Iodide of Arsenic. Asl3. Properly Teriodide of Arsenic, called also the Ioduret or Hydrio-date of Arsenic. Is a compound of 1 Eq. Arsenic = 75 + 3 Eq. Iodine = 378 = 453, Eq. Wt.

Med. Prop. and Action. Alterative and tonic. When given internally, it is absorbed into the system, and is eliminated by the urine, saliva, and perspiration. It is a powerful remedy, and requires to be given with great caution. Externally, it is used in the form of ointment (gr. ij. - iij., Lard oz. j). It should never be applied to a large ulcerated surface.

Dose, gr. 1/20, gradually increased to gr. J.

426. Therapeutic Uses

In Cancer, Dr. "Walshe§; regards the Iodide of Arsenic as one of the most valuable remedies we possess; but it must not be looked upon as a curative agent. After extensive employment of it, Dr. Walshe has drawn the following conclusions on the subject: -

1. Given in doses of from 1/16 to 1/12 of a grain, twice a day, two hours after eating, the Iodide of Arsenic is well borne, and may be continued without risk for several months.

2. The system, generally, soon gives evidence of its action: unusual palpitation, with dryness of the fauces and of the alimentary canal, occur; sometimes slight headache is complained of, but this is rare; and I have known the most violent periodic headache, which had affected a lady for years, disappear while she was under the influence of this salt.

3. The Pain Of The Tumour Decreases In Violence

4. The size of the breast generally diminishes; and, if the tumour itself does not actually lessen in bulk, I have at least found that its enlargement, previously more or less active and apparent, becomes, as far as can be determined, suspended.

5. The General Health Improves

* Lond. Journ. of Med., July 1851.

Op. cit.

Dub. Quart. Journ. of Medicine, Aug. 1857.

§ On the Nature and Treatment of Cancer, p. 201-2.

427. In Lupus, or Noli me Tangere, the Iodide, given internally, in the doses and in the manner directed by Dr. Walshe in Cancer, often occasions temporary and, in some cases, permanent amelioration.

428. In Lepra, Psoriasis, and Impetigo, the Iodide, in doses of 1/10 of a grain, has been employed by Dr. A. T. Thompson with great success. Dr. Neligan,* who has also used it with benefit, advises the following formula: -5 The General Health Improves 41 Liq. Arsenicalis fij., Potass. Iodid. 5ss., Syr. f3ij., Aq. fss., M. Dose, a tea or dessert spoonful, thrice daily, in water. Or with the addition of Iodine: -Liq. Arsenicalis elxxx., Potass. Iod. gr. xvj., Iodi gr. iv., Syr. Flor. Aur. fij. Dose: - A teaspoonful in a wine glass full of water thrice daily. This formula has been found by Dr. T. M'Call Anderson of use in some cases of Eczema.

429. In Tinea Capitis, Dr

Neligan regards the Iodide as the best constitutional remedy. He advises it in doses of 1/10 of a grain, gradually increased to 1/4 for an adult, 1/15 for a child of six years old, and from 1/18 to 1/20 for younger children. It may be given to adults in the form of pill, and to children in a little sugar. The scalp should be washed with an alkaline lotion (see PotassAe Carb. and SodAe Carb.), and an ointment of the Iodide of Lead will complete the cure. The Iodide of Arsenic is, generally, too powerful a medicine for young children.