Plaster, Ammoni′acal. Syn. Dr Kirkland’s volatile plaster; Emplastrum ammoniæ, E. a. hydrochloratis, L. Prep. Take of lead plaster, 1 oz.; white soap (shaved fine), 1⁄2 oz.; melt them together, and, when nearly cold, add of sal ammoniac (in fine powder), 1 dr. Stimulant and rubefacient. Dr Paris, who highly recommends it in pulmonary affections, employs double the above proportion of sal ammoniac. Its efficacy depends on the gradual extrication of free ammonia by the decomposition of the sal ammoniac, on which account it is proper to renew the application of it every 24 hours.
Plaster of Ammoni′acum. Syn. Emplastrum ammoniaci (Ph. L., E., & D.), L. Prep. 1. (Ph. L. & E.) Ammoniacum (strained), 5 oz.; dilute acetic acid (distilled vinegar), 8 fl. oz. (9 fl. oz.—Ph. E.); dissolve, and, frequently stirring, evaporate by a gentle heat to a proper consistence.
2. (Ph. D.) Gum ammoniacum (in coarse powder), 4 oz.; proof spirit, 4 fl. oz.; dissolve by the aid of a gentle heat, and evaporate, as before.
Obs. This plaster is adhesive, stimulant, and resolvent, and is employed in scrofulous and indolent tumours, white swellings, &c. In the Ph. D. 1826 vinegar of squills was ordered instead of distilled vinegar.
Plaster of Ammoniacum with Hem′lock. Syn. Emplastrum ammoniaci cum cicutâ, L. Prep. (Ph. E. 1744.) Gum ammoniacum, 8 oz.; vinegar of squills, q. s. to dissolve; hemlock juice, 4 oz.; gently evaporate, as before. In cancerous and other painful tumours. A better plan is to add 1 dr. of extract of hemlock to 11⁄4 oz. of strained ammoniacum (previously reduced to a proper consistence with a little distilled vinegar), melted by a very gentle heat.
Plaster of Ammoniacum with Mer′cury. Syn. Emplastrum ammoniaci cum hydrargyro (B. P., Ph. L., E., & D.), L. Prep. 1. (Ph. L. & E.) Olive oil, 1 dr.; heat it in a mortar, add of sulphur, 8 gr.; triturate; further add of mercury, 3 oz.; again triturate, and when the globules are extinguished, add it to ammoniacum (strained), 1 lb. (12 oz., B. P.), previously melted by a gentle heat, and mix them well together.
2. (Ph. D.) From ammoniacum plaster, 4 oz.; mercurial plaster, 8 oz.; melted together by a gentle heat, and then stirred constantly until nearly cold.
3. (Wholesale.) Take of mercury, 38 oz.; prepared sevum, 5 oz.; triturate, as last, and add the mixture to strained ammoniacum, 10 lbs., previously sufficiently softened by a gentle heat. Possesses a fine blue colour, and is quickly made.
Obs. This plaster cannot be rolled till considerably cooled, and neither this nor the
simple plaster must be put into water. It is powerfully discutient, and is applied to indurated glands, indolent tumours, &c.