90 VETERINARY SURGICAL OPERATIONS 



of its past popularity in the castration of horses with the 

 wooden clamps. The caustic clamps of the old "gelders," 

 prepared by smearing them with a paste made of flour, water 

 and red precipitate, may still be retained when the clamp 

 method of castration is insisted, upon, as by this paste the 

 clamps are not only made antiseptic but crushed portions of 

 the spermatic cords slough off much earlier than if the caus- 

 tic is omitted. 



Zinc chloride is an effectual caustic, but it is seldom used 

 alone. It is one of the constituents of most all of the popular 

 caustic pastes that are so often reputed as possessing won- 

 derful curative properties in fistulous conditions. Mixed 

 with equal parts of melted Burgundy pitch to which a little 

 linseed oil is added to soften it, it forms a slow but certain 

 caustic for general use in fistulous tracts. In this form it can 

 be rolled into sticks which can be pushed into deep and tor- 

 tuous recesses, owing to their properties. of being both firm 

 and pliable. 



Mercuric iodide, dusted upon granulation surfaces is an 

 excellent caustic wherever indicated. In fistulous tracts it is 

 highly recommended by C. A. Cary, mixed with lard and 

 smeared over gauze which is then packed in the tracts. Its 

 behavior simulates that of all other caustic used in this man- 

 ner. 



Formalin, is a powerful liquid caustic. Injected into fistu- 

 las it immediately mummifies everything with which it comes 

 into contact, but it produces an excruciating and lasting pain 

 that renders its use rather hazardous. In weak solutions, 

 even as low as two per cent, its repeated use will bring about 

 this characteristic mummifying effect that is sometimes de- 

 sirable in destroying infected granulation. 



Argentum nitras is one of the oldest as well as one of the 

 best caustics for general use. It is chiefly used for penciling 

 ulcers and ulcerated surfaces, but may like -any of the other 

 ordinary caustics be used for the cauterization of fistulous 

 tracts, either in the form of tampons.or in pencils. 



Solution of Antimony Chloride. — Among the various 

 liquid substances possessing an active cauterant action solu- 

 tion of antimony chloride is much to be preferred on account 

 of its safety. Applied to diseased surfaces or swabbed into 

 tracts carpeted with granulations, it produces but little pain 

 while at the same time effecting a thorough cauterization of 

 the tissues with which it is brought into contact. It is less 

 apt to destroy tissues beyond point of application, than is the 

 case with the mineral acids. 



