A very bright crimson pigment, obtained by precipitating the colouring matter of cochineal. The preparation is as follows:- Take 4 ounces of cochineal, finely pulverized, which pour into 4 quarts of rain or distilled water, boiled previously in a pewter kettle, and boil the whole for six minutes, adding, during the boiling, 2 drachms of pulverized crystals of tartar. Eight scruples of Roman alum, in powder, must then be added, and the whole be kept on the fire one minute longer. As soon as the gross powder has subsided, and the decoction become clear, decant it into large cylindrical glasses covered over, and keep it undisturbed till a fine powder is observed to have settled at the bottom. Then pour off the liquor from this powder, which is to be gradually dried. From the liquor still coloured, the rest of the colouring matter may be separated by the solution of tin, when it yields a carmine little inferior to the former.