Ammonium, Nitrate of. NH4NO3. Syn. Ammo′′niæ ni′tras, L.; Nitrate d’ammoniaque, 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 dryness 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 mass. It dissolves 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, &c. Chiefly to prepare nitrous oxide or laughing gas (of which nearly 41⁄2 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 dryness, 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.
Ammonium, Nitro-sulphate of. Syn. Ammo′′niæ nitro-sul′phas, L. Dissolve sulphite of ammonium, 1 part; in solution of ammonia, 5 parts; and pass nitric oxide gas through the solution; rapidly wash the crystals that form with solution of ammonia, dry in bibulous paper, without heat, and preserve them in a well-stopped bottle.—Dose, 10 to 20 gr.; in typhoid fevers, &c.
Ammonium, Oxalate of. (NH4)2C2O4. Syn. Ammo′′niæ ox′alis, L.; Oxalate d’ammoniaque, Fr. Neutralise a hot solution of oxalic acid with sesquicarbonate of ammonia; evaporate and crystallise.
Prop. It forms beautiful, colourless, long, rhombic prisms, which effloresce in the air; slightly soluble in cold water; freely soluble in hot water; heated in a retort, it yields ammonia, carbonate of ammonia, cyanogen, and carbonic acid, together with oxamide, which sublimes.
Uses, &c. In chemistry, chiefly as a test for calcium (with which it produces a white precipitate soluble in nitric acid), and to separate lime from magnesium, solutions of the salt of which it does not precipitate. A BINOX′ALATE may also be formed; but it possesses no practical interest.
Ammonium, Phosphate of. (NH4)3PO4. Syn. Ammo′′niæ phos′phas, L. Prep. Saturate a solution of phosphoric acid with sesquicarbonate of ammonium, in slight excess; gently evaporate and crystallise by refrigeration. Diuretic, discutient, and antilithic.—Dose, 3 to 10 gr., or 20 to 30 drops of a saturated solution, 3 or 4 times a day; in gout, rheumatism, and calculus, accompanied with the lithic-acid diathesis; also in rickets and certain forms of dyspepsia.
Ammonium Suc′cinate. Syn. Ammo′′niæ suc′cinas, L. Prep. 1. Succinic acid, 1 part; water, 4 parts; dissolve, neutralise with solution of ammonia, or of ammonium carbonate, in slight excess, and evaporate, and crystallise as directed under the ‘benzoate’ or ‘phosphate,’—Dose, 2 to 10 gr.