HANDBOOK FOR BIO-CHEMICAL LABORATORY. 85 



MILLON'S Reagent (Proteids). Dissolve 1 part mercury in 

 2 parts nitric acid (sp. gr. 1.42), allow to stand some time, 

 and then apply heat. After complete solution of the mer- 

 cury add 1 voh of this solution to 2 vols. of water. Allow 

 to stand a few hours and decant the supernatant liquid. 



This reagent gives with solutions of proteid bodies a precipi- 

 tate which slowly at the ordinary temperature, but quickly at the 

 boiling-point, turns red, depending upon the amount of albu- 

 min. Solid albuminous bodies give the same reaction. This 

 reaction depends on the presence of the aromatic group in 

 the proteid, and is also given by tyrosin and other benzol 

 derivatives with a hydroxyl group in the benzol nucleus. 



MOHR'S Test (HClin Contents of Stomach). A solution of 

 iron acetate (free from alkali acetates) so diluted as to have 

 only a light yellow color is treated with a few drops of a solu- 

 tion of potassium sulpho-cyanide. No change of color should 

 be produced, but if the filtered contents of the stomach are 

 added, and they contain free HC1, an intense red coloration 

 is the result. This color disappears on the addition of sodium 

 acetate. 



MOLISCH'S Test (Glucose). 1. Treat to 1 c.c. of the solu- 

 tion with 2 drops of a 15-20$ alcoholic solution of a naph- 

 thol. The liquid becomes cloudy, due to the precipitation of 

 some of the naphthol, but on the addition of 1-2 c.c. concen- 

 trated sulphuric acid a beautiful deep violet coloration is pro- 

 duced, which forms a violet precipitate on diluting with 

 water. 



2. Instead of employing a solution of a naphthol he also 

 suggests the use of a 15-20$ alcoholic solution of thymol, 

 applied as above. In the presence of glucose it is colored 

 ruby red and becomes carmine red on dilution with water. 



MOORE'S Test ( Glucose). If a glucose solution is treated with 

 about i of its volume of caustic soda or potash and warmed, the 



