CHAI'TKR IV 

 MILK AND ITS PRODUCTS AS FOODS 



hi(;h valuk of milk-fat 



There are two methods for the classification of foodstuffs for 

 animals and man, and both of these will be briefly considered in 

 this chapter, with special reference to milk and its constituents — 

 particularly milk-fat — as not only valuable but indispensable 

 parts of the dietary. 



The older method may be spoken of as the clicmical metliod. 

 It considers and classifies foods largely in accordance with their 

 content of water, protein, carboh}"drates, fats and mineral matter. 

 This, in itself, is quite incomplete, as will be shown later. 



The newer method, which is known as the biological method, 

 is based upon a stud}- of the properties and \'alues of the different 

 foodstuffs, through feeding them and n<jting their effect upon 

 growth, health and reproduction. This method, though compara- 

 tively new, has made very rapid strides, and has established the 

 fact that food constituents which come under the same chemical 

 head are !)}• no means eithei alike or of ecjual nutriti\'e \-alue. 



There is neither the hope nor the expectation that the bio- 

 logical will supersede the chemical classification of foods and 

 foodstuffs, in the sense of dispensing with the aid of chemistry. 

 The true, unbiased student of the problems of nutrition recognizes 

 two things; tirst, that the chemical method has rendered and 

 will continue to render a very large service, and, second, that in 

 itself it is too mechanical and incomplete. 



In the last anal\-sis, the biological classification of foodstuffs 

 must prevail, but this does not mean that it and chemistr}" are 

 at variance with each other. Rather it means that there must 

 be a merging of the chemical into the larger or biological method, 

 and that in future a larger, fuller, more intelligent and less 



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