Origin.—The world’s supply of arsenic and arsenic compounds at the present time is obtained from Germany, Spain, England, Canada and portions of the United States, as Montana and Washington, where considerable quantities of arsenic are being produced as a by-product in the smelting of copper ores. Arsenic ore is roasted and purified by sublimation, before it is used for medical purposes.

ARSENI TRIOXIDUM—ARSENIC TRIOXIDE
ACIDUM ARSENOSUM—ARCENOUS ACID
(White Arsenic)

Derivation.—Arsenical ores are roasted or conducted into condensing chambers and purified by sublimation.

Properties.—A heavy solid, occurring either as an opaque, white powder, or in irregular masses of two varieties; the one amorphous, transparent and colorless, like glass; the other crystalline, opaque, and white, resembling porcelain. Frequently the same piece has an opaque, white outer crust enclosing the glassy variety. Contact with moist air gradually changes the glassy into the white opaque variety. Both are odorless and tasteless. The glassy variety dissolves slowly in thirty parts of water; the porcelain-like in eighty parts of water. Arcenous acid is sparingly soluble in alcohol, but soluble in glycerin, hydrochloric acid and solutions of the alkali hydrates and carbonates. When heated to 424°, arcenous acid is completely volatilized without melting.

Incompatibles.—Lime water, salts of iron and magnesia.

Dose.—Horses, 1 to 5 grs.; cattle, 2 to 8 grs.; sheep and pigs, 1 to 2 grs.; dogs, ¹/₃₀ to ¹/₁₀ gr.

LIQUOR POTASSII ARSENITIS—SOLUTION OF POTASSIUM ARSENITE (Fowler’s Solution)

Derivation.—Arcenous acid, potassium bicarbonate, compound tincture of lavender and distilled water. Strength one part of arcenous acid in 100.

Dose.—Horses, 2 drs. to 1 oz.; cattle, ¹/₂ to 1¹/₂ ozs.; sheep and pigs, 10 to 40 ms.; dogs, 2 to 5 ms. Average dose for horse is ¹/₂ oz. usually given three times daily in drinking water or bran mash.

LIQUOR ACIDI ARSENOSI—SOLUTION OF ARCENOUS ACID

Derivation.—Arcenous acid, diluted hydrochloric acid, and distilled water. Strength one part arcenous acid in 100.

Dose.—Same as liquor potassii arsenitis.

LIQUOR ARSENI ET HYDRARGYRI IODIDI (Donovan’s Solution)

Derivation.—Arcenous iodide, red mercuric iodide, and distilled water, which should contain not less then one per cent of arcenous iodide and one per cent of mercuric iodide.

Dose.—Same as liquor potassii arsenitis.

Actions.—Arsenic and its compounds are gastro-intestinal and pulmonary tonic, a stimulant and alterative, acting particularly on the digestive and respiratory mucous membranes and skin. It is antiperiodic and tonic; also antispasmodic in diseases of the nervous system, and is a nervine tonic. In large doses it is a corrosive-irritant poison, killing either by gastro-enteritis, or nervous paresis. Continued doses produce fatty degeneration. On account of its being a stomachic, small doses promote the appetite and digestion. Large doses inflame the stomach and derange digestion. It increases the cardiac action, respiratory power, and secretion of the intestines. It also stimulates peristalsis. When tolerance is established, large doses are taken with impunity.

Externally.—Arsenic is a very painful escharotic, exciting violent inflammation. It is a caustic, antiseptic, and parasiticide, and is frequently used as a sheep dip. It is eliminated chiefly by the kidneys, skin and saliva and milk of nursing animals.

Uses.—It should not be given in acute diseases. It is given as a general tonic after debilitating diseases especially when the lungs are involved, as in pneumonia, bronchitis and pleurisy. Arsenic combined with bran mashes is beneficial in stocking or swelling of the legs. As for its use in chronic indigestion, other medicines had better be resorted to. It assists in the expulsion of worms. Useful in chronic diseases of the air passage. Arsenic relieves irritable chronic coughs, and roaring in early stages, as well as thick and broken wind and heaves. As an alterative modifying tissue change it is prescribed in early stages of tuberculosis, chronic rheumatism, chorea and epilepsy. It prevents periodically returning fevers. In anaemia it increases both red and white blood corpuscles. For chorea in dogs, commence with a small dose, three times daily and increase a minimum per dose every third or fourth day until the physiological limit is reached as described under (Toxicology of Arsenic).

Actions on the Skin.—Administered internally it stimulates the dermis and hastens the removal of epidermal cells; hence it is useful in all chronic skin diseases, as chronic eczema, scab, mange and warts. To remove warts that occur in the mouth and on the muzzle of animals, give internally and apply locally Fowler’s solution. In chronic skin diseases use Donovan’s or Fowler’s solution or acidum arsenosum and sulphur mixed in the feed. Useful internally in successive eruptions of the skin boils and in chronic urticaria.

External Uses.—The white arsenic or arcenous acid is used to slough out tumors, fistulae, quittors, etc. But I would not recommend it as it is too painful. It is valuable in the treatment of foot-rot. The affected animals should be slowly driven through a trough containing a solution of arsenic. It is used extensively for sheep and cattle to destroy ticks. In this way, animals are sometimes poisoned, as it drips on the grass and other animals eat it.

Toxicology of Arsenic.—Full medical doses if long continued, cause edema and itching of the eyelids, increased flow of saliva nausea, diarrhoea or dysentery, weak heart, soreness to the touch over the region of the stomach, itchy skin with small eruptions, jaundice and albuminuria. In long continued doses it diminishes exudation, decomposes albuminoid tissues and produces fatty degeneration; also lessens the glycogenic functions of the liver.

Chronic Arsenical Poisoning.—Is common in the vicinity of either tin or copper smelting plants. The symptoms are as follows: indigestion, thirst, wasting, chronic diseases of joints and bones, the knee joints swell, the animal becomes lame and hide-bound, hair falls off, skin gets rough and scurfy, teeth get black and fall out and necrosis of the bones follow.

Antagonists and Incompatibles.—The salts of iron, magnesia, lime, and astringents, are chemically incompatible. The hydroxide of iron, or as it is also known, hydrate sesquioxide of iron, freshly made and in soft magma is the antidote to arsenic. To dogs give from half to one tablespoonful every five or ten minutes. From eight to twenty grains of the antidote are required to each grain of arsenic swallowed (when it can be determined). The stomach should first be emptied by the use of cathartics or stomach pump and then give the antidote, and follow with demulcents as oil, milk and mucilaginous drinks. Also administer diluents, as weak alkaline water. Iodide of potassium is valuable as a antidote of arsenical poisoning and should be administered to promote elimination of the poison. In the absence of the antidote, chalk, magnesia and lime water may be freely given. These agents act mechanically by developing the poison and preventing absorption. Dialysed iron is recommended as efficacious as an antidote in doses of five to fifteen minimums for dogs.