BLISTERS. 127 



view to speedy operation ; aud sometimes it seems to succeed 

 tolerably well. It is not a practice^ however, that I can 

 recommend, for in cases of urgency ammonia is more quick 

 and more under our command. 



An old remedy, and one that, in callous swellings, answers 

 our purpose (though it possesses no advantage that I know 

 of over cantharides) is oil of thyme — or oleum origanum. 

 For curbs and sprains it was once held in great estimation. 

 Turpentine annoys and harasses the animal exceedingly : but 

 does not blister. In short, we possess few things that 

 blister better than Spanish flies. 



It has been observed to me — indeed, I have remarked it 

 myself — that horses will sometimes break out into partial 

 sweats. These animals are apparently in good health, and 

 the perspiration lies in spots, where blisters are often applied, 

 and also occupies the space a blister might be supposed to 

 aff"ect. I have therefore concluded, this symptom is exhi- 

 bited upon places where vesication has been produced. The 

 skin suffers from debility after the stimulant has ceased to 

 act. It therefore becomes excited when a moderate exertion 

 has caused a small quantity of blood to raise the temperature 

 of the surface ; it consequently, from innervation, pours forth 

 its secretion before other parts of the body are warm. These 

 partial perspirations are sometimes seen in the stable, and 

 are always signs of weakness. 



A good preparation for a blister (in cold weather par- 

 ticularly) is the soaking or bathing of the part to be blistered 

 in water as hot as the hand can be borne in it. 



Application of Blisters. — The hair should be clipped 

 off the part. Not that this is necessary on all occasions ; 

 for often we can accomplish all we desire by what is called 

 sweating the part ; by which is meant, applying only such 

 strength of blisters as will simply produce a serous oozing 

 from the surface, without tending to separate the hair or 

 the skin. In human medicine it is a common practice to 

 " keep the blister open :^^ that is to say, to dress the sensitive 

 skin with some irritating ointment — such as savin — to con- 

 tinue the inflammation, and thereby cause a purulent matter 



