pressure is variable and any favorable results secured in cardiac cases are 

 independent of the effect on blood pressure. 



Peat and mud baths have a point of thermal indifference considerably 

 above that of water, as high as 39 C. ; in the absence of convection cur- 

 rents and because of the non-conducting layer next the skin the effects of 

 heat are equalized and the skin temperature remains more constant. Pos- 

 sibly the chemical action of the acids and salts found in peat and mud 

 and the physical effects of friction and pressure may affect metabolism ; 

 but there are no entirely trustworthy data as to the effects of such baths 

 and such as are at hand (Tuszkai; Silber) do not show results that are 

 not attributable to temperature effects on metabolism. Sulphur baths 

 seem to have no specific influence on metabolism (Bain, Edgecombe and 

 Frankling; Winternitz and Popischil). 



Radioactive baths and springs have given the opportunity for the 

 publication of a number of papers dealing with the supposed benefits at- 

 tending their extensive use. Radium emanation does not enter the body 

 by the skin (Nagelschmidt and Kohlrausch) and when it was added to a 

 fresh water bath no influence on gaseous metabolism was observed (Silber- 

 gleit(aO). 



Baths and Sweat Secretion 



The influence of baths on the rate of secretion and on the composi- 

 tion of the sweat is of special interest because of a possible vicarious skin 

 excretion under the influence of heat treatment, especially in diseases of 

 the kidney. The data on the composition of human sweat are fragmentary 

 and conflicting partly because of the wide variety of conditions under 

 which sweat has been collected, because the composition changes with 

 changing rate of secretion (Kittsteiner(a) (&)), varies with the different 

 parts of the body from which it comes, and may vary with the diet (Kitt- 

 steiner(c) ; Berry). It is thus not possible to tabulate the results that 

 have been obtained ( Argutinsky ; Benedict (a) ; Schwenkenbecher and 

 Spitta ; Taylor(d), Talbert(a)). The values for nitrogen elimination 

 under different conditions vary from 0.07 to 0.75 gr. per day (or part 

 of a day), half of which is in the form of urea (Plaggemeyer and Mar- 

 shall). Salt excretion is said to vary from 0.33 gr. to 1 gram in profuse 

 perspiration. Whether nephritics eliminate more solids in the sweat than 

 normal persons seems undecided (Kohler; Tachau ; Riggs; Loofs; Strauss 

 (a) ) and figures on the A of the blood in nephritis as influenced by sweat- 

 ing procedures (Bendix; Georgopulos) are not extensive enough 1o be 

 convincing. Even if perspiration leads to a decrease in the urea of the 

 urine, which it does not, always (Leube; Dapper (a ); v. Noorden(c)) 

 the amounts of nitrogenous material and salts which can be eliminated 

 by the skin are a very small fraction of those eliminated by the kidney, 



