Ratio. Gas-liquor contains carbonate of ammonium (chiefly), with chloride, sulphate, hydrosulphate, cyanide, sulphocyanide, &c., of the same radical. On neutralisation with hydrochloric acid, or sulphuric acid, these are converted into chloride or sulphate of ammonium, according to the acid used. By sublimation with chloride of sodium, the sulphate of ammonium is converted, by double decomposition, into chloride of ammonium, which sublimes; and sulphate of sodium, which remains in the subliming pot. A similar change occurs when the solution of the sulphate, prior to crystallisation, is decomposed by the addition of chloride of sodium, or any other chloride. When the ‘gas-liquor’ is at once converted into chloride of ammonium by the addition of hydrochloric acid, the sublimation merely purifies the salt. Like changes occur when bone-spirit is employed.
Comp. Chemically considered, this salt consists of equal VOLUMES of gaseous ammonia and hydrochloric acid gas condensed into the solid form; or, by WEIGHT, according to the ammonia-theory, of—
| Atoms. | Equiv. wt. | Per cent. | |
| Ammonia (NH3) | 1 | 17· | 31·78 |
| Hydrochloric acid (HCl) | 1 | 36·5 | 68·22 |
| —— | ——— | ——— | |
| Hydrochlorate of Ammonia (NH3HCl) | 1 | 53·5 | 100· |
Or, according to the ‘ammonium-theory,’ of—
| Atoms. | Equiv. wt. | Per cent. | |
| Ammonium (NH4) | 1 | 18· | 33·65 |
| Chloride (Cl) | 1 | 35·5 | 66·35 |
| —— | ——— | ——— | |
| Chloride of Ammonium (NH4Cl) | 1 | 53·5 | 100· |
Prop. &c. The sal ammoniac of commerce is found under the form of large white hemispherical, cup-like cakes or masses (or in large fragments which are sections of them), possessing a tough, fibrous, semi-crystalline texture, and very difficult to powder. It is odourless, has a saline taste somewhat sharp or acrid, and sublimes without either fusion or decomposition. It slightly reddens litmus; dissolves in rather less than 3 parts of cold water, and in about 1 part of boiling water; is soluble in alcohol; and when crystallised from water, under favorable circumstances, forms distinct octahedra, or cubes, usually small and aggregated together in rays or feathery masses. By slowly evaporating its aqueous solution, it may be sometimes obtained in cakes an inch in thickness. It is anhydrous. Sp. gr. 1·450.
Pur. It should give a colourless solution with water; wholly sublime with heat; and neither chloride of barium, nor sulphuretted hydrogen, should affect its solution. A solution,
to which a few drops of nitric acid have been added, should not yield a blue precipitate with ferrocyanide of potassium. It often contains sesquichloride of iron, and sometimes lead; both of which may be readily detected by the above tests. Its complete volatility may be easily determined by heating, in the flame of a candle, a small fragment held on the point of a knife.
Tests.—1. It is known to be a salt of ammonium by its cooling ammoniacal fumes when triturated with lime, or when moistened with caustic potassa or soda:—2. It is shown to be a chloride by its solution yielding, with nitrate of silver, a white curdy precipitate, insoluble in boiling nitric acid, soluble in ammonia.
Uses, &c. In the arts, chiefly in the coating and soldering of metals, and the preparation of alloys; in dyeing; and in the manufacture of ammonia-alum; also, in large quantities, to give a factitious pungency to snuff. In chemistry, as a reagent; and, owing to the cold produced during its solution, to form frigorific mixtures. In medicine it is chiefly used externally, as a stimulant and resolvent or discutient; and occasionally, internally, as a diuretic, stimulant, resolvent, alterative, tonic, &c., particularly in chronic inflammations of the mucous and serous membranes, in chronic glandular and visceral enlargements and indurations, and in amenorrhœa. In rather large doses, frequently repeated, it is said to prove often highly beneficial in chronic enlargement and induration of the prostate gland (M. René Vanoye); and also in other like cases.—Dose, 5 to 20 gr., 3 or 4 times daily, either in powder or solution, mixed with some demulcent; as a discutient or resolvent lotion, 1 to 11⁄2 oz., to 1⁄2 pint of water, either with or without 4 or 5 fl. oz. of spirits or strong vinegar (often serviceable in chilblains); as a weak lotion, or a collyrium or injection, 1 to 4 dr., to water, 1 pint. In very large doses it is poisonous; the treatment is emetics and mucilaginous or demulcent drinks.