Alum. The sulphate of Alumina and Potash. A12O3, 3 SO3 + KO, SO3 + 24HO.

Med. Prop, and Action. Alum is astringent and styptic, whether employed internally or externally. Its local effects depend upon a chemical action on the albuminous and gelatinous constituents of the tissue. When administered internally, it is absorbed into the system, and has been detected in the liver, spleen, and urine. "After its absorption," says Pereira, "Alum appears to act as an astringent on the system generally, and to produce, more or less, general astriction of the tissues and fibres, and a diminution of secretion." Its astringent influence is chiefly directed to mucous surfaces; applied locally to relaxed or bleeding surfaces, it corrugates the surrounding tissues and causes contractions of the capillaries. In this manner, it arrests the discharge, and acts as an astringent. Administered internally in large doses it has a purgative action.

Offic. Prep. Alumen Exsiccatum. Dried Alum, a mild escharotic.

Dose of Alum, as an astringent, gr. x. - gr. xx.

93. Modes Of Administration

The usual mode of administering Alum is in solution in water or in some simple infusion; but Sir J. Murray* considers that, employed in this way, many of its most useful effects are in a great measure neutralized. He advises its being reduced to an impalpable powder; and then mixed with a little honey or molasses, so as to form an electuary. In order to prevent it producing constipation, he advises the addition of the Supertartrate of Potash. Given in this manner, the full effects of the medicine will soon evidence themselves. This electuary, without the Potash, diluted with a little water, forms an excellent gargle, which acts, in the opinion of Sir J. Murray, not only as a constringing lotion, diminishing the diameter of enlarged vessels, but as a means of reducing the size of enlarged and turgid glands and tissues. (See also Gargles.) Another mode of administering Alum is in the form of whey, which is made by boiling gr. cxx. of powdered Alum for a few minutes, in Oj. of milk. A teacupful of this, thrice daily, is a popular astringent and tonic in many parts of England. The Liq. Aluminis Co. (Pharm. Lond.) (Alum., Zinci Sulph. aa i. Aq. Ferv. Oiij.) is an excellent form for injections, collyriums, &c.

Incompatible*. Soda, Potash, Magnesia, Lime, and their carbonates; the phosphates, Calomel, Corrosive Sublimate, Acetate of Lead, Barytes, Tannic Acid, and all vegetable infusions containing Tannic Acid.

* Dublin Med. Press, March 14, 1849.

94. Therapeutic Uses

Diseases of the Abdominal Viscera. In Abdominal Typhus, which was epidemic in Vienna in 1838, Drs. Dobler, Sterz, and Folwarezny,* placed their chief reliance on the internal exhibition of Alum, in doses of from gr. ij. - v. every hour. Under every form of the disease, diarrha, delirium, and debility, Alum is stated to have proved equally beneficial. It was found particularly serviceable in checking the exhausting diarrhoea; it apparently acted as an astringent and tonic upon the relaxed and ulcerated mucous follicles of the intestines. Prof. Fouquier. of Paris, also states that he has been in the habit of using Alum in these cases, with marked success.