ng the
substance of the plantar cushion or the plantar aponeurosis.

Should this preliminary probing demonstrate that neither of the fistulas
run dangerously near the joint, then the operation may be decided on.

The animal is cast and chloroformed, the foot firmly fixed, and the horn of
the quarter rasped away quite thin. The sole of the same side is also pared
with the knife until the horn of both the quarter and the sole yields
easily to pressure of the thumb. All that is then needed is three or four
long, round, and pointed irons (about 1/4 to 3/8 inch in diameter) heated
to redness. These are inserted into the fistulas, and the false mucous coat
of these passages thus destroyed. When the iron, on being directed into the
fistulous opening at the coronet, is found to travel alongside the wall,
and to easily reach the sole, it should be made to go further still. The
sole is penetrated, and a dependent opening thus made for the escape of the
discharge that afterwards accumulates.

What happens now, of course, is that an intense and acute inflammation
is set up along the whole track of the fistula, in which position the
inflammatory changes were heretofore chronic. The whole lining of the
fistula, and with it, we hope, all necrotic tissue, is cast as a slough,
leaving nothing but healthy tissue behind. This, with a suitable dressing,
heals and gives no further trouble.

The after-treatment consists in the application of hot poultices. These
tend to greatly ease the pain, and at the same time to facilitate the
removal of the slough. The poulticing should be continued, therefore, until
the sloughing comes about, which happens, as a rule, at about the fifth or
seventh day.

Immediately the slough is cast off, the poultices may be discontinued and
dressing of the wound carried out. This consists of injections of solutions
of zinc chloride 1 in 200, perchloride of mercury 1 in 1,000, carbolic acid
1 in 20, of Villate's solution, or of such other antiseptic as the surgeon
may think fit. The dependent orifice at the sole should be kept open for as
long as possible, being occasionally trimmed round with the drawing-knife,
and scooped out with a sharp-edged director.

Directly a healthy and pink-looking granulation is observed along the
track of the iron, and the discharge therefrom takes on a thick and yellow
appearance, the strength of the antiseptic solutions should be gradually
diminished. This point, in fact, is of gre