rge enough by an occasional trimming with the knife.
Many of the older authors, and with them writers of the present day,
declare that unless this is done the ordinary injection is likely to fail
in a great many instances where it would otherwise have been successful.

Where a counter-opening is thus made it is found that it very readily
closes with granulation tissue, and the purpose for which it was made
defeated. This may be avoided by the use of a seton. In preference to the
seton, however, we ourselves would advise that the opening be kept free by
the occasional use of a sharp-edged director or a fine scalpel.

An interesting modification of the practice of making a counter-opening is
that related by Veterinary-Captain S.M. Smith.[A] In point of severity it
runs a middle course between the making of a simple counter-opening and
the removal of a wedge-shaped portion of the coronary band and the wall, a
method which we shall later describe.

[Footnote A: _Veterinary Record_, vol ii., p. 157.]

To perform this operation, the animal is cast and chloroformed. The foot is
fixed and the parts thoroughly cleansed. The horn of the wall is then sawed
through in a direct line from the coronary margin to the solar edge, the
saw-line running exactly over the seat of the sinus.

A strong scalpel is now introduced at the coronary opening, with its
cutting-edge outwards, and is gradually passed down the opening made by the
saw. In this way the sinus is completely destroyed, and from end to end
converted into an open wound. The parts are then washed in a perchloride of
mercury solution, covered with a mixture of powdered iodoform and boracic
acid, over which a pledget of carbolized tow is placed, and then a bandage
over the whole. This dressing should be left on three or four days, after
which the injury should be treated as an ordinary wound. In conclusion,
the author says: 'I can safely recommend this line of treatment to any
practitioner having an obstinate case under treatment.'

_Removal of the Wall and Excision of the Necrotic Tissue_.--This we
may term the radical operation for sub-horny quittor, for it is often
productive of a successful issue when all other means have failed. No
matter in what position the sinus is, whether at the extreme anterior
portion of the coronet, or whether in the region of the heels, it is to be
thoroughly opened up. To do this, the fistula is carefully explored with
the probe and a knowledge