An eruption resembling that of measles, produced by 3 drops (0.18 Cc.) of Fowler's solution, is reported by Macnal (Medical Times and Gazette, 1868). Falck reports a case in which arsenic produced a discolored sanguinolent eruption with erysipelatous swelling. Papules and erythematous pustules have also been observed.

"Eruptions petechial or ecchymotic, eruptions papular, vesicular, erysipelatous, pustular - such are the principal forms of arsenical exanthemata," described by Imbert-Gourbeyre.

Poisoning. - Large doses of arsenic taken in the form of rat poisons, fly papers, dyes, and parasiticides (Scheele's and Paris green) produce symptoms of acute poisoning, the drug almost immediately manifesting its characteristic effects upon the gastrointestinal canal (to which it is a marked irritant), exciting active inflammation. There are, in from fifteen minutes to one-half hour, colicky pains in the stomach, nausea, vomiting, looseness of the bowels, and edema of the face, indicated by puffiness under the eyelids. The passages are at length similar to the "rice-water" discharges of cholera, although different from the latter in the presence of blood or serum. The purging becomes obstinate and exhausting. In certain cases other choleraic symptoms are especially manifested, as increasing coldness of the body, and cramps.

There is great prostration, pinched, bloodless face, fall in blood-pressure, the urine is scanty or suppressed, headache, collapse. Death may supervene in from one to four hours with small pulse and sighing respiration. Sometimes the patient recovers from the acute attack, and subsequently dies in from two to three days from the secondary degeneration, as in phosphorus-poisoning. As a minimum lethal dose, 1 grain (0.06 Gm.) of arsenous acid may be mentioned as having caused death, though much larger doses have been recovered from.

Chronic Poisoning. - This may arise from a great variety of sources. In some localities by some peoples, as in Styria, large doses are tolerated for considerable periods of time, apparently with not markedly pernicious effects. Undoubtedly, much of the fame of the arsenic eaters' good health is fictitious, but the clinical evidence goes to show that a tolerance for arsenic may be established.

In chronic poisoning, which may arise from the absorption of very minute amounts of arsenic from earths, food, fruit sprays, paints, wall-paper, carpets (dyed with arsenic dyes), beer (arsenic from glucose, from sulphuric acid), the symptoms may be in (1) Intestinal tract - anorexia, nausea, sometimes vomiting, occasional diarrhea, pain; (2) Mucous membranes of eye, nose, throat, as coryza, sneezing, conjunctivitis, puffiness of eyelids; (3) Skin -as eruptions, pigmentation, herpes, increased growth of hair and nails; (4) Nervous System, as paresthesias, followed by peripheral neuritis of arms or legs, or both, neuralgic pains usually accompanying. In terminal stages, mental symptoms, as dementia, with convulsive seizures, etc., may develop.

Treatment of Poisoning. - In the acute poisoning it is necessary that treatment be expeditious, and the agents and methods adopted carefully chosen. Vomiting often renders the use of the stomach-pump unnecessary, yet emetics are frequently serviceable, the cleansing of the stomach being of primary importance. Various antidotes have been successfully used, the best, chemically, being freshly prepared hydrated sesquioxide of iron, administered in water, 2 or 3 tablespoonfuls every fifteen or twenty minutes. Magnesia, chalk, and lime-water also serve as efficient antidotes. The temperature of the patient should be maintained, and demulcents (oil, milk, etc.) freely given. The after-treatment should include mucilaginous drinks, opiates if indicated, cathartics, and, in case of necessity, stimulants. Active vessel tonics, as ergot, adrenalin, etc., may be useful to overcome the collapse.

In the chronic poisoning, withdrawal of the arsenic and general symptomatic treatment is indicated.

Therapeutics. - Externally and Locally. - The chief use of arsenic locally is as an escharotic. For this purpose it is employed to destroy malignant growths, such as cancer, sarcoma of the skin, and multiple sarcomatous degeneration of the lymphatic glands. In the latter affection the parenchymatous injection of 5 minims (0.3 Cc.) of Fowler's solution, diluted with twice the amount of distilled water, is used.

Many of the pastes and "quack" cancer remedies owe most of their efficiency to arsenic. Manec's paste contains arsenous acid, 15 grains (1.0 Gm.); black sulphide of mercury, 75 grains (5.0 Gm.); burnt sponge, 35 grains (2.3 Gm.).

The noted poudre caustique de Frere Cosme ou du Rousselot is a similar preparation, containing about the same quantity of arsenic.

The solution of arsenous acid is an excellent local application to warts and corns. If these growths are very firm and horny, their removal may be facilitated by the previous application of solution of potassa. When used over large surfaces arsenic should be applied in good strength and heroically, so that active inflammation may be excited and the danger of absorption lessened.

Internally. - Arsenic is a peculiarly efficient remedy in chronic scaly skin diseases.

Like all other alteratives, it influences diseases of a chronic nature more favorably than acute disorders, invariably aggravating acute skin diseases. This drug, therefore, is one of the most valued remedies in psoriasis, lepra, and chronic squamous eczema.

Pemphigus, prurigo, acne, and lichen ruber have often been favorably influenced by the continued administration of Fowler's solution. In the successful management of these chronic skin diseases it is necessary that the preparation of arsenic employed be given in as large doses as can be tolerated by the patient, and the treatment continued unremittingly for a long period.

Lymphoma, whether superficial or occupying the great cavities, is frequently benefited greatly by similar treatment.

Asthma and bronchitis, whether acute or chronic, accompanying or succeeding scaly skin diseases, are singularly amenable to this medicine when the dose is carried to the full physiological limit. Another condition, dysmenorrhea, frequently noticed in women with a tendency to asthma or subject to chronic diseases of the skin, is often cured or greatly benefited by arsenic.

The obstinate and often incurable disease known as pernicious anemia yields better to arsenic than to any other known remedy.

The statements in the preceding paragraph apply also to leukemia, whether splenic, myelogenic, or lymphatic, and to Hodgkin's disease.

Arsenic is valuable in the treatment of malaria, particularly in the chronic cachectic types. The modus operandi is not yet known. It may be a protozoa poison, or it may increase certain protective properties of the blood-sera. It may have an action on the spleen.

The neuralgias, anemia, and headache of malarial origin are singularly amenable to this medicine.

Fowler first reported the remarkable efficacy of arsenic in neuralgia of the intercostal and fifth pair of nerves. It is equally valuable in these cases whether the disease be due to malaria or to general debility.

If this drug is specific in any one disease, it is so in chorea, very rarely failing to effect a cure when judiciously administered. It should be given in full doses, and increased as tolerance is established.

This medicine seems to act equally well in gastralgia. It is also an efficient remedy in gastritis or the vomiting of gastritis, especially in that occasioned by the excessive use of alcohol. Many irritative conditions of the stomach are relieved by minute doses of Fowler's solution. Excessive peristalsis, resulting in diarrhea, coming on immediately after taking food, is usually cured completely by very small doses of Fowler's solution, alone or combined with an equal quantity of tincture of opium. Arsenic has also been recommended in gastric ulcer and cancer.

It has proved of great service in hay fever, spasmodic asthma, and acute coryza. It is often very serviceable in catarrhal pneumonia and in chronic bronchitis. Arsenic is useful in diabetes mellitus. Rheumatoid arthritis is more favorably influenced by the use of arsenic than by any other medicine. It should be employed in the treatment of chronic rheumatism. Even in secondary syphilis a combination of mercury and arsenic has produced better results, in some cases, than mercury alone. Anstie has recommended arsenic in angina pectoris, alleging that it mitigates the severity of the attacks. Chronic diarrhea, when induced by intestinal fermentation or chronic malarial infection, is sometimes greatly benefited by this drug.

Finally, arsenic is a valuable adjunct to iron in the treatment of simple anemia and chlorosis.

Contraindications. - In acute skin diseases and pulmonary tuberculosis with a tendency to hemoptysis.

Administration. - Arsenic should be given ordinarily after meals. There are certain conditions, however, requiring its administration in small doses before meals. When it is desired to give arsenic in pill form, the trioxide should be used; and for solutions the liquor potassii arsenitis is usually preferred.

In syphilitic disorders Donovan's solution is an excellent preparation to use.

Children are much less susceptible to the drug than adults, often being able to take adult doses with impunity.

During a course of arsenic the patient should be instructed to watch carefully for the first untoward manifestations, such as puffi-ness about the eyes, itching of the conjunctivae, nausea, diarrhea, or numbness of the fingers. Any one of these symptoms is an indication that the dose should not be increased; and it may be necessary to lessen the dose, or even to discontinue the remedy altogether, for a while.

There are two methods of getting a patient thoroughly under the influence of the drug:

1. Begin with a full dose of Fowler's solution, and decrease I minim (0.06 Cc.) a day until a 1-minim (0.06 Cc.) dose is reached; then repeat the method.

2. Begin with a small dose of Fowler's solution, and increase 1 minim (0.06 Cc.) a day until untoward symptoms appear or the dose has reached 10 to 15 minims (0.6-1.0 Cc.); then either repeat the method or decrease the amount 1 minim (0.06 Cc.) a day.

Cacodylates. - Organic compounds of arsenic are claimed to act much more slowly and less actively than the inorganic compounds. Such compounds are cacodylic acid and sodium caco-dylate, which have been introduced into modern therapy, although first suggested by Schmidt in 1869. It is extensively claimed that these bodies are non-irritating, but this is not the fact, although clinical experience would seem to show that much larger doses of arsenic can be taken as cacodylates than in any other form. The indications are the same as those in ordinary arsenic therapy. Dosage, 1/8-1 grain. Renz in 1865 obtained poisonous effects from doses of from 10 to 18 grains of cacodylic acid. French observers maintain that the hypodermic use of the cacodylates gives different results than when they are given by mouth.