J5LISTER1XG. 461 



BLISTERING. 



We have spoken of the effect of blisters, when treatinf^ of tlie various 

 diseases to which they are applicable. The principle on which they act is, 

 that no two intense inflammations can exist in neighbom-ing parts, or 

 perhaps in the system, at the same time. Hence we apply some irritating- 

 substance to the skin, in order to excite external inflammation, and thns 

 lessen or remove that which exists in some deeper-seated and, generally, 

 not far distant part. Hence, also, we blister the sides in inflammation of 

 the lungs — the abdomen in that of the bowels — the legs in that of the 

 cellular substance sui-rounding the sheaths of the tendons, or the sheaths 

 themselves, and the coronet in inflammation of the navicular joints. 



Blisters have lilvewise the property of increasmg the activity of the 

 neighbouring vessels : thus we blister to bring the tumour of strangles 

 more speedily to a head — to rouse the absorbents generally to more 

 energetic action, and caiise the disappearance of tumours, and even callous 

 and bony substances. 



The judgment of the practitioner will decide whether the desired effect 

 Avill be best produced by a sudden and violent action, or by the con- 

 tinuance of one of a milder character. Inflammation should be met by 

 active blisters ; old enlargements and swellings will be most certainly 

 removed by milder stimulants — by the process which farriers call sweatimj 

 down. 



There are few more active or effectual blisters than the cantharides or 

 Spanish fly, mixed with the proportions of lard and resin that will be 

 hereafter stated. The best liquid or sweating blister is an infusion of the 

 fly in vinegar, olive oil, or spirit of turpentine, according to the degree of 

 activity requii-ed. 



In preparing the horse for blistering, the hair should be clipped or 

 shaved as closely as possible, and the ointment thoroughly rubbed in. 

 Much fault is often found Avith the ointment if the blister does not rise, 

 but the faihu'e is generally to be attributed to the idleness of the operator. 



The head of the horse should be tied up during the first two days ; 

 except that, Avhen the sides are blistered, the body-clothes may be so 

 contrived as to prevent the animal from nibbling and blemishing the part, 

 or blistering Iris muzzle. At the expiration of twenty-four hours, a little 

 olive oil should be applied over the bhster, M^iich will considerably lessen 

 the pain and supple the part, and prevent cracks in the skin that may be 

 difficult to heal. The oil should be applied morning and night, until the 

 scabs peel off. 



Every particle of litter should be carefully removed from the stall, for 

 the sharp ends of the straw coming in contact with a part rendered so 

 tender and irritable by the blister, will cause a very great annoyance to 

 the animal. After the second day the horse may be suffered to lie down ; 

 bvit the possibility of blemishing himself should be prevented by a cradle 

 or wooden necklace, consisting of round strips of wood, strung together, 

 reaching from the lower jaw to the chest, and preventing him from 

 sufficiently turning or bending his head, to get at the blistered jjart. 



A blister thus treated will rarely produce the slightest blemish. When 

 the scabs are all removed, the bhster may be repeated, if the case ahould 

 appear to require it, or the horse may be turned out. 



In inflammations which threaten life, a blirter can scarcely be too active 

 or extensive. In inflammation of the lungs it should reach over the 

 whole of the sides, and the greater part of the brisket, for, should a 

 portion of the fly be absorbed, and ]u-oduce strangury (inflammation, or 

 spasmodic afl'ection of the neck of the bladdei',) even this new irritation 



