The Prosperity of Germany, Part Two

Whoever is ignorant of how to treat such things and how to conduct himself cautiously should abstain his hands and supersede this work and let it be; but whoever is well-versed in the manner of governing the fire will be able to undergo the same operation without danger and perceive no contemptible gain from it. For not rarely do arsenics and orpiments fall into one's hands holding no little amount of fleeting and volatile gold, which, by the work of common fusion, cannot be preserved in the fire but withdraws itself in full flight. But if those minerals are inserted into copper by cementation, and rendered fixed and constant in it by the aid of saltpeter, and finally precipitated into reguli or metallic masses with lead or iron, then finally they bring forth, fixed and constant, whatever they previously hid and kept within themselves that was fleeting and inconstant. What, however, the manner of cementing, of fixing by nitre, and of precipitating metallic reguli may be, will be clear from the following operations. Note: Cementing...