Sparks that in great multitudes do fly upwards do, some of them, stick
to the vaulted Roofs of the Furnaces, in the form of little and (for
the most part) White Bubbles, which therefore the Greeks, and, in
Imitation of them, our Drugsters call _Pompholix_: and others more
heavy partly adhere to the sides of the Furnace, and partly
(especially if the Covers be not kept upon the Pots) fall to the
Ground, and by reason of their Ashy Colour as well as Weight were
called by the same Greeks [Greek: spodos], which, I need not tell you,
in their Language signifies Ashes. I might add, that I have not found
that from Venetian Talck (I say Venetian, because I have found other
kinds of that Mineral more open) from the _Lapis Ossifragus_, (which
the Shops call _Ostiocolla_) from _Muscovia_ Glass, from pure and
Fusible Sand, to mention now no other Concretes; those of my
Acquaintance that have try'd have been able by the Fire to separate
any one of the Hypostatical Principles, which you will the less
scruple to believe, if you consider that Glass may be made by the bare
Colliquation of the Salt and Earth remaining in the Ashes of a burnt
Plant, and that yet common Glass, once made, does so far resist the
violence of the Fire, that most Chymists think it a Body more
undestroyable then Gold it self. For if the Artificer can so firmly
unite such comparative gross Particles as those of Earth and Salt that
make up common Ashes, into a Body indissoluble by Fire; why may not
Nature associate in divers Bodies the more minute Elementary
Corpuscles she has at hand too firmly to let them be separable by the
Fire? And on this Occasion, _Eleutherius_, give me leave to mention to
you two or three sleight Experiments, which will, I hope, be found
more pertinent to our present Discourse, than at first perhaps they
will appear. The first is, that, having (for Tryals sake) put a
quantity of that Fugitive Concrete, Camphire, into a Glass Vessel, and
plac'd it in a gentle Heat, I found it (not leaving behinde, according
to my Estimate, not so much as one Grain) to sublime to the Top of the
Vessel into Flowers: which in Whiteness, Smell, &c. seem'd not to
differ from the Camphire it self. Another Experiment is that of
_Helmont_, who in several places affirms, That a Coal kept in a Glass
exactly clos'd will never be calcin'd to Ashes, though kept never so
long in a strong Fire. To countenance which I shall tell you this
Tryal of my own, That having sometimes distilled some Woods, as
particularly Box, whilst our _Caput mortuum_ remain'd in the Retort,
it continued black like Charcoal, though the Retort were Earthen, and
kept red-hot in a vehement Fire; but as soon as ever it was brought
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