THE LIVER. 151 



the liquid is sufficiently concentrated. The combination of gly- 

 cocoll with HC1 is soluble in water and alcohol. 



Glycocoll is best prepared from hippuric acid by coiling it 10- 

 12 hours with 4 parts of dilute sulphuric acid, 1 : 6. After cooling 

 separate the beuzoic acid, concentrate the filtrate, remove the re- 

 mainder of the benzoic acid by shaking with ether, remove the sul- 

 phuric acid by BaC0 3 , and evaporate the filtrate to crystallization. 



Taurin, C 2 H 7 NS0 3 , or amido-ethylsulphonic acid, NH 2 .C 2 1I 4 . 

 SO a OH. This body is well known as a splitting product of 

 taurocholic acid, and may occur in small quantities 'in the contents 

 of the intestines. It has also been found in the lungs and kidneys 

 of oxen and in the blood and muscles of cold-blooded animals. 



Taurin crystallizes in colorless, often in large, shining, 4-6 sided 

 prisms. It dissolves in 15-16 parts of water at ordinary tempera- 

 tures, but rather more easily in warm water. It is insoluble in abso- 

 lute alcohol and ether; in cold spirits of wine it dissolves slightly, 

 but more when warm. Taurin yields acetic and sulphurous 

 acids, but no alkali sulphides, on boiling with strong caustic alkali. 

 The amount of sulphur can be determined as sulphuric acid after 

 fusing with saltpetre and soda. Taurin combines with metallic ox- 

 ides. The combination with mercuric oxide is white, insoluble, 

 and is formed when a solution of taurin is boiled with freshly-pre- 

 cipitated mercuric oxide (J. LANG). This combination may be 

 used in detecting the presence of taurin. Tauriu is not precipi- 

 tated by metallic salts. 



The preparation of taurin from bile is very simple. The bile is 

 boiled a few hours with hydrochloric acid. The filtrate from the 

 dyslysin and choloidic acid is concentrated well in the water-bath, 

 and filtered so as to remove the common salt and other substances 

 which have separated. Then evaporate to dryness, and treat the 

 residue with strong alcohol, which dissolves the hydrochlorate of 

 glycocoll, while the taurin remains. (The alcoholic solution of 

 hydrochlorate of glycocoll may be used in the preparation of gly- 

 cocoli by evaporating the alcohol and dissolving the residue m 

 water, decomposing the solution with lead hydroxide, filtering,, 

 and freeing the solution from lead by H,S, and strongly concen- 

 trating this filtrate. The crystals which separate are dissolved and 

 decolorized by animal charcoal, and the solution evaporated to crys- 

 tallization.) The above-obtained residue containing the taurin is 

 dissolved in as little water as possible, filtered warm, and treated 



