their being Homogeneous or Heterogeneous, as is apparent in the
Boyling of Water, the Distillation of Quicksilver, or the Exposing of
Bodies to the action of the Fire, whose Parts either Are not (at
least in that Degree of Heat Appear not) Dissimilar, where all that
the Fire can do, is to Divide the Body into very Minute Parts which
are of the same Nature with one another, and with their _Totum_, as
their Reduction by Condensation Evinces. And even when the Fire seems
most so _Congregare Homogenea, & Segregare Heterogenea_, it Produces
that Effect but by Accident; For the Fire does but Dissolve the
Cement, or rather Shatter the Frame, or [tructure [Errata: structure]
that kept the Heterogeneous Parts of Bodies together, under one Common
Form; upon which Dissolution the Component Particles of the Mixt,
being Freed and set at Liberty, do Naturally, and oftentimes without
any Operation of the Fire, Associate themselves each with its Like, or
rather do take those places which their Several Degrees of Gravity and
Levity, Fixedness or Volatility (either Natural, or Adventitious from
the Impression of the Fire) Assigne them. Thus in the Distillation
(for Instance) of Man's Blood, the Fire do's First begin to Dissolve
the _Nexus_ or Cement of the Body; and then the Water, being the most
Volatile, and Easy to be Extracted, is either by the Igneous Atomes,
or the Agitation they are put into by the Fire, first carried up, till
Forsaken by what carried it up, its Weight sinks it down into the
Receiver: but all this while the other Principles of the Concrete
Remain Unsever'd, and Require a stronger Degree of Heat to make a
Separation of its more Fixt Elements; and therefore the Fire must be
Increas'd which Carries over the Volatile Salt and the Spirit, they
being, though Beleev'd to be Differing Principles, and though Really
of Different Consistency, yet of an almost Equal Volatility. After
them, as less Fugitive, comes over the Oyl, and leaves behinde the
Earth and the _Alcali_, which being of an Equal Fixednesse, the Fire
Severs them not, for all the Definition of the Schools. And if into a
Red-hot Earthen or Iron Retort you cast the Matter to be Distill'd,
You may Observe, as I have often done, that the Predominant Fire will
Carry up all the Volatile Elements Confusedly in one Fume, which will
afterwards take their Places in the Receiver, either according to the
Degree of their Gravity, or according to the Exigency of their
respective Textures; the Salt Adhering, for the most part, to the
Sides and Top, and the Phlegme Fastening it self there too in great
Drops, the Oyle and Spirit placing themselves Under, or Above one
another, according as their Ponderousness makes them Swim or Sink. For
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