Tyro-chymicus instructus epistola hermetica

...Sendivogius in Letters 50, 54, and the last one, speaks of nothing other than the universal spirit, and so forth. What then?

Concerning this universal spirit, Basilius Valentinus Basil Valentine, a legendary alchemist, possibly a pseudonym for Johann Thölde (similarly to Sendivogius, both being favorites among all others, which is why I have cited them here) says in his Treatise on natural and supernatural things, and on the first root of the nature of metals, and the universal mercurial spirit, chapter 3: "My universal source of metals is that same unique universal spirit of mercury, which all Philosophers have held, as those who understand through experience will testify to me, nor can they conclude otherwise." And one may see the Cheiragogia Heliana The Helian Hand-Guide in volume 4 of the Theatrum Chemicum The Chemical Theater, a large collection of alchemical texts pages 265 and 285, from Basil himself cited there, regarding what he adds about this universal spirit; where he openly says: "That without this universal spirit nothing can be done in the mastery of this art: and he who desires to fashion our Stone, it is incumbent upon him that he search only for that universal magnet, without which there is nothing, and no one."

Just as he adds in clear words regarding the Antimonial Martial Regulus: "That those people laboring in it wander from the right path like Hawks and Storks, and so forth, and that they do not understand the words of the Wise, and so forth."

From the aforementioned things, therefore, it shines forth most clearly that not only the Regulus, but even gold, silver, and all the common metals, and whatever primary and intermediate minerals are commonly known, are entirely excluded from this art, as Paracelsus confirms in his Collections of Chemistry chapters 7 and 8. And on this point, see also Richardus Anglicus Richard the Englishman, a 14th-century alchemical author...