The dose of the medicine is from two or three to twenty grains, repeated every half hour, hour, or two hours. From five to ten grains every hour or two is the ordinary dose in low fevers. Thirty grains or more will generally vomit. The medicine may be given in pill or solution; but the latter is the better form; because, should the pill come in contact with the mucous coat of the stomach, it would be more apt to excite irritation. But the acrimony of the salt should be covered by mixing it, in solution, with gum arabic and loaf sugar, and the taste corrected by using one of the aromatic waters as the vehicle.

Carbonate of ammonia, broken into minute fragments, and mingled with the volatile oil of bergamot, lavender, or other aromatic, is put into small bottles, and used as smelling salts. The ammoniacal odour, which is rendered agreeable by that of the volatile oils, is pungent and exciting; and the preparation is frequently used by delicate persons to obviate unpleasant nervousness, and to relieve faintness. Indeed, the application of ammoniacal vapour to the nostrils is one of the most efficient of the milder methods of preventing or remedying syncope. For this purpose, either the carbonate may be used, or one of the liquid preparations of ammonia to be mentioned directly. They are simply held to the nostrils, so that the patient, if still breathing, may inhale the vapour with the air; and even without inhalation, a portion of the vapour will enter the nostrils on the principle of the diffusion of gaseous bodies; but caution is necessary, especially when the patient is insensible, that the vapour should not be too concentrated, nor too copiously applied; as there is risk of producing severe inflammation of the nostrils, of the larynx, and even of the bronchial tubes, when it is carried into the lung with the inhaled air.

The salt is sometimes used externally, mixed with olive oil, as a mild rubefacient liniment. A liniment was directed by the London College, though discarded in the British Pharmacopoeia, made by mixing a fluid-ounce of a saturated solution of the salt with three fluidounces of olive oil. An imperfect soap was thus formed; but the union of the oil with the carbonate is less perfect than with the solution of ammonia, and the preparation is consequently less elegant than the officinal liniment of ammonia.

There are several other ammoniacal preparations which are more or less used internally for their stimulant effects.