CHAPTER II 



COMPOSITION OF MILK 



THE constituents of milk are numerous and of 

 diverse character, but may be easily classified into a 

 few well marked groups as follows: (a) water, (b) 

 fats, (c) substances containing nitrogen (albumi- 

 noids), (d) sugar, (e) ash. Excepting the water, they 

 are collectively known as milk solids. The solids 

 exist partly in solution, partly in semi -solution, and 

 partly in suspension in the water. Milk from the 

 various classes of animals has the same general 

 constitution and properties, and varies only in the 

 relative proportions of the various proximate con- 

 stituents. Cow's milk is typical of all milks, and as 

 it is the only milk used in processes of manufac- 

 ture in the United Steites, all of our discussion.', 

 have reference to it alone. In various other coun- 

 tries milk from the goat, ass, mare and ewe is con- 

 siderably used, not only as food but for the man- 

 ufacture of various products. Indeed the peculiar- 

 ities of some of these are supposed to be largely due 

 to their having been made from the milk of ani- 

 mals other than the cow. Koumiss, made from 

 mare's milk in Arabia, and Roquefort cheese, made 

 largely from ewe's milk, are noteworthy examples. 



(16) 



