TREATMENT OF DISEASES OF THE IIOESE. 489 



freezes, or assumes a singular species of crystallisation at 39° below of 

 Fah., and at 660° above of Fah. it boils and rapidly_ evaporates. In its 

 metallic state it appears to have no action on tlie animal system, but its 

 compounds are mostly powerful excitants, and some of tliem are active 



caustics. TO- J x-L i 



Tbe Common Mercurial Ointment may be used for rmgworm, and that 

 species of acarus whicb seems to be the source, or the precui^sor of, mange. 

 The compound mercurial ointment is also useful in the destruction of the 

 same insect. For most eruptions connected with or simulating mange, 

 the author of this work has been accustomed to apply the following omt- 

 ment with considerable success : — 



Subhmed sulphur 1 pound. 



Common turpentine . . . . 4 oz. 



Mercurial ointment . . . . 2 oz. 



Linseed oil 1 piii*- 



The Mercurial Ointment is prepared by rubbing quicksilver with lard, 

 in the proportion of one part of mercury to three of lard, until no globules 

 appear. The practitioner should, if possible, prepare it hunself, for he 

 can seldom get it pure or of the proper strength from the druggist. _ It is 

 employed with considerable advantage in preparing splints, spavins, or 

 other bony or callous tumours, for blistering or firing. One or two 

 drachms, according to the nature and size of the swelling, may be daily 

 weU rubbed in ; but it should be watched, for it sometimes salivates the 

 horse very speedily. The tumours more readily disperse, at the application 

 of a stronger stimulant, when they have been thus prepared. Mercurial 

 ointment in a weaker state is sometimes necessary for the cure of mallen- 

 ders and saUenders ; and in very obstinate cases of mange, one-eighth part 

 of mercurial ointment may be added to the ointment recommended at 



page 357. . 



Calomel, the submuriate or protochloride of mercury,_is obtained by 

 mixing together mercury and sulphuric acid, adding chloride of sodium, 

 and then sublimed by heat. It is useful in some cases of chronic cough, 

 in farcy, and in jaundice. Alone it has little purgative effect on the horse, 

 but it assists the action of other aperients. It is given in doses from a 

 scruple to a drachm. As soon as the gums become red, or the animal 

 begius to quid or drop his hay, it must be discontiaued. 



^Corrosive SuUimate, the oxymuriate or bichloride of mercury, combined 

 with chlorine in a double proportion, is a useful tonic in farcy. It should 

 be given in doses often grains daily, and gradually increased to a scruple, 

 untn the horse is purged, or the mouth becomes sore, when it niay be 

 omitted for a few days, and resumed. Some have recommended it as a 

 diuretic, but it is too dangerous a medicine for this purpose. It is used 

 externally in solution ; in substance in quittor, as a stimulant to foul ulcers; 

 and ia the proportion of five grains to an ounce of rectified spii-it in obsti- 

 nate mange, or to destroy vermin on the skin. It is, however, too uncer- 

 tain and too dangerous a medicine for the horse-proprietor to venture on 



its use. . , n, 1 • 



JEtMop's Mineral, the black sulphuret of mercury, is not otten used m 

 horse practice, but it is a good alterative for obstinate surfeit or foulness 

 of the skin, in doses of three drachms daily. Four drachms of cream of 

 tartar may be advantageously added to each dose. 



Infusions.— The active matter of some vegetable substances is partly 

 or entirely extracted by water. Dried vegetables yield their properties 

 more readily and perfectly than when in their green state. Boilmg water 

 is poured on the substance to be infused, and which should have been pre- 

 viously pounded or powdered, and the vessel then covered and placed 



