The Prosperity of Germany, Part Two

I know some who, understanding the method of fixing cobalt and bismuth by saltpeter, have evoked much silver from them. There are also some who, by the help of the same niter, know how to tame and restrain arsenical substances and realgars so that, tolerating liquefaction, they bring forth their hidden gold and silver. But he who knows the reason and way of joining imperfect metals containing hidden gold with them will institute his operation with a far happier success, especially if he has procured iron containing gold, which is for sale at a vile price, and has made the niter himself. This fixation or separation of volatile minerals will cost little indeed, but it will yield much interest.

NB. But if anyone is held by the desire of capturing greater profit from this separatory operation, he must betake himself to the hearths, ignoring crucibles and melting-pots; in these, a huge quantity of volatile minerals, fixed by niter, is melted, precipitated into reguli, the reguli are separated from the scoriae, purged by niter, and recalled into use, so much so that they could bring as much emolument as the huge mines of metals hardly offer, from whose innermost bowels the greatest heaps of metals must be dug out at the highest expense.

Besides this method, which we have taught up to now, there is another certain wet way which, by the help and aid of niter, renders all immature and volatile minerals so fixed that they provide gold and silver constant in the fire, by which as much, if not more, is acquired as can be obtained by the aid of the dry way. The operation is as follows. Dissolve any volatile mineral, whether it be cobalt, zinc, bismuth, calamine stone, arsenic, orpiment, or anything similar, with sufficiently strong and effective aqua fortis, which you will separate after the solution is made by distilling it again, so that a white calx remains at the bottom, fixed by the operation of the same water such that it can be smelted with lead, reduced into scoriae, and