ave recovered,
blisters (mustard) on the loins, the lower part of the abdomen, or between
the thighs may be resorted to with success. Two drams of copaiba or of
solid extract of belladonna or 2 grains Spanish flies daily may serve to
restore the lost tone. These failing, the use of electric currents may
still prove successful.

URINARY CALCULI (STONE OR GRAVEL).

Stone or gravel consists of hard bodies mainly made up of the solid earthy
constituents of the urine which have crystallized out of that liquid at
some part of the urinary passage, and have remained as small particles
(gravel), or have concreted into large masses (stone, calculus). (See Pl.
XI, figs. 1, 2, 3.) In cattle it is no uncommon thing to find them
distending the practically microscopic tubes in the red substance of the
kidney, having been deposited from the urine in the solid form almost as
soon as that liquid has been separated from the blood. These stones appear
as white objects on the red ground formed by cutting sections of the
kidney, and are essentially products of the dry feed of winter, and are
most common in working oxen, which are called upon to exhale more water
from the lungs and skin than are the slop-fed and inactive cows. Little
water being introduced into the body with the feed and considerable being
expelled with the breath and perspiration in connection with the active
life, the urine becomes small in amount, but having to carry out all waste
material from the tissues and the tissue-forming feed it becomes so charged
with solids that it is ready to deposit them on the slightest disturbance.
If, therefore, a little of the water of such concentrated urine is
reabsorbed at any point of the urinary passages the remainder is no longer
able to hold the solids in solution, and they are at once precipitated in
the solid form as gravel or commencing stone. In cattle, on the other hand,
which are kept at pasture in summer, or which are fed liberally on roots,
potatoes, pumpkins, apples, or ensilage in winter, this concentrated
condition of the urine is not induced, and under such circumstances,
therefore, the formation of stone is practically unknown. Nothing more need
be said to show the controlling influence of dry feeding in producing
gravel and of a watery ration in preventing it. Calculus in cattle is
essentially a disease of winter and of such cattle as are denied succulent
feed and are confined to dry fodder as their exclusive ration.