eighteen or twenty-four hours after it is drawn, of small, indigo-blue
spots, which rapidly enlarge until the whole surface is covered with a
blue film. If the milk be allowed to stand a few days, the blue is
converted into a greenish or reddish color. This coloration of the milk
is due to the growth of microscopic organisms. The butter made from
'blue milk' is dirty-white, gelatinous, and bitter.