Aciäum Sulphuricum. — Sulphuric acid. "A liquid composed of not less than 925 per cent of absolute sulphuric acid. A colorless, oily liquid, inodorous, and having strong acid and corrosive qualities. The specific gravity of sulphuric acid should be not less than 1·835. It is miscible in all proportions with water and alcohol, with the evolution of heat."

The official preparations into which sulphuric acid enters are aci-dum sulphuricum aromaticum and acidum sulphuricum dilutum.

Acidum Sulphuricum Dilutum

Diluted sulphuric acid. "Sulphuric acid, 100 grm. ; distilled water, 825 grm. This contains 10 per cent of the official sulphuric acid, and has the specific gravity of 1·070 nearly." Dose, τη, ν—τη, xxx, and should be well diluted with water when administered.

Acidum Sulphuricum Aromaticum

Aromatic sulphuric acid, or elixir of vitriol. "Sulphuric acid, 100 c. c. ; tincture of ginger, 50 c. c. ; oil of cinnamon, 1 c. c. ; and sufficient alcohol to make 1,000 c. c. The specific gravity should be 0·955. Dose, τηv— 3 j, well diluted with water.

Acidum Hydrochloricum

Hydrochloric acid, muriatic acid. "A liquid composed of 31·9 per cent of absolute hydrochloric acid and 68·1 per cent of water. It should have a specific gravity of 1·163. It is a fuming, colorless liquid, of a pungent, suffocating odor, and an intensely acid taste and reaction." The official preparations into which hydrochloric acid enters are acidum hydrochloricum dilutum, acidum nitrohydrochloricum, and acidum nitrohydrochloricum dilutum.

Acidum Hydrochloricum Dilutum

Diluted hydrochloric acid. "Hydrochloric acid, 100 grm. ; distilled water, 219 grm. This mixture contains 10 per cent of absolute hydrochloric acid, and has a specific gravity of 1·050.

Acidum Nitricum

Nitric acid. "A colorless, fuming, very caustic and corrosive liquid, of a peculiar, somewhat suffocating odor, and a strongly acid reaction. Specific gravity, 1·414. It is composed of 68 per cent by weight of absolute nitric acid, and 32 per cent of water.

Acidum Nitricum Dilutum

Diluted nitric acid. Nitric acid, 100 grm. ; distilled water, 580 grm. Dose, τη, ij—τη, χ, in sufficient water.

Acidum Nitrohydrochloricum

Nitrohydrochloric acid, also known as aqua regia. Nitric acid, 180 c. c. ; hydrochloric acid, 820 c. c. Dose, τη, ij—τη χ, well diluted.

Acidum Nitrohydrochloricum Dilutum

Diluted nitrohydrochloric acid. Nitric acid, 40 c. c. ; hydrochloric acid, 180 c. c. ; distilled water, 780 c. c. A colorless, faintly yellow liquid, odorless, or having a faint odor of chlorine, and a very acid taste and reaction. Dose, τη ν—τη xx, in sufficient water.

Acidum Phosphoricum

Phosphoric acid. A liquid composed of not less than 85 per cent of absolute orthophosphoric acid, and not more than 15 per cent of water. Specific gravity, 1·710. Dose, τη j —τη χ, well diluted.

Acidum Phosphoricum Dilutum

Phosphoric acid, 100 grm. ; distilled water, 750 grm. Dose, τη ν—τη xx, in sufficient water.

Acidum Hypophosphorosum Dilutum

Diluted hypophosphorous acid. Consists of 10 per cent by weight of absolute hypophosphorous acid and 90 per cent of water.

Antagonists and Incompatibles

Alkalies and their carbonates, salts of lime and lead.

Physiological Actions of Mineral Acids

By assisting digestion and by correcting an abnormal condition of the alimentary mucous membrane, acids directly contribute to the blood-forming process, and indirectly, through the blood, to the construction of tissue, and the bettering, in general, of the bodily condition.

The mineral acids grouped above agree in the general qualities of their actions, but differ in some particulars. They attack the living tissues with great energy, abstract the water, and combine with the potash, soda, and lime bases. In virtue of this affinity for water and this power of combination with bases, they cause destruction of tissue and are called escharotics. Some of them are more powerful than others : thus, sulphuric and phosphoric acids penetrate more deeply than the others. Nitric acid stains the skin yellow ; sulphuric acid carbonizes or blackens. Hence in cases of accident, or when these acids are used with criminal intent, it is very obvious at a glance which has been taken or given : nitric acid making a yellow stain of the face, lips, and mouth, and sulphuric carbonizing or blackening those parts. In the stomach they produce the same effects. When concentrated, they destroy the mucous membrane of the mouth, epiglottis, oesophagus, and stomach. The systemic effects are those of the irritant and corrosive poisons. The appropriate remedies are chemical and mechanical: alkalies, magnesia, soda, lime, soap, to neutralize the acid; and eggs, milk, oil, etc., to protect mechanically the tissues. The depression of the powers of life which immediately follows the ingestion of a mineral acid should be treated by opium, nutrient and stimulating enemata, and the intra-venous injection of ammonia.

The mineral acids, when administered in medicinal doses, must on reaching the stomach act in accordance with their chemical position. They will combine with the bases and form salts. Hydrochloric, and to a less degree phosphoric, aid digestion, acting as synergists to pepsin, and contribute to the formation of peptones. Sulphuric unites with bases to form insoluble sulphates, and precipitates the albuminous substances from their solution in the gastric juices; hence this acid, although for a brief period it improves, soon disorders digestion. It is true of all the mineral acids that their long-continued use diminishes the production of acid gastric juice, and in this way after a time they cause the very troubles for the relief of which they were originally administered. An acid solution on one side of an animal membrane, and an alkaline solution on the other, is the condition most favorable to osmosis. Hence the introduction of an acid into the stomach with sufficient frequency and in sufficient quantity must impair the production of acid gastric juice. In practice this is found to be the case. The mineral acids are among the most diffusible substances known, and of these hydrochloric stands at the head. So much of these acids as does not enter into combination in the stomach diffuses quickly into the blood, and the salts which they form by combination with bases follow the laws of diffusion according to their class. The acids, especially the hydrochloric, and next nitric, diminish the alkalinity of the blood, and in this way accomplish all that they are capable of doing as systemic remedies.