Origin. - Prepared by a complicated process by heating in an iron or earthen retort a mixture of sal ammoniac and chalk.

Description and Properties. - White, hard, translucent, striated masses having a strongly ammoniacal odor without empyreuma, and a sharp, saline taste. On exposure to the air the salt loses both ammonia and carbonic acid, becoming opaque, and is finally converted into friable porous lumps or a white powder. Slowly but completely soluble in about 5 parts of water at 15o C. (59o F.), and decomposed by hot water, with the evolution of carbonic acid and ammonia. By prolonged boiling with water the salt is completely dissipated. The aqueous solution possesses a strongly alkaline reaction and effervesces with acids.

Dose. - 3-10 grains (0.18-0.6 Gm.).

Official Preparation

Spiritus Ammoniae Aromaticus - Spiritus Ammoniae Aromatici - Aromatic Spirit of Ammonia. - Composition: Ammonium carbonate, ammonia water, aromatic oils, alcohol, and water.

Description and Properties. - A nearly colorless liquid when freshly prepared, but gradually acquiring a somewhat darker tint. It has a pungent, ammoniacal odor and taste.

Dose. - 1/2-1 fluidram (1.8-3.7 Cc.) [30 minims (2 Cc), U. S. P.].

Antagonists and Incompatibles. - The alkalies and their carbonates are incompatible with acids and with metallic salts. The ammonium carbonate is incompatible with the acidulous salts and with lime water.

Synergists. - Agents promoting waste, such as vegetable acids, mercury, iodine, etc., increase the therapeutic activity of the alkalies.

Physiological Action. - The alkalies mentioned in this group may be divided into direct antacids, or those which neutralize or lessen the acidity of the stomach, and indirect antacids, or those which, being oxidized in the blood, are excreted as carbonates, diminishing the acidity of the urine and increasing the alkalinity of the blood, although not influencing the acidity in the stomach.

The direct antacids are lime water, prepared chalk, and magnesia.

The indirect antacids are potassium acetate, bitartrate, citrate, and tartrate, sodium acetate, and lithium citrate.

The following alkalies are both direct and indirect antacids: solution of potassa, solution of soda, carbonates and bicarbonates of potassium, sodium, lithium, magnesium, and ammonium.

The physiological action of the various alkalies will now be considered in detail.

Externally and Locally. - The hydrates of potassium and sodium are caustic and rubefacient. The solutions of soda and potassa, when applied undiluted, irritate the surface of the skin and soften and dissolve the epidermis and horny tissues, uniting with the albumin of the various structures to form a soluble alkali-albu-minate. The carbonates and bicarbonates exert a similar, though much weaker, action, while the acetates, bitartrates, citrates, and tartrates have no local influence.

The ammonium salts do not affect the epidermis in the manner of those previously mentioned, penetrating without dissolving it, irritating the underlying structures, and inducing an effusion of lymph, thus acting as vesicants. Should a strong solution of ammonia be applied to the skin and evaporation be prevented, suppuration and sloughing may ensue.

Internally. - Digestive System. - Potassium salts in small doses promote the secretion of gastric juice. Large doses neutralize free acid in the stomach, and, by rendering the chyme neutral or alkaline, interefere with the secretion from the pancreas, liver, and intestines, thereby deranging digestion.

The statement that alkaline carbonates given before a meal increase the secretion of gastric juice seems to rest more on clinical interpretation than on experimental evidence, for lower animals, at least. The so-called "law of contraries," taught for so many years, has little foundation in experimental work. The therapeutic results sometimes obtained must be explained on other grounds.

Circulatory System. - The alkaline salts of potassium, by lessening the acidity of the gastric juice and entering the circulation, increase the alkalinity of the blood. The bicarbonates, however, taken in large doses upon an empty stomach, enter the circulation unchanged, where, by decomposing the neutral phosphate of sodium present, they form the acid phosphate of sodium, reducing the alkalinity of the blood and increasing the acidity of the urine.

The acetates, citrates, and bitartrates enter the blood unchanged. The acid radical being destroyed, and the base combining with the carbon dioxide formed, the salts are converted into the alkaline carbonates, increasing the alkalinity of the blood and urine.

Should the caustic alkalies be injected directly into the blood, death quickly ensues from coagulation of that fluid, arising from excessive formation of alkali-albuminate. Under very large or poisonous doses the heart-muscle is weakened, decreasing the force of its contractions, arrest taking place in diastole. Even medicinal doses, if long continued, may occasion cardiac depression, diminishing the force of the circulation. Small doses may increase blood-pressure, though the pulse-rate be diminished. Minute amounts of potassium salts applied to muscle diminish or paralyze its contractile power.

Nervous System. - When potassium salts are administered in medicinical doses and for a reasonable length of time, no important action upon the nervous system is produced; but if excessive doses be taken, the nerve-centers and motor nerves are paralyzed, after a period of temporary excitement. Owing, however, to the fact that potassium is a protoplasmic poison, affecting alike the muscles and nerve-tissues, its salts should not be given in full doses for too long a period without counteracting their depressing influence by the use of muscle and nerve-tonics.

Respiratory System. - The only action of importance upon the respiratory system is the increased amount and diminished viscidity of the secretion from the bronchial tubes.