LESSON THIRTY-EIGHT 
MILK 
1. Composition.—Milk contains water, casein, albumen, 
fat, sugar and ash. The average composition is as fol- 
lows: Water, 87 per cent; casein, 2.6 per cent; albumen, 
Oy (ih 
-1% 5% 
COMPOSITION OF NORMAL Cow’s MILK 
0.7 per cent; fat, 4 per cent; sugar, 5 per cent; and ash, 
0.7 per cent. The greatest variation is in fat, which fluc- 
tuates in individuals and varies widely with breeds. 
Some breeds yield milk low in fat, and others milk much 
richer in this constituent. In general, about 3 per cent 
is the minimum, and 6 to 7 per cent the normal maximum, 
although some cows, during the close of the lactation 
period, may yield milk containing 8 or 9 per cent of fat. 
2. Fat globules.—Butter fat consists of a number of 
separate and distinct fats which unite into particles, or 
globules. These fats are of two kinds—the volatile and 
non-volatile oils. The former give to milk its distinctive 
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