A LABORATORY MANUAL 



OF 



PHYSIOLOGICAL AND PATHOLOGICAL 

 CHEMISTEY. 



CHAPTER I. 

 EXAMINATION OF MILK. 



I. General Properties of Milk. 

 II. Separation of Milk into its Constituents. 



III. Precipitation with Magnesium Sulphate. 



IV. Action of Rennin on Milk. 

 V. Preparation of Lactic Acid. 



I. GENERAL PROPERTIES. 



1. The reaction of milk is usually amphoteric, i.e., it red- 

 dens blue litmus paper, turns red litmus paper blue, and does 

 not act on violet litmus paper. Towards phenol-phthalein 

 it reacts acid, towards lacmoid alkaline. 



2. On heating fresh milk to boiling, 1 it does not coagulate, 

 its general appearance is not changed. When heated for a 

 longer time it forms a skin on the surface consisting essen- 



1 All reactions or tests are to be performed in test-tubes unless other- 

 wise directed. 



