CHAP. IV.] GLYCOCINE. TAURINE. 311 



Glycocine possesses a sweet taste ; it is soluble in 4*3 parts of 

 water, very slightly soluble in spirits of wine and insoluble in cold 

 absolute alcohol and ether : it 'is very sparingly soluble in boiling 

 alcohol. Its solutions possess an acid reaction. When heated to 

 232 236 C. glycocine becomes brown, evolves gas bubbles and melts. 

 A solution of glycocine is coloured red by ferric chloride. 



Compounds Glycocine forms compounds with acids, with bases, 



of glycocine. 



1. When a solution of glycocine is treated with an excess of 

 of HC1 and evaporated on the water bath, it yields crystals of the 

 hydrochlorate having the composition CH 2 NH 2 COOH, HC1, which 

 are readily soluble in water and in alcohol. 



2. Boiling solutions of glycocine dissolve freshly precipitated 

 cupric hydrate, and deposit on cooling dark blue needles, which 

 are insoluble in alcohol, and soluble with difficulty in cold water, 

 and which have the composition represented by the formula 

 <CH 2 (NH 2 )COO) 2 Cu + H 2 O. Similarly, by substituting silver oxide 

 for cupric hydrate, there is formed the compound having the com- 

 position CH 2 (NH 2 )COOAg. 



3. Glycocine forms crystalline compounds with chlorides, nitrates 

 and sulphates. The following are examples : CH 2 (NH 2 )COOH, 

 AgNO 3 : 2 (GH 2 (NH 2 )COOH), BaCl 2 . 



Methods of Having separated glycocine, it is recognised by its 

 lentification. cr y s t a lline form, its great solubility in water, its 

 insolubility in alcohol and ether, and the solubility of its crystalline 

 hydrochlorate in alcohol. Further, if the quantity of the body be 

 sufficient, its taste, the reaction which it exhibits with ferric chloride, 

 the formation of its Cu compound, and its decomposition by nitrous 

 acid, with evolution of N (see general reactions of amido-acids, p. 231) 

 will furnish confirmatory evidence. 



Taurine, C 2 H 7 NSO 3 

 (p-Amido-ethyl-sulphonic acid, H 2 N.CH 2 .CH 2 .S0 2 .OH). 



Occurrence Since taurine was obtained as one of the primary 



products of the decomposition of taurocholic acid, under 

 the influence of acids and alkalies, it has been shewn, by Limpricht 

 and by Jacobsen, to occur in minute quantities in the muscles of the 

 horse and, by Valenciennes and Fremy, in the muscles of mollusca. 

 It is only, however, by decomposing bile rich in taurocholic acid 

 that it can be obtained in any quantity. 



Method of A little strong hydrochloric acid is added to ox-bile 



(reparation. &Q ag ^ Q p rec jpjtate its mucoid nucleo-albumin. After 



this has been separated by filtration, a little more strong hydrochloric 



acid is added and the liquid is then boiled for some hours in a large 



