8I shall now speak of vermilion. This is said to have been first found in the Cilbian fields of the Ephesians, and the manner of procuring and preparing it is very curious. A clod of earth is selected, which, before it is manufactured into vermilion, is called Anthrax, wherein are veins resembling iron, but of a red colour, and having a red dust round them. When dug up, it is beaten with iron bars till a great number of drops of quicksilver exude from it; these are immediately collected by the excavators.
2The clods, when collected in the laboratory, on account of their great dampness, are thrown into a furnace to dry; and the fumes that rise from them through the action of the fire fall condensed on the floor of the furnace, and are found to be quicksilver. But as, from the smallness of the drops which thus remain, they cannot be gathered up, they are swept into a vessel of water, in which they run together and re-unite. These, when they fill a vessel of the capacity of four sextarii, weigh one hundred pounds.
3If quicksilver be placed in a vessel, and a stone of a hundred pounds weight be placed on it, it will swim at the top, and will, notwithstanding its weight, be incapable of pressing the liquid so as to break or separate it. If this be taken out, and only a single scruple of gold be put in, that will not swim, but immediately descend to the bottom. This is a proof that the gravity of a body does not depend on its weight, but on its nature.
4Quicksilver is used for many purposes; without it, neither silver nor brass can be properly gilt. When gold is embroidered on a garment which is worn out and no longer fit for use, the cloth is burnt over the fire in earthen pots; the ashes are thrown into water, and quicksilver added to them: this collects all the particles of gold, and unites with them. The water is then poured off, and the residuum placed in a cloth: which, when squeezed with the hands, suffers the liquid quicksilver to pass through the pores of the cloth, but retains the gold in a mass within it.