108 STORRS AGRICULTURAL EXPERIMENT STATION. 
Variation in composition of cows’ milk.—By averaging over 
2400 American analyses, the Vermont Station (Report 1890, 
p. 97) found the relationship of the solid ingredients to each 
other in milk containing different percentages of fat. | 
Table 37 shows that as the solids increase in mixed milk the 
various ingredients increase also, but not all in the same pro- 
portion. ‘The total solids increase from 11 pounds to 16 pounds 
in 100 pounds of milk, or 45 per cent.; the fat increases from 
3.07 pounds to 6 pounds, or 95 per cent.; the casein and albu- 
men increase from 2.92 pounds to 4.30 pounds, or 47 per cent.; 
and the milk sugar and ash, from 5.01 pounds to 5.70 pounds, 
OleLe< per, Cenc, 
TABLE 38. 
Amount of ingredients tn roo pounds of total solids. 




ee 5 
eu Do 
QUALITY OF MILK AS TO . as a 
TOTAL SOLIDS. fy OS MO 
He S5 
ux 2 
Per Cent. Lbs. Lbs. Lbs. 
tie “ - - - - - 27.50 26.5 45.5 
12° - - - ~ - - 29.1 25.6 45.2 
ic ema iter te ge iat a rer nt 30.7 25.4 43.9 
I4,/- = i + + 33-4 25.5 41.2 
15, - - - - - - - 35.8 26.6 Bik 
pe = 2 - - - - eves. 26.8 35.6 

Table 38 shows the pounds of ingredients in 100 pounds of 
total solids in milk of varying quality. The fat increases 
from 27.9 to 37.5 pounds, the milk sugar and ash decrease 
from 45.5 to 35.6 pounds, while the casein and albumen remain 
about one-quarter of the total solids. 
Table 39 shows that the muscle forming material and the 
material that might be used in the body for protein protection 
are about the same in all milk solids. The number of calories 
and the value of the solids for fat formation increase with the 
increase of the milk’s per cent. in fat. 
Few if any experiments have been made showing the food 
value of milk poor in fat as compared with milk relatively rich 
in fat. No data are at hand upon which to base an opinion 
concerning the food value of a pound of milk solids from milk 
