Emery Cloth is prepared by brushing the surface of thin cotton cloth over with liquid glue, and sifting the emery powder over the surface while still warm.
Emery Paper is made in the same way as emery cloth. Both are used either with or without oil, in the same way as glass paper.
Emery Sticks are made of pieces of wood in the same way, and are used for the same purposes, as emery paper.
Emery Stones are formed of emery, of the
requisite coarseness, mixed with about half its weight of good Stourbridge loam, and water q. s. to make a stiff paste, which is forced into metallic moulds by a powerful press. The pieces, when thoroughly dry, are exposed in a muffle for a short time to a temperature just under a full white heat. In this way ‘discs’ and ‘laps’ are generally made. For ‘wheels,’ only 1⁄4th of loam is used. Another method, applicable for ‘cutting stones’ generally, is to press the flour emery, previously moistened with water, into moulds, with strong pressure, as before, without any other addition, and then to fire it at nearly a full white heat.
EMETIA. Syn. Emetin, Emetina. A feebly basic or alkaloidal body, existing in and forming the active principle of ipecacuanha.
Prep. 1. (Medicinal—Emetic Extract.)—a. Ipecacuanha (in coarse powder) is digested first in ether, and then in rectified spirit for 3 or 4 days; the alcoholic tincture is next expressed and evaporated (distilled) to dryness; the residuum is dissolved in distilled water, and the solution precipitated with acetate of lead; the precipitate is then diffused through distilled water, in a tall glass vessel, and sulphuretted hydrogen is passed through it, to throw down the lead; after which the liquor is decanted, filtered, evaporated to the consistence of a thick syrup, and spread in a thin layer on warm plates of glass, and allowed to dry in a current of warm air, or by a gentle heat in a stove. The maceration in ether is frequently omitted.
b. Ipecacuanha, 1 part; rectified spirit (·835), 7 parts; make a tincture, distil off the spirit, dissolve in cold distilled water, 5 parts; filter the solution, and evaporate, &c., as before. Inferior to the last.
c. (P. Cod.) As the last, nearly.
Obs. Medicinal or impure emetia is brownish, red, deliquescent, and emetic in doses of 1⁄4 to 1⁄2 gr.