Plaster, Can′cer. Syn. Emplastrum anticancrosum, L. Prep. 1. Wax plaster, 1 oz.; extract of hemlock, 1 dr.; levigated arsenious acid, 1⁄2 dr.
2. (Richter.) Extract of hemlock, 1 oz.; extract of henbane, 1⁄2 oz.; powdered belladonna, 1 dr.; acetate of ammonia, q. s. to form a plaster. Both the above must be used with great caution. See Cancer, &c.
Plaster of Canthar′ides. Syn. Blistering plaster, Vesicant p., Plaster of Spanish
flies; Emplastrum cantharidis (B. P., Ph. L., E., & D.), E. c. vesicatoræ, E. lyttæ, L. Prep. 1. (Ph. L.) Yellow wax and suet, of each 71⁄2 oz.; lard, 6 oz.; resin, 3 oz.; melt them together, remove the vessel from the fire, and, a little before they concrete, sprinkle in of cantharides (in very fine powder), 1 lb. (12 oz. B. P.), and mix.
2. (Ph. E.) Cantharides, beeswax, resin, and suet, equal parts; as the last.
3. (Ph. D.) Spanish flies, 6 oz.; prepared lard, resin, and yellow wax, of each 4 oz.; proceed as before, and “stir the mixture constantly until the plaster is cool.”
4. (Wholesale.) From beeswax and good lard, of each 4 lbs.; flies and yellow resin, of each 6 lbs.; suet, 10 lbs. A commonly used formula, the product of which is, however, greatly inferior to that of the Pharmacopœia.
Obs. All the above are used to raise blisters. The plaster is spread on white leather with a cold knife, and is surrounded with a margin of resin plaster to make it adhere. A piece of thin muslin or tissue paper is usually placed between the plaster and the skin to prevent absorption. A little powdered camphor is sometimes sprinkled on the surface of the spread plaster, to prevent strangury. A better mode of obviating the action on the urinary organs is by the copious use of diluents. This plaster should be rolled in starch powder, and not with oil.
Plaster of Cantharides (Compound). Syn. Emplastrum cantharidis compositum, L. Prep. (Ph. E.) Venice turpentine, 41⁄2 oz.; cantharides and Burgundy pitch, of each 3 oz.; beeswax, 1 oz.; verdigris (in fine powder), 1⁄2 oz.; powdered mustard and black pepper, of each 2 dr.; mix at a heat under 212° Fahr. Stronger than the last, and quicker in its action; but it causes more pain, and is much more apt to occasion troublesome ulcerations. Used in gout, spasms of the stomach, &c.
Plaster, Capuchin′. See Plaster of Euphorbium.