Prep. By reducing the carbonate of ammonia to fine powder, spreading it out on a sheet of paper, and exposing it to the air for twenty-four hours, then keeping it in a well-stoppered bottle.

Prop. & Comp. A white powder when thus prepared, but it can be crystallized in six-sided prisms from a solution in water, of which, in the cold, about 8 parts are required for its solution; it has very little ammoniacal odour, and a saline, slightly pungent, taste. Composition (Nh4 O, Co2 + HO, Co2), or a double carbonate of ammonia and water.

Therapeutics. Very slightly stimulant and antispasmodic, but increases the capillary circulation and the secretions of the skin and mucous membranes.

Pose. 10 gr. to 30 gr. or more, dissolved in water, etc.