VII. BILIARY COMPOUNDS,* 



1. Glycocholic acid, C 26 H 43 N0 6 . Fresh ox-bile is 

 evaporated to dry ness over a water-bath, the residue 

 exhausted with absolute alcohol, the alcohol separated 

 from the filtered solution by evaporation or distillation, 

 and the residue, which, if necessary, is diluted with 

 water, mixed with milk of lime, and gently warmed, 

 the greater part of the pigment present being by this 

 means thrown down in combination with lime. The 

 mixture is filtered and to the cold filtrate dilute sul- 

 phuric acid is added until turbidness remains (an ex- 

 cess to be avoided). In a few hours the whole liquid 

 has become a pulpy mass, consisting of crystals of gly- 

 cocholic acid, which is purified by pressing, dissolving 

 in a great deal of lime-water, and reprecipitating with 

 sulphuric acid. Or the bile, evaporated to dryness, is 

 extracted when cold with absolute alcohol, the solu- 

 tion decolorized by digesting with animal charcoal, 

 filtered and treated with a little ether; hereupon, after 

 standing for several hours, a plastery, colored mass is 

 deposited ; from this the liquid is poured off, and 

 again treated with fresh ether. After a long time a 

 mixture of sodium glycocholate and taurocholate (crys- 

 tallized bile) is deposited in fine, colorless needles, 

 which, after the liquid is poured off, is washed with a 

 little ether, and then dissolved in water. This solu- 

 tion is mixed with dilute sulphuric acid until it is 

 decidedly milky, and then allowed to stand. In 

 twenty-four hours the liquid has become filled with 



* On the occurrence of these substances in the bile, see the section 

 Animal Chemistry, Bile. 



