Permanganate of potash is prepared by heating together ten parts of binoxide of manganese and twelve of potassa. It occurs in slender, prismatic crystals of a dark-purple color, inodorous, of a sweetish, disagreeable taste, and very soluble in water, with which they form a solution varying from a purplish black to a beautiful reddish lilac, according to the strength. When kept dry and not exposed to the atmosphere, the permanganate of potash is a perma- nent salt, but whenever in solution it is brought into contact with an organic body, it at once gives up its oxygen to the latter, and is converted into potassa and the black oxide of manganese. (Dr. H.