Mirror of Lights.

...to be fully purified original: "pfari," likely "purificari" from every corrupt color and whitened if by itself from those things which [result in] cause 5. It is the case that if by art, copper, iron, tin, and lead can become silver cause 6, because copper, iron, tin, and lead can by art be made into pure gold cause 7. For whatever copper, iron, tin, and lead can be fully purified from all corruption and rust, they can become pure gold. If cause 8 by themselves from the six [metals], whichever they are, copper, iron, tin, and lead can be fully purified by art from their corruption and rust, if they possess it by themselves. cause 9 whichever and that if by art copper, iron, tin, and lead can become pure gold. From the aforementioned things it is evidently clear that the science which is called alkyia (alchemy) is a true science and a firm art. For alchemy is the preparation of metals; wherefore alchemy is said to be from "alkimi" in Greek original: "alkimi grece", which is a "broad mass" This is a common medieval folk etymology attempting to link the word to the physical mass of the metals. For by this art the mass of metals, which in their mines are corrupted and imperfect, are brought back from corruption to health and from imperfection to perfection. cause 10

Solution

But some object cause 11 against the science through the word of Aristotle, who says that if the craftsman of alchemy knows [them], the spirits (volatile substances like mercury or sulfur) of mixed metals are not able [to be fixed]. And that many have found many good things in the operations of alchemy and yet achieved nothing because through the first [way] they have cause 1 a face [appearance] of the science that is neglected original: "obliatur," likely "oblivio" or "oblitio" because of porous vessels the spirit would exhale. cause 2 and it was seen that some neglected the spirits to the full, yet even if the vessels are fine and not porous, and besides with those spirits they were not able to perform [the work], because they did not act well upon the molten metal. cause 3 and cause 4 it was seen that some performed neglects, solutions, and decantations...

Mirror of Lights.

...yet it stood upon the established preparations, but they performed the neglect cause 5 [and] the fixation too quickly. Solution. Distillation. Therefore it was necessary to note that the spirit was infected and blackened, and the water infected and turbulent. Regarding cause 6 it is said that from powders only in [this] way much is neglected; through fixation the tincture (the substance that changes the color/nature of a metal) is produced. Therefore the defect is not in the science; it is not to be imputed to the science that they deceive themselves and others with false metal, because they did not know the science and therefore acted thus. Regarding cause 7 it is said that it is admirable that those spirits did not enter the metals nor tint them because they were not treated with oil in the science; for without oil, the spirits cannot immediately have entry into the metals and consequently cannot tint them. Regarding cause 8 it is said that the white vanished because the spirits receded from the copper, because the copper was not calcined (reduced to a powder by heat to remove impurities) and purified from its corruption, and as it is said, the spirits cannot be mixed with them cause 9 and united unless the metal be calcined and prepared from all preparations. Wherefore they tinted copper that was not calcined, not cleansed of its corruption, and not whitened to the white state as the science teaches. Aristotle then shows a personal defect in that he was ignorant of the science, and it is not a defect of the science itself. From the aforementioned it is manifestly clear that alchemy is a fine art and a very true science, and cause 10 by the present part of the book it is concluded, etc.

Having investigated the truth of this art which is called alchemy, [we turn to] the dictions which are preparations for alchemy. It will be noted. And first what is called...