Origin. - Prepared by the action of carbon dioxide upon a solution of the carbonate.

Description and Properties. - Colorless, transparent, monoclinic prisms, odorless, and having a saline and slightly alkaline taste. Permanent in the air, soluble in 3.2 parts of water at 15 C. (590 F.) and in 1.9 parts at 500 C. (122o F.). At a higher temperature the solution rapidly loses carbon dioxide, and, after boiling, contains only potassium carbonate. It is almost insoluble in alcohol. The drug should be kept in well-stoppered bottles.

Dose. - 10-40grains (0.6-2.5 Gm.) [30 grains (2 Gm.), U. S. P.].