ffensive and irritating fatty acids.

The milk of the very young cow is usually more watery than that of the
mature animal, and that of the old cow has a greater liability to become
acid. It varies much with the breed, the Channel Island cattle being
notorious for the relatively large quantity of cream, while the Holsteins,
Ayrshires, and Shorthorns are remarkable rather for the quantity of casein.
The milk of cows fed on potatoes and grass is very poor and watery; that
from cows fed on cabbage or Swedish turnips has a disagreeable taste and
odor (from the former an offensive liquid has been distilled).

Cows fed on overkept, fermented, and soured rations have acid milk, which
readily turns and coagulates. Thus old, long-kept brewer's grains, swill,
the refuse of glucose factories, and ensilage which has been put up too
green all act in this way. The same may come from disease in the cow's
udder, or any general disease of the cow with attendant fever, and in all
such cases the tendency is to rapid change and unwholesomeness. If the milk
is drawn and fed from a pail, there is the added danger of all sorts of
poisonous ferments getting into it and multiplying; it may be from the
imperfect cleansing and scalding of the pail; from rinsing the pails with
water that is impure; from the entrance of bacterial ferments floating in
the filthy atmosphere of the stable, or from the entrance of the volatile
chemical products of fermentation.

In addition to the dangers coming through the milk, the calf suffers in its
digestive powers from any temporary illness, and among others from the
excitement attendant on the cutting of teeth, and impaired digestion means
fermentations in the undigested masses and the excessive production of
poisonous ptomaines and toxins.

Whatever may be the starting or predisposing cause of this malady, when
once established it is liable to perpetuate itself by contagion and to
prove a veritable plague in a herd or a district.

_Symptoms._--The symptoms of a diarrhea may appear so promptly after birth
as to lead to the idea that the cause already existed in the body of the
calf, and it usually shows itself before the end of the second week. It may
be preceded by constipation, as in retained meconium, or by fetid
eructations and colicky pains, as in acute indigestion. The tail is stained
by the liquid dejections, which are at first simply soft and mixed with
mucus with a sour odor, accompanied with a pecul