A handbook of local therapeutics / edited by Harrison Allen.

Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: A handbook of local therapeutics / edited by Harrison Allen. Source: Wellcome Collection.

    66/554 (page 54)
    3 j) as a caustic in the treatment of Epithelioma. The crusts or horny epithehum covering the diseased patch having been removed by scraping or the apphcation of caustic potassa, the ointment is applied, spread upon a rag cut out somewhat smaller than the area to be operated upon and secured firmly to its place. This is renewed daily, the debris being scraped away. The pyrogallic acid seems to have a selective affinity for the diseased tissue. Its effect should be watched and not allowed to go too far. A number of applications are usually necessary, but the caustic is almost or entirely painless. In the Vegetable Parasitic Diseases, particularly in Parasitic Syco- sis, an ointment of 20 to 30 grains to the ounce is very effective. Pyrogallic acid has been used in the treatment of Lupus Vulgaris, in the form of ointment, one drachm to the ounce. Also in the treatment of Phagedenic Ulcers. These are first scraped and then an ointment of one hundred grains to the ounce is applied. ACIDUM SALICYLICUM. Salicylic Acid. A crystalline acid obtained by the combination of the elements of carbolic acid with those of carbonic acid gas, and subsequent purification, or from natural salicylates, such as the oils of wintergreen and sweet birch. (Ph. Br.) The first process spoken of was patented in all countries by Prof. Kolbe, its discoverer, and is practically the only process used, as obtained in any other way its cost is several times greater than it is by this method. The patent has recently expired in this country. Sahcylic acid, when pure, is in fine, white, light, prismatic, needle-shaped crystals, permanent in the air, free from odor of carbolic acid, but sometimes having a slight aromatic odor, of a sweetish and slightly acid taste, and an acid reaction. (U. S. P.) It is soluble in 450 parts of water and two and a half parts of alcohol; in 14 parts of boiling water; very soluble in boiling alcohol; also soluble in two parts of ether, two parts of absolute alcohol, and in 80 parts of chloroform. (U. S. P.) A ten per cent alcoholic solution may be diluted with water without precipitation. It is much more soluble in solutions of some neutral salts than it is in water; for instance, in solution of citrate of ammonium, phosphate of sodium, nitrate of potassium, and sulphate of sodium. It unites with bases to form salts of which the salicylate of sodium is the best known. Salicylates of the alkaloids are recommended for hypodermic use, with the theory that the combined salicylic acid will prevent decomposition of the solutions. Its power of preventing decomposition and fermentation is well known. An ointment of salicylic acid is official in the Ph. Br., containing one part of the acid in twenty-eight of the ointment. The salicylic acid prepared from the natural oils of wintergreen and sweet birch, has a slightly higher melting point than that prepared synthetically by Kolbe's process, and is as a rule much purer. It is, therefore, almost devoid of the unpleasant effects that follow the administration of the ordinary acid, no matter how much the latter may be purified by dialysis or other means. A salicylated cotton (Thiersch's) is prepared by steeping absorbent cotton in a solution of salicylic acid. The proportion of acid in the solution is not fixed, and may vary from three to ten per cent.