These pores were so exceeding small and thick, that in a line of them, 1/18
part of an Inch long, I found by numbring them no less then 150. small
pores; and therefore in a line of them an Inch long, must be no less then
2700. pores, and in a circular _area_ of an Inch diameter, must be about
5725350. of the like pores; so that a Stick of an Inch Diameter, may
containe no less then seven hundred and twenty five thousand, besides 5
Millions of pores, which would, I doubt not, seem even incredible, were not
every one left to believe his own eyes. Nay, having since examin'd _Cocus,
black and green Ebony, Lignum Vitae_, &c. I found, that all these Woods
have their pores, abundantly smaller then those of soft light Wood; in so
much, that those of _Guajacum_ seem'd not above an eighth part of the
bigness of the pores of Beech, but then the _Interstitia_ were thicker; so
prodigiously curious are the contrivances, pipes, or sluces by which the
_Succus nutritius_, or Juyce of a Vegetable is convey'd from place to
place.
This _Observation_ seems to afford us the true reason of several
_Phaenomena_ of Coals; as
First, why they look black; and for this we need go no further then the
_Scheme_, for certainly, a body that has so many pores in it as this is
discover'd to have, from each of which no light is reflected, must
necessarily look black, especially, when the pores are somewhat bigger in
proportion to the intervals then they are cut in the _Scheme_, black being
nothing else but a privation of Light, or a want of reflection; and
wheresover this reflecting quality is deficient, there does that part look
black, whether it be from a porousness of the body, as in this Instance, or
in a deadning and dulling quality, such as I have observ'd in the _Scoria_
of Lead, Tin, Silver, Copper, &c.
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