Benzoate of Ammonia, NH4O,C14H5O3 + HO. Prep. Neutralize oz. ij. of Benzoic Acid with fl. oz. iij. of Solution of Ammonia mixed with fl. oz. viij. of Distilled Water. Evaporate at a gentle heat and crystallize.

Med. Prop. and Action. A stimulating diuretic and stimulant to the mucous membrane of the urinary passages. It has the same action as Benzoic Acid, but it is preferable on account of its greater solubility.

Dose, gr. x. - gr. xx.

Phys. Action. Benzoate of Ammonia is rapidly absorbed, and its Benzoic Acid is converted into Hippuric Acid by the assumption of the elements of glycocoll, probably of glycocoll itself, which exists in the blood. Benzoic Acid C14H6O4+Glycocoll C4H5NO4=Hippuric Acid C18H9NO6+Water 2HO. The urine is altered in character, from the presence of the Hippuric Acid, which is eliminated by the kidneys; hence it becomes more acid and irritating. Like Benzoic Acid, Benzoate of Ammonia has no influence on the formation or secretion of Uric Acid. The Ammonia with which the Benzoic Acid is combined does not interfere with its acidifying action on the urine. The Ammonia does not pass through the renal organs, it is supposed to be either oxidised and converted into Nitric Acid, or eliminated by the skin and mucous membranes. ||

138. Therapeutic Uses

Generally the same as those of Benzoic Acid. In Chronic Inflammation of the Bladder, Dr. Garrod has found much benefit from its employment. It is of considerable service where a tendency to phosphatic deposit exists.*

* Med. Gaz. April 4, 1849.

Dispensatory, p. 886.

Lib. of Med. vol. iii. p. 211.

§ Cyc. Pract. Med. vol. i. p. 52. || Garrod, Med. Times and Gazette, Feb. 6, 1864, p. 147.