Nine Books on the Nature of Things

The regeneration and renewal of metals occurs as follows. Just as a person can return to the mother’s womb—that is, to the earth from which the first human came—and thus be born anew on the last day, so all metals can return to living Mercury, become Mercury, and be regenerated and clarified through fire if they remain for forty weeks in continuous warmth, like a child in the mother’s womb. What are born then are tinging metals rather than common metals. If Silver is regenerated as described, it will afterward tinge all other metals into Silver; likewise Gold will tinge the remaining metals into Gold. The same must be understood of every other metal.