The Prosperity of Germany, Part Two

melted together, put into a pure and clean crucible with three times the weight of lead, cover the crucible against falling coals, which would corrupt the mass, and melt it thoroughly in a wind furnace. With the cover removed, cast a little saltpeter reduced to powder onto the melted regulus with a spoon, cover it again with the lid, and take total care that no coals fall into the crucible and bring detriment to the operation. In this way, it will happen that the saltpeter, melted with the regulus by a strong flux, draws all the iron and antimony to itself and hardens together with them. If this operation is repeated with another injection of saltpeter and melting, the antimony and all the iron, receiving the part of the lead into the saltpeter, will be changed into scoriae; however, some part of the lead not changed into scoriae will retain the gold which the antimony and iron possessed. This, placed under a cover in the assay cupel and melted by the fervor of the fire, will vanish and will show the true and certain weight of the gold left behind.

NB. In this labor, however, a just proportion must be observed so that too much saltpeter is not consumed in this washing or conversion into scoriae, and all the lead at the same time departs into dross. Instead, the ratio must be calculated so that out of those three added parts of lead, at least one remains and is not reduced into scoriae with the antimony and iron. This, subsiding into a leaden regulus, must be poured into a casting cone with the scoriae, freed from the scoriae after refrigeration, and separated through the cupel.

NB. Everyone desiring to wash metals and reduce them into scoriae in this manner with the help of saltpeter must concentrate his diligent care on this one thing: to take primary care that no coals fall into the crucible and ignite the saltpeter, for they would precipitate those things which that salt has already seized, and thus defraud the operator of the separated fruit. Furthermore, let it also be advised and tested in this place that every arsenic is rich in gold, and one is richer than another, and not a few iron and copper metals have gold, which is known and perceived by no one, nor can it be performed with profit by the trite and vulgar way of separation by lead. But someone might say, from where shall I seek