SWEAT. 105 



case detect the presence of sulphates in fresh sweat, although 

 I always found them in the incinerated residue ; from this cir- 

 cumstance I am led to infer that some of the constituents of 

 sweat contain sulphur. 



In 100 parts of the solid residue of sweat Anselmino found : 



Substances insoluble in water and alcohol, chiefly salts of lime . 2-0 



Water-extract and sulphates . . . .21-0 



Spirit-extract, with chlorides of sodium and potassium . 48-0 



Alcohol-extract, acetic acid, and acetates (lactates) . . 29*0 



These figures must be regarded merely as approximative. In 

 1000 parts of sweat there are contained, according to Anselmino : 



Water .... 995-000 987-500 



Epidermis and salts of lime . . -100 -250 



Water-extract and sulphates . . 1-050 2-625 



Spirit-extract, chlorides of sodium and potassium 2-400 6-000 

 Alcohol-extract, acetates, lactates, and free acetic 



acid . . . 1-450 3*625 



From 100 parts of dried residue of sweat Anselmino obtained 

 22'9 of fixed salts, consisting of carbonates, sulphates, and phos- 

 phates of soda and (in small quantity) of potash, chloride of 

 sodium, phosphate and carbonate of lime, and traces of per- 

 oxide of iron. 



The peculiar odour of sweat from different parts of the body 

 is dependent in a great measure on the secretion of the seba- 

 ceous glands in those parts : thus it is well known that the sweat 

 from the feet of many persons has a very penetrating odour, 

 that the sweat from the axilla gives off a peculiar ammoniacal 

 smell, and that the sweat of the external organs of generation 

 contains and smells faintly of butyric acid. 



The gases which are given off by the skin are, according to 

 Collard de Martigny, 1 carbonic acid and nitrogen ; they are not 

 exhaled in constant, but in varying proportions, and generally 

 in the greatest quantity after meals and after violent exertion. 

 Collard has observed that an excess of carbonic acid is exhaled 

 after the use of vegetable food, and an excess of nitrogen after 

 a nitrogenous diet. Since these gases are contained in a state 



1 Magendie's Journal, vol. 10, p. 162. 



