THEIR CHEMICAL CONSTITUENTS. 381 



of butyrin or of butyric acid to be detected, although, as we shall 

 presently see, this acid is very frequently secreted by the sudori- 

 parous glands. 



Of lipoids I found in the smegma proeputii a little cholesterin, 

 besides a body soluble in ether and hot alcohol, and very similar to 

 cholesterin, but not crystallizable ; in the vernix caseosa I found 

 only this substance, and could not detect any cholesterin. 



No phosphorised fatty bodies were found either in the vernix 

 caseosa or in the preputial secretion. 



The alcoholic extract of these secretions consists for the most 

 part of the margarates and oleates of potash, soda, and ammonia; 

 here also no alkaline butyrates can be detected; the ammonia- 

 soaps preponderate considerably in the preputial secretion. 



In addition to the soaps, the alcohol-extract contains only a 

 little organic matter which does not admit of further determination, 

 unless a substance peculiar to a special secretion or some inci- 

 dental matter happen to be present, of which we shall speak further 

 presently. 



Berzelius* obtained from the cerumen a fat which was soft, 

 white, opaque, easily fusible, devoid of action on litmus, and when 

 treated with potash, yielded an extremely fetid soap, which, on the 

 addition of hydrochloric acid, deposited the fatty acids in the form 

 of a white powder ; these acids did not readily rise to the surface 

 of the solution, and fused at about 40. 



Vauquelin found that the fat of human hair was oleaginous 

 and coloured, and that it contained sulphur. 



The fatty sweat which adheres to undressed wool consists, accord- 

 ing to Vauquelin,f chiefly of a potash-soap ; while, on the other 

 hand, Chevreul,J who has more recently examined it, found non- 

 saponifiable fats containing neither sulphur nor nitrogen, one of 

 which fuses at 60, while the other is fluid at 15; to these two 

 fats he gave the respective names of stearerin and elaerin. 



I found that the alcohol-extract in the vernix caseosa amounted 

 to 15-0, in the human preputial smegma to 7' 4 , and in that of 

 the horse to 9*6. 



The resinous constituents of the castoreum soluble in alcohol 

 still require a more accurate investigation than they have yet 

 received. The amount of these matters in castoreum is extremely 



* Lehrb. d. Chem. Bd. 9, S. 536. 

 f Ann. de Chim. T. 47, p. 276. 

 J Compt. rend. 1840. No. 16. 



