WOUNDS AND THEIR. TREATMENT. 505. 
application of caustics which will cause a sloughing of all of tne 
wnhealthy tissue, and will also stimulate a rapid increase of healthy 
organized material to replace that destroyed in the course of the 
development and treatment of the.disease. Threads or cords soaked 
in gum-arabic solution and rolled in powdered corrosive sublimate 
may be introduced into the canal and allowed to remain. The skin 
on all parts of the shoulder and leg beneath the fistula should be 
carefully greased with lard or oil, as this will prevent the discharge 
that comes from the opening after the caustic is introduced from 
irritating or blistering the skin over which it flows. In obstinate 
cases a piece of caustic potash (fused) 1 to 2 inches in length may 
be introduced into the opening and should be covered with oakum or 
cotton. The horse should then: be secured so that he can not reach 
the part with his teeth. After the caustic plug has been in place for 
24 hours, it may be removed and hot fomentations applied. As soon 
as the discharge has become again established the abscess should be 
opened from its lowest extremity, and the passage thus formed may 
be kept open by the introduction of a seton. If the pipes become 
established in the deep tissues beneath the shoulder blade or among 
the spines of the vertebral column, it will often be found impossible 
to provide proper drainage for the abscess from below, and treat- 
ment must consist of caustic solutions carefully injected into all parts 
of the suppurating sinuses. A very effective remedy for this pur- 
pose consists of 1 ounce of chlorid of zinc in half a pint of water, 
injected three times during a week, after which a weak solution of 
the same may be occasionally injected. Injections of Villate’s solu- 
tion or alcoholic solution of corrosive sublimate, strong carbolic acid, 
or possibly oil of turpentine will also prove beneficial. Pressure 
should be applied from below, and endeavors made to heal the vari- 
ous pipes from. the bottom. 
Should the swelling become general, wtbout forming-a well-defined 
tumor, the placing of 20 to 80 grains of arsenious acid, wrapped in a 
single layer of tissue paper, in a shallow incision beneath the skin, will 
often produce a sloughing of the affected parts in a week or 10 days, 
after which the formation of healthy tissue follows. The surround- 
ing parts of the skin should be protected from any damage from 
escaping caustics by the application of lard or oil, as previously 
suggested. 
Although the successful treatment of fistulas requires time and 
patience, the majority of cases are curable. The sinuses must be 
opened at their lowest extremity and kept open. Caustic applications 
must be thoroughly used once or twice, after which mild astringent 
antiseptic washes should be persistently used until a cure is reached. 
It sometimes happens that the erosions have burrowed so deeply or 
in such.a direction that the opening of a drainage passage becomes 
