ARSENIC. — Arsenic (As), a native metal, appears as a lustrous, crystalline, brittle mass, of a steel-gray color, with out odor or taste. It volatilizes above 100° C. Commercial white arsenic is prepared from the native ore by a proc ess of roasting and sublimation.
White arsenic (arsenic, acidum ar senosum, arsenous oxide or anhydride, arsenic trioxide, when pure, is a white, amorphous powder, odorless and tasteless. It is soluble in 30 parts of cold and 15 parts of boiling water; also in hydrochloric acid and glycerin. When thrown upon a heated surface a garlicky odor is emitted and the fumes resulting from volatilization are very poisonous.
Preparations and Dose.—Arsenic, to grain.
Liquor acidi arsenosi (1 per cent.), 1 to 10 minims.
Liquor potassii arsenitis (1 per cent.
—howler's solution), 1 to 10 minims. Liquor sodii arsenitis (1 per cent.— Pearson's solution), 1 to 10 minims. Liquor arsenii et hydrargyri iodidi (Donovan's solution), 1 to 10 minims. Arsenii to grain. Arsenii sulphidum, to 1, grain. Sodii arsenias, 1/24 to grain. Cupric arsenite, to grain. SUBCUTANEOUS USES.—Liquor potas sii arsenitis, 1 to 4 minims.
Liquor sodii arsenitis, 1 to 4 minims.
Arsenic, in the form of 1 part of an hydrous sodium arseniate to 100 parts of water, the dose being about twice that of Fowler's solution, recommended for hypodermic use. H. N. Moyer (Then. Gaz., Jan., '91).
Scheele's green, or Paris green, is an impure arsenite of copper.
Clemens's solution—a solution of the bromide of arsenic—is prepared by boil ing 57 1, grains each of arsenous acid and carbonate of potash in S finidounces of distilled water and allowing the solu tion to cool, to which is then added sufficient distilled water to make fluidounces. To this are added 115 grains of pure bromine. The resulting solution is kept for four weeks, being frequently shaken during the first week, or until it remains clear. Dose, 1 to 5 minims, freely diluted, after meals.
Cacodylic acid (dimethyl-arsenic kako dylie acid), a supposedly non-toxic and easily absorbed preparation of arsenic, is obtained from cacodyl and mercurous oxide in the presence of water (As0 It occurs in large perma nent prisms, slightly sour and odorless; it is soluble in water and alcohol and melts at 200° C.
where large doses of arsenic must be given. It is absolutely safe even in massive doses, being non-toxic in com parison with other arsenical compounds. It may be given hypodermically in doses of from 1 to grains daily, and, by the mouth and rectum, 6 grains daily. C. W. Hcitzman (Med. News, Aug. 17, 1901).
When administering arsenic the pos sibility of intolerance on the part of the patient should be thought of and the first doses should be small.
A patient who, after taking a very small quantity, was seized with a severe attack of diarrhoea and a generalized oedema. He stated that ten years pre viously he had had a similar attack after simply touching arsenic. All symptoms disappeared after the cessation of the drug. II. Nicholson (London Lancet, Feb. 11, '93).
Results of experiences with rectal in jections of arsenic. It is administered in solution containing grain in drachms. Three injections may be given daily. This treatment may be continued for months without having to be inter rupted in consequence of gastric intoler ance. Should any rectal irritation be caused the addition of a few drops of laudanum will obviate it. This treat ment highly recommended in tuber culosis, especially in the early stage; in diabetes mellitus, and in exophthalmic goitre. Renaut (Les Nouveaux Remedes, Apr. 24, '98).
Physiological Action. — If moistened and applied to the skin arsenic acts as an irritant, its power as such, however, depending upon the concentration of the preparation. The action upon the mucous membranes is identical.
Arsenic is readily absorbed, and must therefore be used with care.