Characters. - Thin white four-sided laminar crystals, permanent in the air, having a slight odour of benzoic acid, a saline, bitter, afterwards slightly acrid taste, and a neutral reaction.

Reactions. - When strongly heated the salt melts, emits vapours having the odour of ammonia and of benzoic acid, and is finally wholly dissipated.

Uses. - It is used as a diuretic, and to render the urine acid where there is a tendency to phosphatic deposits.