94: HANDBOOK FOR BIO-CHEMICAL LABORATORY. 



with ammonia and a drop of calcium chloride solution and 

 carefully re-evaporate to dryness. With inosit a rose-red 

 residue is obtained. 



SCHERER'S Test (Leucin). Carefully evaporate the leucin 

 with nitric acid on a platinum foil. No markedly colored 

 residue is left, but on gently warming this with a few drops 

 of caustic soda solution a color varying from a pale yellow to 

 a brown (depending on the purity of the leucin) is produced, 

 and on further concentrating over the flame it agglomerates 

 into an oily drop which rolls about on the foil. 



SCHERER'S Test (Ty rosin). Evaporate the substance care- 

 fully to dryness with nitric acid on a platinum foil. A beau- 

 tiful yellow residue (nitro-tyrosin nitrate) is obtained, which 

 gives a deep reddish-yellow color with caustic soda. 



SCHIFF'S Test (Uric Acid). Dissolve the substance in 

 sodium carbonate and add silver nitrate solution, when a re- 

 duction of black silver oxide is obtained. If a drop of the 

 solution of the substance in sodium carbonate is placed on a 

 piece of filter-paper which has been previously treated with 

 silver nitrate solution, a reduction of black silver oxide will 

 also be formed on the paper. 



SCHIFF'S Test (Carbohydrate). Strips of paper are dipped 

 in a mixture of equal volumes of glacial acetic acid and 

 xylidin, treated with very little alcohol, and dried. On ex- 

 posing such paper to the furfurol vapors produced by treating 

 glucose with sulphuric acid the paper will be colored red. 



SCHIFF'S Reaction (Cholesterin). Evaporate the substance 

 in a porcelain dish over a small flame with a few drops of a 

 mixture of 2-3 vols. concentrated hydrochloric or sulphuric 

 acid and 1 vol. of a medium solution of ferric chloride. In 



