220 STABLE MANUAL AND HORSE DOCTOR 



when the case is not of a veiy desperate description. But 

 there are also instances in which it is to be preterred to an 

 actual blister, as in strains, where some remains of heat and 

 inflammation are present, but without activity; in such 

 cases the sweating blister is very often efficacious. The 

 mode of application is to rub it in of sufficient strength to 

 irritate in a mild degree only ; repeating it every day, until 

 considerable swelling is occasioned, when the application 

 should cease and the enlargement be allowed to subside. 



Caustics, called in medicine escharotics, are external 

 remedies applied by cloth, brush, or sponge to the part 

 where fungous excrescence is to be destroyed, or indolent 

 ulceration stimulated to granulation. They are of two 

 kinds, viz., first, the actual cautery, consisting in the 

 application of the hot iron, and called firing, which will 

 come under notice elsewhere ; and secondly, the potential 

 cautery, by means of the powers of mineral caustics, such 

 as potass, lunar caustic, etc. 



The Mineral Acids are active caustics. Sulphuric acid, 

 or "oil of vitriol," is now seldom used. Nitrous acid (Aqua 

 Fortis) may be applied by means of a camel's-hair pencil to 

 fungus on the foot. 



The Chloride or Muriate of Antimony, commonly called 

 the butter of antimony, is a caustic in very general use in 

 veterinary practice. Applied to a raw surface it instantly 

 changes it white, destroying a thin layer of substance ; 

 hence it is a very convenient application in cankered feet, 

 as, by means of a small camel's-hair brush, it can be spread 

 over as much or as little a portion of parts as is necessary. 

 In sandcrack, when the sensitive substance protrudes, it 

 may be applied in a similar way. In obstinate cases of 

 grease, the buds are sometimes beneficially touched with it, 

 but in quittor, poll-evil, and other sinuses, it is not so 

 proper as some other escharotics. 



Nitrate of Silver (Argenti Nitras), popularly called 

 " lunar caustic," is a preparation from silver, which renders 

 it expensive: it is, however, essentially necessary to the 

 veterinarian's dispensary, from its being so completely under 

 command in its actions; not extending its efiects beyond 

 the immediate part it is applied to. It proves the most 

 convenient caustic for destroying the edges of a contamin- 

 ated wound, when not too extensive, as the bite of a rabid 

 animal. Dissolved in five, six, or eight times its own weight 



