, and though it be somewhat Nice to make, yet I am willing to
Acquaint You with, because the thing Produc'd, though it be but a
Curiosity, is wont not a little to please the Beholders, and it is a way of
turning by the help of a Dry Substance, an almost Golden-Colour'd Concrete,
into a White one, the Several Tryals are not at present so fresh in my
Memory to enable me to tell you Certainly, whether an Equal onely or a
Double weight of Common Sublimate must be taken in reference to the
Tinglass, but if I mistake not, there was in the Experiment that succeeded
best, Two parts of the Former taken to One of the Latter. These Ingredients
being finely Powdred and Exactly mix'd, we Sublim'd together by degrees of
fire (the due Gradation of which is in this Experiment a thing of main
Importance) there ascended a matter of a very peculiar Texture, for it was
for the most part made up of very Thin, Smooth, Soft and Slippery Plates,
almost like the finest sort of the Scales of Fishes, but of so Lovely a
White Inclining to Pearl-Colour, and of so Curious and Shining a Gloss,
that they appear'd in some respect little Inferiour to Orient Pearls, and
in other Regards, they seem'd to Surpass them, and were Applauded for a
sort of the Prettiest Trifles that we had ever prepar'd to Amuse the Eye. I
will not undertake that though you'l hardly miss changing the Colour of
your shining Tinglass, yet you will the first or perhaps the second time
hit Right upon the way of making the Glistring Sublimate I have been
mentioning.

_EXPERIMENT IX._

When we Dissolve in _Aqua Fortis_ a mixture of Gold and Silver melted into
one Lump, it usually happens that the Powder of Gold that falls to the
bottom, as not being Dissoluble by that _Menstruum_, will not have its own
Yellow, but appear of a Black Colour, though neither the Gold, nor the
Silver, nor the _Aqua Fortis_ did before manifest any Blackness. And divers
Alchymists, when they make Solutions of Minerals they would Examine, are
very Glad, if they see a Black Powder Praecipitated to the Bottom, taking it
for a Hopefull Sign, that those Particles are of a Golden Nature, which
appear in a Colour so ordinary to Gold parted from other Metalls by _Aqua
Fortis_, that it is a trouble to the Refiner to Reduce the Praecipitated
_Calx_ to its Native Colour. For though, (as we have try'd,) that may be
Quickly enough done by Fire, which will make this Gold look very Gloriously
(as indeed 'tis at least one o