In the mean while I will prove clearly, that the separation of tin and iron by common lead, thereby to get their gold and silver, is of no value, which being left in them, are turned into ashes and dross.
Take any tin, and reduce it into ashes by lead, or agitation, on a smooth earthen vessel (tryed before, by the common way, for distinction sake, which calcine well, that the corporeal tin powdered, may be calcined, or being melted, may be separated from the ashes). Then take of these ashes one part, and of the following flux, or of that a little after six parts or more; being mixt, fuse them in a strong crucible with a strong fire, until the Flux have Consumed or drunk up all the calx of the Tin, and of them both shall be made one, viz. yellow or red Glass, which may be tryed with a crooked wier put in: which if it seem not clear, the crucible must be covered again, and a greater Fire be given, until the Fire be perfect; which labour in one half hour is finished: which done, pour it into a brass mortar, afterward to be covered, until it be a cold, that it leap not out and be lost.
Afterward powder it, which with calx of Tin, mix the equal weight of filings of Iron; being mixt, put them into a strong Crucible (because the Flux is very penetrative) covered, and give a strong fire for fusion half an hour: which done, pour it out, for the Tin hath made separation, and reduced some part of the Lead out of the Flux, sinking to the bottom to be separated when it is cold, to be reduced into dross on a test, and then to be cupelled, and you shall find grain Gold drawn from Tin without Silver. And if before you weigh the calx of Tin by the lesser Hundred weight, and after that the grains of Gold, you may easily conjecture how much Gold is contained in the whole hundred weight of Tin ashes, viz. at the least 3, 4, 5, or 6. Lotones, or half Ounces, if thou work aright.
See then the Fault is not to be imputed to the metals, but us, being ignorant of the separation of the Gold and Silver.
You should not perswade your self by this means to get much wealth out of Tin; for I have not written this for that end, but only to demonstrate the possibility. And if thou think that Gold will come out of Iron by the fluxing powder, mingle then filings of Iron with the Flux, before thou put in the calx of Tin, and thou shalt find in so doing, that Gold doth come neither from the Flux or Iron, but out of Tin; then being hereby assured, that ’tis the Tin which contains Gold, thou mayst consider, how most conveniently that may be extracted, viz. with other Lead, and another way, as shall be hereafter taught. Neither think that Tin contains no more Gold than you have heard; for more there is if you can wisely extract it: neither do I deny, that more Gold may be extracted out of the Tin, but more care than this is to be given, if you desire more plenty. But Gold may thence be extracted, not only by Flux, but diverse other wayes, in diverse weights; for what is written, is only for demonstration of the possibility, that the Gold contained in the imperfect metals, may be extracted by a secret separation.
The Fluxing Powder requisite to this Work.
℞ one part of very pure and white Sand, or Flints, having no Gold fusible; to which, add three parts of Litharge of Lead; being mixt, fuse in a very strong Fire, that thereof a transparent Glass may be made of it, which pour out, that it may be cold, and reduce it to powder; which use in the aforesaid manner. But you may ask, why Sand and Flints are mingled, seeing they are not of a metallick nature: to which I say, the calx of Tin, cannot, as also other Fossiles be Examined by Lead alone, for the following Reasons, viz. because in the Calcination of Tin, its metallick nature is hidden, but the impure and earthy parts are manifest, wherefore it hath no longer affinity with Lead and other metals; unless the hidden parts of the lead be manifest, and also other metals and the manifest be hidden, for then they easily embrace one the other, and are again mingled well, and not altered.
What belongs to the alteration of other metals doth not belong hither; for to this place only pertain Lead and Tin, the alteration of which is demonstrated by this tryal; whereby it appears to be thus.
Lead reduced into ashes, by it self, or into Litharge, and deprived of its metallick form, cannot so in this work be used without the flints or sand, for the following reason. The lead and glass thereof made by it self is very fusible and volatile; but the calx of tin is very difficultly fused: which two calxes, although they should be mingled to fuse in a crucible, yet would not be mingled, nor being fused, embrace one the other, by reason of the difference of their fusibility; because the calx of lead alone being fused by a small fire, will perforate and penetrate the crucible, the calx of Tin being left in the crucible: wherefore you must add sand or flints to the lead, viz. to hinder its fusibility, that it may endure the same degree of heat with those that are difficultly fused, and further their flux. For like things do mutually affect and embrace each other; as water doth water, oyl oyl, and glass glass; and metals other metals; but water is not mingled with oyl; neither are glasses mingled with metals, but metals with metals, and glass with glass, whether it be made of metals or out of sand. Wherefore they greatly err who mingle the calx of metals difficultly miscible, or other hard things with lead to prove or examin, not considering that corporeal lead hath no affinity with them: who remaining in their errour, and not weighing the thing further, consequently can find nothing of any moment.
But when the calx of metals united with lead by a medium, as flints or sand, are brought together into transparent glass; then the lead being precipitated and separated from the mixture, it cannot be, but that the gold and silver contained in them must be carried away with it. This is a true and philosophical tryal, and not to be contemned, for many things may be by it performed.