in natural history, is either native or factitious. The native cinnabar is an ore of quick-silver, moderately compact, very heavy, and of an elegant, striated red colour. In this ore the quick-silver is blended in different proportions with sulphur. It is so rich an ore, as to be no other than mercury impregnated with a small quantity of sulphur; just enough to reduce it to that state, being commonly more than six parts of mercury to one of sulphur; and even the poorest cinnabar yields one half mercury; it is of a very bright, glittering appearance, when fresh broken, and is usually found lodged in a bluish, indurated clay, though sometimes in a greenish talc stone.

For the method of separating mercury from cinnabar, see Mercury.

Factitious Cinnabar, a mixture of mercury and sulphur sublimed, and thus reduced into a fine red glebe. The best is of a high colour, and full of fibres, like needles.

The receipt for making it, according to the late college-dispensatory, is as follows. Take of purified quick-silver, twenty-five ounces; of sulphur, seven ounces; melt the sulphur, and stir the quick-silver into it while fluid; if it take fire, let it be immediately extinguished, by covering it with another vessel. When cold, let it be rubbed into a fine powder. Let this powder be put into a subliming vessel, and setting it over a gentle fire, raise it by degrees till the whole is sublimed into a red, striated, heavy mass, which perfectly resembles native cinnabar. This, as well as the native cinnabar, is excellent in epilepsies, and in all complaints of the head and nerves. But the factitious is rather to be preferred, as it doth not excite nausea, vomitings, and other disorders which arise from vitriolic and perhaps arsenical particles blended by nature among some of the masses of the native mineral.

Cinnabar is likewise used by painters as a colour, and is rendered more beautiful, by grinding it with gum-water and a little saffron.