Ammonium, Nitrate of

NH 4 NO 3 . Syn. Ammo′′niæ ni′tras , L.; Nitrate d’ammonia que , Fr. Prep. Saturate nitric acid (diluted with 3 or 4 times its weight of water) with sesquicarbonate of ammonium, evaporate by a gentle heat, and crystallise. When not required in a crystalline form, it is usually evaporated to dryne at about 212° Fahr.; and the heat being carefully raised to about 250°, the fused salt is poured out on a polished slab of iron or stone, and when solidified broken up and put into bottles. Prop. When the evaporation of the solution is conducted at a heat under 100° Fahr., the salt is obtained in beautiful hexagonal prisms; when at 212°, in long silky fibres; when by rapid evaporation and fusion, it forms a white, compact, and usually foliated ma . It di olves in about twice its weight of water; is slightly deliquescent; melts at 230°, and is decomposed into nitrous gas and water at 460° Fahr. It deflagrates, like nitre, on contact with heated combustible matter. Uses, . Chiefly to prepare nitrous oxide or laughing gas (of which nearly 4 1 ⁄ 2 cubic feet may be procured from every lb. avoir.); and with water, to form freezing mixtures, for which purpose it may be used for any number of times by simply evaporating the solution to dryne , when the salt, obtained unaltered, is ready for another operation. Care, however, should be taken not to expose it to too great a heat, as at a certain temperature it deflagrates with violence. It is occasionally employed in the laboratory to promote the combustion of organic bodies during incineration; and sometimes, though seldom, in medicine, as a diuretic and diaphoretic. It is said to reduce the frequency of the pulse, and the animal heat, without affecting the head, chest, or stomach. (Wibmer.)— Dose , 10 to 30 gr.