"Take of hydrochlorate of ammonia, ten ounces; lime newly burnt, eight ounces; water, two pints. Put the lime, mingled with part of the water, into a retort, then add the hydrochlorate of ammonia, in fragments, and, lastly, the remaining water. Distil fifteen ounces of the solution of ammonia.

Aqua Ammoniae, Edin. Water of Ammonia.

"Take of muriate of ammonia, one pound; lime newly burnt, one pound and a half; distilled water, one pound; water, nine ounces. Upon the lime broken to pieces, pour the water in an iron or earthen vessel, cover it up, until the lime have fallen into powder and become cold, then rub the muriate to a fine powder, and triturate it with the lime in a mortar; after which put them directly into a green-glass retort. Place the retort in a sand bath, and adapt to it a receiver furnished with a tube passing into a phial containing the distilled water; the phial, however, being sufficiently large to hold double the quantity of water. Then apply the fire, gradually raising it, until the bottom of the iron pot be red-hot, and as long as gas and vapour are produced. The specific gravity of this solution of ammonia is to that of distilled water as 0.939 to 1000. It should be preserved in small phials well stopped."

Ammoniae causticae Aqua, Dub. Water of Caustic Ammonia.

"Take of muriate of ammonia, in powder, three parts; lime newly burnt, two parts; water, ten parts. Pour one part of the water, made hot, upon the lime placed in an earthen vessel, and cover it up. Dissolve the salt in the rest of the water also heated. After the saline solution is cold, add it to the lime now in powder, cooled and put into a retort; distil five parts, with a medium heat, into a receiver kept cool. The specific gravity of this solution should be to that of distilled water as 0.950 to 1000."

Syn. Dissolution d'ammoniaque (F.), Atzender Ammonium-liquor (G), Vlugtiger etzender Salamoniak gecst (Dutch), Liquore di Ammoniaco (I.).

In these processes, the lime having a superior affinity for hydrochloric acid, decomposes the hydrochlorate, from which the ammonia is disengaged, and passes over in combination with the watery vapour. If the temperature of the water rise to 130°, the ammonia is again separated in the form of gas; and thence the necessity of keeping the receivers cold; but water at 60° takes up 780 times its bulk of gaseous ammonia: which increases the bulk of the liquid two thirds. The product thus obtained is an aqueous solution of ammonia; while hydrochlorate of lime remains in the retort, and may be dissolved out by twice its weight of water. The best proportions for extricating the ammonia, are equal parts of hydrochlorate of ammonia and of lime; thence in the London and the Dublin processes much of the ammonia is lost. A solution of sp. gr. 0.960 is obtained by adding two fluid ounces of water to one fluid ounce of the liq. ammonise fortior of commerce.1 Qualities.-Liquid ammonia is a limpid, colourless fluid. It has a very strong pungent odour, an extremely acrid taste, and corrodes the skin.

Obtained according to the London College, its specific gravity is 0.960, to the Edinburgh .9039, while that of the Dublin College is .9310. The following table shows the strength of liquid ammonia of different degrees of specific gravity within a certain range (temp. 50° Fahr., pressure 29.8 barom.): -

1 Aqua ammoniae pur P. L. 1787.

But Mr. Phillips says that the liquid ammonia of the London College of sp. gr. 0.960 is a compound of ammoniacal gas 10, water 90 parts, in 100.J For ordinary purposes it is useful to know that a phial capable of containing 224 grains of distilled water, can hold no more than 216 grains of the strong solution. At 46° Fahr. the ammonia in this solution crystallizes, and at 68° the fluid assumes the appearance of a thick jelly, and becomes almost inodorous.

1 In the notes in the present London Pharmacopoeia the quantity of water, is improperly stated: "cuiquc fluidunciae adjectis fluidunciis tribus aquae distillate."

2 Davy's Researches, p. 68. 3 Trans, of Pharm. p. 96.

Liquid ammonia assists the oxidizement of copper and of zinc; dissolves many of the metallic oxides; and unites with all the acids without effervescence, forming neutral salts. It dissolves oils, resins, and many other vegetable principles. Its affinity for carbonic acid is so powerful, that it rapidly attracts it from the atmosphere; and hence the necessity of preserving it in well-stopped, small phials, as directed by the Edinburgh College. The acids, the metallic salts, and alum, are incompatible in formulae with it. The constituents of the ammonia it contains, according to the latest experiments of Sir H. Davy, admitting the sp. gr. of ammonia to be 0.5902, or that of the concentrated solution 0.936, are 74 measures, by bulk, of hydrogen gas, and 26 of nitrogen gas; or, according to the analysis of Dr. Henry, 100 parts of ammonia consist of 80.36 of nitrogen, and 19.64 of hydrogen, by weight.1 Mr. Phillips says 17.64 of hydrogen, and 82.36 of nitrogen; or it is 3 equivalents of hydrogen - 3 + 1 equivalent of nitrogen = 14.15; making the equivalent 17.15.2 The presence of carbonic acid in solution of ammonia may be readily detected by its effervescing with acids, and by adding to it hydrochlorate of lime, which forms a precipitate if carbonic acid be present.

Medical properties and uses, - This solution of ammonia is stimulant, antacid, and rubefacient. It is usefully employed, when largely diluted, in paralysis, hysteria, and syncope: and is, perhaps, superior to all the other antacids in relieving cardialgia and other symptoms of acidity of the stomach. As a local stimulant it is applied to the nostrils in faintings; and a rag moistened with it, and laid over the scrobiculus cordis, sometimes raises an instantaneous blister, and, by quickly inflaming the skin, always proves useful in spasms and gout in the stomach. Combined with a small portion of oil, it forms a saponaceous rubefacient, which is beneficially applied to the throat in inflammatory sore throat, and as a friction in deep-seated inflammation and rheumatism. The dose of the solution is from x. to xx. in a large cupful of cold water or milk. When taken as a poison, if death be not the immediate result, the best antidote is vinegar.

Officinal preparations. - Hydro-sulphuretum Ammoniae, E. D. Oleum ammoniatum, E. Spiritus Ammoniae aromaticus, L. Lini-mentum Ammoniae, L. D. Hydrargyri Submurias ammoniatum, D. Calcis Phosphas prcecipitatum, D. Spiritus Ammoniae foetidus, L. Lin. Campnorae comp., L.

1 Philosophical Transactions, 1809. 2 Transl. of Pharm. p, 38,

Aqua Ammonieae diluta, Edin. Diluted Water of Ammonia,

"Take of water of ammonia, one part; distilled water, two parts. Mix them together."

This preparation is probably intended for facilitating extemporaneous prescription; but, as the solution of ammonia is never given except in a diluted form, it appears to be superfluous.