Prev | Current Page 145 | Next

Boyle, Robert, 1627-1691

"Experiments and Considerations Touching Colours (1664)"

I might add
that _Crocus_ _Martis_ (_per se_ as they call it) made by the Lasting
violence of the Reverberated flames is not so near a Kin to White, as the
Iron or Steel that afforded it was before its Calcinations; but that I
suppose, these Instances may Suffice to satisfie you, that Minerals are to
be excepted out of the forementioned Rule, which perhaps, though it seldome
fail in substances belonging to the Vegetable or Animal Kingdome, may yet
be Question'd even in some of these, if that be true, which the Judicious
Traveller _Bellonius_ affirms, that Charcoales made out of the Wood of
_Oxycaeder_ are White; And I could not find that though in Retorts Hartshorn
and other White Bodies will be Denigrated by Heat, yet Camphire would not
at all lose its Whiteness, though I have purposely kept it in such a heat,
as made it melt and boyl.
_EXPERIMENT V._
And now I speak of Camphire, it puts me in mind of adding this Experiment,
That, though as I said in Clos'd Glasses, I could not Denigrate it by Heat,
but it would Sublime to the sides and top of the Glass, as it was before,
yet not only it will, being set on fire in the Free Air, send forth a
Copious smoak, but having purposely upon some of it that was Flaming, clapt
a Large Glass, almost in the form of a Hive, (but more Slender only) with a
Hole at the top, (which I caus'd to be made to trye Experiments of Fire and
Flame in) it continued so long burning that it Lin'd all the Inside of the
Glass with a Soot as Black as Ink, and so Copious, that the Closeness of
the Vessel consider'd, almost all that part of the White Camphire that did
take Fire, seem'd to have been chang'd into that deep Black Substance.


Pages:
133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157
brak hosta 906 system wymiany linkow 906 sprawdz strone