DOI Page / Citation link:
https://doi.org/10.11588/diglit.68888#0168
io8 MlCROGRAPHi a.
by the most accomplish’d Mr. F/velin^ my highly honour’d friend, to be
inserred and published among those excellent Observations wherewith
his Sylva is replenish’d, and would therefore have been here omitted5had
not the Figure of them, as they appear d through the Microfcope been
before that engraven.
This Petrify d substance resembled Wood, in that
First, all the parts of it seem’d not at all dissocated^ or alter’d from
their natural Position, whil’st they were Wood, but the whole piece re-
tain’d the exast shape of Wood, having many of the conspicuous pores
of wood (till remaining pores, and (hewing a manifest difference visible
enough between the grain of the Wood and that of the bark, eipecially
when any side of it was cut smoothand polite 5 for then it appear’d to
have a very lovely grain, like that of some curious close Wood.
Next (it resembled Wood) in that all the smallerand (if I may so call
thole which are onely visible with a good magnifying Glass) Microfcopi-
cal pores os it appear (both when the substance is cut and polish’d tranf
verfly and parallel to the pores of it) perfectly like the Mier ofcopic al poxes
ofseveral kinds of Wood, eipecially like and equal to those of several
sorts of rotten Wood which I have since observ’d, retaining both the
(hape,position and magnitude of soch pores. It was differing from Wood :
First, in weighty being to common water as 34 to 1. whereas there are
few os our Englijb Woods, that when very dry are found to be full as
heavieas water.
Secondly, in hardnesf being very neer as hard as a Flint 5 and in some
places of it also resembling the grain of a Flint: and, like it, it would
very readily cut Glass, and would not without difficulty, eipecially in
some parts of it, be scratch’d by a black hard Flint: It would also as rea-
dily strike fire against a Steel, or against a Flint, as any common Flint.
Thirdly, in the closenessoi it, for though all the Microfcopical pores of
this petrify d substance were very conspicuous in one position ,yet by al-
tering that position of the polish’d sorface to the light, it was also mani-
fest, that those pores appear’d darker then the rest of the body, onely
because they were fill’d up with a more duskie substance, and not be-
cause they were hollow.
Fourthly, in its incontbujiibleness, in that it would not burn in the fire 5
nay,though I kept it a good while red-hot in the ssame of a Lamp, made
very intenfe by the blast of a small Pipe, and a large Charcoal, yet it
seem’d not at all to have diminish’d its extension 5 but only I found it to
have chang’d its colour, and to appear of a more dark and duskie brown
colour 5 nor could I perceive that those parts which seem’d to have been
Wood at first, were any thing wasted, but the parts appear’d as solid and
close as before. It was further observable also, that as it did not consome
like Wood, so neither did it crack and ssie like a Flint, or such like hard
Stone, nor was it long before it appear’d red-hot.
Fifthly, in its dissblublenessj for putting some drops of distill’d Vinegar
upon the Stone, I found it presently to yield very many Bubbles, just like
those which maybe observ’d in spirit of Vinegar when it corrodes coral^
though
by the most accomplish’d Mr. F/velin^ my highly honour’d friend, to be
inserred and published among those excellent Observations wherewith
his Sylva is replenish’d, and would therefore have been here omitted5had
not the Figure of them, as they appear d through the Microfcope been
before that engraven.
This Petrify d substance resembled Wood, in that
First, all the parts of it seem’d not at all dissocated^ or alter’d from
their natural Position, whil’st they were Wood, but the whole piece re-
tain’d the exast shape of Wood, having many of the conspicuous pores
of wood (till remaining pores, and (hewing a manifest difference visible
enough between the grain of the Wood and that of the bark, eipecially
when any side of it was cut smoothand polite 5 for then it appear’d to
have a very lovely grain, like that of some curious close Wood.
Next (it resembled Wood) in that all the smallerand (if I may so call
thole which are onely visible with a good magnifying Glass) Microfcopi-
cal pores os it appear (both when the substance is cut and polish’d tranf
verfly and parallel to the pores of it) perfectly like the Mier ofcopic al poxes
ofseveral kinds of Wood, eipecially like and equal to those of several
sorts of rotten Wood which I have since observ’d, retaining both the
(hape,position and magnitude of soch pores. It was differing from Wood :
First, in weighty being to common water as 34 to 1. whereas there are
few os our Englijb Woods, that when very dry are found to be full as
heavieas water.
Secondly, in hardnesf being very neer as hard as a Flint 5 and in some
places of it also resembling the grain of a Flint: and, like it, it would
very readily cut Glass, and would not without difficulty, eipecially in
some parts of it, be scratch’d by a black hard Flint: It would also as rea-
dily strike fire against a Steel, or against a Flint, as any common Flint.
Thirdly, in the closenessoi it, for though all the Microfcopical pores of
this petrify d substance were very conspicuous in one position ,yet by al-
tering that position of the polish’d sorface to the light, it was also mani-
fest, that those pores appear’d darker then the rest of the body, onely
because they were fill’d up with a more duskie substance, and not be-
cause they were hollow.
Fourthly, in its incontbujiibleness, in that it would not burn in the fire 5
nay,though I kept it a good while red-hot in the ssame of a Lamp, made
very intenfe by the blast of a small Pipe, and a large Charcoal, yet it
seem’d not at all to have diminish’d its extension 5 but only I found it to
have chang’d its colour, and to appear of a more dark and duskie brown
colour 5 nor could I perceive that those parts which seem’d to have been
Wood at first, were any thing wasted, but the parts appear’d as solid and
close as before. It was further observable also, that as it did not consome
like Wood, so neither did it crack and ssie like a Flint, or such like hard
Stone, nor was it long before it appear’d red-hot.
Fifthly, in its dissblublenessj for putting some drops of distill’d Vinegar
upon the Stone, I found it presently to yield very many Bubbles, just like
those which maybe observ’d in spirit of Vinegar when it corrodes coral^
though