Characters. - A white powder, or small shining scales permanent in the air, odourless or having a faint benzoin-like odour; of a cooling sweetish taste, and a faintly acid reaction.

Reactions. - When heated, the salt fuses; at a higher temperature it chars, emits inflammable vapours having a benzoin-like odour, and finally leaves a black residue of an alkaline reaction, and imparting a crimson colour to a non-luminous flame. On mixing the aqueous solution with a dilute solution of ferric sulphate, a flesh-coloured precipitate is produced.

Dose. - 8-30 grains (0.5-2 gm.).

Uses. - It has been used as a remedy for gout and uric acid.