OBSERV. XVI . (HOOKE-E3-P1,100.3) OF CHARCOAL , OR BURNT VEGETABLES (HOOKE-E3-P1,100.4) 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 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-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 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 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 , (HOOKE-E3-P1,101.12) for the apparent interstitia , 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 Microscope , 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 area 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 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 , (HOOKE-E3-P1,101.22) but then the Interstitia were thicker ; (HOOKE-E3-P1,101.23) 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 . (HOOKE-E3-P1,101.24) This Observation seems to afford us the true reason of several Phaenomena of Coals ; as First , why they look black ; (HOOKE-E3-P1,101.25) and for this we need go no further then the Scheme , (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 Scheme , 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 Scoria 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) and that is from the even breaking off of the stick , (HOOKE-E3-P1,102.31) the solid interstitia 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 Interstitia 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 divulsion or solution of its continuity . (HOOKE-E3-P1,102.35) It is not my design at present , to examine the use and Mechanisme 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 Interstitia also so dry and opacous , 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 Crucible , 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 Retort , or the like , (HOOKE-E3-P1,102.43) and the several fluid substances that come over may be receiv'd in a fit Recipient , which will yet further countenance this Hypothesis : (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. John Evelin , in the , , , pages of his Sylva , to which I shall therefore refer the curious Reader that desires a full information of it . (HOOKE-E3-P1,102.46) Next , we may learn what part of the wood it is that is the combustible 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 combustible , and that most of that which is left behind is so , it follows , that the solid interstitia of the Wood are the combustible 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 aeolipiles , 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 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 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 , that the Air 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 menstruum , or universal dissolvent of all Sulphureous bodies . (HOOKE-E3-P1,103.53) Secondly , that this action 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 menstruums . (HOOKE-E3-P1,103.54) Thirdly , that this action 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 menstruums , of which I could give multitudes of Instances . (HOOKE-E3-P1,103.56) Fourthly , that this action is perform'd with so great a violence , and does so minutely act , and rapidly agitate the smallest parts of the combustible matter , that it produces in the diaphanous medium 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 , that the dissolution 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 Salt-peter , which by multitudes of Experiments that may be made with Saltpeter , will , I think , most evidently be demonstrated . (HOOKE-E3-P1,103.58) Sixthly , that in this dissolution 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 metalline or other body dissolv'd into any menstruums , does follow the motions and progresses of that menstruum 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 Coagulum , or precipitation , as one may call it , which causes it to be separated from the Air , (HOOKE-E3-P1,103.60) but this precipitate 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 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 Salt that may be extracted out of Soot . (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 Saline concrete 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 Soot , 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 aerial menstruum , 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 Salt , which Chymists call Alkali : (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 Hypothesis does so exactly agree with all Phaenomena 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 Phaenomena ; (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 Saline menstruums , 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 menstruum 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 Salt-peter is a menstruum , 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 Eleventh place , it is observable , that , as in other solutions , if a copious and quick supply of fresh menstruum , though but weak , be poured on , or applied to the dissoluble body , it quickly consumes it : (HOOKE-E3-P1,104.78) So this menstruum of the Air , if by Bellows , or any other such contrivance , it be copiously apply'd to the shining body , is found to dissolve it as soon , and as violently as the more strong menstruum of melted Nitre . (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 Homogeneal primitive and generating Element ; but that that shining transient body which we call Flame , 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 aerial 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 Menstruum 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 menstruum , especially such as either-2 create heat or bubbles . (HOOKE-E3-P1,105.82) Now , that action of the Menstuum {COM:sic} or Air , on the dissoluble parts , is made with such violence , or is such , that it imparts such motion or pulse to the diaphanous parts of the Air , as I have elsewhere shewn is requisite to produce light . (HOOKE-E3-P1,105.83) This Hypothesis 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 though all the world has hitherto liv'd and breath'd in , and been unconversant about 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 till of late 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 Phaenomena 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 Hypotheses , and unintelligible Solutions of some few Phaenomena 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 animals , 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 Hypothesis , 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 Lignum fossile shewn to the Royal Society , by the eminently Ingenious and Learned Physician , Doctor Ent , who receiv'd it for a Present from the famous Ingenioso Cavalliero de Pozzi , it being one of the fairest and best pieces of Lignum fossile he had seen ; Having I say 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 Crucible 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 Francisco Stelluto , who wrote a Treatise in Italian of that Subject , which was Printed at Rome , 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 according to the several natures of the encompassing adjacent parts either rotted and turn'd into a kind of Clay , petrify'd 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 subterraneous fires which are affirm'd by that Authour to abound much about those parts namely , in a Province of Italy , call'd Umbria , now the Dutchie of Spoletto , in the Territory of Todi , anciently call'd Tudor , and between the two Villages of Collesecco and Rosaro not far distant from the high-way leading to Rome , where it is found in greater quantity then elsewhere 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 : OBSERV. XVII . (HOOKE-E3-P1,107.95) OF PETRIFY'D WOOD , AND OTHER PETRIFY'D BODIES . (HOOKE-E3-P1,107.96) Of this sort of substance , I observ'd several pieces of very differing kinds , both-2 for their outward shape , colour , grain , texture , hardness , &c. 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 petrify'd . (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 Oak , 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 petrify'd substance ; (HOOKE-E3-P1,107.102) and with a Microscope , I found that all those Microscopical 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 Vegetables charr'd ; but with this difference , that they seem'd much larger then I have seen any in Char-coals ; nay , even then those of Coals made of great blocks of Timber , which are commonly call'd Old-coals . 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 interstitia between them , then in the rotten Wood , where that natural juice seems onely to be wash'd away by adventitious 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 adventitious moystures , and so by degrees settled in those postures . (HOOKE-E3-P1,107.104) And this I likewise found in the petrify'd Wood , that the pores were somewat bigger then those of Charcoal , 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 Scheme , between the small specks or pores in the first Figure which representeth the pores of Coal or Wood charr'd and the black spots of the second Figure which represent the like Microscopical pores in the petrify'd Wood (HOOKE-E3-P1,107.106) for these last were drawn by a Microscope that magnify'd the object above six times more in Diameter then the Microscope 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 petrify'd substance , that a while since , by the appointment of the Royal Society , I made , and presented to them an account of , were these that follow , which had the honour done them by the most accomplish'd Mr. Evelin , my highly honour'd friend , to be inserted and published among those excellent Observations wherewith his Sylva is replenish'd , and would therefore have been here omitted , had not the Figure of them , as they appear'd through the Microscope been before that engraven . (HOOKE-E3-P1,108.109) This Petrify'd substance resembled Wood , in that First , all the parts of it seem'd not at all dislocated , 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 it resembled Wood in that all the smaller and if I may so call those which are onely visible with a good magnifying Glass Microscopical pores of it appear both-2 when the substance is cut and polish'd transversly and parallel to the pores of it perfectly like the Microscopical 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 weight , being to common water as 3 1$$4 to 1 . whereas there are few of our English Woods , that when very dry are found to be full as heavie as water . (HOOKE-E3-P1,108.113) Secondly , in hardness , 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 closeness of it , (HOOKE-E3-P1,108.118) for though all the Microscopical pores of this petrify'd 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 incombustibleness , 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 intense 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 dissolubleness ; (HOOKE-E3-P1,108.127) for putting some drops of distill'd Vinegar upon the Stone , I found it presently to yield very many Bubbles , just like those which may be observ'd in spirit of Vinegar when it corrodes corals , though perhaps many of those small Bubbles might proceed from some small parcels of Air which were driven out of the pores of this petrify'd substance by the insinuating liquid menstruum . (HOOKE-E3-P1,109.128) Sixthly , in its rigidness and friability , 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 touch , feeling more cold then Wood usually does , and much like other close stones and minerals . (HOOKE-E3-P1,109.130) The Reasons of all which Phaenomena seem to be , That this petrify'd Wood having lain in some place where it was well soak'd with petrifying water that is , such a water as is well impregnated with stony and earthy particles did by degrees separate , either by straining and filtration , or perhaps , by precipitation , cohesion or coagulation , abundance of stony particles from the permeating water , which stony particles , being by means of the fluid vehicle convey'd , not onely into the Microscopical pores , and so perfectly stoping {COM:sic} them up , but also into the pores or interstitia , which may , perhaps , be even in the texture or Schematisme of that part of the Wood , which through the Microscope , 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 Char 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 petrify'd substance appear'd of a dark brown colour after it had been burnt . (HOOKE-E3-P1,109.133) By this intrusion of the petrifying particles , this substance also becomes hard and friable ; (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 transmutation 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 Metamorphoses wrought almost on all kind of substances , both Vegetable and Animal , which Histories , it is not my business at present , either-3 to relate , or epitomise , but only to set down some Observation {COM:sic} I lately made on several kind of petrify'd Shels , found about Keinsham , which lies within four or five miles of Bristol , which are commonly call'd Serpentine-stones . (HOOKE-E3-P1,109.140) Examining several of these very curiously figur'd bodies which are commonly thought to be Stones form'd by some extraordinary Plastick virtue latent in the Earth it self 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 petrify'd drops , which are commonly found at the Peak , and in other subterranean caverns , 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 Cockle or Scolop-shels , which some of them most accurately resembled , were very dissoluble in common Vinegar , (HOOKE-E3-P1,110.151) others of them especially those Serpentine , or Helical stones 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 sutures , such as are observ'd in the skulls of several kinds of living creatures , which sutures 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 Microscope ; (HOOKE-E3-P1,110.157) all these sutures , by breaking some of these stones , I found to be the termini , or bounding of certain diaphragms , or partitions , which seem'd to divide the cavity of the Shell into a multitude of very proportionate and regular cells or caverns , (HOOKE-E3-P1,111.158) these Diaphragms , 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 mother-of-pearl colour'd . (HOOKE-E3-P1,111.159) As for the cavities between those Diaphragms , 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 tartareous petrify'd substance , which stuck about the sides , and was there shot into very curious regular Figures , just as Tartar , or other dissolv'd Salts are observ'd to stick and crystallize about the sides of the containing Vessels ; or like those little Diamants 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 metalline or marchasite-like substance , which with a Microscope 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 Plastick virtue 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 petrifying 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 spirallied and separated with Diaphragmes , were some kind of Nautili or Porcelane shelle ; and that others were shells of Cockles , Muscles , Periwincles , Scolops , &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 petrify'd 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 Cockle , Muscle , Periwincle , 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 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 petrify'd 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 I am very apt to think find reason to suppose their generation or formation to be ascribable to some such accidents as I have mention'd , and not to any Plastick virtue : {COM:sic} (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 as farr as the knowledge of man has yet been able to reach 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 maxime , that Nature does nothing in vain ; (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 which many of them are adorn'd and contriv'd with generated or wrought by a Plastick virtue , 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 Thunderstones , Lapides Stellares , Lapides Judaici , and multitudes of other , whereof mention is made in Aldrovandus , Wormius , and other Writers of Minerals . (HOOKE-E3-P1,112.171)