194 THE SECRETIONS: 



even in a more marked degree, with decolorized bile, and with 

 pure bilin. 



Another test has been recently proposed by Schwertfeger. 

 He recommends that the urine should be treated with basic 

 acetate of lead. When bile is present the precipitate is yellow. 

 On treating this precipitate with alcohol containing some sul- 

 phuric acid, we obtain a green solution, to which (as has been 

 suggested by Dr. Griffith) Pettinkofer's test may be applied with 

 advantage.] 



For the purpose of forming a quantitative analysis of the 

 bilin in the urine, we must evaporate a weighed portion, pre- 

 cipitate the water-extract and the salts insoluble in alcohol 

 with spirit of 0-85, evaporate the spirituous solution, and extract 

 the residue with anhydrous alcohol. The alcohol of this last 

 solution is expelled, the residue dissolved in a little water, and 

 some hydrochloric acid added ; it is then allowed to digest till 

 the resinous matter of the bile has separated itself, which must 

 be washed, dried, and weighed. The presence of bile offers no 

 impediment to the determination of the urea, for which purpose, 

 however, a different portion of urine must be used. 



When icteric urine contains a sediment, it is usually of a 

 yellow or brown colour, and in addition to the ordinary con- 

 stituents of urinary deposits, it contains biliphsein. The sedi- 

 ment, in these cases, must be separated, and extracted with 

 alcohol. This alcoholic solution must be united with the spi- 

 rituous solution of the residue of the urine, from which the bilin 

 was determined. The sediment must be analysed according to 

 the rules already laid down for the separation of uric acid, the 

 urates, and earthy phosphates. 



8. Sugar. 



In diabetes mellitus the urine frequently contains a large 

 quantity of grape or diabetic sugar, while the urea is at the same 

 time either absolutely or relatively diminished. When the quan- 

 tity of sugar is considerable its presence can be detected without 

 difficulty. The urine must be evaporated, and the syrupy residue 

 treated with alcohol of 0-83. The alcoholic solution must 

 then be evaporated till a yellow and very sweet syrup is left. 

 Trommer, of Berlin, has discovered that the smallest quantity 



