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 most part make it Sadder than that of the
Unwetted Parts of the same Bodies. And so you may see, that when in the
Summer the High-ways are Dry and Dusty, if there falls store of Rain, they
will quickly appear of a much Darker Colour than they did before, and if a
Drop of Oyl be let fall upon a Sheet of White Paper, that part of it, which
by the Imbibition of the Liquor acquires a greater Continuity, and some
Transparency, will appear much Darker than the rest, many of the Incident
Beams of Light being now Transmitted, that otherwise would be Reflected
towards the Beholders Eyes.