between this Vapour and Flame, as between rotten Wood shining without
heat and burning Coals of Fire? In distilling hot Spirits, if the Head
of the Still be taken off, the Vapour which ascends out of the Still
will take fire at the Flame of a Candle, and turn into Flame, and the
Flame will run along the Vapour from the Candle to the Still. Some
Bodies heated by Motion, or Fermentation, if the heat grow intense, fume
copiously, and if the heat be great enough the Fumes will shine and
become Flame. Metals in fusion do not flame for want of a copious Fume,
except Spelter, which fumes copiously, and thereby flames. All flaming
Bodies, as Oil, Tallow, Wax, Wood, fossil Coals, Pitch, Sulphur, by
flaming waste and vanish into burning Smoke, which Smoke, if the Flame
be put out, is very thick and visible, and sometimes smells strongly,
but in the Flame loses its smell by burning, and according to the nature
of the Smoke the Flame is of several Colours, as that of Sulphur blue,
that of Copper open'd with sublimate green, that of Tallow yellow, that
of Camphire white. Smoke passing through Flame cannot but grow red hot,
and red hot Smoke can have no other appearance than that of Flame. When
Gun-powder takes fire, it goes away into Flaming Smoke. For the Charcoal
and Sulphur easily take fire, and set fire to the Nitre, and the Spirit
of the Nitre being thereby rarified into Vapour, rushes out with
Explosion much after the manner that the Vapour of Water rushes out of
an olipile; the Sulphur also being volatile is converted into Vapour,
and augments the Explosion. And the acid Vapour of the Sulphur (namely
that which distils under a Bell into Oil of Sulphur,) entring violently
into the fix'd Body of the Nitre, sets loose the Spirit of the Nitre,
and excites a great Fermentation, whereby the Heat is farther augmented,
and the fix'd Body of the Nitre is also rarified into Fume, and the
Explosion is thereby made more vehement and quick. For if Salt of Tartar
be mix'd with Gun-powder, and that Mixture be warm'd till it takes fire,
the Explosion will be more violent and quick than that of Gun-powder
alone; which cannot proceed from any other cause than the action of the
Vapour of the Gun-powder upon the Salt of Tartar, whereby that Salt is
rarified. The Explosion of Gun-powder arises therefore from the violent
action whereby all the Mixture being quickly and vehemently heated, is
rarified and converted into Fume and Vapour: which Vapour, by the
violence of that action, becoming so hot as to shine, appears in the
form of Flame.
_Qu._ 11. Do not great Bodies conserve their heat the longest, their
parts heating one another, and may not great dense and fix'd Bodies,
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