12 THE DISEASES OF HOUSES, 



There are numerous drugs used as blistering agents, and the formula) for 

 making blisters are also exceedingly numerous. The needless multiplica- 

 tion of remedial agents of any class is to be deprecated, and far more so 

 " ringing the changes " on the slightest variations of their compounds. 

 Nearly every farrier, country druggist and stableman has his own form of 

 blister kept a profound secret, and claiming to have special virtues of 

 its own. These agents cannot be too simple in their composition ; the 

 more complicated they are the less likely are they to act effectually, 

 and the more likely to create sores troublesome to heal. Euphorbium, 

 once greatly in vogue amongst farriers is little, if at all, used by the vete- 

 rinary surgeon, and the highly dangerous practice of adding white mer- 

 cury (corrosive sublimata), and other mineral poisons cannot be too 

 strongly condemned. The great vesicatory is cantharides, or Spanish fly. 

 This is use.i mixed with fatty matter, or the active principle held in solution 

 by various solvents, such as acetic acid, turpentine, olive oil, &c. ; 

 these are used of different strengths, according to the amount of irrita- 

 tion it is desired to produce. A mild form is the vinegar of cantharides, 

 made by digesting one part by weight of flies in eight parts of diluted 

 acetic acid, and filtering. A very useful mild blister is made as follows. 

 It may be kept at hand of this strength when it can be easily increased, if 

 needed, by the addition of more flies. It should be kept in a jar covered 

 with bladder, and should be kept in a cool and dry place. 



Mild Blister. — Take lard 6oz., beeswax loz., camphor loz., powdered 

 cantharides loz. ; melt the wax and lard with a gentle heat, and place in 

 them the camphor, previously cut very small, or reduced to powder. Stir 

 in the powdered cantharides, stirring occasionally till cold to ensure the 

 ingredients being thoroughly mixed. 



The biniodide of mercury blister is referred to in the article on bruises 

 (p. 24). 



In applying blisters to the horse the hair should be clipped off 

 very short, and the blister rubbed in with considerable friction. If the 

 part has been previously well fomented or poulticed, the action of tho 

 blister will be greatly assisted. In six or eight hours after the applica- 

 tion vesication will have taken place, and on the following day the part 

 should be carefully and tenderly freed from the irritating substance by 

 bathing with warm water and a soft sponge ; the part should then be 

 dressed with some spermaceti ointment, fresh lard, or lead liniment 

 made thus : 



Lead Liniment. — Mix one part of extract of lead with five parts of best 

 olive oil. 



It is sometimes desired to keep a blister open. This can be done by 

 dressing with savine ointment, or with a very mild preparation of can- 

 tharides. 



Blood Spavin.— See Spavin. 



Bloody Urine, or Passing" of Blood.— This may be caused by calculus 

 and sometimes by hard riding, causing rupture of one or more small 



