Chloride of Zinc. ZnCl. Called also the Muriate, the Hydrochlorate, or Butter of Zinc. Comp. 1 Eq. Zinc = 32.5, + 1 Chlorine 35.5 = 68, Eq. Wt.

* Lancet, vol. iii. p. 109. Med. Zeitung, 1855.

Edin. Monthly Journ., April 1854. § Med. Circular, Dec. 18, 18C1.

Med. Prop. and Action. Powerful and penetrating escharotic. "Its local action as a caustic," observes Dr. Pereira,* "depends partly on its affinity for albumen and gelatine; so that when placed in contact with living parts, into whose composition these organic compounds enter, the Chloride, exercising its affinity, destroys the life of the parts, and, uniting with the albuminous and gelatinous matters present, forms an eschar." Internally, in small doses largely diluted, it is a nervine tonic; but it is rarely administered. Sir W. Burnett's Disinfecting and Antiseptic Fluid is a solution of the Chloride of Zinc. Sp. gr. 2.0. This fluid, taken internally, is a powerful corrosive poison. The Chloride requires to be kept in well-stoppered bottles, as it rapidly deliquesces on exposure to the air.

Dose, gr. 1/2 - gr. j. or gr. ij., largely diluted.

2833. Therapeutic Uses

In Cancer, the topical application of the Chloride was proposed by Dr. Canquoin, in 1837, and was shortly afterwards employed in England by Mr. Ure Great expectations were raised at the time, that an effectual remedy for Cancer had been discovered; it being asserted that its operation was not only that of an escharotic, but that it established a new action in the surrounding parts. It has, however, disappointed the anticipations of its warmest advocates. In some instances, it is productive of temporary benefit, but it does nothing towards the eradication of the cancerous diathesis. The constitutional irritation to which it gives rise is a great objection to its use. When it is to be applied, one part of the Chloride is to be mixed with three of Plaster of Paris or Gypsum, finely powdered. This is to be made into a paste with a little water, and then applied to the affected surface. The irritation which it causes lasts for a few hours; a greyish eschar forms, which separates in ten or twelve days. In applying this caustic, the surrounding parts should be well moistened with vinegar; and about a quarter of an hour after its application, the sore should be covered with a soft poultice. When Gypsum cannot be obtained, flour may be substituted; and in India the fine white clay of Bengal may be used. When the disease has progressed to any extent, and the constitution evidences a cancerous predisposition, the utility of this or any other caustic is very doubtful; but in the earliest stage of the affection, when the diseased part is of limited extent, and the constitution uncontaminated, it may be applied with a prospect of benefit.

2834. In Lupus, the Chloride has been employed by Cazenave, and other French practitioners. Dr. Ranking § states that, in this disease, he has found no caustic application nearly so beneficial as the Chloride of Zinc. He mentions a case in which he had tried every other means, for several months, without effect, but which yielded to the use of this substance. In stubborn Ulcers, with callous, hard, everted edges, the Chloride has been found to establish a healthier action, and rapidly to effect a cure. (Mode of application, see Cancer.)

* Mat. Med., vol. i. p. 773. Lond. Med. Gaz.. vol. xvii. p. 371, and vol. xviii. p. 371.

Annal. des Malad. de la Peau, Oct. 1844.

§ App. to Trans. of Lugol on Scrofula, p. 218.

2835. In the severer forms of Toothache, when cauterants are advisable, the most efficacious is the Chloride of Zinc, diluted with ten parts of Plaster of Paris. A little roll of softened wax should be dipped into this powder, and inserted into the cavity of the tooth. (Druitt.*)

2836. In Gonorrha, Mr

Lloyd speaks highly of the efficacy of injections of a solution of the Chloride (gr. j. ad Aq. fj.). Half a small syringeful of this should be very gently injected every six or eight hours. Saline aperients, warm fomentations, and strict antiphlogistic regimen, should form the remainder of the treatment. He relates five cases, recent and chronic, out of many, as illustrative of its efficacy. In some chronic cases, the strength of the injection was gradually increased to gr. iij. in Aq. fj.

2837. Gonorrhal Ophthalmia, both in children and in adults, has been successfully treated by Mr. Lloyd, by a collyrium containing the Chloride of Zinc (gr. j. ad Aq. fj.). Its use, he States, is attended with marked and almost immediate benefit.