several Forms or Asperity that may Diversifie the Surfaces of Colour'd
Bodies, may perchance somewhat assist us to make some Conjectures in the
general, at several of the ways whereby 'tis possible for the Experiments
hereafter to be mention'd, to produce the suddain changes of Colours that
are wont to be Consequent upon them; for most of these _Phaenomena_ being
produc'd by the Intervention of Liquors, and these for the most part
abounding with very Minute, Active, and Variously Figur'd Saline
Corpuscles, Liquors so Qualify'd may well enough very Nimbly after the
Texture of the Body they are imploy'd to Work upon, and so may change the
form of Asperity, and thereby make them Remit to the Eye the Light that
falls on them, after another manner than they did before, and by that means
Vary the Colour, so farr forth as it depends upon the Texture or
Disposition of the Seen Parts of the Object, which I say, _Pyrophilus_,
that you may not think I would absolutely exclude all other ways of
Modifying the Beams of Light between their Parting from the Lucid Body, and
their Reception into the common Sensory.

18. Now there seem to me divers ways, by which we may conceive that Liquors
may Nimbly alter the Colour of one another, and of other Bodies, upon which
they Act, but my present haste will allow me to mention but some of them,
without Insisting so much as upon those I shall name.

19. And first, the Minute Corpuscles that compose a Liquor may early
insinuate themselves into those Pores of Bodies, whereto their Size and
Figure makes them Congruous, and these Pores they may either exactly Fill,
or but Inadequately, and in this latter Case they will for the most part
alter the Number and Figure, and always the Bigness of the former Pores.
And in what capacity soever these Corpuscles of a Liquor come to be Lodg'd
or Harbour'd in the Pores that admit them, the Surface of the Body will for
the most part have its Asperity alter'd, and the Incident Light that meets
with a Grosser Liquor in the little Cavities that before contain'd nothing
but Air, or some yet Subtiler Fluid, will have its Beams either Refracted,
or Imbib'd, or else Reflected more or less Interruptedly, than they would
be, if the Body had been Unmoistned, as we see, that even fair Water
falling on white Paper, or Linnen, and divers other Bodies apt to soak it
in, will for some such Reasons as those newly mention'd, immediately alter
the Colour of them, and for the mos