The first of these is the ancient and the last the modern name for the same substance, which is a mineral of beauteous shining rcd color, and is an ore of mercury or quicksilver. Artificially prepared cinnabar is much preferred to the native; as a pigment, because of its freedom from earthy impurities, and it has long been an object of chemical manufacture, and is generallJ known as vermillion. It is a compound of sulphur, with mercury, each in equivalent proportions. To manufacture it, about five or six parts of mercury are added to one of melted sulphur, and when thoroughly combined and constantly stirred, heat and light are evolved, and a violent cracking and spitting indicate the termination of this part of the process. The result is a dirty, blackish red mass ; this crude product, after being pounded, is mixed with a small quantity of sulphur, this is placed in a glass flask until it is about half full, when it is closed with a charcoal stopper. The flask is then placed on a bed of hot sand (kept hot by a slow drawing furnace), and is left to remain thus red-hot for some hours, at the end of which time the cinnabar is found sublimed in the flask. In Amsterdam, where it was first made, they still pursue a similar method to the one they have always done, but the one we have given is the essence of them all. Of all kinds of vermilion now made, the Chinese is the best, being sold for about six times the price of home made ; it has a rich, almost inclining to carmine color, and no foreign substance cau be detected in it, except a little glue. At the present time we apply the term minium to red lead, which is made by roasting lead in a slow reverberatory furnace having a broad hearth so that a great surface can be exposed to the action of the heated air. It is kept continually worked up and down until the whole mass changes to the well-known color of l'ed lead. Minium is often used to adulterate vermilion, and it is a fair supposition that the rcason why our ancestors called them both by tile Same name was that they did not know whkh was which.
This article was originally published with the title "Minium or Cinnabar" in Scientific American 13, 11, 83 (November 1857)