92 VETERINARY MATERIA MEDICA. 



Alumen Exsiccatum, Almnen Ustum, dried alum. 

 A white granular powder, attracting moisture when 

 exposed to the air, odorless, having a sweetish, astrin- 

 gent taste, and slowly but entirely soluble in 20 parts 

 of water. 



Incompatihles are salts of iron, manganese, bis- 

 muth, antimony, lead, and salts of most of the alka- 

 loids; it is therefore best given alone. 



Physiological Actions.— Alum is a very mild 

 caustic, a good astringent, but is not so active as the 

 copper and zinc salts. It stimulates muscular con- 

 traction, coagulates albumin, at first excites the flow 

 of saliva, and then greatly diminishes it. Having 

 the power to coagulate and precipitate pepsin, it ar- 

 rests digestion, stops peristalsis, and usually causes 

 constipation. Large repeated doses act as a violent 

 gastro-intestinal irritant and frequently cause diar- 

 rhoea. Weak solutions coagulate albumin, but enter 

 the blood, constrict the capillaries, check secretions, 

 especially those of mucous surfaces, and arrest capil- 

 lary hemorrhages. Alum is also given as an emetic, 

 is very efficient, and leaves no depressant after-effects. 



Therapeutics.— Small doses are serviceable in 

 gastric catarrh and to check hemorrhage at distant 

 points. Leucorrhoea and gonorrhoea are satisfactor- 

 ily treated with injections of alum, zinc sulphate, and 

 borax. To ulcers, sores — the dried alum as a stimu- 

 lant and caustic. Aphthous, ulcerated conditions of 

 the mouth, sore throat— spray, gargle, or wash of 

 alum with carbolic acid. Catarrhal ophthalmia, in 

 the acute stage— a collyrium of alum grs. v. to the 



