A. Vesicles, pustules, furuncles, Hahnemann, Reine Arzneimittellehre, 4: 822-5-8. Furuncles, Alexander (oral. com.).

C. Acne, Cane, 137, 2/78, 215; 206; 209. Eczema, Hutchins (oral com.); (H.G.P.)

Furuncles, Smith, 109, April 10, '77; Huse, 149, '79, 154; Hardaway, 168, July, '79, 18; Sexton, 192, Jan. '79, 41; 203; 209; (H.G.P.)

A tenth of a grain of sulphide of calcium, given hourly or every two hours, will generally prevent the formation of fresh boils, while it lessens the inflammation and reduces the area of existing boils, and qquickly liquefies the core, so that it separates much more speedily, , 63. Ecthyma, 209.

D. Favus, Gamberini, 131, 3: 134. Psoriasis, 72, 309; 97, 1: 379; 209. Trichophytosis, Cannon, 41, 242.

Remarks

One of the earlier uses of this drug was as an antidote to the effects of mercury. As such it is mentioned by Paping * in the last century. For some years it maintained its reputation in this connection, but gradually, and I think unwisely, fell into disuse. Later it was recommended by Hahnemann under its then pharmaceutical title, Hepar Sul-phuris Calcarea, as a remedy for furuncles, abscesses, and excessive suppuration. These applications of the drug were confined, I believe, almost exclusively to homoeopaths, until a few years ago, when Ringer brought it forward as a remedy for the same conditions. He was followed by Cane, who advised its use in acne. Since then pills of calcium sulphide are found in every pharmacy. Sulphide of calcium is a very unstable salt; and, on exposure to the atmosphere, becomes converted in a short time into an insoluble and comparatively inert sulphate of calcium. This may explain the unsuccessful use of it by many who prescribed it on Ringer's recommendation, as, until recently, the sulphide of calcium of the drug stores was rarely of good quality. It also explains the very large doses (three to five grains) that have been recommended by some. As a rule, from one-tenth to one-fifth of a grain has, in my experience, been ample, and a larger dose gave rise to discomfort. My own observations as to its therapeutic efficacy harmonize with those recorded by others. In 1878 I experimented with it largely in unopened buboes, in patients in the venereal wards of the Charity Hospital. In these cases it certainly seemed to exert a decided influence over the suppurative process.

* Dr. Sulpureto Calcis, optimo contra Salivationem mercurialem remedio. Gro-ningae, 1796.

It may be noted that the Hepar sulph. of the homoeopaths is not pure sulphide of calcium, but contains other substances derived from the oyster-shell used in its preparation. Whether the calcium sulphide of ordinary pharmacy is the pure salt I have not been able to learn.