potassium

n. [ NL. See Potassa, Potash. ] (Chem.) An Alkali element, occurring abundantly but always combined, as in the chloride, sulphate, carbonate, or silicate, in the minerals sylvite, kainite, orthoclase, muscovite, etc. Atomic weight 39.0. Symbol K (Kalium). [ 1913 Webster ]

☞ It is reduced from the carbonate as a soft white metal, lighter than water, which oxidizes with the greatest readiness, and, to be preserved, must be kept under liquid hydrocarbons, as naphtha or kerosene. Its compounds are very important, being used in glass making, soap making, in fertilizers, and in many drugs and chemicals. [ 1913 Webster ]

Potassium permanganate, the salt KMnO4, crystallizing in dark red prisms having a greenish surface color, and dissolving in water with a beautiful purple red color; -- used as an oxidizer and disinfectant. The name chameleon mineral is applied to this salt and also to potassium manganate. --
Potassium bitartrate. See Cream of tartar, under Cream. [ 1913 Webster ]