6 



BUTTER-MAKING AND COMPOSITION OF MILK 



different months of the year, was used in the experiment. The 

 per cent of total solids of this herd seems to average a little high 

 all through the ten months. The total solids were found to be 

 14 per cent during the first month, decreasing to 13.47 per cent 

 during the next two months, then gradually increasing with the 

 advance of the lactation period. In the tenth month the average 

 total solids was 14.83 per cent. Pingree, of Pennsylvania, reports 

 having found normal milk from a cow which contained 17.01 

 per cent total solids. Sherman l reports a very high average 

 total of the milk solids. He treated the milk from thirteen cows, 

 and found it to contain on an average 18.03 per cent of total 

 solids. Konig reports a minimum of total solids of 9.31 per cent, 

 a maximum of 19.68 per cent, and an average of 12.83 P 61 " cent. 

 The average total solids quoted above from Richmond is 12.65 

 per cent, which agrees closely with Konig's results. 



The difference in total solids of milk from some of the leading 

 breeds has also been studied by Dr. Van Slyke, and the results 

 are as follows : 



The maximum and minimum amounts of total solids men- 

 tioned above are abnormal cases. The normal variations of 

 the solids in milk are within comparatively narrow limits. For 

 this reason the minimum standard for total milk solids, in States 

 where dairy laws are in force, is fixed by law. Usually 12 per 

 cent is the minimum. 



Water. From what has been said above concerning the total 

 milk solids, it will be seen that water constitutes by far the largest 



1 Jour. Am. Chem. Soc. 



