MARKET DAIRYING. 



CHAPTER I. 



CHEMICAI, AND PHYSICAI< PROPERTIES OF MILK. 



Milk, in a broad sense, may be defined as the normal 

 secretion of the mammary glands of animals that suckle 

 their young. It is the only food found in Nature con- 

 taining all the elements necessary to sustain life. More- 

 over it contains these elements in the proper propor- 

 tions and in easily digestible and assimilable form. 



Microscopic appearance of milk showing^ relative size of fat globules and 

 bacteria.— Russell's Dairy Bacteriology. 



Physical Properties. Milk is a whitish opaque fluid 

 possessing a sweetish taste and a faint odor suggestive 

 of cows' breath. It has an amphioteric reaction, that is, 



7 



