HANDBOOK FOR BIO-CHEMICAL LABORATORY. 69 



deep red coloration will be the result. Creatinin gives this 

 same reaction even in the cold, also acetone, though faintly. 



BRUCKE'S Reagent (Proteids). Saturate a boiling 10 per 

 cent solution of potassium iodide with freshly precipitated 

 mercuric iodide; on cooling this is filtered, and the filtrate 

 employed with hydrochloric acid as a precipitant for the pro- 

 teids. 



CAPRAXICA'S Reactions (Guaniri). 1. A warm solution of 

 guanin hydrochloride with a cold saturated solution of picric 

 acid gives a yellow precipitate, consisting of silky needles. 



2. With a concentrated solution of potassium chromate 

 guanin solutions give an orange-red crystalline precipitate, 

 very insoluble in water. 



3. On the addition of a concentrated solution of potassium 

 ferricyanide to a guanin solution a prismatic, yellowish-brown 

 precipitate is formed. 



CAPRANICA'S Reaction (Bile Pigments). Shake the solution 

 with chloroform containing some bromine ; it becomes first 

 green, indigo blue, violet, yellowish red, and lastly colorless. 

 If the green or blue solution is shaken with HC1, the color is 

 taken up by the acid. 



CELLULOSE. See Sclmlze, Schweitzer. 



CHAUTARD'S Test (Acetone). Pass sulphurous acid through 

 a solution of 0.25 grms. fuchsin in 500 c.c. water until the 

 solution is yellow in color. Add to a portion of this the liquid 

 to be tested for acetone. If present, the liquid will be colored 

 violet. 



CHOLESTERIN. See Liebermann, and Burchard, Obermul- 

 ler, Salkowski, Scliiff, Scliidze, Zwenger. 



