CHAPTER III. 
PROPERTIES OF MILK. 
Color.—The color of normal milk ranges between bluish 
white and golden yellow, according to breeds, foods, and sea- 
sons of the year. The milk yielded by Jersey cows generally 
is more yellow, due chiefly to the larger amount of fat which 
it contains. Holstein cows yield milk of a whiter color. Focds 
such as grass and certain roots (mangles and carrots) have 
the power of giving to milk a higher color. As has been pre- 
viously mentioned, the coloring substance in milk has been 
named lactochrome, and so far as known is associated with 
the palmitin fat. 
Flavor.—Milk has a sweet flavor, and a faint odor. Fresh 
milk has a peculiar cowy taste and odor, which pass off when 
exposed to the air. The flavor is affected by foods and con- 
ditions of the cow, as mentioned under “‘ Abnormal Milk.” 
Opacity of Milk.—Milk is opaque, except when seen in 
very thin layers; then it is slightly transparent. The opacity 
of milk is due to the presence of the fat and nitrogenous mat- 
ter. When these substances are filtered away on a fine clay 
filter (the Chamberland), the filtrate which passes through 
is clear and transparent. It has been maintained that the 
fat in milk is the chief cause of its opacity, and that the per- 
centage of fat could be determined according to the degree 
of opacity and transparency of milk with an instrument named 
pioscope; but it was soon found out that the size of the 
fat-globules, as well as the number, had considerable influence 
upon the degree of opacity of milk. For that reason, this 
method of determining the amount of fat in milk was not 
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