noorden[239] only 1 gramme. Leube discovered, about thirty years ago, that the amount of nitrogen in the urine was 2 grammes less on such days as sweating processes had been used than was usual on other occasions. Kovesi and Roth-Schulz found 29 grammes of nitrogen and 29 grammes of common salt in the sweat of patients suffering from Bright’s disease. Strasser and Blumenkranz found, after electric light baths, a considerable increase in the elimination of common salt up to 18 grammes, 4 grammes more than had been ingested. Nitrogenous bodies have also been eliminated in larger quantities than have been introduced, as has also more water. This has been proved in experiments on the effects of bathing, in which people with diseased kidneys have been used as the subjects. In these cases the elimination of common salt and nitrogenous products is certainly greater than in normal individuals. Still there can be no doubt that with such, by perspiration and bathing, an increased elimination of these products can be obtained. Footnote 239: v. Noorden: Pathologie des Stoffwechsel, vol. i, 1906.