(a) Give an alkali before meals to increase the secretion of acid, or

(b) An acid after meals to supply the deficiency.

Name the mineral acids.

The mineral acids are sulphuric, nitric, hydrochloric, nitro-hydrochloric and phosphoric.

What are their physiological effects?

Locally the strong acids are escharotics, abstracting water from the tissues and combining with the bases. Sulphuric and phosphoric acids penetrate the tissues more deeply than the others. Sulphuric produces a black, while nitric acid causes a yellow eschar.

Internally, in a diluted state and in medicinal doses, they increase the appetite, digestion and nutrition (hydrochloric and phosphoric being more pronounced in their effects). If taken for some time continuously, they diminish the acid of the gastric juice and disorder digestion (sulphuric acid more quickly than the others). Sulphuric acid possesses an astringent influence over the secretions of the skin and bowels; nitric acid, on the contrary, appears to increase the alimentary secretions and that of the liver.

They are eliminated by the secretions of the kidneys, bowels and skin. In large doses they act as irritant corrosive poisons.

How should poisoning by the mineral acids be treated?

1. Give alkalies or alkaline earths (tooth powder or soap may be used) to neutralize the acid.

2. Give eggs, milk, or other demulcents to protect the surface. 3. Give opium and nutritive and stimulating enemata, or intravenous injection of ammonia, to counteract the resulting depression.

4. As stricture of the œsophagus often follows in these cases if they survive, the passage of an oesophageal bougie should be practiced within 3 or 4 months after the poisoning.

What are the therapeutic uses of the mineral acids?

1. For their effects on digestion and nutrition. To prevent excessive formation of acid (both where too much is secreted and where it is formed by fermentation of the food), diluted hydrochloric or phosphoric acid is given before meals; or in atonic dyspepsia and indigestion due to deficient acid, they may be taken after meals (often

combined with pepsin). In fevers, they are used to aid digestion and secretions generally and allay thirst (by stimulating the secretions of the mouth and fauces, thus keeping these parts moist).

2. For their effects on secretion. Diluted nitric or nitro-hydro chloric acid is used internally to increase the secretions, and as a bath (f3iij to water Cj), in chronic hepatic congestions and inflammations, in malarial and catarrhal jaundice and in duodenal catarrh. As an astringent in diarrhoeas, dysentery and cholera diluted sulphuric acid is given combined with opium'; and to arrest profuse sweating diluted or aromatic sulphuric acid may be temporarily employed. 3. As a hæmostatic the same agent is often used in uterine or intestinal hemorrhage and occasionally in purpura.

4. In the treatment of, or as a preventive to, lead poisoning diluted sulphuric acid is administered (forming an insoluble lead sulphate). 5. Locally, as an escharotic, fuming nitric acid may be applied to chancroids, phagedenic ulcers, hospital gangrene or gangrene in wounds. It is also used to remove warts, and as an intra-uterine application in various forms of endometritis. As a stimulating lotion to unhealthy granulations, and to check bleeding from hemorrhoids, weak solutions of nitric acid are used.

What are the preparations of the mineral acids, and what are their doses?

1. ACIDUM SULPHURICUM (sulphuric acid-oil of vitriol) contains not less than 92.5 per cent. of absolute sulphuric acid, and is too strong for internal use.

ACIDUM SULPHURICUM DILUTUM (diluted sulphuric acid) contains 10 per cent., by weight, of the official sulphuric acid, and is used internally as a tonic, refrigerant, astringent, and haemostatic; dose mij-xx (0.123-1.23) freely diluted.

ACIDUM SULPHURICUM AROMATICUM (aromatic sulphuric acidelixir of vitriol) contains 10 per cent. of the official acid with alcohol, tincture of ginger, and oil of cinnamon. It is used as a pleasant substitute for the preceding preparation and is given in the same doses.

2. ACIDUM NITRICUM (nitric acid) contains 68 per cent. of the absolute acid, and is not employed internally.

ACIDUM NITRICUM DILUTUM (diluted nitric acid) contains 10 per cent., by weight, of absolute nitric acid; dose mij-xx (0.123-1.23) freely diluted.

3. ACIDUM HYDROCHLORICUM (hydrochloric acid-muriatic acid) contains nearly 32 per cent., by weight, of absolute acid, and is not used internally.

ACIDUM HYDROCHLORICUM DILUTUM (diluted hydrochloric acid -diluted muriatic acid) contains 10 per cent. of the absolute acid. It is (probably) a normal constituent of the gastric juice, and is used as an aid to digestion; dose mv-xx (0.31-1.23) freely diluted.

4. ACIDUM NITROHYDROCHLORICUM (nitrohydrochloric acidnitromuriatic acid-aqua regia) is used as a stomachic tonic and to increase the secretions of the liver and intestines; dose mij-x (0.123-1.23) freely diluted.

ACIDUM NITROHYDROCHLORICUM DILUTUM (diluted nitrohydrochloric acid-diluted nitromuriatic acid); dose mij-xx (0.123–1.23) freely diluted.

5. ACIDUM PHOSPHORICUM (phosphoric acid) contains 85 per cent., by weight, of absolute ortho-phosphoric acid, and is not used internally.

ACIDUM PHOSPHORICUM DILUTUM (diluted phosphoric acid) contains 10 per cent., by weight, of absolute ortho-phosphoric acid, and is chiefly used as an aid to digestion; dose mv-xxx (0.31−1.85) freely diluted.

What medicines are incompatible with the mineral acids?

1. Alkalies and their carbonates and the salts of lime and lead are incompatible with the mineral acids, which also decompose salts of the vegetable acids, uniting with their bases.

2. The mercurial salts should not be given during the administration of hydrochloric or nitro-hydrochloric acids or their preparations, as they may react with the mercury and form corrosive subli

mate.

How and when are these acids administered?

They are administered before or after meals, according to the indications present, and may be given freely diluted with water either alone or with glycerin and syrup, or with some of the bitters.

They should be taken through a glass tube to prevent injury to the teeth, or the mouth may be washed out immediately after their use with some weak alkaline solution.

ACIDUM LACTICUM-LACTIC ACID.

What is lactic acid?

Lactic acid is a syrupy liquid, formed by the souring of milk.

What are its effects and uses?

It is a normal ingredient of the gastric juice. In medicinal doses it increases the appetite, aids digestion and stimulates nutrition. In large doses (f3j) or long continued it disorders digestion, causing flatulency and epigastric pain. Injected into the peritoneal cavity (dog's) it produces endocarditis, and when given for a very long time (in diabetes) it has caused acute rheumatism. Lactic acid is used to diminish the acidity of the gastric juice, or to replace the deficiency of the acid; to aid digestion and nutrition in oxalic, phosphatic or uric acid diathesis; in diabetes, and locally as a solvent for the false membranes of croup and diphtheria. It has been claimed that it is a hypnotic in insomnia due to nervous excitement, but this is still sub judice.

What are its preparations and doses?

ACIDUM LACTICUM (lactic acid) contains 75 per cent. of absolute lactic acid. Dose mv-xxx (0.30–1.85) freely diluted and often prescribed in a mixture with pepsin.

ORDER III.-ALTERATIVES.

What are alteratives?

Alteratives are medicines which, without exerting any very perceptible action on any particular organ, so modify the nutritive processes as to enable nature to restore healthy action in many diseased conditions.

Mention the principal alteratives.

The preparations of mercury and of gold; iodine and the iodides: the arsenical preparations; cod-liver oil; the phosphates and hypophosphites; the chlorides of ammonium and calcium; colchicum; sarsaparilla; guaiac; and perhaps mezereon; menispermum; calendula; sassafras, stillingia, dulcamara, and lappa.

What is mercury?

HYDRARGYRUM-MERCURY.

Mercury is a liquid metal principally obtained from the native sulphide or cinnabar.

What are the physiological effects of mercury?

Metallic mercury (quicksilver) is inert either when swallowed or applied to the skin, but if retained in the alimentary canal or after prolonged contact with the skin, it often becomes converted into an oxide and produces constitutional effects. When inhaled in a state

of vapor it frequently causes salivation, ulceration of the mouth, necrosis and wasting; or in other cases loss of memory, vertigo, shaking palsy and other nervous symptoms.

Minute doses of mercurials, not too frequently repeated, increase the number of red corpuscles in the blood and improve nutrition. In small and repeated doses they stimulate the secretions of the skin and mucous membranes, the liver and kidneys and the salivary glands and pancreas, and promote absorption. Corrosive sublimate is an hepatic stimulant of considerable power, but the other preparations probably increase the flow of bile by irritating the duodenal mucous membrane, thus causing reflex contractions of the gall bladder. By stimulating the liver, corrosive sublimate increases the formation of urea, and thus proves diuretic. It also feebly stimulates the intestinal glands. In moderate doses the mercurials are cathartic (especially calomel and blue mass). In large doses, or continued for some time, the secretions are much increased and become pathological; the gums are swollen and tender, the mouth sore, the teeth feel elongated, salivation occurs, which becomes profuse if the medicine is continued; the breath is offensive, a metallic taste is experienced; the proportion of albumen, fibrin and red corpuscles to the fluid of the blood is diminished; the body wastes, and, if the abuse of mercury be continued, mercurial fever, diarrhoea, ulceration and sloughing of the gums, loosening of the teeth and sometimes necrosis of the alveolar processes, albuminuria, marasmus and grave nervous symptoms occur. Salivation (ptyalism) is more easily caused by blue mass and calomel, less so by corrosive sublimate and mercury with chalk.

Corrosive sublimate, beside its cholagogue and diuretic properties,