Combinations of sulphur with the alkaline metals calcium, barium, and strontium rapidly destroy the hair; for this reason tanners use the “gas lime” from gas works, which contains calcium sulphide, for removing the hair from hides. All the depilatories used cosmetically, even rhusma employed in the Orient for removing the beard, owe their activity to the presence of calcium sulphide. CALCIUM SULPHIDE has usually been lauded as a perfectly harmless depilatory. This is a great mistake, however, since it has often done serious harm, through careless application by persons unfamiliar with its caustic and corrosive effects. It is absolutely necessary to protect the _skin_ against its action; otherwise superficial irritation, or even destruction of the skin may result. Calcium sulphide cannot be made by the action of sulphuretted hydrogen upon lime. It is usually made by heating at a low red heat, in a securely closed crucible, an intimate mixture of 100 parts of finely powdered quicklime with 90 parts of precipitated sulphur. Mix together: Calcium sulphide 4 oz. Sugar 2 oz. Water 2 oz. Starch powder 2 oz. Oil of lemon 30 grains. Oil of peppermint 10 grains. The resulting mass must be filled at once into an air-tight jar, as the calcium sulphide is decomposed in the atmosphere. For use, some of the mass is moistened with water, painted on the skin, and washed off with water after thirty to forty-five minutes. This and all other depilatories act only temporarily, that is, they destroy only the hair projecting above the surface without killing the hair bulbs; after some time the hair grows again and the preparation must be reapplied. BARIUM SULPHIDE, which is likewise used as a depilatory, is made by heating barium sulphate with charcoal, extracting the residue with water, and mixing the resulting product with starch paste. In its effects barium sulphide equals the preceding preparation, but it decomposes more readily. DEPILATORY PASTE. Powdered caustic lime 2 lb. Starch powder 2 lb. Sodium sulphide 21 oz. Sodium sulphide is made by saturating strong caustic soda solution with sulphuretted hydrogen. The other ingredients are added to the solution of sodium sulphide. RHUSMA is a depilatory made by mixing powdered quicklime (unslaked) with orpiment (yellow sulphide of arsenic). Take of: Quicklime 4 lb. Orpiment 10½ oz. Mix intimately and preserve the powder in tightly closed vessels. For use, take some of the powder, reduce it to a thin paste with water, and apply it to the place upon which the hairs are to be destroyed. Owing to its poisonousness and the destructive effects of the caustic lime on the skin, this preparation should never be employed in cosmetic perfumery. CHAPTER XXIX. WAX POMADES, BANDOLINES, AND BRILLIANTINES.