HANDBOOK FOR BIO-CHEMICAL LABORATORY. 93 



precipitate produced by the ammonia will be gradually col- 

 ored pink. This coloration diminishes on standing. 



SALKOWSKI'S Keaction (Cholesteriii). Dissolve the sub- 

 stance in chloroform and then treat with an equal volume of 

 concentrated sulphuric acid. The cholesterin soiution be- 

 comes first bluish red, then gradually more violet red, while 

 the sulphuric acid appears dark red with a greenish fluores- 

 cence. If the chloroform solution is poured into a porcelain 

 dish, it becomes violet, then green, and finally yellow. 



SALKOWSKI'S Modification of HOPPE SEYLER'S Test (CO 

 in Blood). Dilute the blood to be tested with 20 vols. water 

 and add thereto an equal volume of a caustic soda solution 

 of sp. gr. 1.34. If the blood contains carbon monoxide, the 

 mixture will become milky in a few moments and then 

 bright red. On standing red flakes form, which collect on 

 the surface of the liquid. Normal blood treated in this way 

 gives a dirty brown coloration. 



SALKOWSKI'S Reaction (Creatinin). If a few drops of a 

 freshly prepared very dilute solution of sodium nitro-prusside 

 are added to a dilute creatinin solution and then a few drops 

 of caustic soda, a ruby-red liquid is obtained which quickly 

 turns yellow (Weyl's reaction). If this yellow solution is 

 treated with an excess of acetic acid and heated, the solution 

 becomes first green and then blue, and finally a precipitate of 

 Prussian blue is obtained. 



SALKOWSKI'S Test (LidoI).^-AM a few drops nitric acid to 

 the indol solution and then, drop by drop, a 2$ solution of po- 

 tassium nitrite. In the presence of indol a red color is pro- 

 duced, and lastly a red precipitate of nitroso-indol nitrate. 



SCHERER'S Test (Inosit}. Evaporate the substance to dry- 

 ness on a platinum foil with nitric acid and treat the residue 



