l Asperity. But among the
_Moderns_, the formerly mention'd _Gassendus_, perhaps invited by this Hint
of _Democritus_, has Incidentally in another Epistle given us, though a
very Short, yet a somewhat Clearer account of the Nature of Blackness in
these words: _Existimare par est corpora suapte Natura nigra constare ex
particulis, quarum Superficieculae scabrae sint, nec facile lucem extrorsum
reflectant._ I wish this Ingenious Man had enlarg'd himself upon this
Subject; For indeed it seems, that as that which makes a Body White, is
chiefly such a Disposition of its Parts, that it Reflects (I mean without
much Interruption) more of the Light that falls on it, than Bodies of any
other Colour do, so that which makes a Body Black is principally a Peculiar
kind of Texture, chiefly of its Superficial Particle, whereby it does as it
were Dead the Light that falls on it, so that very little is Reflected
Outwards to the Eye.

2. And this Texture may be Explicated two, and perhaps more than two
several ways, whereof the first is by Supposing in the Superficies of the
Black Body a Particular kind of Asperity, whereby the Superficial Particles
reflect but Few of the Incident Beams Outwards, and the rest Inwards
towards the Body it self. As if for Instance, we should conceive the
Surface of a Black Body to be Asperated by an almost Numberless throng of
Little Cylinders, Pyramids, Cones, and other such Corpuscles, which by
their being Thick Set and _Erected_, reflect the Beams of Light from one to
another Inwards, and send them too and fro so often, that at length they
are Lost before they can come to Rebound out again to the Eye. And this is
the first of the two mention'd ways of Explicating Blackness. The other way
is by Supposing the Texture of Black Bodies to be such, that either by
their Yielding to the Beams of Light, or upon some other Account, they do
as it were Dead the Beams of Light, and keep them from being Reflected in
any Plenty, or with any Considerable Vigour of Motion, Outwards. According
to this Notion it may be said, that the Corpuscles that make up the Beams
of Light, whether they be Solary _Effluviums_, or Minute Particles of some
AEtherial Substance, Thrusting on one another from the Lucid Body, do,
falling on Black Bodies, meet with such a Texture, that such Bodies receive
Into themselves, and Retain almost all the Motion communicated to them by
the Corpuscles that make up the Beams of Light, and consequently Ref