Prep. (Solution of ammonia, three fluid ounces; benzoic acid, two ounces; distilled water, eight fluid ounces; dissolve and set aside to crystallize.)

Prop. & Comp. It occurs in colourless laminar crystals, which are readily soluble in water, in this respect differing from benzoic acid; soluble also in alcohol. The watery solution, when acidulated with hydrochloric acid, deposits benzoic acid. Heated with caustic potash it evolves ammonia. It is entirely sublimed by heat. The aqueous solution gives a bulky yellow precipitate with persalts of iron. The composition is represented by the formula, Nh4o, C14,H5O3 + HO.

Therapeutics. Benzoate of ammonia acts as a diuretic and slight stimulant; it is employed in cases of chronic inflammation of the bladder, etc, where there is a tendency to phosphatic de. posits. On account of its ready solubility it is much more readily administered than benzoic acid. It appears in the urine as hip. puric acid.

Pose. 10 gr. to 20 gr.