CARMINE, a pigment of a bright red colour obtained from cochineal. It may be prepared by exhausting cochineal with boih’ng water and then treating the clear solution with alum, cream of tartar, or acid oxalate <>f potassium; the colouring and animal matters present in the liquid are thus precipitated. Or an aqueous decoction of black cochineal is made, and treated with stannic chloride: a slow deposition of carmine then takes place; the liquid is poured off, and the carmine dried. Another process is to add to 15 quarts of boiling river water 1 ß> of cochineal, and a clear solution of 6 drachms of carbonate of soda in 1 lb of water, and boil for thirty minutes. The liquid is then cooled, and 6 drachms of powdered alum are stirred in. After twenty minutes the resulting scarlet liquid is decanted, mixed well with the white of two eggs beaten up in ½ B⅛ of water, and again boiled for a short time; it is then left quiet for about half an hour, after which it is decanted, and the carmine which has been deposited is drained on a cloth, spread out on plates with an ivory or silver spatula, covered with white paper, and dried. By this process about 1 ½ oz. of carmine is obtained from 1 lb of cochineal. Another method is to add 3 oz. of nitre and 4 oz. of acid oxalate of potassium to an infusion of 1 & of cochineal, and to boil for ten minutes. After four hours’ standing, the liquid is poured into flat dishes, where it is left for three weeks. At the end of this time it is freed of the coating of mould formed upon it, and is drawn off, leaving a firm layer of carmine of fine colour. There are several other modes of preparing carmine, in some of which gelatine is used to assist its precipitation. The quality of carmine is affected by the temperature and the degree of ...