The Prosperity of Germany, Part Two

But in the other way, their fleeting nature is taken away from minerals, and they are reduced into bodies when, in the due reason, they are joined to metals and united by the fire of cementation heating in a sealed vessel, so that the fleeting and volatile mineral enters the metallic body, becomes metal, and acts as an augmentation to that body, which the lapis calaminaris manifests by its own example, which, joined to copper and roasted by the fire of cementation, penetrates it, and by penetrating, increases it and converts it into brass, when nevertheless by common fusion no metal can be elicited from it itself. By the same reason, arsenics of any kind will penetrate copper by cementation, will take the body to themselves in the same, and will tinge it, not indeed with a yellow color, as the lapis calaminaris, but with a white color. And although the copper, not enduring the hammer, remains friable and fragile, it does not, however, lack its profit if it is afterwards whitened and driven to the bottom by certain methods of precipitation, so that it may be received by the reguli pure metallic buttons/masses or metallic masses subsiding at the bottom; lest the metallic masses, afterwards roasted in a cupel or ash-test and properly burned, or cleaned with saltpeter, finally bring forth the gold snatched from the arsenic and other minerals of that kind and deliver it to the artisan, when yet before no metallic body could have been squeezed out from arsenic, orpiment, or cobalt by fusion and liquefaction. But so that this work may be duly brought to effect, it will have to be instituted with the following apparatus and manner: Small pieces or segments of copper, cut up into little bits, are to be moistened with linseed oil, sprinkled with the powder of arsenic, orpiment, cobalt, or otherwise realgar arsenic sulfide, and placed in a melting pot or crucible in such a way that, by alternating turns, the arsenic and copper cover one another, which is "layer upon layer" to the chemists. The pot, thus filled, properly covered with a lid, and sealed with clay, is to be surrounded by a circular fire, and the fire itself is to be moved closer and closer until at last the pot glows; in which, when cooled, will be found black copper, rendered fragile by the arsenic which has thoroughly penetrated into it. This friable copper, reduced into powder by pounding, if afterwards ignited with saltpeter, and cleaned by the conflagration of the same, the gold fleeting and volatile in the arsenic assumes a body to itself, and becoming constant, it does not leave the ash-test, or "test" as they call it, with the other metals remaining in the fire, so that in this way, from all arsenics, orpiments, cobalts, and other fleeting, poisonous, and rejected minerals, gold and silver satisfying all tests can be extracted. Note: This operation is quite dangerous for the inexperienced and those rude in the art of pyrotechnics who do not know how to guard themselves; it warns everyone to pay close attention to the procedure so that no one may proceed rashly and to their own destruction.