Sex, I have convinc'd them, by Tryall, that of two Pieces of Silken
Stuff given me by themselves, and expos'd in their Presence, to the same
Window, Shin'd on by that Sun, the White was _considerably_ Heated, when
the Black was not so much as _Sensibly_ so.

9. Sixthly, I remember, that Acquainting one Day a _Virtuoso_ of
Unsuspected Credit, that had Visited Hot Countries, with part of what I
have here Deliver'd concerning Blackness, he Related to me by way of
Confirmation of it, a very notable Experiment, which he had both others
make, and Made himself in a Warm Climate, namely, that having carefully
Black'd over Eggs, and Expos'd them to the Hot Sun, they were thereby in no
very Long time well Roasted, to which Effect I conceive the Heat of the
Climate must have Concurr'd with the Disposition of the Black Surface to
Reflect the Sunbeams Inward, for I remember, that having made that among
other Tryals in _England_, though in Summer-time, the Eggs I Expos'd,
acquir'd indeed a considerable Degree of Heat, but yet not so Intense a
One, as prov'd Sufficient to Roast them.

10. Seventhly, and Lastly, Our Conjectures at the Nature of Blackness may
be somewhat Confirm'd by the (formerly mention'd) Observation of the Blind
_Dutch-man_, that Discerns Colours with his Fingers; for he Says, that he
Feels a greater Roughness upon the Surfaces of Black Bodies, than upon
those of Red, or Yellow, or Green. And I remember, that the Diligent
_Bartholinus_ says,[9] that a Blind Earl of _Mansfield_ could Distinguish
White from Black only by the Touch, which would Sufficiently Argue a great
Disparity in the Asperities, or other Superficial Textures of Bodies of
those two Colours, if the Learn'd Relator had Affirm'd the Matter upon his
own Knowledge.

[9] Hist. Anatom. Cent. 3. Hist. 44.

II. These, _Pyrophilus_, are the chief things that Occurr to me at present,
about the Nature of Whiteness and Blackness, which it they have Rendred it
so much as Probable, that in _Most_; or at least _Many_ Cases, the Causes
of these Qualities may be such as I have Adventur'd to Deliver, it is as
much as I Pretend to; for till I have Opportunity to Examine the Matter by
some further Tryals, I am not sure, but that in some White and Black
Bodies, there may Concurr to the Colour some peculiar Texture or
Disposition of the Body, whereby the Motion of the Small Corpuscles that
make up the Incident Beams of Light, may be Differingly Modify'd, before
they