BUTYRIC ACID. 61 



carbonaceous acids, do not occur in the sweat with or in place of 

 butyric acid. In examining the watery extract of a night-dress 

 steeped in perspiration, taken from a woman a few days after 

 delivery, I found, on saponification, a rancid-smelling, volatile 

 acid. 



In the milk, in addition to other fats, as olein and margarin, 

 there occurs a fat which has never yet been isolated in a state 

 of purity, and which, on saponification, yields butyric acid, 

 together with other acids of this group, namely, caproic, ca- 

 prylic, and capric acids. The best investigations in reference 

 to this substance were made, first by Chevreul*, in his classical 

 work on the fats ; subsequently by Bromeisf ; and lastly by 

 LerchJ> under the direction of Redtenbacher. Even in butter 

 there is only a little of this substance, which yields butyric acid. 

 From 100 parts of tolerably pure butyrin, Chevreul only obtained 

 7 parts of volatile acids; Simon || and Herbergerlf were able to 

 obtain only very minute quantities of volatile acids from the fat of 

 woman's milk. 



That there are fats in the blood which, on saponification, yield 

 volatile acids, may be demonstrated by any one who operates with 

 care on large quantities of the fatty matter collected from this fluid. 

 From the blood taken from a woman within the first few days after 

 her delivery, I obtained, by distillation with dilute sulphuric acid, 

 volatile acids whose general properties coincided with those of this 

 group. 



[Free butyric acid has likewise been detected in the/tf?s by 

 Ragsky and Percy.** G. E. D.] 



Origin. After what has been stated regarding the different ways 

 in which butyric acid may be formed, we need not wonder that it 

 is sometimes met with in the primes vice ; since it may, and indeed 

 must principally be formed from the non-nitrogenous constituents of 

 the food. The belief that farinaceous and saccharine foods are 

 converted into butyric acid in the primce vice, and that they thus 

 constitute the first step in the formation of fat, is based on a fiction 

 regarding the possible formation of fat in general, which is at pre- 

 sent devoid of any scientific proof. No one has as yet succeeded 

 in ascertaining the presence of butyric acid, either in the prima 



Recherches sur les corps gras. 



t Ann. d. Ch. u. Pharm. Bd. 42, S. 46 ff. 



t Ibid. Bd. 49 f S. 212 ff. 



Recherches sur les corps gras, p. 193. 



II Frauenmilch, S. 41. 



f Brande's Arch. Bd. 20, S. 3. 



** Chemical Gazette. Vol 8, p. 104. 



