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New York AcricutturaL Experiment Station. 351 
VII. COMPARISON OF DIFFERENT BREEDS OF DAIRY 
COWS WITH REFERENCE TO THE PRODUCTION OF 
CHEESE. 
In the Tenth Annual Report of this Station, pp. 364-9, the 
chemist made a comparison of dairy breeds of cattle with refer- 
ence to the production of cheese. The amount of cheese was 
calculated from the composition of the milk; the method of 
calculation was based upon some preliminary experiments in 
cheese manufacture and the results were put forward as tenta- 
tive. Since then our very extended series of experiments in 
cheese making have brought to our knowledge a more definite 
understanding of the relation of composition of milk to composi- 
tion and yield of cheese. We are, therefore, now in possession 
of facts that enable us to determine with great exactness from 
the composition of milk the yield and composition of cheese 
made from such milk. In an investigation of this kind it would 
be impracticable to make cheese, and it is found to be unneces- 
sary, Just as we find it unnecessary to make butter in order to 
ascertain the butter yield. 
Our cheese investigation has established the fact that two, and 
only two, constituents of milk are concerned, to any extent, in 
cheese-making; these two are fat and casein. Casein, as used 
here, includes only the compound precipitated by rennet and acids. 
The amount of fat and casein in cheese depends mainly upon the 
amount of these two compounds in milk, 
The amount of water, which constitutes most of the cheese 
that remains after removing fat and casein, is found to vary in 
a manner independent of the composition of the milk. Such vari- 
ation in the amount of water in cheese depends largely upon the 
conditions of manufacture. Portions of the same milk can be 
made into cheese containing greatly varying amounts of water. 
But under the same conditions, a given amount of fat and of 
casein will make the same amount of cheese, because they will 
retain the same amount of water. 
If we know the amount of fat and casein in milk, we can cal- 
culate the amount of cheese yield with as great accuracy as we 
