Arsenic is eliminated by the liver, kidneys, intestinal canal and bronchial tubes; and it is thought that some of the symptoms produced by it have their origin in the local effects of the poison on the channels of excretion.

The symptoms of gastro-intestinal arsenical poisoning - the more common form - are described by Bartholow as follows: Burning sensation at the epigastrium, and extending over the abdomen; violent and uncontrollable vomiting; excessive dryness of the mouth and fauces, intense thirst, intestinal irritation, bloody and offensive stools, retracted abdomen, strangury, suppression of urine, or bloody urine, and in females menorrhagia; rapid and feeble action of the heart, oppressed breathing, great agitation and restlessness, shrunken features, cold breath, involuntary evacuations, collapse; consciousness being retained to the end.

The symptoms of the cerebral form of arsenical poisoning are profound insensibility and coma, similar to extreme opium narcosis. The effects of arsenical poisoning, when not fatal, are felt for a long time in the form of gastro-enteric irritability, an irritable condition of the skin, stiffness of the joints, neuralgic pains, numbness, formication, paralysis, etc.

After death from arsenical poisoning, the gastro-intestinal mucous membrane exhibits deep redness, erosions, ecchymosis and softening. Death generally occurs in the midst of convulsions, followed by rigid spasm of the whole body.

When arsenic has been injudiciously administered for too long a period, in addition to the irritation of the conjunctiva, swelling of the face, desquamation of the skin, etc., salivation has been observed in some instances, and at times a peculiar silvery whiteness of the tongue.

Dose

Of arsenious acid, gr. 1/60 to gr. 1/12, in pills with bread crumb three times a day. Of liquor potassii arsenitis (Fowler's Solution), Dose 371 three times a day; each fluid drachm contains half a grain of arsenious acid.

Arsenic is contraindicated in infancy and childhood; in all sthenic diseases accompanied by strong arterial action; in all irritable conditions of the stomach and alimentary canal; and in all inflammatory and pulmonary affections.

Therapeutic Uses

In intermittent and periodic diseases, such as malaria, neuralgia and spasmodic affections, being of great value in neuralgia, especially when of a malarial type, hemicrania, chronic rheumatism, asthma, whooping-cough, chorea, diseases of the skin, vomiting of pregnancy, hay fever, irritative dyspepsia, uterine affections, bites of venomous snakes, etc. Externally it is applied to cancerous growths; hypodermically, in cases of local chorea.

Arsenic is also employed medicinallv in the forms of arseniate of iron (Ferri Arsenias) and arseniate of soda {Sodae Arsenias).

Dental Uses

The devitalizing power of arsenious acid being far more powerful than its escharotic power, it has been employed for many years to destroy the vitality of the pulps of teeth, for which purpose it is generally combined with either the acetate or sulphate of morphia and sufficient creasote to form a paste, to prevent, or at least mitigate, the extremely painful action of the arsenic when topically applied to living tissue. It was formerly supposed that creasote was a solvent for the arsenic, but this is now denied. Carbolic acid may be substituted for the creasote.

As the danger of absorption is great, there is considerable risk in applying arsenious acid to the teeth of young persons, or those very susceptible to the influence of this agent; hence other escharotics, such as repeated applications of carbolic acid, or pepsina porci, with dilute hydrochloric acid, or nitric acid, chromic acid, or chloride of zinc, or the galvanic cautery, or the surgical method of introducing into the body of the pulp a barbed wire, are employed in such cases. The arsenious acid, when employed for the devitalization of dental pulps, has been combined with pulverized charcoal, under the impression that the latter prevents the rapid absorption of the arsenic, and thus limits its action mechanically rather than therapeutically.

The creasote (or carbolic acid), employed in combination with the arsenious acid as a nerve paste, obtunds sensibility, acting as a styptic, antiseptic and escharotic; hence some depend upon this agent alone to modify the action of the arsenic, and dispense with the morphine.

Tannic acid and tincture of aconite are sometimes substituted for the morphine and creasote, or carbolic acid in the preparation of a nerve paste. Arsenious acid is also employed alone, in the form of a dry powder, to devitalize pulps of teeth; but it is not only more painful, but less prompt in its action than when it is combined with other agents. Previous to the application of the arsenical preparation, chloroform, tincture of aconite, sulphate of atropine, cocaine, etc., may be applied to the exposed portion of the pulp, and the painful effect of the arsenic be thus modified. The spray of rhigolene, or absolute ether, has also been employed for this purpose.

The quantity of arsenious acid to be employed for devitalization will depend upon the structure and class of the tooth, varying from the 1/100, 1/60, 1/40 to the 1/25 of a grain; also the length of time the arsenical preparation should remain in the tooth, as the condition of the pulp and tooth, the age of the patient, the quality of the tooth structure and the susceptibility of the patient should all be considered. While in most cases pulps are readily devitalized by the application of a moderate quantity of the agent, in other cases it appears to be impossible to accomplish this object without extra measures are resorted to. In teeth of a soft, frail structure, owing to an excess of organic matter, the arsenic is rapidly absorbed; but if, on the other hand, the tooth is of a dense structure, the retention of the arsenical preparation for a much longer time may not be attended with any injurious effects, such as peridental inflammation. From twelve to twenty-four hours are generally required to enable the arsenious acid to properly devitalize the pulp of a tooth; the difference in time depending upon the quantity of the acid employed, as well as upon other circumstances already enumerated. To produce a speedy effect, the pulp should be freely exposed by the careful application of the excavator, and the devitalizing agent applied directly to the exposed surface of the organ. Accuracy as to the quantity of the arsenious acid to be employed may be arrived at by having a grain, in the form of the dry powder, divided into forty, sixty, or one hundred parts. A pellet of cotton, on the end of an excavator, may then be saturated with creasote or carbolic acid or, what may be more painless, oil of cloves, and the desired quantity of the powder, being taken up on the pellet, can be placed directly in contact with the exposed surface of the pulp, and secured in the carious cavity by means of a second pellet of cotton, saturated with either sandarach or shellac varnish, a solution of gutta percha and chloroform, wax, or softened gutta percha. To properly secure the arsenical preparation in the cavity of a tooth, a concave disk of thin platinum may be placed over it, and a temporary filling of soft gutta percha, or oxy-phosphate of zinc, introduced into the carious cavity. Many condemn the use of sandarach or other varnish to seal the arsenic into cavities, preferring a filling of denser material, such as softened gutta percha, chloro-percha and cotton, zinc cement, etc., to confine the arsenic more securely.