Fourthly, they were very different, as to their outward covering, some having the perfect Shell, both 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, others of them, especially those Serpentine, or Helical stones were cover’d 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; on other parts it was pretty thick, and retained a white coat, or flaky substance on the top, just like the outsides of such Shells; 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: 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; all these sutures, by breaking some of these stones, I found to be the termini, or boundings 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, 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.

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, 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; 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.

From all which, and several other particulars which I observ’d, I 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 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 extraordinary cause 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 shells; and that others were shells of Cockles, Muscles, Periwincles, Scolops, &c. of various sorts; that these Shells 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 impressions, both 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 others of these Shells, according to the nature of the substances 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. 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, for so many differing substances have I found in one of these petrify’d Shells, and perhaps all these differing from the encompassing earth or stone; the means how all which varieties may be caus’d, I think, will not be difficult to conceive, to any one that has taken notice of those Shells, which are commonly found on the Sea shore: 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: 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; 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 consider all the circumstances of such kind of Figur’d bodies, will, I think, have great reason to believe, though, I confess, one cannot presently be able to find out what Nature’s designs are. 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 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 Thunder-stones, Lapides Stellares, Lapides Judaici, and multitudes of other, whereof mention is made in Aldonandus, Wormius, and other Writers of Minerals.

Observ. [XVIII]. Of the Schematisme or Texture of Cork, and of the Cells and Pores of some other such frothy Bodies.

I took a good clear piece of Cork, and with a Pen-knife sharpen’d as keen as a Razor, I cut a piece of it off, and thereby left the surface of it exceeding smooth, then examining it very diligently with a Microscope, me thought I could perceive it to appear a little porous; but I could not so plainly distinguish them, as to be sure that they were pores, much less what Figure they were of: But judging from the lightness and yielding quality of the Cork, that certainly the texture could not be so curious, but that possibly, if I could use some further diligence, I might find it to be discernable with a Microscope, I with the same sharp Penknife, cut off from the former smooth surface an exceeding thin piece of it, and placing it on a black object Plate, because it was it self a white body, and casting the light on it with a deep plano convex Glass, I could exceeding plainly perceive it to be all perforated and porous, much like a Honey-comb, but that the pores of it were not regular; yet it was not unlike a Honey-comb in these particulars.

First, in that it had a very little solid substance, in comparison of the empty cavity that was contain’d between, as does more manifestly [Schem. 11.]
Fig. 1. appear by the Figure A and B of the XI. Scheme, for the Interstitia, or walls (as I may so call them) or partitions of those pores were neer as thin in proportion to their pores, as those thin films of Wax in a Honey-comb (which enclose and constitute the sexangular celts) are to theirs.

Next, in that these pores, or cells, were not very deep, but consisted of a great many little Boxes, separated out of one continued long pore, by certain Diaphragms, as is visible by the Figure B, which represents a sight of those pores split the long-ways.

I no sooner discern’d these (which were indeed the first microscopical pores I ever saw, and perhaps, that were ever seen, for I had not met with any Writer or Person, that had made any mention of them before this) but me thought I had with the discovery of them, presently hinted to me the true and intelligible reason of all the Phænomena of Cork; As,

First, if I enquir’d why it was so exceeding light a body? my Microscope could presently inform me that here was the same reason evident that there is found for the lightness of froth, an empty Honey-comb, Wool, a Spunge, a Pumice-stone, or the like; namely, a very small quantity of a solid body, extended into exceeding large dimensions.