26 HANDBOOK FOR BIO-CHEMICAL LABORATORY. 



of cholalic acid as well as those of choleic and stearic acids. 

 Now dilute with water until it does not contain more than 

 20$ alcohol, and add a dilute solution of barium chloride as 

 long as a precipitate occurs. Filter, and add to the nitrate, 

 which should yield no further precipitate with Ba01 2 , hydro- 

 chloric acid. Allow the precipitate of cholalic acid to stand 

 with the liquid and it will be found to become crystalline; 

 purify by recrystallization from ethyl alcohol and then from 

 methyl alcohol. (Mylius.) 



Properties. Cholalic acid crystallizes with 1 molecule of 

 water in rhombic plates or prisms, or in larger rhombic tetra- 

 hedra or octahedra with 1 mol. alcohol of crystallization. 

 They are quite insoluble in water (4000 parts cold and 750 

 parts boiling), rather soluble in alcohol, but soluble with 

 difficulty in ether. It is somewhat soluble in glycerin and 

 almond-oil. Its solutions have a bitter-sweetish taste. The 

 water-free acid melts at 195 C. In the free state, as well as 

 in combination the acid is dextro-rotatory. The specific 

 rotatory power of the sodium salt is (a) D = +31.4. The 

 watery solution of the alkali-salts, when not too dilute, is 

 precipitated immediately or after some time by sugar of lead 

 or by barium chloride. The barium salt, (C 24 H 39 6 ) 2 Ba, 

 crystallizes in fine, silky needles, which are soluble in 30 parts 

 cold and 23 parts boiling water, but more soluble in alcohol. 



Grlycocoll or Glycocine, C 2 H 5 NO,. 



Preparation. 1 part hippuric acid is boiled from 10 to 12 

 hours, in a flask connected with a return condenser, with 4 

 parts dilute sulphuric acid (1 to 6). After allowing to cool 

 pour the contents of the flask into a porcelain dish and allow 

 to stand for 24 hours. Filter off the benzoic acid and wash 

 with cold water; concentrate the filtrate by evaporation, and 

 shake with ether to remove any traces of benzoic acid. 

 Dilute this acid solution and just neutralize with barium 



