Two different methods of proceeding are adopted in this process. In the one the dry pulverulent ingredients are mixed together, and the resulting gas distilled over into the water placed in the receivers. In the other the lime is made into a ‘pap’ with water, and the ammonia-salt, in coarse powder, being added, the whole is rapidly blended together, before closing the retort, and applying heat. In either case a proportionate quantity of water is put into the condensers, and the operation is nearly similar; but the latter method requires the least heat, and so far as the receivers and refrigerators are concerned, is, perhaps, the one most easily managed. It is that which is always, and necessarily followed, when sulphate of ammonia is employed. _Prop., Uses, &c._ Highly pungent, caustic, and alkaline; lighter than water, and presenting in a liquid form most of the characteristics of pure ammonia. When strongest has a sp. gr. of ·875, and contains about 39 per cent. of ammonia, but the usual strong ammonia of commerce has a sp. gr. of but ·88. The liquor ammonia fortior, B. P., has a sp. gr. of about ·893, and contains 32·5 per cent. of ammonia, while the liquor ammoniæ B. P. has a sp. gr. of about ·940, and contains about 10 per cent. of ammonia. As a medicine it is antacid, diaphoretic, rubefacient, stimulant, and counter-irritant; and is used in various affections in which these remedies are indicated. As a vesicant it is superior to cantharides, and as a caustic it is used with advantage in the bites of rabid animals, especially those of serpents and insects. Its vapour is a common nasal stimulant in faintings, epilepsy, &c. In its concentrated form it is a corrosive poison.——_Dose_, 5 to 25 drops, in cold water, or milk and water. It enters into the composition of several valuable external remedies, and is in constant employment in the _chemical laboratory_, both as a reagent and for the preparation of other compounds. _Ant., &c._ When the fumes have been inhaled, the patient should be exposed to a current of fresh air; and when the liquid has been swallowed, vinegar or lemon-juice mixed with water may be administered; followed by an emetic, or, on its failure, by the stomach-pump.