PROPERTIES.--A white granular powder, odorless, having a sweetish astringent taste, soluble in twenty parts of water at 60° F. Is a powerful astringent and escharotic. ALUMINI HYDROXIDUM--ALUMINUM HYDROXIDE DERIVATION.--Made from alum, 100 parts; monohydrate sodium carbonate, 43 parts; water, a sufficient quantity. Mix hot, boiling solutions of alum and sodium carbonate. Precipitate strained, washed and dried. PROPERTIES.--A white, light, amorphous powder; odorless and tasteless; permanent in dry air; insoluble in water or alcohol. DOSE.--Same as alum. ALUMINI SULPHAS--ALUMINUM SULPHATE DERIVATION.--Aluminum hydroxide is dissolved in diluted sulphuric acid, and the solution is filtered and evaporated to dryness. PROPERTIES.--A white, crystalline powder, without odor, having a sweetish and afterwards astringent taste; permanent in the air; soluble in one part of water; insoluble in alcohol. DOSE.--Same as alum. ACTIONS.--Astringent, at first excites flow of saliva, then markedly decreases it; coagulates pepsin, thus it would derange or entirely arrest digestion; it also stops peristalsis and produces constipation, though sometimes it induces diarrhoea by irritation. It arrests secretions in general and in the circulation contracts the capillaries; it is in this way it arrests secretions, especially those of mucous surfaces, and stops capillary hemorrhage. The sulphate of aluminum is mildly caustic, astringent and antiseptic. Dried alum is caustic and astringent. EXTERNALLY.--Dried alum is a caustic, in contact with raw sores, on account of its affinity for water. Alum has no action on unbroken skin, but applied to mucous membranes or denuded parts it is antiseptic and astringent; coagulates albumin of discharges; precipitates or coagulates albumin of the tissues; squeeze blood out of the vessels; reduces inflammation and makes the part whiter, brings together and denser. Alum is a hemostatic, stopping bleeding by compression of the structures surrounding the vessels and by causing blood to clot.