BILIARY SALTS. 263 



of these substances dates from the analysis of ox-bile by 

 Strecker. He obtained two peculiar acids, cholic and choleic 

 acid, which he found in the bile, in combination with soda. 1 

 In the subsequent researches of Lehmann, these acids are 

 called, respectively, glycocholic and taurocholic acid, and 

 the salts, glycocholate and taurocholate of soda. 2 



In human bile, the proportion of glycocholate of soda is 

 very small, the biliary matter existing almost entirely in the 

 form of the taurocholate. The taurocholate may be precipi- 

 tated from an alcoholic extract of bile by ether, in the form 

 of dark, resinous drops. These do not crystallize, and the 

 amount of glycocholate, which is precipitated in the same 

 way and soon assumes a crystalline form, is very slight. 

 Prof. Dalton, who has studied the biliary salts very closely, 

 at first was unable to obtain any crystalline matter from 

 human bile, but he has lately found it in minute quantity. 3 



Taurocholate of Soda (NaO,C M H 4i NO 14 S,). There is 

 some doubt whether the resinous drops obtained by the ad- 

 dition of an excess of ether to a strong alcoholic extract of 

 bile consist of a proximate principle in a perfectly pure 

 state. These drops are not crystallizable, and this has led 

 to the opinion, expressed by Robin and Yerdeil, that they 

 are impure. 4 In fact, even now, there is a certain amount 

 of obscurity with regard to the character of these peculiar 

 biliary salts. In ox-bile, the non-crystallizable and the 

 crystallizable salts exist together; but in human bile, the 



1 STRECKER, Untersuchung der Ochsgalle. Annalen der Chemie und Pharmacie, 

 Heidelberg, 1848, Bd. Ixv., S. 1, et seq. ; Beobacktungen iiber die Gratte ver- 

 schiedener Thiere, Idem, 1849, Bd. Ixx., S. 149, et seq. An analysis of these ob- 

 servations is given in the Journal de pharmacie et de chimie, Paris, 1848, tome 

 xiii., p. 215 ; 1849, tome xv., p. 153 ; and tome xvi., p. 450. 



2 LEHMANN, Physiological Chemistry, Philadelphia, 1855, vol. ii., p. 201, 

 ct seq. 



3 DALTON, Treatise on Human Physiology, Philadelphia, 1867, p. 167. 



4 ROBIN ET YERDEIL, Traite de chimie anatomique, Paris, 1853, tome ii., 

 p. 473. 



