Characters. - In colourless, inodorous, translucent, fibrous masses, tough, and difficult to powder.

Solubility. - It is soluble in water and in rectified spirit. Reactions. - When heated it volatilises without decomposition, and leaves no residue. Its solution in water gives the reactions of ammonia (p. 634) and a chloride (p. 594).

Preparation. U.S.P.

Dose.

Trochisci Ammonii Chloridi.

2 grains in each ...............

1 every hour or two.

Dose. - 5 to 20 grains.

Action and Uses. - Cold is produced during the process of solution in water of ammonium chloride, and so its solution has been used locally in headache, inflammation of the brain, mania, and apoplexy. It has been employed as a lotion to remove ecchy-moses, to prevent discoloration in bruises and sprains, and to allay itching in prurigo. It has been applied locally as a dressing in abscess of the mamma, and to remove glandular enlargements. As a gargle, it has been used to cause contraction of the enlarged flabby uvula, and to relieve the cough which the tickling of the pharynx by the uvula often causes.

A small dose of 5 to 7 grs. of ammonium chloride has no effect, but if taken frequently it causes discomfort and heat in the stomach, slight headache, diuresis, and an increased secretion of mucus from the intestine, although the stools are not more numerous.

Large doses given to animals often cause pain and excitement, then collapse (no diarrhoea), convulsions, and death. The stomach is congested, the mucous membrane swollen, and the epithelial cells easily separated.

The same symptoms are produced when ammonium chloride is applied to a wound, and the same post-mortem appearances are seen in the stomach.

It thus seems to have a special action on the gastric mucous membrane. It is used in Germany in cases which are usually supposed to be due to a catarrhal state of the stomach - viz. when there is loss of appetite, sickness, bad taste in the mouth, fulness in the stomach, and flatulence, with a coated tongue, and along with these bronchial catarrh without fever. Ammonium carbonate is preferred when there is much cough or the person is weak.

1 Rohmann, Centralblatt f. klin. Med., No. 36,1884.

It is also used alone in bronchial catarrh, when this has either come on without fever, or the feverish symptoms have passed off. It is supposed to have the power of increasing the secretion of mucus in the bronchi as well as in the intestine, and it is therefore not given when the expectoration is profuse, but only when it is scanty and difficult to bring up.

It has been given to relieve the vomiting and heartburn occurring in cancer of the stomach. It is said to have a powerful action on the liver (p. 636), and has been strongly recommended in chronic congestion and hepatic abscess, as well as in dropsy depending upon hepatic disease. For its alterative action it has been given in muscular rheumatism, rheumatic pains, and neuralgia. In neuralgia it should be given in half-drachm doses several times a day; but if the pain is not relieved after four or five doses have been given, it may be discontinued. It is also useful in neuralgic headaches.