HANDBOOK FOR BIO-CSEMICAL LABORATORY. 59 



a dry filter into a distilling flask and the chloroform distilled 

 off. The residue in the flask is washed with ether, which 

 only dissolves very little of the urobilin. This residue is 

 again dissolved in chloroform, filtered, and allowed to evapo- 

 rate at a very moderate temperature. (Melm.) 



2. Precipitate the urine with basic lead acetate, wash the 

 precipitate with water, dry at the ordinary temperature, and 

 then boil it with alcohol, acidified with sulphuric acid. The 

 filtered alcoholic solution is diluted with water, now satu- 

 rated with ammonia, and then treated with a zinc-chloride 

 solution. This new precipitate is washed free from chlorine 

 with water, boiled with alcohol, dried, dissolved in ammonia, 

 and this solution precipitated with sugar of lead. This pre- 

 cipitate, which is washed with water and boiled with alcohol, is 

 decomposed by alcohol containing sulphuric acid; the filtered 

 alcoholic solution is mixed with -J vol. chloroform, diluted 

 with water and shaken repeatedly, but not too energetically. 

 The urobilin is taken up by the chloroform. This last is washed 

 once or twice with a little water and then filtered, leaving the 

 urobilin on evaporation of the chloroform. It may be further 

 purified by treating with ether. 



3. The urine is treated with ammonia in not too great ex- 

 cess, filtered, and the filtrate precipitated with a concentrated 

 watery or alcoholic solution of zinc chloride. If the filtrate 

 from this precipitate is still deeply colored, precipitate 

 by adding more ammonia and filtering. The voluminous, 

 generally red or reddish-brown precipitate is washed free 

 from chlorine by first using cold and then hot water, now 

 boiling with alcohol, and drying at a low temperature. The 

 mass is powdered and dissolved in ammonia, leaving a small 

 residue, and this ammoniacal solution is precipitated with 

 sugar of lead, and the red precipitate filtered off and washed 

 with water until the coloring matter commences to go into 

 solution. The precipitate is now digested with alcohol acidi- 

 fied with sulphuric acid, filtered, and the filtrate repeatedly 



