en once or twice refracted (through a
Prisme, for example) must affect the eye with the same kind of stroke as if
it had not been refracted at all. Nor will it be enough for a Defendant of
that _Hypothesis_, to say, that perhaps it is because the refractions have
made the Rays more weak, for if so, then two refractions in the two
parallel sides of a _Quadrangular Prisme_ would produce colours, but we
have no such _Phaenomena_ produc'd.

There are several Arguments that I could bring to evince that there are in
all transparent bodies such atomical pores. And that there is such a fluid
body as I am arguing for, which is the _medium_, or Instrument, by which
the pulse of Light is convey'd from the _lucid body_ to the enlightn'd. But
that it being a digression from the Observations I was recording, about the
Pores of _Kettering Stone_, it would be too much such, if I should protract
it too long; and therefore I shall proceed to the next _Observation_.

* * * * *

Observ. XVI. _Of _Charcoal_, or burnt _Vegetables_._

Charcoal, or a Vegetable burnt black, affords an object no less pleasant
than instructive, for if you take a small round Charcoal, and break it
short with your fingers, you may perceive it to break with a very smooth
and sleek surface, almost like the surface of black sealing Wax; this
surface, if it be look'd on with an ordinary _Microscope_, does manifest
abundance of those pores which are also visible to the eye in many kinds of
_Wood_, rang'd round the pith, both a in kind of circular order, and a
radiant one. Of these there are a multitude in the substance of the Coal,
every where almost perforating and drilling it from end to end; by means of
which, be the Coal never so long, you may easily blow through it; and this
you may presently find, by wetting one end of it with Spittle, and blowing
at the other.

But this is not all, for besides those many great and conspicuous irregular
spots or pores, if a better _Microscope_ be made use of, there will appear
an infinite company of exceedingly small, and very regular pores, so thick
and so orderly set, and so close to one another, that they leave very
little room or space between them to be fill'd with a solid body, for the
apparent _interstitia_ or separating sides of these pores seem so thin in
some places, that the texture of a Honey-comb cannot be more porous. Though
this be not every where so, the intercurrent partitions i