MILK AND MILK PRODUCTS 5 



The whey of any given milk has practically the same com- 

 position, whether taken from the original milk, skimmed milk, 

 or cream. 



Average Proportion of Solids in Milk. — The most extensive 

 data on this point are those obtained by Vieth. The total 

 number of samples was 120,540. The averages of the entire 

 series are as follows : 



Fat, 4.1 per cent. 



Non-fatty solids, 8.8 " 



Total solids, 12.9 " 



Richmond's results for several years have confirmed these 

 figures. 



Seasonal Variations in the Composition of Milk. — The poor- 

 est quality usually occurs during the first half of the year, es- 

 pecially in April. A low figure is also frequently noted about 

 July. In autumn the quality rises, being highest in October 

 and November. 



Deficient Solids. — The following are some instances of de- 

 ficiency of solids in milk known to be genuine : 



Total 

 Sp. Ge. Fat. S. N. F. Solids. Analyst. 



1029.6 3.38 7.95 11-33 Cochran. 



1030.0 3.62 8.31 11-93 Cochran. 



1029.3 3.63 8.02 11-65 Cochran. 



3.99 8.36 12.35 Leffmann and Beam. 



3. II 8.33 11-44^ Monthly averages N. 



3-05 8.33 11-38^ J. State Agricul- 



3.23 8.44 11.67 J tural Exp. Station. 



The following analyses of milk from individual cows were 

 made by Cochran. The samples were taken under precau- 

 tions which insured their genuineness. The data are all direct 

 determinations. The total solids were obtained by drying in 

 the usual manner, and the fat by the L-B. method. Low milks 

 have been often noted in the vicinity of Philadelphia. 



