70 HANDBOOK FOR BIO-CHEMICAL LABORATORY. 



Cholesterin. 1. The crystal is treated with a mixture of 5 

 parts sulphuric acid and 1 part water, when colored rings are 

 produced, first a bright carmine red and then violet. 



2. On the addition of a little iodine solution to the above 

 the crystals will be colored variously blue, red, green, violet. 



3. If a trace of cholesterin is gradually heated to dryness 

 with a few drops of nitric acid, a yellow spot is produced, 

 which turns red on the addition of ammonia. This red 

 color is not changed by the addition of caustic soda, thus dif- 

 fering from the murexid test for uric acid. 



CIAMICIAN and MAGNANINI'S Test (Skatol). On warming 

 skatol with sulphuric acid a beautiful purple-red coloration is 

 produced. 



COHEN'S Test (Albumin). Add a solution of potassium 

 iodide and potassium bismuthic iodide to the acid solution of 

 albumin. Precipitation of the albumin occurs. Alkaloids 

 are also precipitated. 



CREATININ. See Jaffe, Kerner, v. MascJike, Salkowski, 

 Weyl. 



CRISMER'S Test (Glucose). A solution of 1 part safranine 

 in 1000 parts water is decolorized or yields a pale yellow color 

 when heated to boiling with an alkaline solution of glucose. 

 Safranine solution is not decolorized when heated in alkaline 

 solution with uric acid, creatin, or creatinin. 



CYSTEIN. See AndreascTi. 



CYSTIN. See Baumann and Goldmann, Liebig, Milller. 



DAVY'S Test (Phenol). Add 3-4 drops molybdic-sulphuric 

 acid (a solution of 1 part molybdic acid in 10 or more parts 

 cone, sulphuric acid) to 1-2 drops of the phenol solution. A 

 pale yellow or yellowish-brown coloration is the result, which 



