The Prosperity of Germany, Part Two

or fungi, provided he has obtained minerals of a better grade, which are especially suitable for separation. But someone will say, from where shall I obtain minerals of a proven grade? Who will certify me of their quality or malice, of their fertility or sterility regarding gold, so that I do not waste oil and labor by wandering astray in my work? Here I would have him know that if he does not have an explored and understood method for putting some mineral to the test of examination, and does not know how to distinguish whether it is gold-bearing or not, he would be far better off to declare himself completely unfit and unable for this work of separation, and would consult his own interests much better if he let such labors go. Nevertheless, so that no one may be able to desire even the least bit from me, I will add to the things demonstrated thus far an examination of minerals, which explores which minerals are endowed with the properties of a golden nature, and which are conversely destitute of them.

Regarding all realgar, such as arsenic, orpiment, cobalt, and the like, you must first unite them with copper through cæmentatio cementation, a process of heating with chemical agents in a closed vessel, then smelt and separate them like any raw ore using lead, so that a grain of silver may appear, in which the gold must be sought and investigated through a docimastic analytical/testing examination. But according to how much or how little that investigation yields to you, you will also discover by calculating whether that mineral is rich enough to bear the necessary expenses. Copper smelted with lead alone can be separated, and the remaining grain of silver can be examined with the benefit of aqua fortis nitric acid to see if it holds any hidden gold.

Antimony and iron are joined, and placed in a test under a cover, which they call a muffula muffle, or two parts of iron and one of antimony are cast into a proper cup or crucible, and in a furnace, with the aid of wind raising the fire, they are melted with a very strong flux so that the regulus the pure metallic button formed at the bottom of the crucible seeks the bottom. This is smelted with lead in a test, and once smelted, it is kept fluid in a cupella cupel, a small porous vessel for assaying for as long as it takes for all volatile parts to vanish and a grain of silver to remain, which, when dissolved in aqua fortis, deposits gold if it holds any, and demonstrates how much gold the iron contains. NB. This type of examination is indeed reliable, but yet it is so arranged,