Physiological Action. — Ammonium carbonate possesses to a smaller degree the stimulating properties of ammonia. It excites the functions of the skin, the kidneys, the bronchial glands, and the epithelium. It reduces the normal gas tric acidity and tends to irritate the stomach and cause vomiting if given in , too large doses. It is thought to play an important role in the formation of urea and glycogen when penetrating the liver with a carbohydrate, the adminis tration of food with ammonium salts being known to encourage the excretion of urea. Carbonate of ammonia also possesses antiseptic properties.
A 5- to S-per-cent. ammonium solution will preserve rabbit-fat ten months from decomposition. A 5-per-cent. solution of ammonium carbonate also acts as an antiseptic. Meat, animal organs, etc., kept in fumes of this drug, look nearly the same after six months. C. Gott brecht (Archly fiir cxp. Path. and Pharm., B. 25, H. 5, 0, '90).
Therapeutics.—This drug is especially valuable in diseases of the respiratory tract. It acts as an active expectorant. In bronchitis, especially in the chronic form, when the dyspncea is marked and the general adynarnia is caused by inter ference with the functions of the pul monary tract, it probably represents the best agent at our command. H. C. Wood regards it as the best preparation for continuous use in typhoid pneumonia. In both of the diseases mentioned it may be given in doses of from 5 to 10 grains, repeated every two hours, the effects of this dose upon the system lasting no longer than that time.
It is a valuable drug as a cardiac and nervous stimulant in the capillary bron chitis — broncho-pneumonia — of chil dren.
In acute coryza it is also employed with satisfactory results.
The best means of aborting an attack of acute coryza is the administration of rather large and frequently-repeated doses of carbonrrte of ammonia. Beverly Robinson (Boston Med. and Surg. Jour., Nov. 14, '89).
Ammonium Chloride.
Chloride of ammonium—or, as it used to be preferably called, muriate of am monia, or "sal ammoniac"—is a white, translucent salt, having no odor, but a sharp, saline taste.. It dissolves in three parts of cold and in one part of boiling water, and sublimes without decomposi tion at red heat.
Dose. — The usual dose is 5 to 10 grains, but when a sudden effect is to be produced, as in alcoholism, from 30 to 60 grains may be administered, with a copious draught of water.
Physiological Action.—Applied in its solid form or in saturated solution, am monium chloride acts as an irritant upon mucous membranes. When given con tinuously for some time, it is thought to produce a profound impression upon the blood itself, lessening its plasticity and impairing its constitution; it may then cause prostration accompanied by the extravasation of blood under the skin, lapematuria, and haemorrhages from the mucous membranes. In smaller doses
long continued it tends to impoverish the blood, the latter containing less than the normal percentage of solids. It in creases very notably all the solids of the urine, except the uric acid. It affects the mucous membranes, encouraging nu tritive changes and the exfoliation of epithelium. Its chief elimination takes place through the kidneys.
Ammonium-Chloride Poisoning.—The experimental evidence published is con tradictory, but it tends to show that this salt does not possess much toxic power even in large doses.
Gourinsky, after some experiments on frogs and pigeons poisoned with am monium chloride, reached the following conclusions: In frogs whose spinal cord has been divided below the medulla oblongata, ammonium chloride produces from the first a marked augmentation of reflex acts. In frogs deprived of cer tain parts of the central nervous system (spinal cord, medulla oblongata, the cerebellum alone being retained) this augmentation is preceded by a marked depression. In normal frogs and pigeons chloride of ammonium produces at first depression of the central nervous system, then convulsions: that is, the higher centres exercise a great inhibitory influ ence on the spinal reflexes. When the poison is introduced rapidly the first stage (that of depression) is but slightly marked, and soon gives place to the second stage (that of irritation, ushered in by convulsions). When the poison is introduced slowly the general nervous depression is well marked and lasts a long time. In frogs and pigeons de prived of the cerebral hemispheres only, whatever be the method of introducing the poison, convulsions are not preceded by depression, but the latter is sometimes replaced by irritability. All the facts can be explained only by the reciprocal action of the nervous centres on each other, modified by the poison.
In a ease in which a large quantity of ammonium hydrate had been taken the mucous membrane of the anterior part of the mouth was denuded, and the peculiar fact was noted that after three days. when solid nourishment was again taken, the food appeared to be saltless. P. Caries (Jour. de Mdd. de Bordeaux, July 13, '90).
Therapeutics. — Ammonium chloride is especially valuable in all disorders in which the mucous membrane is involved.