int of tepid water.

The removal of the stone in the horse is a much more difficult
proceeding. It consists in cutting into the urethra just beneath the
anus and introducing the lithotomy forceps from this forward into the
bladder, as in the mare. It is needful to distend the urethra with
tepid water or to insert a sound or catheter to furnish a guide upon
which the incision may be made, and in case of a large stone it may be
needful to enlarge the passage by cutting in a direction upward and
outward with a probe-pointed knife, the back of which is slid along in
the groove of a director until it enters the bladder.

The horse may be operated upon in the standing position, being simply
pressed against the wall by a pole passed from before backward along the
other side of the body. The tepid water is injected into the end of the
penis until it is felt to fluctuate under the pressure of the finger, in
the median line over the bone just beneath the anus. The incision is
then made into the center of the fluctuating canal, and from above
downward. When a sound or catheter is used as a guide it is inserted
through the penis until it can be felt through the skin at the point
where the incision is to be made beneath the anus. The skin is then
rendered tense by the thumb and fingers of the left hand pressing on the
two sides of the sound, while the right hand, armed with a scalpel, cuts
downward onto the catheter. This vertical incision into the canal should
escape wounding any important blood vessel. It is in making the
obliquely lateral incision in the subsequent dilatation of the urethra
and neck of the bladder that such danger is to be apprehended.

If the stone is too large to be extracted through the urethra, it may be
broken down with the lithotrite and extracted piecemeal with the
forceps. The lithotrite is an instrument composed of a straight stem
bent for an inch or more to one side at its free end so as to form an
obtuse angle, and having on the same side a sliding bar moving in a
groove in the stem and operated by a screw so that the stone may be
seized between the two blades at its free extremity and crushed again
and again into pieces small enough to extract. Extra care is required to
avoid injury to the urethra in the extraction of the angular fragments,
and the gravel or powder that can not be removed in this way must be
washed out, as advised below.

When a pultaceous magma of carbonate of lime accumulates in