Ammonium carbonate consists of a mixture of ammonium bicarbonate and ammonium carbamate.

Properties : It occurs as white, hard masses, having a strong odor of ammonia and a sharp, saline taste. On exposure to the air the salt loses both ammonia and carbon dioxid. Ammonium carbonate is slowly but freely soluble in water, the ammonium carbamate being thereby converted into normal ammonium carbonate. Alcohol dissolves the carbamate and leaves the bicarbonate.

Incompatibilities: Ammonium carbonate is incompatible with acids, which decompose it, forming salts of ammonium and evolving carbon dioxid (C02). It precipitates the carbonate or the hydroxid of most metals and the insoluble alkaloids from solutions of their salts.

Action and Uses: Ammonium carbonate is largely decomposed (hydrolyzed) when dissolved in water, and its solutions are irritant to mucous membranes from the action of the ammonia set free. It is used by inhalation or in solutions as a reflex or diffusible stimulant in syncope, or arrest of respiration, and as a liquefying expectorant in bronchitis.

Dosage: 0.25 gm. or 4 grains, dissolved in sufficient water to avoid too great irritation, which may result in nausea and vomiting. On the other hand, as the action of the remedy depends on its irritating qualities, it should not be too greatly diluted.