the
new surface meets the old 2-1/2 or 3 inches from the heel. The same
sloping shape is to be observed in cutting downward toward the bottom of
the foot, at which point the wall is to retain its normal thickness. The
foot is now blistered all round the coronet with Spanish-fly ointment;
when this is well set, the patient is to be turned to pasture in a damp
field or meadow. The blister should be repeated in three or four weeks,
and, as a rule, the patient can be returned to work in two or three
months.

The object of the tip is to throw the weight on the frog and heels,
which are readily spread after the horn has been cut away on the sides
of the wall. The internal structures of the foot at the heels, being
relieved of excessive pressure, regain their normal condition if the
disease is not of too long standing. The blister tends to relieve any
inflammation which may be present, and stimulates a rapid growth of
healthy horn, which, in most cases, ultimately forms a wide and normal
heel. In old, chronic cases, with a shrunken frog and increased
concavity of the sole, accompanied with excessive wasting of all the
internal tissues of the foot, satisfactory results can not be expected
and are rarely obtained. Still, much relief, if not an entire cure, may
be effected by these measures.

When thrush is present as a complication, its cure must be sought by
measures directed under that heading. If sidebones, ringbones, navicular
disease, contracted tendons, or other diseases have been the cause of
contracted heels, treatment will be useless until the cause is removed.

SAND CRACKS.

A sand crank is a fissure in the horn of the wall of the foot. These
fissures are quite narrow, and, as a general rule, they follow the
direction of the horny fibers. They may occur on any part of the wall,
but ordinarily are only seen directly in front, when they are called toe
cracks; or on the lateral parts of the walls, when they are known as
quarter cracks. (Plate XXXVI.)

Toe cracks are most common in the hind feet, while quarter cracks nearly
always affect the fore feet. The inside quarter is more liable to the
injury than the outside, for the reason that this quarter is not only
the thinner, but during locomotion receives a greater part of the weight
of the body. A sand crack may be superficial, involving only the outer
parts of the wall, or it may be deep, involving the whole thickness of
the wall and the soft tissues beneath.

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