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ELEMENTS OF MATERIA MEDICA.

an emmenagogue, in those cases in which the disease depends on, or isconnected with inactivity of the uterus.

Externally it is sometimes employed, on account of the cold producedduring its solution, in headache, mania, apoplexy, See, When used forthis purpose it must he applied as soon as the salt is dissolved. Mr.Walker {Phil. Trans. 1801, p. 120) found that two parts of this salt,with five parts of nitrate of potash and sixteen parts of water, loweredthe thermometer from 50° F. to 10° F. A mixture of this kind placed ina bladder has been recommended by Sir A. Cooper as an applicationto liemial tumors. It may be applied to the head instead of ice.

Sal ammoniac has been employed externally as a stimulant, or resolventor discutient. Dr. Paris ( Pharmacologia ) strongly recommends tirefollowing stimulant and rubefacient plaster in pulmonary complaints andin rheumatic affections of the muscles of the chest: soap Si. lead plaster-ip, liquified together, to which, when nearly cold, is added of hydro-chlorate of ammonia finely powdered, 5**;?,-.The efficacy of this plasterdepends on the evolution of ammoniacal gas in consequence of the actionof the alkali of the soap on the hydrochloric acid of the hydrochlorate:hence it should be renewed every twenty-four hours. A strong solutionof sal ammoniac (as one or two ounces of the salt to twelve ounces ofwater) is employed in the cure of contusions and ecchymosis, unaccom-panied by any wound of the skin ; in chronic tumors, as of the breast;in local dropsies, as hydrocele and dropsy of the thyroid gland; inchilblains ; in sphacelus after the requisite scarifications, &c. Weakersolutions (as from one to four drachms of the salt to a pint of water) areemployed as washes in scabies and ulcers, as gargles in cynanche, andas injections in gonorrhoea and leucorrhcea. This salt in powder issometimes used as a tooth-powder.

Administration.- —For internal use the dose of it is from five to thirtygrains every two or three hours, either in a pulverent form, combinedwith sugar or gum, or in solution with some saccharine or mucilaginoussolution, to which an aromatic should be added.

Antidote. —In the event of poisoning by this salt, warm water andmucilaginous and demulcent liquids should be given to promote vomit-ing. No chemical antidote or counterpoison is known. Gastro-enteritisis of course to be combated by the usual means.

Liquor Ammo'nim Aceta'tis.—Solution of Ace'tate of Ammo'nia .

History and Sy'nonymes. —This solution appears to have been firstdescribed in 1732, by Boerhaave , who introduced it into the MateriaMedica. It was subsequently employed by Minderer or Mindererus;and hence obtained one of its names, spiritus seu liquor Mindereri.

Natural History. —Acetate of ammonia is, I believe, always an arti-ficial compound.

Preparation. —In the London Pharmacopoeia this compound is or-dered to be prepared by dissolving, in four pints of distilled vinegar, fourounces and a half (or as much as may be sufficient to saturate the aceticacid) of sesquicarbonate of ammonia. Every equivalent, or 51 parts of