182 FIRST PRINCIPLES OF AGBICULTURE. 



CHAPTER XV. 



The Products of the Dairy; Their Character and Composition; 

 Dairy Management. 



The distinct products of the dairy are milk, cream, 

 butter, and cheese; and the waste or by-products, skim- 

 milk, buttermilk, and whey. 



The primary purpose of the milk of the cow is to feed 

 and nourish her young. The secretion or formation of a 

 larger quantity than is required for this purpose is, there- 

 fore, an acquired character, and is the result, in large 

 measure, of artificial conditions. 



Milk is a Pood in the fullest sense. It not only con- 

 tains the nutrients necessary to sustain life and to cause 

 growth, viz., fats, albuminoids, carbohydrates, and min- 

 eral salts, but these exist in such a form as to be readily 

 digested. Milk also possesses physical properties which 

 distinguish it from other products. It is a white fluid, 

 throughout which the fat is distributed in the form of 

 small globules. The fat is lighter than the remainder of 

 the fluid, which contains the albuminoids, carbohydrates, 

 and salts in solution ; hence, on standing, the fat globules 

 rise to the surface. This property is taken advantage 

 of in the preparation of the products, cream and butter. 



Fat of Milk, or Butter-Fat, consists of a number of 

 distinct kinds of fat, the chief of which are palmatin, 



