84 HANDBOOK FOR BIO-CHEMICAL LABORATORY. 



Zinc sulphide may be substituted for the ultramarine, 

 using a knife-point of the powder to 20 c.c. of the filtered 

 contents of the stomach. 



MANDEL'S Test (Proteids). A 5 per cent solution of chro- 

 mic acid produces a precipitate with solutions of proteids. 

 If the solution is first made acid with acetic or citric acid, the 

 precipitate produced is flocculent and settles rapidly. It 

 produces a marked cloudiness with 1 part albumin dissolved 

 in 50,000 parts water. Chromic acid solution may be substi- 

 tuted for nitric acid in Heller's test, using a 10 per cent 

 solution. 



MARECHAL (Bile Pigments). See SMITH'S Test. 



v. MASCHKE'S Reaction (Creatinin). Dissolve the creatinin 

 in a cold saturated solution of sodium carbonate and add a 

 a few drops of Fehling's solution. An amorphous flocculent 

 precipitate is obtained in the cold, but better on warming 

 to 50-60 C. 



MEHU'S Test (Albumin). Shake 100 vols. of the solution 

 with 2-3 vols. nitric acid and 10 vols. of a solution of 1 part 

 phenol and 1 part acetic acid in 2 parts 90$ alcohol. In the 

 presence of albumin a precipitate is produced. Instead of 

 nitric acid one half a volume of a saturated solution of 

 sodium sulphate may be used. 



MELANIN. See Eiselt, v. Jakscli, ThormdJikn, Zeller. 



MICHAILOW'S Test (Proteids). Treat the solution with 

 ferrous sulphate, and allow concentrated sulphuric acid to 

 flow under the solution, and then add carefully very little 

 nitric acid. Besides a brown ring, a blood-red coloration will 

 also be produced, 



