Emplastrum Saponis.—Soap Plaster.
Preparation.—"Soap, dried and in coarse powder, one hundred grammes (100 Gm.) [3 ozs. av., 231 grs.]; lead plaster, nine hundred grammes (900 Gm.) [1 lb. av., 15 ozs., 327 grs.); water, a sufficient quantity. Rub the soap with enough water to reduce it to a semi-liquid state; then mix it with the lead plaster, previously melted, and evaporate to the proper consistence"—(U.S. P.). It is important that the soap be in powder form, in order to insure a perfect mixture with water, and that the water be afterward evaporated, so that the plaster will possess good adhesive qualities.
Action and Medical Uses.—This plaster, spread on leather, is used as a discutient and mechanical support. It will be found very useful as an application for constant wear, to aid in softening and removing corns, after they have been carefully shaved down. The addition of iodine and camphor will greatly improve its utility in this respect.