Kufflerus:  Artist, I found-in my own Laboratory, an Aqua-fortis.  Secondly, I again found another in the Laboratory, Caroli de Roy; this Aqua-Fortis I poured upon the Calx of Sol, prepared of Gold, in the Vulgar manner, and after the third Cohobation, it sublimed the Tincture of Gold with it self in the Neck of the Retort; this Tincture I mixed with Silver, precipited in the vulgar manner, and I saw that one ounce of the sublimed Tincture of Gold, with ordinary Flux in a Crucible, had transmuted one ounce, and halfe of the two ounces of precipitate Silver, into the best Gold:  but a third part of the Silver yet remaining, was a white and fixed Gold:  the other two parts thereof were perfect Silver, fixed in every examen of Fire.  This is my experience, after this time, we could never find the like Aqua-fortis.  I Helvetius saw this Gold white, and without Tincture.

The same.

There is yet one other Example very rare; of what was done at the Hague by a Silver-Smith, whose name was Grill:  how he in the year 1664. by Spirit of Salt, not prepared in the Vulgar manner, transmuted Lead so, as from one pound, he received three parts of the best Silver, and two ounces of most fixed Gold.

At the Hague, a certain Silver-Smith, and a much exercised Disciple of Alchimy, but according to the nature of Alchimy, a very poor man; did sometime since require Spirit of Salt, not vulgarly prepared, of a loving Friend of Mine, a Cloath-Dyer, by name, John Casparus Knottnerus.  My Friend giving the same to him; demanded, whether he would use that Spirit of Salt, he now had, for Metals, or not?  Grill made answer; for Metalls.  And accordingly he afterward powred this Spirit of Salt upon Lead, which he had put into a Glass Dish, usual for Conditures and Confections.  The space of two Weeks being elapsed, supernatant on the Spirit of Salt, appeared a most splendid Silver-Starre, so exceeding curious, as if it had been made With an Instrument by a most ingenious Artist.  At the sight of which, the said Grill, filled with Exceeding Joy, signified to us, that he had seen the Signate Star of Philosophers, touching which he had read in Basilius, as he thought.  I, and many other honest Men, did behold this Star supernatant on the Spirit of Salt, the lead in the mean while remaining in the bottom of an ash colour, and swollen like a Sponge.  But in the space of seven or nine dayes, that humidity of the Spirit of Salt, being absumed by the exceeding heat of the Aire, in July, did vanish; but the Star settled down, and still stood above that Earthly Spongeous Lead.  That was a thing worthy of admiration, and beheld by not a few Spectators.  At length Grill himself having taken part of Cinereous, or Ash-like Lead, with the Star adhering, cupellated in a Test, and found from one ounce of this Lead, twelve ounces of Cupellate Silver, and from these twelve ounces, he also had two ounces of the best Gold.