492 



PHYSIOLOGY 



CHAP. 



istic odour of sweat are made up of formic, acetic, butyric, 

 propionic, and capronic acid. Ethereal sulphates of phenol and 

 scatole are also present, but only in small amounts (Kast). The 

 perspiration from the armpit sometimes stains the underclothing 

 blue, from the indican present in the sweat. It is, however, 

 doubtful whether this indican comes from indoxyl secreted in the 

 sweat, or from indoxyl developed by chromogenic bacteria. 



Lastly, human sweat nearly always contains a small amount 

 of protein (0*045 per cent, which is a normal constituent in the 

 sweat of horses, and causes the characteristic foam of their 

 perspiration), as well as two enzymes, one diastatic or saccharify- 

 ing, the other tryptic or proteoclastic. 



Eeference should be made, in reviewing the more recent 

 work on the chemical constitution of the sweat, to the researches 

 of W. Carnerer, jun. (1901), who collected the perspiration from 

 healthy subjects in light-, hot-air, or vapour-baths, and analysed it 

 accurately with the following results : 



TABLE I. 



TABLE II. 



