In some forms of discharging skin disease, such as chronic eczema, an alum lotion of moderate strength (1 dr. to 6 or 8 oz.) will act favorably as an astringent; it is also useful if sponged over the surface in profuse or exhausting perspirations. On indolent sores and fungous granulations the powder may be sprinkled, opium being added, if desirable, to lessen the pain that may be caused: this combination, combined with catechu, has also been praised in hospital gangrene. The "lapis divinus," which is prepared with equal parts of alum, blue stone, and nitre, fused together, is a stimulant application to ulcerated and discharging surfaces, much used on the Continent, and compounds of alumina have lately proved very serviceable as disinfectant and alterative dressings.

The acetate of alumina, and the double sulphate of alumina and zinc, have been specially recommended in lotion for foetid perspiration and ulceration. Thorey prescribed the chloride for diphtheritic and gangrenous sores, though others report it unduly irritating.

For antiseptic surgery Professor Maas and Dr. Pinner have recently reported favorably, after extensive trial, of alumina acetate (Berlin. Klin. Woch., 12-13, 1880, and Medical Times, i., 1880). Since the salt is not stable as a solid, they make a solution of 1,000 parts of "colloidal alumina" in 800 parts of dilute acetic acid (thus giving a proportion of about 15 per cent.) for preparing an antiseptic gauze, which is cheaper than, and quite as efficient as, the carbolic. For the spray, a strength of 2 1/2 per cent. is chosen; this is strong enough to lessen hemorrhage, and does not anaesthetize the hands: for washing the skin and the instru-ments, carbolic solutions are still retained.