from being dissipated into those Principles, whereof one at least is
acknowledged to be Fugitive enough; and so justly did the Spagyricall
Poet somewhere exclaim,
_Cuncta adeo miris illic compagibus harent._
And I must not omit on this occasion to mention to you, _Eleutherius_,
the memorable Experiment that I remember I met with in _Gasto
Claveus_,[2] who, though a Lawyer by Profession, seems to have had no
small Curiosity and Experience in Chymical affairs: He relates then,
that having put into one small Earthen Vessel an Ounce of the most
pure Gold, and into another the like weight of pure Silver, he plac'd
them both in that part of a Glass-house Furnace wherein the Workmen
keep their Metal, (as our English Artificers call their Liquid Glass)
continually melted, and that having there kept both the Gold and the
Silver in constant Fusion for two Moneths together, he afterwards took
them out of the Furnace and the Vessels, and weighing both of them
again, found that the Silver had not lost above a 12th part of its
weight, but the Gold had not of his lost any thing at all. And though
our Author endeavours to give us of this a Scholastick Reason, which I
suppose you would be as little satisfied with, as I was when I read
it; yet for the matter of Fact, which will serve our present turne, he
assures us, that though it be strange, yet Experience it self taught
it him to be most true.
[Footnote 2: _Gasto Claveus_ Apolog. Argur. & Chrysopera.]
And though there be not perhaps any other Body to be found so
perfectly fix'd as Gold, yet there are divers others so fix'd or
compos'd, at least of so strictly united parts, that I have not yet
observ'd the Fire to separate from them any one of the Chymists
Principles. I need not tell you what Complaints the more Candid and
Judicious of the Chymists themselves are wont to make of those
Boasters that confidently pretend, that they have extracted the Salt
or Sulphur of Quicksilver, when they have disguis'd it by Additaments,
wherewith it resembles the Concretes whose Names are given it;
whereas by a skilful and rigid _Examen_, it may be easily enough
stript of its Disguises, and made to appear again in the pristine form
of running Mercury. The pretended Salts and Sulphurs being so far from
being Elementary parts extracted out of the Bodie of Mercurie, that
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