<P_100>

<heading>

OBSERV. XVI . (HOOKE-E3-P1,100.3)

OF CHARCOAL , OR BURNT VEGETABLES (HOOKE-E3-P1,100.4)

</heading>

Charcoal , or a Vegetable burnt black , affords an object no less
pleasant than instructive ; (HOOKE-E3-P1,100.6)

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 ;
(HOOKE-E3-P1,100.7)

this surface , if it be look'd on with an ordinary <font> Microscope
</font> , does manifest abundance of those pores which are also visible
to the eye in many kinds of <font> Wood </font> , rang'd round the pith
, both-3 $in $a {TEXT:a_in} kind of circular order , and a radiant one
. (HOOKE-E3-P1,100.8)

Of these there are a multitude in the substance of the Coal , every
where almost perforating and drilling it from end to end ; by <P_101>
means of which , be the Coal never so long , you may easily blow
through it ; (HOOKE-E3-P1,101.9)

and this you may presently find , by wetting one end of it with Spittle
, and blowing at the other . (HOOKE-E3-P1,101.10)

But this is not all , (HOOKE-E3-P1,101.11)

for besides those many great and conspicuous irregular spots or pores ,
if a better <font> Microscope </font> 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 , (HOOKE-E3-P1,101.12)

for the apparent <font> interstitia , </font> or separating sides of
these pores seem so thin in some places , that the texture of a
Honey-comb $can $not {TEXT:cannot} be more porous . Though this be not
every where so , the intercurrent partitions in some places being very
much thicker in proportion to the holes . (HOOKE-E3-P1,101.13)

Most of these small pores seem'd to be pretty round ,
(HOOKE-E3-P1,101.14)

and were rang'd in rows that radiated from the pith to the bark ;
(HOOKE-E3-P1,101.15)

they all of them seem'd to be continued open pores , running the whole
length of the Stick ; (HOOKE-E3-P1,101.16)

and that they were all perforated , I try'd by breaking off a very thin
sliver of the coal cross-ways , and then with my <font> Microscope
</font> , diligently surveying them against the light ,
(HOOKE-E3-P1,101.17)

for by that means I was able to see quite through them .
(HOOKE-E3-P1,101.18)

These pores were so exceeding small and thick , that in a line of them
, 1$$18 of an Inch long , I found by numbring them no less then small
pores ; (HOOKE-E3-P1,101.19)

and therefore in a line of them an Inch long , must be no less then
pores , (HOOKE-E3-P1,101.20)

and in a circular <font> area </font> of an Inch diameter , must be
about 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 .
(HOOKE-E3-P1,101.21)

Nay , having since examin'd <font> Cocus , black and green Ebony ,
Lignum Vitae , </font> &c. I found , that all these Woods have their
pores , abundantly smaller then those of soft light Wood ; in so much ,
that those of <font> Guajacum </font> seem'd not above an eighth part
of the bigness of the pores of Beech , (HOOKE-E3-P1,101.22)

but then the <font> Interstitia </font> were thicker ;
(HOOKE-E3-P1,101.23)

so prodigiously curious are the contrivances , pipes , or sluces by
which the <font> Succus nutritius </font> , or Juyce of a Vegetable is
convey'd from place to place . (HOOKE-E3-P1,101.24)

This <font> Observation </font> seems to afford us the true reason of
several <font> Phaenomena </font> of Coals ; as First , why they look
black ; (HOOKE-E3-P1,101.25)

and for this we need go no further then the <font> Scheme </font> ,
(HOOKE-E3-P1,101.26)

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 <font>
Scheme </font> , black being nothing else but a privation of Light , or
a want of reflection ; (HOOKE-E3-P1,101.27)

and wheresoever 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 <font> Scoria </font> of Lead , Tin , Silver , Copper ,
&c . (HOOKE-E3-P1,101.28)

Next , we may also as plainly see the reason of its shining quality
(HOOKE-E3-P1,101.29)

<P_102>

and that is from the even breaking off of the stick ,
(HOOKE-E3-P1,102.31)

the solid <font> interstitia </font> having a regular termination or
surface , and having a pretty strong reflecting quality , the many
small reflections become united to the naked eye , (HOOKE-E3-P1,102.32)

and make a very pretty shining surface . (HOOKE-E3-P1,102.33)

Thirdly , the reason of its hardness and brittleness seems evident ,
(HOOKE-E3-P1,102.34)

for since all the watery or liquid substance that moistn'd and toughn'd
those <font> Interstitia </font> of the more solid parts , are
evaporated and remov'd , that which is left behind becomes of the
nature almost of a stone , which will not at all , or very little ,
bend without a <font> divulsion </font> or <font> solution </font> of
its <font> continuity </font> . (HOOKE-E3-P1,102.35)

It is not my design at present , to examine the use and <font>
Mechanisme </font> of these parts of Wood , that being more proper to
another Enquiry ; but rather to hint , that from this Experiment we may
learn , First , what is the cause of the blackness of many burnt bodies
, which we may find to be nothing else but this ; that the heat of the
fire agitating and rarifying the waterish , transparent , and volatile
water that is contain'd in them , by the continuation of that action ,
does so totally expel and drive away all that which before fill'd the
pores , and was dispers'd also through the solid mass of it , and
thereby caus'd an universal kind of transparency , that it not onely
leaves all the pores empty , but all the <font> Interstitia </font>
also so dry and <font> opacous </font> , and perhaps also yet further
perforated , that the light onely is reflected back which falls upon
the very outward edges of the pores , all they that enter into the
pores of the body , never returning , but being lost in it .
(HOOKE-E3-P1,102.36)

Now , that the Charring or coaling of a body is nothing else , may be
easily believ'd by one that shall consider the means of its production
, which may be done after this , or any such manner .
(HOOKE-E3-P1,102.37)

The body to be charr'd or coal'd , may be put into a <font> Crucible
</font> , Pot , or any other Vessel that will endure to be made red-hot
in the Fire without breaking , and then cover'd over with Sand , so as
no part of it be suffer'd to be open to the Air , then set into a good
Fire , and there kept till the Sand has continu'd red hot for a quarter
, half , an hour or two , or more , according to the nature and bigness
of the body to be coald or charr'd , (HOOKE-E3-P1,102.38)

then taking it out of the fire , and letting it stand till it be quite
cold , (HOOKE-E3-P1,102.39)

the body may be taken out of the Sand well charr'd and cleans'd of its
waterish parts ; (HOOKE-E3-P1,102.40)

but in the taking of it out , care must be had that the Sand be very
neer cold , (HOOKE-E3-P1,102.41)

for else , when it comes into the free air , it will take fire , and
readily burn away . (HOOKE-E3-P1,102.42)

This may be done also in any close Vessel of Glass , as a <font> Retort
</font> , or the like , (HOOKE-E3-P1,102.43)

and the several fluid substances that come over may be receiv'd in a
fit <font> Recipient </font> , which will yet further countenance this
<font> Hypothesis </font> : (HOOKE-E3-P1,102.44)

And their manner of charring Wood in great quantity comes much to the
same thing , namely , an application of a great heat to the body , and
perserving it from the free access of the devouring air ;
(HOOKE-E3-P1,102.45)

this may be easily learn'd from the History of Charring of Coal , most
excellently describ'd and publish'd by that most accomplish'd Gentleman
, Mr. <font> John Evelin </font> , in the , , , pages of his <font>
Sylva </font> , to which I shall therefore refer the curious Reader
that desires a full information of it . (HOOKE-E3-P1,102.46)

<P_103>

Next , we may learn what part of the wood it is that is the <font>
combustible </font> matter ; (HOOKE-E3-P1,103.48)

for since we shall find that none , or very little of those fluid
substances that are driven over into the Receiver are <font>
combustible </font> , and that most of that which is left behind is so
, it follows , that the solid <font> interstitia </font> of the Wood
are the <font> combustible </font> matter . (HOOKE-E3-P1,103.49)

Further , the reason why uncharr'd Wood burns with a greater flame then
that which is charr'd , is as evident , because those waterish or
volatil parts issuing out of the fired Wood , every way , not onely
shatter and open the body , the better for the fire to enter , but
issuing out in vapours or wind , they become like so many little <font>
aeolipiles </font> , or Bellows , whereby they blow and agitate the
fir'd part , and conduce to the more speedy and violent consumption or
dissolution of the body . (HOOKE-E3-P1,103.50)

Thirdly , from the Experiment of charring of Coals <paren> whereby we
see that notwithstanding the great heat , and the duration of it , the
solid parts of the Wood remain , whilest they are preserv'd from the
free access of the air undissipated </paren> we may learn , that which
has not , that I know of , been publish'd or hinted , nay , not so much
as thought of , by any ; (HOOKE-E3-P1,103.51)

and that in short is this . (HOOKE-E3-P1,103.52)

First , <font> that the Air </font> in which we live , move , and
breath {COM:sic} , and which encompasses very many , and cherishes most
bodies it encompasses , that this Air is the <font> menstruum </font> ,
or universal dissolvent of all <font> Sulphureous </font> bodies .
(HOOKE-E3-P1,103.53)

Secondly , <font> that this action </font> it performs not , till the
body be first sufficiently heated , as we find requisite also to the
dissolution of many other bodies by several other <font> menstruums
</font> . (HOOKE-E3-P1,103.54)

Thirdly , <font> that this action </font> of dissolution , produces or
generates a very great heat , and that which we call Fire ;
(HOOKE-E3-P1,103.55)

and this is common also to many dissolutions of other bodies , made by
<font> menstruums </font> , of which I could give multitudes of
Instances . (HOOKE-E3-P1,103.56)

Fourthly , <font> that this action </font> is perform'd with so great a
violence , and does so minutely act , and rapidly agitate the smallest
parts of the <font> combustible </font> matter , that it produces in
the <font> diaphanous medium </font> of the air , the action or pulse
of light , which what it is , I have else-where already shewn .
(HOOKE-E3-P1,103.57)

Fifthly , <font> that the dissolution </font> of sulphureous bodies is
made by a substance inherent , and mixt with the air , that is like ,
if not the very same , with that which is fixt in <font> Salt-peter
</font> , which by multitudes of Experiments that may be made with
<font> Saltpeter </font> , will , I think , most evidently be
demonstrated . (HOOKE-E3-P1,103.58)

Sixthly , <font> that in this dissolution </font> of bodies by the Air
, a certain part is united and mixt , or dissolv'd and turn'd into the
air , and made to fly up and down with it in the same manner as a
<font> metalline </font> or other body dissolv'd into any <font>
menstruums </font> , does follow the motions and progresses of that
<font> menstruum </font> till it be precipitated . (HOOKE-E3-P1,103.59)

Seventhly , That as there is one part that is dissoluble by the Air ,
so are there other parts with which the parts of the Air mixing and
uniting , do make a <font> Coagulum </font> , or <font> precipitation
</font> , as one may call it , which causes it to be separated from the
Air , (HOOKE-E3-P1,103.60)

but this <font> precipitate </font> is so light , and in so small and
rarify'd or porous clusters , that it is very volatil , and is easily
carry'd up by the motion of the Air , though afterwards , when the heat
and <P_104> agitation that kept it rarify'd ceases , it easily
condenses , (HOOKE-E3-P1,104.61)

and commixt with other diissoluble parts , it stickes and adheres to
the next bodies it meets withall ; (HOOKE-E3-P1,104.62)

and this is a certain <font> Salt </font> that may be extracted out of
<font> Soot </font> . (HOOKE-E3-P1,104.63)

Eighthly , that many indissoluble parts being very apt and prompt to be
rarify'd , and so , whilest they continue in that heat and agitation ,
are lighter then the Ambient Air , are thereby thrust and carry'd
upwards with great violence , (HOOKE-E3-P1,104.64)

and by that means carry along with them , not onely that <font> Saline
concrete </font> I mention'd before , but many terrestrial , or
indissoluble and irrarefiable parts , nay , many parts also which are
dissoluble , but are not suffer'd to stay long enough in a sufficient
heat to make them prompt and apt for that action . (HOOKE-E3-P1,104.65)

And therefore we find in <font> Soot </font> , not onely a part , that
being continued longer in a competent heat , will be dissolv'd by the
Air , or take fire and burn ; but a part also which is fixt ,
terrestrial , and irrarefiable . (HOOKE-E3-P1,104.66)

Ninthly , that as there are these several parts that will rarifie and
fly , or be driven up by the heat , so are there many others , that as
they are indissoluble by the <font> aerial menstruum </font> , so are
they of such sluggish and gross parts , that they are not easily
rarify'd by heat , and therefore $can $not {TEXT:cannot} be rais'd by
it ; the volatility or fixtness of a body seeming to consist only-8 in
this , that the one is of a texture , or has component parts that will
be easily rarify'd into the form of Air , and the other , that it has
such as will not , without much ado , be brought to such a constitution
; (HOOKE-E3-P1,104.67)

and this is that part , which remains behind in a white body call'd
Ashes , which contains a substance , or <font> Salt </font> , which
Chymists call <font> Alkali </font> : (HOOKE-E3-P1,104.68)

what the particular natures of each of these bodies are , I shall not
here examine , intending it in another place , (HOOKE-E3-P1,104.69)

but shall rather add that this <font> Hypothesis </font> does so
exactly agree with all <font> Phaenomena </font> of Fire , and so
genuinely explicate each particular circumstance that I have hitherto
observ'd , that it is more then probable , that this cause which I have
assign'd is the true adequate , real , and onely cause of these <font>
Phaenomena </font> ; (HOOKE-E3-P1,104.70)

And therefore I shall proceed a little further , to shew the nature and
use of the Air . (HOOKE-E3-P1,104.71)

Tenthly , therefore the dissolving parts of the Air are but few ,
(HOOKE-E3-P1,104.72)

that is , it seems of the nature of those <font> Saline menstruums
</font> , or spirits , that have very much flegme mixt with the spirits
, (HOOKE-E3-P1,104.73)

and therefore a small parcel of it is quickly glutted ,
(HOOKE-E3-P1,104.74)

and will dissolve no more ; (HOOKE-E3-P1,104.75)

and therefore unless some fresh part of this <font> menstruum </font>
be apply'd to the body to be dissolv'd , the action ceases ,
(HOOKE-E3-P1,104.76)

and the body leaves to be dissolv'd and to shine , which is the
Indication of it , though plac'd or kept in the greatest heat ; whereas
<font> Salt-peter </font> is a <font> menstruum </font> , when melted
and red-hot , that abounds more with those Dissolvent particles , and
therefore as a small quantity of it will dissolve a great sulphureous
body , so will the dissolution be very quick and violent .
(HOOKE-E3-P1,104.77)

Therefore in the <font> Eleventh </font> place , it is observable ,
that , as in other solutions , if a copious and quick supply of fresh
<font> menstruum </font> , though but weak , be poured on , or applied
to the dissoluble body , it quickly consumes it : (HOOKE-E3-P1,104.78)

So this <font> menstruum </font> of the Air , if by Bellows , or any
other such contrivance , it be copiously apply'd to the shining body ,
is found to <P_105> dissolve it as soon , and as violently as the more
strong <font> menstruum </font> of melted <font> Nitre </font> .
(HOOKE-E3-P1,105.79)

Therefore twelfthly , it seems reasonable to think that there is no
such thing as an Element of Fire that should attract or draw up the
flame , or towards which the flame should endeavour to ascend out of a
desire or appetite of uniting with that as its <font> Homogeneal
</font> primitive and generating Element ; but that that shining
transient body which we call <font> Flame </font> , is nothing else but
a mixture of Air , and volatil sulphureous parts of dissoluble or
combustible bodies , which are acting upon each other whilst they
ascend , (HOOKE-E3-P1,105.80)

that is , flame seems to be a mixture of Air , and the combustible
volatil parts of any body , which parts the encompassing Air does
dissolve or work upon , which action , as it does intend the heat of
the <font> aerial </font> parts of the dissolvent , so does it thereby
further rarifie those parts that are acting , or that are very neer
them , whereby they growing much lighter then the heavie parts of the
<font> Menstruum </font> that are more remote , are thereby protruded
and driven upward ; (HOOKE-E3-P1,105.81)

and this may be easily observ'd also in dissolutions made by any other
<font> menstruum </font> , especially such as either-2 create heat or
bubbles . (HOOKE-E3-P1,105.82)

Now , that action of the <font> Menstuum </font> {COM:sic} or <font>
Air </font> , on the dissoluble parts , is made with such violence , or
is such , that it imparts such motion or pulse to the <font> diaphanous
</font> parts of the Air , as I have elsewhere shewn is requisite to
produce light . (HOOKE-E3-P1,105.83)

This <font> Hypothesis </font> I have endeavoured to raise from an
Infinite of Observations and Experiments , the process of which would
be much too long to be here inserted , and will perhaps another time
afford matter copious enough for a much larger Discourse , the Air
being a Subject which <paren> though all the world has hitherto liv'd
and breath'd in , and been unconversant about </paren> has yet been so
little truly examin'd or explain'd , that a diligent enquirer will be
able to find but very little information from what has been <paren>
till of late </paren> written of it : (HOOKE-E3-P1,105.84)

But being once well understood , it will , I doubt not , inable a man
to render an intelligible , nay probable , if not the true reason of
the <font> Phaenomena </font> of Fire , which , as it has been found by
Writers and Philosophers of all Ages a matter of no small difficulty ,
as may be sufficiently understood by their strange <font> Hypotheses
</font> , and unintelligible Solutions of some few <font> Phaenomena
</font> of it ; so will it prove a matter of no small concern and use
in humane affairs , as I shall elsewhere endeavour to manifest when I
come to shew the use of the air in respiration , and for the
preservation of the life , nay , for the conservation and restauration
of the health and natural constitution of mankind as well as all other
aereal <font> animals </font> , as also the uses of this principle or
propriety of the air in chymical , mechanical , and other operations .
(HOOKE-E3-P1,105.85)

In this place I have onely time to hint an <font> Hypothesis </font> ,
which , if God permit me life and opportunity , I may elsewhere
prosecute , improve and publish . (HOOKE-E3-P1,105.86)

In the mean time , before I finish this Discourse , I must not forget
to acquaint the Reader , that having had the liberty granted me of
making some trials on a piece of <font> Lignum fossile </font> shewn to
the Royal Society , by the eminently Ingenious and Learned Physician ,
Doctor <font> Ent </font> , who receiv'd it for a Present from the
famous <font> Ingenioso Cavalliero de Pozzi </font> , it being one of
the fairest <P_106> and best pieces of <font> Lignum fossile </font> he
had seen ; Having <paren> I say </paren> taken a small piece of this
Wood , and examin'd it , I found it to burn in the open Air almost like
other Wood , (HOOKE-E3-P1,106.87)

and insteed {COM:sic} of a resinous smoak or fume , it yielded a very
bituminous one , smelling much of that kind of sent :
(HOOKE-E3-P1,106.88)

But that which I chiefly took notice of , was , that cutting off a
small piece of it , about the bigness of my Thumb , and charring it in
a <font> Crucible </font> with Sand , after the manner I above
prescrib'd , I found it infinitely to abound with the smaller sort of
pores , so extreme thick , and so regularly perforating the substance
of it long-ways , that breaking it off a-cross , I found it to look
very like an Honey-comb ; (HOOKE-E3-P1,106.89)

but as for any of the second , or bigger kind of pores , I could not
find that it had any ; so that it seems , whatever were the cause of
its production , it was not without those small kind of pores which we
have onely-3 hitherto found in Vegetable bodies ; (HOOKE-E3-P1,106.90)

and comparing them with the pores which I have found in the Charcoals
that I by this means made of several other kinds of Wood , I find it
resemble none so much as those of Firr , to which it is not much unlike
in grain also , and several other proprieties {COM:sic} .
(HOOKE-E3-P1,106.91)

And therefore , what ever is by some , who have written of it , and
particularly by <font> Francisco Stelluto </font> , who wrote a
Treatise in <font> Italian </font> of that Subject , which was Printed
at <font> Rome </font> , 1637 , affirm'd that it is a certain kind of
Clay or Earth , which in tract of time is turn'd into Wood , I rather
suspect the quite contrary , that it was at first certain great Trees
of Fir or Pine , which by some Earthquake , or other casualty , came to
be buried under the Earth , and was there , after a long time's
residence <paren> according to the several natures of the encompassing
adjacent parts </paren> either rotted and turn'd into a kind of Clay ,
<font> petrify'd </font> and turn'd into a kind of Stone , or else had
its pores fill'd with certain Mineral juices , which being stayd in
time , and in tract of time coagulated , appear'd , upon cleaving out ,
like small Metaline Wires , or else from some flames or scorching forms
that are the occasion oftentimes , and usually accompany Earthquakes ,
might be blasted and turn'd into Coal , or else from certain <font>
subterraneous </font> fires which are affirm'd by that Authour to
abound much about those parts <paren> namely , in a Province of <font>
Italy </font> , call'd <font> Umbria </font> , now the <font> Dutchie
</font> of <font> Spoletto </font> , in the Territory of <font> Todi
</font> , anciently call'd <font> Tudor </font> , and between the two
Villages of <font> Collesecco </font> and <font> Rosaro </font> not far
distant from the high-way leading to <font> Rome </font> , where it is
found in greater quantity then elsewhere </paren> are by reason of
their being encompassed with Earth , and so kept close from the
dissolving Air , charr'd and converted into Coal . (HOOKE-E3-P1,106.92)

It would be too long a work to describe the several kinds of pores
which I met withall , and by this means discovered in several other
Vegetable bodies ; (HOOKE-E3-P1,106.93)

nor is it my present design to expatiate upon Instances of the same
kind , but rather to give a Specimen of as many kinds as I have had
opportunity as yet of observing , reserving the prosecution and
enlarging on particulars till a more fit opportunity ;
(HOOKE-E3-P1,106.94)

and in prosecution of this design , I shall here add : <P_107>
<heading> OBSERV. XVII . (HOOKE-E3-P1,107.95)

OF PETRIFY'D WOOD , AND OTHER PETRIFY'D BODIES . (HOOKE-E3-P1,107.96)

</heading>

Of this sort of substance , I observ'd several pieces of very differing
kinds , both-2 for their outward shape , colour , grain , <font>
texture </font> , hardness , <font> &c. </font> some being brown and
redish {COM:sic} ; others gray , like a Hone ; others black , and
Flint-like : some soft , like a Slate or Whetstone , others as hard as
a Flint , and as brittle . (HOOKE-E3-P1,107.98)

That which I more particular {COM:sic} examin'd , was a piece about the
bigness of a mans hand , which seem'd to have been a part of some large
tree , that by rottenness had been broken off from it before it began
to be <font> petrify'd </font> . (HOOKE-E3-P1,107.99)

And indeed , all that I have yet seen , seem to have been rotten Wood
before the petrifaction was begun ; (HOOKE-E3-P1,107.100)

and not long since , examining and viewing a huge great <font> Oak
</font> , that seem'd with meer age to be rotten as it stood , I was
very much confirm'd in this opinion ; (HOOKE-E3-P1,107.101)

for I found , that the grain , colour , and shape of the Wood , was
exactly like this <font> petrify'd </font> substance ;
(HOOKE-E3-P1,107.102)

and with a <font> Microscope </font> , I found that all those <font>
Microscopical </font> pores , which in sappy or firm and sound Wood are
fill'd with the natural or innate juices of those Vegetables , in this
they were all empty , like those of <font> Vegetables charr'd </font> ;
but with this difference , that they seem'd much larger then I have
seen any in <font> Char-coals </font> ; nay , even then those of Coals
made of great blocks of Timber , which are commonly call'd <font>
Old-coals </font> . The reason of which difference may probably be ,
that the charring of Vegatables , being an operation quickly performed
, and whilest the Wood is sappy , the more solid parts may more easily
shrink together , and contract the pores or <font> interstitia </font>
between them , then in the rotten Wood , where that natural juice seems
onely to be wash'd away by <font> adventitious </font> or unnatural
moisture ; (HOOKE-E3-P1,107.103)

and so though the natural juice be wasted from between the firm parts ,
yet those parts are kept asunder by the <font> adventitious </font>
moystures , and so by degrees settled in those postures .
(HOOKE-E3-P1,107.104)

And this I likewise found in the <font> petrify'd </font> Wood , that
the pores were somewat bigger then those of <font> Charcoal </font> ,
each pore being neer upon half as bigg again , (HOOKE-E3-P1,107.105)

but they did not bear that disproportion which is exprest in the tenth
<font> Scheme </font> , between the small specks or pores in the first
Figure <paren> which representeth the pores of Coal or Wood charr'd
</paren> and the black spots of the second Figure <paren> which
represent the like <font> Microscopical pores </font> in the <font>
petrify'd </font> Wood </paren> (HOOKE-E3-P1,107.106)

for these last were drawn by a <font> Microscope </font> that magnify'd
the object above six times more in Diameter then the <font> Microscope
</font> by which those pores of Coal were observ'd .
(HOOKE-E3-P1,107.107)

Now , though they were a little bigger , yet did they keep the exact
figure and order of the pores of Coals and of rotten Wood , which last
also were much of the same cize . (HOOKE-E3-P1,107.108)

The other Observations on this <paren> petrify'd </font> substance ,
that a while since , by the appointment of the <font> Royal Society
</font> , I made , and presented to them an account of , were these
that follow , which had the honour done them <P_108> by the most
accomplish'd Mr. <font> Evelin </font> , my highly honour'd friend , to
be inserted and published among those excellent Observations wherewith
his <font> Sylva </font> is replenish'd , and would therefore have been
here omitted , had not the Figure of them , as they appear'd through
the <font> Microscope </font> been before that engraven .
(HOOKE-E3-P1,108.109)

This <font> Petrify'd </font> substance resembled Wood , in that First
, all the parts of it seem'd not at all <font> dislocated </font> , or
alter'd from their natural Position , whil'st they were Wood , but the
whole piece retain'd the exact shape of Wood , having many of the
conspicuous pores of wood still remaining pores , and shewing a
manifest difference visible enough between the grain of the Wood and
that of the bark , especially when any side of it was cut smooth and
polite ; (HOOKE-E3-P1,108.110)

for then it appear'd to have a very lovely grain , like that of some
curious close Wood . (HOOKE-E3-P1,108.111)

Next <paren> it resembled Wood </paren> in that all the smaller and
<paren> if I may so call those which are onely visible with a good
magnifying Glass </paren> <font> Microscopical </font> pores of it
appear <paren> both-2 when the substance is cut and polish'd <font>
transversly </font> and <font> parallel </font> to the pores of it
</paren> perfectly like the <font> Microscopical </font> pores of
several kinds of Wood , especially like and equal to those of several
sorts of rotten Wood which I have since observ'd , retaining both the
shape , position and magnitude of such pores . (HOOKE-E3-P1,108.112)

It was differing from Wood : First , in <font> weight </font> , being
to common water as 3 1$$4 to 1 . whereas there are few of our <font>
English </font> Woods , that when very dry are found to be full as
heavie as water . (HOOKE-E3-P1,108.113)

Secondly , in <font> hardness </font> , being very neer as hard as a
Flint ; and in some places of it also resembling the grain of a Flint :
(HOOKE-E3-P1,108.114)

and , like it , it would very readily cut Glass , (HOOKE-E3-P1,108.115)

and would not without difficulty , especially in some parts of it , be
scratch'd by a black hard Flint : (HOOKE-E3-P1,108.116)

It would also as readily strike fire against a Steel , or against a
Flint , as any common Flint . (HOOKE-E3-P1,108.117)

Thirdly , in the <font> closeness </font> of it , (HOOKE-E3-P1,108.118)

for though all the <font> Microscopical </font> pores of this <font>
petrify'd </font> substance were very conspicuous in one position , yet
by altering that position of the polish'd surface to the light , it was
also manifest , 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 because they were hollow . (HOOKE-E3-P1,108.119)

Fourth , in its <font> incombustibleness </font> , in that it would not
burn in the fire ; (HOOKE-E3-P1,108.120)

nay , though I kept it a good while red-hot in the flame of a Lamp ,
made very <font> intense </font> by the blast of a small Pipe , and a
large Charcoal , yet it seem'd not at all to have diminsh'd its
extension ; (HOOKE-E3-P1,108.121)

but only I found it to have chang'd its colour , and to appear of a
more dark and duskie brown colour ; (HOOKE-E3-P1,108.122)

nor could I perceive that those parts which seem'd to have been Wood at
first , were any thing wasted , (HOOKE-E3-P1,108.123)

but the parts appear'd as solid and close as before .
(HOOKE-E3-P1,108.124)

It was further observable also , that as it did not consume like Wood ,
so neither did it crack and flie like a Flint , or such like hard Stone
, (HOOKE-E3-P1,108.125)

nor was it long before it appear'd red-hot . (HOOKE-E3-P1,108.126)

Fifthly , in its <font> dissolubleness </font> ; (HOOKE-E3-P1,108.127)

for putting some drops of distill'd <font> Vinegar </font> upon the
Stone , I found it presently to yield very many Bubbles , just like
those which may be observ'd in spirit of <font> Vinegar </font> when it
corrodes <font> corals </font> , <P_109> though perhaps many of those
small Bubbles might proceed from some small parcels of Air which were
driven out of the pores of this <font> petrify'd </font> substance by
the insinuating liquid <font> menstruum </font> . (HOOKE-E3-P1,109.128)

Sixthly , in its <font> rigidness </font> and <font> friability </font>
, being not at all flexible but brittle like a Flint , insomuch that I
could with one knock of a Hammer break off a piece of it , and with a
few more , reduce that into a pretty fine powder .
(HOOKE-E3-P1,109.129)

Seventhly , it seem'd also very differing from Wood to the <font> touch
, feeling </font> more cold then Wood usually does , and much like
other close stones and minerals . (HOOKE-E3-P1,109.130)

The Reasons of all which <font> Phaenomena </font> seem to be , That
this <font> petrify'd </font> Wood having lain in some place where it
was well soak'd with <font> petrifying </font> water <paren> that is ,
such a water as is well <font> impregnated </font> with stony and
earthy particles </paren> did by degrees separate , either by straining
and <font> filtration </font> , or perhaps , by <font> precipitation ,
cohesion </font> or <font> coagulation </font> , abundance of stony
particles from the permeating water , which stony particles , being by
means of the fluid <font> vehicle </font> convey'd , not onely into the
<font> Microscopical </font> pores , and so perfectly stoping {COM:sic}
them up , but also into the pores or <font> interstitia </font> , which
may , perhaps , be even in the texture or <font> Schematisme </font> of
that part of the Wood , which through the <font> Microscope </font> ,
appears most solid , do thereby so augment the weight of the Wood , as
to make it above three times heavier then water , and perhaps , six
times as heavie as it was when Wood . (HOOKE-E3-P1,109.131)

Next , they thereby so lock up and fetter the parts of the Wood , that
the fire $can $not {TEXT:cannot} easily make them flie away ,
(HOOKE-E3-P1,109.132)

but the action of the fire upon them is onely-3 able to <font> Char
</font> those parts , as it were , like a piece of Wood , if it be
clos'd very fast up in Clay , and kept a good while red-hot in the fire
, will by the heat of the fire be charr'd and not consum'd , which may
, perhaps , also be somewheat of the cause , why the <font> petrify'd
</font> substance appear'd of a dark brown colour after it had been
burnt . (HOOKE-E3-P1,109.133)

By this <font> intrusion </font> of the <font> petrifying </font>
particles , this substance also becomes hard and <font> friable </font>
; (HOOKE-E3-P1,109.134)

for the smaller pores of the Wood being perfectly wedg'd , and stuft up
with those stony particles , the small parts of the Wood have no places
or pores into which they may slide upon bending , (HOOKE-E3-P1,109.135)

and consequently little or no flexion or yielding at all can be caus'd
in such a substance . (HOOKE-E3-P1,109.136)

The remaining particles likewise of the Wood among the stony particles
, may keep them from cracking and flying when put into the fire , as
they are very apt to do in a Flint . (HOOKE-E3-P1,109.137)

Nor is Wood the onely substance that may by this kind of <font>
transmutation </font> be chang'd into stone ; (HOOKE-E3-P1,109.138)

for I my self have seen and examin'd very many kinds of substances ,
(HOOKE-E3-P1,109.139)

and among very credible Authours , we may meet with Histories of such
<font> Metamorphoses </font> wrought almost on all kind of substances ,
both <font> Vegetable </font> and <font> Animal </font> , which
Histories , it is not my business at present , either-3 to relate , or
<font> epitomise </font> , but only to set down some Observation
{COM:sic} I lately made on several kind of <font> petrify'd </font>
Shels , found about <font> Keinsham </font> , which lies within four or
five miles of <font> Bristol </font> , which are commonly call'd <font>
Serpentine-stones </font> . (HOOKE-E3-P1,109.140)

<P_110>

Examining several of these very curiously figur'd bodies <paren> which
are commonly thought to be Stones form'd by some extraordinary <font>
Plastick virtue latent </font> in the Earth it self </paren> I took
notice of these particulars : (HOOKE-E3-P1,110.142)

First , that these figured bodies , or stones , were of very differing
substances , as to hardness : some of Clay , some Marle , some soft
Stone , almost of the hardness of those soft stones which Masons call
Fire-stone , other as hard as Portland stone , others as hard as Marble
, and some as Hard as a Flint or Crystal . (HOOKE-E3-P1,110.143)

Next , they were of very differing substances as to transparency and
colour , some white , some almost black , some brown , some Metalline ,
or like Marchasites ; some transparent like white Marble , others like
flaw'd Crystal , some gray , some of divers colours ; some radiated
like these long <font> petrify'd drops </font> , which are commonly
found at the <font> Peak </font> , and in other <font> subterranean
caverns </font> , which have a kind of pith in the middle .
(HOOKE-E3-P1,110.144)

Thirdly , that they were very different as to the manner of their
outward figuration ; (HOOKE-E3-P1,110.145)

for some of them seem'd to have been the substance that had fill'd the
Shell of some kind of Shel-fish ; others , to have been the substance
that had contain'd or enwrapp'd one of those Shels , on both which ,
the perfect impression either-5 of the inside or outside of such Shells
seem'd to be left , (HOOKE-E3-P1,110.146)

but for the most part , those impressions seem'd to be made by an
imperfect or broken Shell , the great end or mouth of the Shell being
always wanting , and oftentimes the little end , and sometimes half ,
(HOOKE-E3-P1,110.147)

and in some there were impressions , just as if there had been holes
broken in the figurating , imprinting or moulding Shell ;
(HOOKE-E3-P1,110.148)

some of them seem'd to be made by such a Shell very much brused or
flaw'd , insomuch that one would verily have thought that very figur'd
stone had been broken or brused whilst a gelly , as $'t $were
{TEXT:'twere} , and so hardned , (HOOKE-E3-P1,110.149)

but within in the grain of the stone , there appear'd not the least
sign of any such bruse or breaking , but onlye on the very uttermost
superficies . (HOOKE-E3-P1,110.150)

Fourthly , they were very different , as to their outward covering ,
some having the perfect Shell , both-1 in figure , colour , and
substance , sticking on upon its surface , and adhering to it , but
might very easily be separated from it , and like other common <font>
Cockle </font> or <font> Scolop-shels </font> , which some of them most
accurately resembled , were very dissoluble in common <font> Vinegar
</font> , (HOOKE-E3-P1,110.151)

others of them especially those <font> Serpentine </font> , or <font>
Helical stones </font> were cover'd (HOOKE-E3-P1,110.152)

or retained the shining or Pearl-colour'd substance of the inside of a
Shel , which substance , on some parts of them , was exceeding thin ,
and might very easily be rubbed off ; (HOOKE-E3-P1,110.153)

on other parts it was pretty thick , (HOOKE-E3-P1,110.154)

and retained a white coate , or flaky substance on the top , just like
the outsides of such Shells ; (HOOKE-E3-P1,110.155)

some of them had very large pieces of the Shell very plainly sticking
on to them , which were easily to be broken or flaked off by degrees :
(HOOKE-E3-P1,110.156)

they likewise , some of them retain'd all along the surface of them
very pretty kind of <font> sutures </font> , such as are observ'd in
the skulls of several kinds of living creatures , which <font> sutures
</font> were most curiously shap'd in the manner of leaves , and every
one of them in the same Shell , exactly one like another , which I was
able to discover plainly enough with my naked eye , but more perfectly
and distinctly with my <font> Microscope </font> ;
(HOOKE-E3-P1,110.157)

all <P_111> these <font> sutures </font> , by breaking some of these
stones , I found to be the <font> termini </font> , or bounding of
certain <font> diaphragms </font> , or partitions , which seem'd to
divide the cavity of the Shell into a multitude of very proportionate
and regular <font> cells </font> or <font> caverns </font> ,
(HOOKE-E3-P1,111.158)

these <font> Diaphragms </font> , in many of them I found very perfect
and compleat , of a very distinct substance from that which fill'd the
cavities , and exactly of the same kind with that which covered the
outside , being for the most part whitish , or <font> mother-of-pearl
</font> colour'd . (HOOKE-E3-P1,111.159)

As for the cavities between those <font> Diaphragms </font> , I found
some of them fill'd with Marle , and others with several kinds of
stones , others , for the most part hollow , (HOOKE-E3-P1,111.160)

onely the whole cavity was usually covered over with a kind of <font>
tartareous petrify'd </font> substance , which stuck about the sides ,
and was there shot into very curious regular Figures , just as <font>
Tartar </font> , or other dissolv'd Salts are observ'd to stick and
<font> crystallize </font> about the sides of the containing Vessels ;
or like those little <font> Diamants </font> which I before observed to
have covered the vaulted cavity of a Flint ; (HOOKE-E3-P1,111.161)

others had these cavities all lin'd with a kind of <font> metalline
</font> or <font> marchasite-like </font> substance , which with a
<font> Microscope </font> I could as plainly see most curiously and
regularly figured , as I had done those in a Flint .
(HOOKE-E3-P1,111.162)

From all which , and several other particulars which I oberv'd , I $can
$not {TEXT:cannot} but think , that all these , and most other kinds of
stony bodies which are found thus strangely figured , do owe their
formation and figuration , not to any kind of <font> Plastick virtue
</font> inherent in the earth , but to the Shells of certain
Shel-fishes , which , either-5 by some Deluge , Inundation , Earthquake
, or some such other means , came to be thrown to that place , and
there to be fill'd with some kind of Mudd or Clay , or <font>
petrifying </font> Water , or some other substance , which in tract of
time has been settled together and hardned in those shelly moulds into
those shaped substances we now find them ; that the great and thin end
of these Shells by that Earthquake , or what ever other extraordinay
cause {COM:sic} it was that brought them thither , was broken off ; and
that many others were otherwise broken , bruised and disfigured ; that
these Shells which are thus <font> spirallied </font> and separated
with <font> Diaphragmes </font> , were some kind of <font> Nautili
</font> or <font> Porcelane shelle </font> ; and that others were
shells of <font> Cockles , Muscles , Periwincles , Scolops </font> ,
&c. of various sorts ; that these Shelles in many , from the particular
nature of the containing or enclos'd Earth , or some other cause , have
in tract of time rotted and mouldred away , and onely left their
impressionss , both-14 on the containing and contained substances ; and
so left them pretty loose one within another , so that they may be
easily separated by a knock or two of a Hammer . That other of these
Shells , according to the nature of the substance adjacent to them ,
have , by a long continuance in that posture , been <font> petrify'd
</font> and turn'd into the nature of stone , just as I even now
observ'd several sorts of Wood to be . That oftentimes the Shell may be
found with one kind of substance within , and quite another without ,
having , perhaps , been fill'd in one place , and afterwards translated
to another , which I have very frequently observ'd in <font> Cockle ,
Muscle , Periwincle </font> , and other shells , which I have found by
the Sea side . (HOOKE-E3-P1,111.163)

Nay , further , that some parts of the same Shell may be fill'd in one
place , and <P_112> some other caverns in another , and others in a
third , or a fourth , or a fifth place , (HOOKE-E3-P1,112.164)

for so many differing substances have I found in one of these <font>
petrify'd </font> Shells , (HOOKE-E3-P1,112.165)

and perhaps all these differing from the encompassing earth or stone ;
(HOOKE-E3-P1,112.166)

the means how all which varieties {COM:sic} may be caus'd , I think ,
will not be difficult to conceive , to any one that has taken notice of
these Shells , which are commonly found on the Sea shore :
(HOOKE-E3-P1,112.167)

And he that shall throughly examine several kinds of such curiously
form'd stones , will <paren> I am very apt to think </paren> find
reason to suppose their generation or formation to be ascribable to
some such accidents as I have mention'd , and not to any <font>
Plastick virtue : {COM:sic} </font> (HOOKE-E3-P1,112.168)

For it seems to me quite contrary to the infinite prudence of Nature ,
which is observable in all its works and productions , to design every
thing to a determinate end , and for the attaining of that end , makes
use of such ways as are <paren> as farr as the knowledge of man has yet
been able to reach </paren> altogether consonant , and most agreeable
to man's reason , and of no way or means that does contradict , or is
contrary to humane Ratiocination ; whence it has a long time been a
general observation and <font> maxime </font> , that <font> Nature does
nothing in vain </font> ; (HOOKE-E3-P1,112.169)

It seems , I say , contrary to that great Wisdom of Nature , that these
prettily shap'd bodies should have all those curious Figures and
contrivances <paren> which many of them are adorn'd and contriv'd with
</paren> generated or wrought by a <font> Plastick virtue </font> , for
no higher end then onely to exhibite such a form ; which he that shall
throughly {COM:sic} consider all the circumstances of such kind of
Figur'd bodies , will , I think , have great reason to believe , though
, I confess , one $can $not {TEXT:cannot} presently be able to find out
what Nature's designs are . (HOOKE-E3-P1,112.170)

It were therefore very desirable , that a good collection of such kind
of figur'd stones were collected ; and as many particulars ,
circumstances , and informations {COM:sic} collected with them as could
be obtained , that from such a History of Observations well rang'd ,
examin'd and digested , the true original or production of all those
kinds of stones might be perfectly and surely known ; such as are
<font> Thunderstones , Lapides Stellares , Lapides Judaici </font> ,
and multitudes of other , whereof mention is made in <font> Aldrovandus
, Wormius </font> , and other Writers of Minerals .
(HOOKE-E3-P1,112.171)

