Note (15) — BOOK V.
James Greive translation
15. Calcined copper.) The metal was calcined by being put into a pot, stratum super stratum, with sulphur and salt.—Or else the copper was kept for several days in the fire in a pot by itself.—Others again added allum to it, or sulphur alone, which last gave it a sooty colour.—It was washed in a mortar, and the water changed four times a day, till no froth arose in it. Dioscorid. lib. v. cap. 861.