POULTICES 729 



dextrin, tripoli, gum arable, plaster of Paris, alum, gutta- 

 percha, or flour and white of egg. Velpeau's plaster con- 

 sists of dextrin 100 parts, camphor tincture and hot water, 

 of each 50 parts. Alum, 16 ounces, and alcohol, 35 ounces, 

 heated until the mixture assumes the consistence of syrup ; 

 or dextrin and alcohol, without the addition of water, 

 solidify quickly and form strong adhesives. 



POULTICBS-CATAPLASMATA 



Poultices are local baths or semi-solid packs, used for 

 the topical application of heat and moisture. They closely 

 resemble fomentations, and are often employed to soften 

 the horn of the horse's foot. They constitute an important 

 form of emollient. They are made of such farinaceous 

 substances as linseed meal, bran, or oatmeal, stirred into 

 boiling water until the fitting consistence is reached ; or of 

 carrots or turnips, either steamed or boiled. Bread and 

 starch make bland porous poultices, and spent hops are 

 indicated where the poultice should be light. Unless nicely 

 prepared, soft, fresh, and changed every two or three hours, 

 they merit Liston's condemnation, that they are associated 

 4 with putrefaction and nastiness.' In order to secure 

 softening of the skin, as well as the soothing of peripheral 

 nerve-endings, medicated poultices are sometimes laid 

 directly on wounds or contusions, or with only a very thin 

 substance intervening. When used, however, either directly 

 or reflexly, to relieve congestion or pain, they are placed in 

 a well- warmed flannel bag, or in folds of flannel, which, 

 conducting heat slowly, justifies their application at a higher 

 temperature than could otherwise be borne, and, moreover, 

 preserves heat longer. Poultices arrest superficial and 

 circumscribed inflammation in the early stages ; and in 

 more advanced stages, when white corpuscles have escaped 

 through the vessels, or pus has begun to form, they promote 

 maturation of the abscess. They should not be used for 

 wounds, which, if kept dry or treated antiseptically, will 

 heal by first intention or adhesion, nor for chronic injuries 

 where the parts have become relaxed and deficient in tone, 

 in which cases cold applications are indicated. Heat, 



