CAUSTICS. 297 



unless there is a muzzle on, the dog soon gets the bandage off, and 

 uses his tongue. The chief are cantharides, turpentine, sulphuric 

 acid, mustard, ammonia, tincture of iodine, and biniodide of mer- 

 cury; the last two having some peculiar effect in producing ab- 

 sorption of any diseased substance lying beneath. In all cases the 

 hair ought to be cut off as closely as possible. 



A mild blister : 



25. Powdered cantharides, 5 or 6 drachms. 

 Venice turpentine, 1 ounce. 

 Lard, 4 ounces. Mix, and rub in. 



Strong blister : 



26. Strong mercurial ointment, 4 ounces. 

 Oil of origanum, i ounce. 

 Finely powdered euphorbium, 3 drachms. 

 Powdered cantharides, i ounce. Mix. 



Very quick blister : 



27. Flour of mustard, 4 ounces. 

 Spirit of turpentine, 1 ounce. 

 Strong liquor of ammonia, i ounce. 



Mix the mustard with water into a paste, then add the other ingredients 

 and rub in. 



For bony growths or other tumors : 



28. Tincture of Iodine. 

 Painted on every day, by means of a common painter's brush. 



or, 

 29. Biniodide of mercury, 1 to H drachms. 



Lard, 1 ounce. 



Mix, and rub in a piece the size of a nutmeg every day, keeping the 

 part wet with tincture of arnica, i ounce, mixed with half a pint 

 of water. 



CAUSTICS. 



This name is given to substances which either actually or po- 

 tentially destroy the living tissue. The actual cautery is an iron 

 heated iu the fire, the potential of some chemical substance, such 

 as corrosive sublimate, lunar caustic, caustic potash, a mineral 

 acid, or the like. The actual cautery, or firing, is not often used 



