croscope_ would give us an
account of the Variableness of Colour, that is so Conspicuous and so
Delightfull in Mother of Pearl, in Opalls, and some other resembling
Bodies: For though I remember I did formerly attempt something of that Kind
(fruitlesly enough) upon Mother of Pearl, yet not having then the advantage
of my best _Microscope_, nor some Conveniences that might have been wish'd,
I leave it to you, who have better Eyes, to try what you can do further;
since 'twill be _Some_ discovery to find, that, in this case, the best Eyes
and _Microscopes_ themselves can make _None_.

10. I confess, _Pyrophilus_, that a great part of what I have deliver'd,
(or propos'd rather) concerning the differing forms of Asperity in Bodies,
by which Differences the incident Light either comes to be Reflected with
more or less of Shade, and with that Shade more or less Interrupted, or
else happens to be also otherwise Modify'd or Troubl'd, is but Conjectural.
But I am not sure, that if it were not for the Dullness of our Senses,
either these or some other Notions of Kin to them, might be better
Countenanc'd; for I am apt to suspect, that if we were Sharp sighted
enough, or had such perfect _Microscopes_, as I fear are more to be wish'd
than hop'd for, our promoted Sense might discern in the Physical Surfaces
of Bodies, both a great many latent Ruggidnesses, and the particular Sizes,
Shapes, and Situations of the extremely little Bodies that cause them, and
perhaps might perceive among other Varieties that we now can but imagine,
how those little Protuberances and Cavities do Interrupt and Dilate the
Light, by mingling with it a multitude of little and singly undiscernable
Shades, though some of them more, and some of them less Minute, some less,
and some more Numerous; according to the Nature and Degree of the
particular Colour we attribute to the Visible Object; as we see, that in
the Moon we can with Excellent _Telescopes_ discern many Hills and Vallies,
and as it were Pits and other Parts, whereof some are more, and some less
Vividly illustrated, and others have a fainter, others a deeper Shade,
though the naked Eye can discern no such matter in that Planet. And with an
Excellent _Microscope_, where the _Naked_ Eye did see but a Green powder,
the _Assisted_ Eye as we noted above, could discern particular Granules,
some of them of a Blew, and some of them of a Yellow colour, which
Corpuscles we had beforehand caus'd to be exquisitly m