BILIAKY SALTS. 265 



cholate in solution. The glycocholate of lead is then sepa- 

 rated by filtration, and the subacetate of lead is added to the 

 filtered fluid. This decomposes the taurocholate, and the 

 taurocholate of lead is precipitated. The subacetate of lead 

 will decompose both the glycocholate and the taurocholate, 

 but the glycocholate only is acted upon by the acetate of 

 lead. The glycocholate and the taurocholate of lead are 

 then carefully washed and treated separately with the car- 

 bonate of soda, which gives the original salts in nearly a 

 pure state. 



The taurocholate of soda is a proximate principle of 

 the bile, and it is not necessary to describe fully in detail 

 the purely chemical processes by which it is decomposed. 

 With a little care, the taurocholic acid may be obtained in a 

 state of tolerable purity, and by prolonged boiling with pot- 

 ash, may be decomposed into a new acid and taurine. Some 

 confusion exists in the books about the name of this new 

 acid. Strecker calls it cholalic acid, and applies the name 

 of cholic acid to what we have described as glycocholic acid. 

 As we have adopted the nomenclature of Lehmann, we will 

 call it cholic acid. Its formula is C 48 H 89 O 9 HO. The for- 

 mula for taurine is C 4 H 7 NO 8 S 2 . It must be remembered, 

 however, that these substances are formed artificially and are 

 not true proximate principles. They have been described in 

 explanation of the name taurocholic acid, which has been 

 applied to it on the assumption that the different biliary 

 acids are formed of cholic acid united with taurine or other 

 basic substances. 



If human bile be treated in the manner just described, 

 frequently no crystalline matter is obtained, and when it 

 exists, it is in very small quantity. The great mass of the 

 precipitate is composed of the taurocholate of soda. This, 

 when it has been thoroughly purified, is whitish and gummy, 

 very soluble in water and alcohol, and insoluble in ether. 

 It is melted with slight heat, and is inflammable. Its reac- 

 tion is neutral. It has a peculiar, sweetish-bitter taste. The 



