est
about an hour before feeding. If water is now offered him it will in
many cases be refused, or at least he will drink but sparingly. The
danger, then, is not in the "first swallow" of water, but is due to the
excessive quantity that the animal will take when warm if he is not
restrained.

Ice-cold water should never be given to horses. It may not be necessary
to add hot water, but we should be careful in placing water troughs
about our barns to have them in such position that the sun may shine
upon the water during the winter mornings. Water, even though it is thus
cold, seldom produces serious trouble if the horse has not been deprived
for a too great length of time.

In reference to the purity of water, Smith, in his "Veterinary Hygiene,"
classes spring water, deep-well water, and upland surface water as
wholesome; stored rain water and surface water from cultivated land as
suspicious; river water to which sewage gains access and shallow-well
water as dangerous. The water that is used so largely for drinking
purposes for stock throughout some States can not but be impure. I refer
to those sections where there is an impervious clay subsoil. It is the
custom to scoop, or hollow out, a large basin in the pastures. During
rains these basins become filled with water. The clay subsoil, being
almost impervious, acts as a jug, and there is no escape for the water
except by evaporation. Such water is stagnant, but would be kept
comparatively fresh by subsequent rains were it not for the fact that
much organic matter is carried into it by surface drainage during each
succeeding storm. This organic matter soon undergoes decomposition, and,
as the result, we find diseases of different kinds much more prevalent
where this water is drunk than where the water supply is wholesome.
Again, it must not be lost sight of that stagnant surface water is much
more certainly contaminated than is running water by one diseased animal
of the herd, thus endangering the remainder.

The chief impurities of water may be classified as organic and
inorganic. The organic impurities are either animal or vegetable
substances. The salts of the metals are the inorganic impurities. Lime
causes hardness of water, and occasion will be taken to speak of this
when describing intestinal concretions. Salts of lead, iron, and copper
are also frequently found in water; they also will be referred to.

About the only examination of water that can be made by t