SECT. I.

THough it will not perchance prove very difficult to propose to you my Conjecture about the Causes of the Vertues of Precious Stones; yet I fear it will not be easy for me to acquaint you fully with the Grounds of it. For unless I should transcribe for you my whole Discourse of the Origine of Mi­nerals in General (of which you know Stones make a part) I cannot well lay [Page 2] before you all the Considerations, by which I have been induc'd to take [...] the Conjecture or Hypothesis I am about to propound: and consequently I can­not well comply with your curiosity about Gems, without either omitting several things which might much coun­tenance the following Discourse, or proposing (without amply proving them,) some things, that I confess seem not cleer, nor some of them so much as probable, by their own Light. But since you will have it so; I will, rather than disobey you, present you in one Discourse several things concerning Gems, whereof some belong to others of my little Tracts about the Origine of Minerals from Fluid or at least Soft Bodies; thô some indeed were more directly written concerning Gems: not­withstanding that they were deliver'd not as an entire Tract about that subject, but as Corollaries that might be drawn from, and applications that might be made of, what had been in a more general way discours'd about the origi­nation of Stones and other Minerals. [Page 3] And therefore presuming that you will suppose with me in this Discourse some few particulars, that, I think, I have elsewhere made probable, and might perhaps do so from some of the Phae­nomena mentioned in this Writing it self, I would immediately address my self to the subject of it, if I did not think a previous Admonition very requisite.

For, I must at the very entrance of this Discourse desire you to take notice, that when I propose my Conjectures about the Virtues of Gems, I do not suppose the truth of all, or so much as the tenth part of those wonderful pro­perties, that Men have been pleased to ascribe to them. For not only some of the Writers of Natural Magick, but men of note, who should be more cau­tious and sober, have delivered in their Writings many things concerning Gems, which are so unfit to be credited, and some of them perhaps so impossible to be true, that I hope the Believers of them will among the Votaries to Philo­sophy be as great rarities, as Gems them­selves are among Stones. And those [Page 4] that can admit such unlikely Fables, will be as much despis'd by the Judici­ous, as Jewels can be priz'd by the Rich.

For my part, I never saw any great feats perform'd by those hard and costly Stones, (as Diamonds, Rubies, Saphires,) that are wont to be worn in Rings. But yet because Physitians have for so many Ages thought fit to receive the frag­ments of pretious Stones into some of their most celebrated cordial Composi­tions; because also divers eminent Men of that profession, some of them fa­mous Writers, and some Virtousi of my own acquaintance, have by their Wri­tings, or by word of Mouth, inform'd me of very considerable effects of some Gems, (especially Christal,) upon their own particular Observations: And lastly, because that (as I shall shew a­non,) I find no impossibility that at least some costly and less hard, (though in­deed more valuable) Gems, may have considerable operations upon humane Bodies, some few of which I have had opportunity to be convinc'd of, I will [Page 5] not indiscriminately reject all the Medi­cinal Virtues, that Tradition and the Writers about pretious Stones have ascribed to those Noble Minerals: Con­tenting my self to declare in a word, that suspecting most of them to be fa­bulous, my Conjectures aim only at giving one of the Causes of those Vir­tues ascrib'd to Gems which Experience warrants to be real and true.

Having thus explain'd in what sense my Conjecture about the Virtues of pretious Stones is to be understood; it follows that I propose the Conjecture or Hypothesis it self; the substance of which may be compriz'd in these Two particulars: First, That many of these Gems, and Medical Stones, either were once fluid Bodies, as the Transparent ones; or in part made up of such sub­stances as were once fluid: And second­ly, That many of the real Virtues of such Stones may be probably deriv'd from the mixture of Metalline and other Mineral substances, which (though un­suspectedly,) are usually incorporated with them: And the Greatness of the [Page 6] Variety and Efficacy of those Virtues may be attributed to some happy Con­current Circumstances of that Commix­ture. The first of these heads relates properly to the Origine of Gems. The second, partly to that, and partly to the kinds and degrees of their Virtues.

But that any Gems, especially the hardest sorts of them, should have a la­ter Begining, then that of the Earth it self, will probably be thought to relish of a Paradox; and I doubt not, it will pass with many for a great one, that some of these hardest of solid Bodies should have been once fluid ones or Liquors: Wherefore I shall endeavour to Countenance this Hypothesis by the following Considerations.

1. And first the Diaphaneity of Dia­monds, Rubies, Saphires, and many other Gems agrees very well with this Conjecture, and thereby seems to fa­vour it. For 'tis not so likely, that Bo­dies that were never fluid should have that arrangement of their Constituent parts, that is requisite to transparency, as those that were once in a Liquid [Page 7] Form, during which it was easie for the Beams of Light to make themselves pas­sages every way, and dispose the solid Corpuscles after the manner requisite to the Constitution of a transparent Body. Therefore we see, that Silver in Aqua Fortis, or Lead in Spirit of Vineager, ha­ving by that solution had their particles reduc'd into a fluid Form, those parti­cles, though before Opacous, are so dispos'd of as to make not only a Dia­phanous solution, but, if one pleases, transparent Christals. And what Chy­mists usually try with those Metals, I have had the Curiosity to try with seve­ral Stones, which I may hereafter have occasion to name to you. But this Ar­gument I bring rather to confirm than evince my Conjecture.

Secondly, The Origine assign'd to Gems may be also countenanc'd by the External figuration of divers of them. For we plainly see, that the Corpuscles of Nitre, Allom, Vitriol, and even Common Salt, being suffer'd to coagu­late in the Liquors they swam in before, will convene into Christals of curious [Page 8] and determinate shapes. And the like I have try'd in several metalline Bodies dissolv'd in several Menstruums. But unless a Concreting stone, or other like Body be either surrounded with, or in good part contiguous to a Fluid, 'tis not easie, to conceive how it should acquire a Curious Angular and determinate shape. For Concrescent Bodies, as I may so speak, if they have not room enough in an Ambient Fluid for the most congruous ranging of their parts, cannot cast themselves into fine and Re­gular shapes, such as I shall presently show that divers Gems seems to affect; but the Matter they consist of must con­form to the Figures of the Cavity that contains it, and which in this case has not so much the Nature of a Womb, as of a Mold. And so we see that Salt-Petre, and divers other Salts, if the Water, they were dissiolv'd in, be much too far boyl'd away before they are suf­fer'd to shoot, will, if the Liquor fill the Glass, sometimes coagulate into a Mass, fashion'd like the inside of the contai­ning Vessel, or if a pretty quantity of [Page 9] Liquor remains after the coagulation, [...]hat part of the nitrous Mass, that was [...]educ'd to be concreted next the Glass, will have the shape of the Internal sur­ [...]ace of it, whatever that be; but those Christals that are contiguous to the re­maining Liquor, having a Fluid Ambi­ent to shoot in, will have those parts of [...]heir Bodies, that are contiguous to the Liquor, curiously form'd into such Prismatical shapes as are proper to Ni­ [...]re.

To apply this now to Gems; That [...]ivers kinds of them have Geometrical [...]nd determinate shapes, though it be [...]ot vulgarly observ'd, because we are [...]ont to see them when they are cut, if [...]ot also set in Rings and Jewels; yet have often had the opportunity to take [...]otice of it, by having had the curiosity [...]o look upon many of them rough as Nature has produc'd them, and the good [...]ortune to take divers of them out of [...]heir Wombs. For I remember, I have [...]aken a good number of Indian Granats [...]out of a Lump of heterogeneous Mat­ [...]er, whose distinct Cavities like so many [Page 10] Cells, contained stones, on some of whose surfaces you might see Triangles, Parallelograms, &c. And being once near the Rock, whence those Stones are chiefly fetch'd that are commonly call'd Bristol stones, I remember, I rid thither and procur'd a Workman or two to dig me up a Number of them, divers of which I found to be curiously and determinately shap'd, much like some Christals of Nitre that I have taken pleasure to compare with them. And the like figuration I have also observ'd in divers Cornish Diamonds, and in a fair and large one, which one that knew not what it was, found growing with many lesser in Ireland, and presented me. And to let you see, that 'tis not only in these softer Gems that this cu­rious figuration is to be met with, I shall add, that I found among many Stones, I had and took to be Rubies (and those the Jewellers will tell you are ex­ceeding hard) a considerable number, whose shapes, though not the same with those of the Cornish and Irish Stones, were yet fine and Geometrical. And [Page 11] the like I have observed even in those hardest of Bodies, Diamonds them­selves; of which remembring that in my Collection of Minerals I had a pretty large one that was rough, I perceiv'd that the Surface of it consisteth of se­veral Triangular Planes, which were not exactly flat, but had as it were smal­ler Triangles within them, that for the most part met at a point, and did seem to constitute, as it were, a very obtuse solid Angle: Incourag'd by this, I ex­amin'd several other rough Diamonds, and found the most of them to have Angular and determinate shapes, not unlike that newly mention'd. And ha­ving thereupon consulted an expert Jeweller, that was also a Traveller, though he could not name to me the shapes of the un-cut Diamonds, he had met with; yet he told me, he generally found them to be shap'd like that I shew'd him; insomuch that such a shape was a mark, by which he usually judg'd a Stone to be a right Diamond, if he had not the opportunity to exa­mine it by the hardness.

[Page 12]And this I shall add in favour of the Comparison, I lately intimated betwixt the coagulation of Petre and that of Gems, that having once made an odd Menstruum, wherein I was able to dissolve some pretious stones, there shot in the liquor, Christals pretty large, and so transparent and well shap'd, that they might well have pass'd for Christals of Nitre; and yet, if I much misremember not, they were insipid. And I have divers times taken notice in such stones, as the Bristol Diamonds, That though that part, which may be look'd upon as the upper part of the stone, were curiously shap'd, having six smooth sides, which at the top were as it were cut off sloping so as to make six triangles, that terminated like those of a Pyramid in a Vertex; yet that which may be look'd upon as the root or lower part of the stone, was much less transparent (if not opacous) and devoid of any regular figuration; of which the reason seems to be, that this being the part whereby the stone ad­her'd to its womb, it was sully'd by [Page 13] the muddiness of it, and reduc'd to conform it self to whatever shape the contiguous part of the Cavity chanc'd to be of; whereas the upper part of the stone was not only form'd of the clea­ [...]er part of the Lapidescent Juice be­ [...]ore the waterish vehicle was exhal'd, [...]ut had room and opportunity to shoot [...]nto the curious figure belonging to its Nature. And this is much more con­ [...]picuous, where many of these Christals grow as it were in Clusters out of one Mineral Cake or Lump; as I have seen [...]ot only in those soft but yet transpa­ [...]ent Concretions, which some of the [...]ter Mineralists (for the ancient seem [...]carce to have known them) call fluores, [...]nd particularly in a very fine mineral [...]mp, that I had once the honour to have [...]ew'd me by a great Prince, and no less [...]reat a Virtuoso, to whom it was then [...]ewly presented. For this mass consisted [...]f two flat Parallel Cakes, that seem'd [...]ompos'd of a dirty kind of Cristalline [...]bstance, and out of each Cake there [...]rew towards the other a great Num­ [...]er of stones, some of which by their [Page 14] cohaesion kept the two cakes together, and most of these stones, having each of them a little void space about it, wherein it had room to shoot regularly▪ were Geometrically shap'd, and, which look'd very prettily, were colour'd lik [...] a (German) Amethyst. And I have my self a pretty large stone, taken up her [...] in England by a Gentleman of my Acquaintance, which consists (as it were) of four parts: The lowermost is a thi [...] and broad flake of coarse stone, only adorn'd here and there with very minute glistering particles, as if the [...] were, (as probably they may be) of [...] Metalline Nature; over this is sprea [...] another thin white, but opacous, bed which is so inclos' [...] between the fir [...] nam'd bed, and the two others, th [...] without defacing the stone I canno [...] well examine it: The third consists of [...] congeries of minute Cristals exceedingly thick set, which therefore look wh [...] tish, having little or no tincture of thei [...] own; and this part no more then eithe [...] of the former, is not much thicker tha [...] a Barly Corn. The fourth and uppe [...] [Page 15] most part, which yet seems in great part to be the same Christals, which as they grow higher and spread, acquire a deeper colour, is made up of a great Number of Amethysts, some paler, and some highly tincted, which are of very differing figures, and bignesses, accor­ding (as one may ghess) as they had conveniency to shoot; these at one end of the stone lying in a flat bed (as it were) and scarce exceeding a Barly Corn in length; whereas those at the other end shoot up to a good height into figur'd Cristals, some of them as big as the top of my little finger, and those are the most deeply colour'd, being also of a good hardness, since I found that they would easily grave lines upon Glass.

I remember also, that going to visit a famous Quarry, that was not very far from a Spring which had somewhat of a petrescent faculty in it, I caus'd divers solid pieces of rough and opacous stones to be broken, out of hope I had to find in them some finer juice coagu­lated into some finer substances; and [Page 16] accordingly I found, that in divers places, the solid and massy stone had cavities in it, within which, all about the sides, there grew Concretions, which by being transparent like Chri­stal, and very curiously shap'd, seem'd to have been some finer Lapidescent juice, that by a kind of percolation through the substance, that grosser stone was made of, had at length ar­riv'd at those Cavities, and upon the evaporation of the superfluous and aqueous parts, or by their being soak'd up by the neighbouring stone, had opportunity to shoot into these fine Christals, which were so numerous as quite to overlay the sides of the Cavi­ties, as I can show you in some large Clusters of them that I brought from thence. And inquiring of an ancient Digger, whether he had not sometimes met with greater quantity of them? he told me, that he had, and presented me a great Lump or mass made up of a Numerous Congeries of soft Christals, (but nothing so colourless as these other newly mentioned) sticking to one [Page 17] another, but not any of them to any part of the Rock: So that they seem'd to have been hastily coagulated in some cleft or Cavity, as it were in a Mould, where meeting & mingling before Con­cretion with some loose particles of Clay, the mass may thereby be discolourd.

Our Argument drawn from the figu­ration of transparent Stones may be much strengthened by the coalition I have sometimes observed, of two or more of such Stones, and the congruity in the shape of some of them to the figures of those parts of the others, that were contiguous to them and seem'd to have been form'd after them. But though this Phenomenon be considerable to the scope of my Discourse, yet per­ceiving that I shall have occasion to insist on it hereafter, I shall not do it now.

Thirdly, Nor is it only the external fi­guration of these Gems, but the internal Texture that favours our Hypothesis, some of them seeming much to imitate in their Coagulation several of those substances, which I have observ'd to [Page 18] have once been fluid. That common Salt may be made up of small saline Particles, that by a Convenient Juxta-Position may be associated into great Lumps, divers of which are cubically shap'd, is an observation easie enough to be made. And that such Coalitions of particles may constitute solid and con­siderably hard Bodyes, I have try'd by breaking some of the larger Cubes of Sal Gem, and the Lumps of the Isle of Mayo-Salt, whereof the first is fossile, the other marine, and both Natural. I have likewise found by Tryal, that, though Silver dissolv'd in Aqua-fortis appears usually to shoot, if it be taken notice of, into flat and exceeding thin flakes; yet 'tis very possible so to order the coagulation, that many of these thin Plates shall in their Convention have their flat sides so plac'd over one another, as to make up pretty large and thick Christals, whose very outsides will be finely shap'd as being some peculiar kind of Vitriol. Nor are these the onely fluid Bodies, which I have reduc'd to coagulate into Conventions, of such a [Page 19] flaky Texture; wherefore I began to suspect that divers transparent Minerals may have the like; and in some Dia­phanous kinds of Talk, whose outsides were Mathematically figur'd, I found Encouragement to try, whether ev'n some Gems themselves, notwithstanding their hardness, might not have such an Internal figuration. Nor was I deterr'd by considering, that 'tis taken for gran­ted, that Gems are of an uniform Tex­ture, and that there must be a strange thinness in the Plates that make up transparent stones, since no such thing has been noted by the most curious Eye, but men have taken it for granted, that the Texture of all Gems is Uni­form, without any grain or fibres, no more than there is in Gold. But as to the thinness of the Plates, I remember, I have several times taken pleasure to hold a peice of good Muscovia-glass against the Light, when it was of such a thinness, that the spectators, though provok'd to look with curious Eyes, could scarce see the Plate it self, and would by no means be brought to [Page 20] think that it was possible to split it, till I did actually do it; and sometimes I then subdivided it beyond ev'n my own Expectation. But to examine this Con­jecture, I took some stones that had Geometrical figures on part of their Surfaces, and which I had other grounds to think to have been once fluid sub­stances, and having diligently surveyed some of them, which seem'd likeliest to give me satisfaction, I manifestly e­nough perceiv'd, not only with my assi­sted, but with my naked Eyes, divers parallel Commissures, which seem'd plainly to be made by the contiguous Edges of little thin Plates of stone, that appear'd to lye one over another, almost like the Leaves of a Book that is a little open'd.

I remember that holding a large and rough Grizolette (as Artificers call hard Gems, of a blewish colour, brought them from East India) against the Light and curiously observing it, I have some­times plainly discern'd a grain, as they call it, in the Stone, and was answered by a skilful Artist that us'd to make [Page 21] Seals of them, that such Stones would usually split according to the Ductus of their Grain. I will not urge, that in some other Precious Stones, that were cut and Polish'd, as particularly the Hyacinth, and ev'n the Saphire, by obverting them several wayes to the Light, I have been able to observe, as it were, Commissures, which were so fine, as not to hinder, or call in Question the Intireness of the Stone, for the La­pidaries purpose. This I say I forbear insisting on, because the Phaenomenon is far less considerable than what I have several times observ'd in New English Granats, wherein, especially when they are broken, the Edges and Commissures of the thin Plates or Flakes, whereof they consisted, were very easily discer­nable. And to try whether this ob­servation would hold even in the har­dest Stones, I had recourse to a pretty big Diamond unwrought, which being plac'd in a Microscope, shew'd me the Commissures of the Flakes I look'd for, whose Edges were not so exactly dis­pos'd into a plain, but that some of them [Page 22] were very sensibly extant like little Ridges, but broad at the Top above the level of the rest. And these Pa­rallel flakes together with their Com­missures, I could in a somewhat large Diamond plainly enough discern even with my unassisted Eyes. And for fur­ther satisfaction, I went to a couple of Persons, whereof the one was an Emi­nent Jeweller, and the other an Artifi­cer, whose Trade was to cut and polish Diamonds, and they both assur'd me upon their repeated and constant Ex­perience, and as a known thing in their Art, that 'twas almost Impossible, (though not to break, yet) to split Dia­monds, or cleave them smoothly cross the Grain, (if I may so speak,) but not very difficult to do it at one stroke with a Steeled Tool, when once they had found out from what part of the Stone, and towards what part the splitting In­strument was to be impell'd: By which 'tis evident that Diamonds themselves have a grain, or a flaky Contexture not unlike the fissility, as the Schools call it, in Wood; which you will easily grant [Page 23] to consist of assimilated water or Jui­ces; which having been once fluid Bo­dies, were fit to have their Particles so rang'd or dispos'd, as to constitute a Body far more easie to be cleft accor­ding to the Ductus of the Fibres (or Planes) than otherwise. And I remember that having, as I thought, observ'd in a rough Diamond, which I purposely exa­min'd, that the Flakes whose Edges were terminated in one plain, were far enough from being parallel to those whose Ed­ges compos'd another plain, (I speak of Physical planes of the same Stone,) I imagin'd that if this Diamond were to be cleft, it would not be smoothly split into two peices, because the Commis­sures did probably make Angles in the Body of the Stone; and accordingly I learned of the ancientest of these Diamond Cutters, that sometimes he met with Stones, that eluded all his skill, and would by no means be split like others into two parts, but, before they were cleft quite through, would break in pieces; which was a defect in the Stone he could not certainly foresee, [Page 24] but was fain to learn from the unwel­come Event.

Fourthly, It seems not unprobable, that the Colours of divers Gems (for I do not say of all) are adventitious, and were imparted to them, either by some colour'd Mineral Juice, or some tinging Mineral exhalation, whil'st the Gem or Medical Stone was either in Solutis Principiis, or of a Texture open enough to be penetrable by Mineral Fumes. Which Arguments considera­bleness makes me hold it unfit to be lightly touched in this place; though I cannot discourse any thing fully of it in few words, because it not only suggests divers observations and other particu­lars, but requires also the mention of some of the chief of them; which there­fore I shall now subjoin.

1. And the first shall be, That many Gems, not to say almost all of them, have been observ'd to be depriv'd of their Colour, if having fallen, or been put into the Fire they have layn too long there: Insomuch that I have found it affirm'd upon the Testimony [Page 25] of the Learned and Experienced Boe­tius de Boot, that all Gems will loose their colour in the Fire except Bohe­mian Granats. How far this may be true I have not had opportunity tho­roughly to examine. But I well re­member that having purposely expos'd divers Gems to the fire, though that were but moderate, and had a Crucible interpos'd between it and them, some of them seem'd to have their Tincture much impair'd, and others quite de­stroy'd. But I must be so free as to admonish you, that if these Tryals be not warily made, they may easily im­pose upon us; especially if we do not consider the nature and cause of White­ness. For any Diaphanous Body, as far as I have yet observ'd, being divided into a multitude of very minute parts, and consequently acquiring a multitude of distinct superficies's, which do briskly reflect the Light every way outwards, will appear to have a white colour that will be more or less vivid as the par­ticles are more or less numerous, mi­nute, and otherwise fitted to scatter the [Page 26] incident Beams of Light; as you may see by reducing to powder fine Venice-Glass, which will be white; and ev'n red Inck, if so shaken or beaten as to be brought to a froth, consisting of many minute Bubbles, will seem to have put on a whiteness. So that if by too hasty an Ignition, or too hasty a cooling of the fir'd Gems, they come to be flaw'd with innumerable little Cracks, they may be thought to be made white by having their Tincture driven away, when their whiteness really proceeds from the mul­titude of those little flaws which are singly unperceiv'd; and the rather, be­cause the Body may still retain its for­mer shape or seeming intireness. To illustrate which, I have sometimes ta­ken pleasure to heat a piece of Christal red hot in a Crucible and then quench it in Cold Water: For ev'n when the parts did not fly or fall asunder, but the Body retain'd its former shape, the multitude of little Cracks that were by this operation produc'd in it, made it quite loose its transparency and appear a White Body. In making which ex­periment, [Page 27] the multitude of produc'd flaws may be pretty well discover'd to the incredulous, if, as I have sometimes done, the ignited Chrystal be warily and dextrously quench'd not in Water but in a very deep solution of Cocha­neel made with Spirit of Wine, in which operation, if it be well performed, (but not otherwise,) enough of the red Par­ticles of the solution will get into the cracks of the Chrystal, to give it a Pleasing Colour.

The other tryals that I have made about the reducing of Whiteness or paleness in bodies, either transparent, or even Semi-Diaphanous only, Note: About Tincture of Coral. belonging to an other paper, I shall here forbear to mention them, having already said enough for my present purpose, which is not so much to affirm positively, that no Proof at all can be drawn from the operation of fire upon the Colour of Gems, as to make you cautious, what Proofs drawn from thence you admit.

2. Wherefore declining to say any [Page 28] thing more about the first, I shall now proceed to the next Circumstance, that belongs to our Argument, (which you may think to be more Considerable then the former) namely that the Co­lours of several Gems, when they are not destroy'd by fire, will be alter'd thereby; which being a thing that happens to divers fossile Pigments (of which some I imploy to tinge Glass,) and other Bodies confessedly Mineral, argues a Commixture of Mineral sub­stances in those Stones whose Colour receives some of the Alterations I speak of; which last words I add, be­cause I would not impose upon you by concealing, that there may be a change of Colour produc'd by the fire without any alteration of the tinging parts as such. For by flawing the hea­ted Gem in very many parts, a degree of whiteness or paleness emerging there­upon may somewhat change the former Colour. But this Alteration being but a kind of Dilution, is not that which I here mean. For I remember I have taken Indian Granats, and having in a [Page 29] Crucible expos'd them to the fire, I found they had exchang'd their red­dish Colour for a Dark and Dirty one, like that of Iron that has been long kept in the Air. And having taken some pieces of Agate prettily enough adorn'd with waves of differing Co­lours, and kept them a competent time (for they should not be kept too long) in the fire, I found, as I conjectur'd, that the greatest part of the Agate seem'd to be depriv'd of its Tincture, being reduc'd to a pleasant Whiteness: But in some places where there were stains of a differing kind from the rest, and where there ran little Veins, that I ghess to be of a Metalline Nature, there, I say, the Colour was not de­stroy'd, but chang'd, and the Veins of Pigment thus colour'd acquir'd a deep redness, which they will retain, if let [...]lone; though I was induc'd to think by some Tryals made on other pieces of Indian Agate, that even these Me­ [...]alline Tinctures were not so fix'd but [...]hat a lastinger fire would drive them [...]way, and leave the stones purely white. [Page 30] Such a change of Colours as I lately mention'd in the Veins of Agate, is like­wise found in those of some other Stones, as also in some Pebbles, amongst divers of which, that lost only their Transparency by Ignition and Extinction in Water, one or two acquir'd so much deeper a Colour then it had before, that I thought it remarkable.

3. Another Circumstance that seem to favour our Conjecture may be this▪ That it has been observed not unfrequently, that near many of the places where colour'd Gems are found, som [...] Mines or Veins of Metals are to be me [...] with. And I think it not unlikely, th [...] if search were skilfully made, man [...] more Discoveries would be made o [...] Veins either of Metalline Oar or som [...] other Mineral, Liquid or Concreted whence, by way of Juices or Fume [...] the Gems may be presum'd to have receiv'd Tinctures. But usually whe [...] pretious Stones are found, Mens Ind [...] stry and Curiosity is too much confin [...] to those rich Minerals, and does n [...] make them solicitous to look after i [...] feriour [Page 31] Ones. Besides, that in East-India, whose Countreys are best for the most Gems, they are wonderfully un­skillful at digging Mines; as I have gather'd from the Answers of some, who purposely went to visit the Dia­mond Mines, as they call them. To this may be also referr'd, that Gems are several times found in the Metalline Veins themselves, or very near them: As I can shew you divers Amethysts that an ingenious Gentleman of my Acquaintance took himself out of a piece of Ground abounding with the Ores of Iron and Tin, the latter of which was there plentifully dug up. And in those colder Countryes, such as Germany and England, where hard Gems are more unfrequent, those soft ones that Mineralists call Fluores, are often to be found in or near Metalline Veins, so finely tincted by Mineral Juices, that, were it not for their softness, they might pass at least among most Men, for Eme­raulds, Rubies, Saphires, &c. as I have been inform'd, not only by some Mine­ral Writers of good credit, but also [Page 32] by eye witnesses, and partly by my own Observation.

4. The fourth Circumstance which may be alleag'd to the same purpose with the three foregoing, is, That it seemes possible, from some Gems by Menstruums to obtain Tinctures that seem rather Extractions, than Dissoluti­ons strictly so call'd: I will not urge the Chymical Processes that may be met with in some Authors to this Effect, because some Circumstances in the things and in the Writers, made me so far suspect those I could try, (and those that requir'd undiscover'd Menstruums, as they may be true, so, for ought I know, they may not,) as to keep me from medling with them. But I re­member, I once made a Menstruum, (I say once, because its preparation is so subject to casualty, that I have often fail'd in it) which being pour'd upon well colour'd Granats, not only not cal­cin'd, but intire, was in no long time beautifi'd with a high and lovely Tin­cture, which was admir'd by very skil­ful Persons, to whom I shew'd it, because [Page 33] the Menstruum was not more corrosive than White-Wine; and which yet I therefore took to be a genuin Tincture, partly because it was drawn in the Cold, partly because the Liquor would not tinge it self by standing, if no Body were put in it, and partly because it drew a Tincture from Antimony of a very diffe­ring colour from this we speak of. Nor are Granats the only Gems, which I have made the Liquor work on, in the Cold.

5. To these Four Circumstances I shall add this Fifth; That some Gems, which Jewellers affirm without scruple to be Rubies, Saphires, &c. either are colourless, or have other colours than those that are wont to belong to them. That famous Gold-Smith, Benvenuto Cellini, in his little Italian Tract of his own Profession, admonishes his Reader, Note: Page 10. that there are one kind of Rubies, that are Naturally white, (and not made so by Art) which he proves by the degrees of hardness pe­culiar to Rubies. And the same Author elsewhere tells us of Berills, Topazes, and Amethysts, that are white. And it [Page 34] seems, by what he says not far from that place, that the Italian Jewellers did not look upon the Tinctures of Gems as any thing near so Essential to them, as they are commonly reputed, since they reckon Topazes and Saphires, whereof one is Blew and the other Yellow, but both extreamly hard in comparison of other Gems than Diamonds (and perhaps Rubies,) to be of the same species. The Degree of hardness of Rubies and Saphires is oftentimes so equal, that I knew an expert English Jeweller, who for that only Reason (for he knew not whence the difference of Colours might proceed) took Rubies and Saphires to be of the same kind of Stone.

And that Gems, referr'd by Lapi­daries to the same kind, may be very differingly ting'd, is a truth, whereof I have seen notable Instances in Dia­monds themselves; which I therefore prefer to other Instances, because the extream hardness of Diamonds is such as keeps Jewellers from mistaking any other Stone for a true Diamond, if they are permitted to put them on their ra­pidly [Page 35] mov'd Wheels employ'd to cut them. Now of true Diamonds I have seen some, that were Yellowish, others that were more Yellow, and among the rest, one that was so perfectly Yellow, that I at first took it for a fair Topaz, though it were a Diamond valued at near three pound weight of Gold: I have also seen Diamonds and those rough, as they came directly out of the Indies, and were soon after bought by Traders in Diamonds for such, which were either Blewish or Greenish. And I particularly contemplated one Stone, which, if its shape and other things had not convinc'd me of the contrary, was so Green, that I should have taken it for an Emerald.

I remember I had once occasion to buy a considerable number of small Rubies, divers of which were very cu­riously shap'd, and coming to look upon the whole parcel more leasurely than my hast would permit me when I bought it, I found in a great number of other Stones one, and but one, that was devoid of any Colour; but in other [Page 36] respects was so like the rest, as invited me to conclude that it would have en­creas'd their number, but that it was coagulated and harden'd before the Mineral Pigment had ting'd it of the same Colour with the rest. In which guess I was confirm'd, when, having met with a Gentleman, who had been in the chief Places of the East Indies, where Rubies are found, and particu­larly at the River of Siam, or Pegu, near which he liv'd a good while, and where he frequently saw Rubies taken out of the bottom of the Water, and sometimes took them out himself; I learn'd of him by enquiry, that he had there seen several Stones, each of which was partly a Ruby and partly colour­less: And sometimes in the same Stone there would be two portions of one sort, and the third, though lying be­twixt them, of another: Which has frequently obliged the Jewellers con­siderably to lessen the Bulk of such Stones by cutting off the untincted part. And, if my memory do not much deceive me, I saw in a great and curious [Page 37] Princes Cabinet, among other rarities, a Ring, in which was set a Stone of a moderate bigness, whereof onely one half, or thereabouts, was well tincted, the other being colourless. In Gems that are less precious, and not so transpa­rent, especially in Agats and in Opacous Gems, I could easily give a multitude of Instances of the differingly tincted parts of the same entire Stone. And I usually wear in a Ring a small Sardonix that was once a great Princes, wherein there are three Portions one within a­nother, the uppermost, Black, the mid­dlemost of a kind of Chesnut colour, the other of a Blew, almost like a Tur­quois, each of which portions is exactly of a fine Oval figure, and each of the two uttermost is thoroughout of a very uniform Breadth as well as colour, and exactly parallel to the other. But 'twould not be here so proper as 'twill be hereafter, to multiply Instances of Opacous Gems: Wherefore (having mentioned only the Sardonix, because 'tis not alwaies Opacous,) I shall add concerning Transparent ones, That [Page 38] Jewellers reckon among Saphires not only that sort of Azure Gems which usually pass for such, but also another sort of Stones, because of their Saphi­rine degree of hardness; though for their want of Tincture they call them white (Saphires.)

6. The Sixth and last Circumstance belonging to the foregoing Argument or Consideration is this, That some­times one may find Gems that are partly tincted and partly not: As if the tinge­ing Pigment mixing with one part of the matter whereof the Stone consisted whilst it was Liquid or soft, were not copious enough to diffuse it self to the Whole, nor to give an equally intense Colour to all that portion that it tinges. 'Tis true that in some cases the Diffu­sion may be stopp'd by the Petrescent Juices coagulating first in another part than that with which the Tincture was mix'd. And perhaps, in some other Cases, the different Colours may have belonged to differing portions of mat­ter, coagulating upon or against each other, at differing times, yet so as to [Page 39] seem one intire Stone, as I may have hereafter occasion to declare. Yet since, which soever of these explications be admitted, it will, if it belong not to this place, at least confirm our main Hy­pothesis (of the Origine of Gems from fluid or soft materials:) I shall return to what I was saying about Gems, part­ly tincted and partly colourless. And having onely intimated upon the by, that in some hard Semidiaphanous Stones, Europaean and East Indian, I have observed a very unequal and irregular diffusion of the Tincture: I shall add to the things, that may be gather'd in favour of the propos'd Conjecture from some of the things before (as also since) related, these two Particulars.

The one, That I have (as I think I elsewhere mentioned) seen in Italy, a­mong Rarities, a large piece of Chri­stal about the bigness of my two fists, whereof the Pyramidal part was of a Transparent Green, the Vertex being richly ting'd like an Emerald; but the further the colour spred from the Ver­tex, the fainter and paler it grew; so [Page 40] that, before it came neer the Base, it was quite spent, if I may so speak, leaving the bigger part of the Stone transparent, but colourless, like ordinary Christal. And by this perhaps we may explain an Expression of Josephus Acesta, where he sayes, that Emeralds grow in Stones like unto Christals, and that he had seen them in the same Stone fa­shioned like a Vein; And they seem, adds he, by little and little to thicken and re­fine. And in the same place this Lear­ned Author has a memorable observa­tion, that may confirm both what I have just now related, and what we mentio­ned a little above, about colourless Gems: I have seen, sayes he, some that were half White and half Green; others all White, and some Green and very perfect. And this is the first Particular I was to men­tion.

The Other is afforded me by the way I have us'd and elsewhere describ'd, of giving to pieces of Rock Christal pas­sably good Tinctures by Mineral Fumes. And supposing the thus colour'd pieces to be as intire Stones as the beholders [Page] have generally believed them, the in­stance will be pertinent to our purpose in spite of an objection. For though the Colours thus given are not wont to pervade them very deep, and have their penetration assisted by no faint degree of heat; yet 'tis to be consider'd on the other side, that these pieces of Chrystal had attain'd their full hardness, and after their colouration, are cut and polish'd like other Chrystals: Whereas the Gems that our Conjecture means, are suppos'd to have been ting'd under ground when they were yet fluid, or at least soft. That there are sometimes generated in the Bowels of the Earth Mineral Exhalations capable of apply­ing themselves to the Stones they meet with there, Note: Of Subterraneal [...]ires, &c. I have in another Discourse sufficiently declar'd. That also some hard and stony substances have been actually tinged with such Mineral Steams, I shall, in the subse­quent part of this Discourse, have oc­casion to take notice. And I remember too, that even in so hard a Gem as a [Page 42] Saphire, I have observ'd the efficacy of these Subterraneal Fumes; having di­vers times seen one of those Stones, wherein a fine Seal was cut, which con­tinu'd so oddly ting'd notwithstanding what had been taken off to reduce it to an exquisite shape, that having inquir'd of a skilful Person of my acquaintance by whom it had been Ingraven, he both assur'd me that he had found it of the full hardness of a Saphire, and confess'd to me, that the Mineral Fumes had so oddly ting'd it, that in his opinion it might, by the Looks, pass (rather) for a Chalcedonian.

And now, Sir, I fear I may need your pardon for having been so prolix in Discoursing of one of the Particulars belonging to our Argument; to excuse which, I have no other Apology to make, but that I hope what hath been deliver'd, will scarce seem impertinent, and that I might easily have made it more tedious, if, to decline doing so, I had not purposely made some omis­sions.

Having then said thus much about [Page 43] our fourth Consideration, I proceed now to add in the fifth place, on the be­half of the Hypothesis hitherto fa­vour'd, an Argument which I presume you will not think inconsiderable; Namely, that Solid Gems may include Heterogeneous matter in them. Seve­ral Instances of this sort in opacous Stones, I elsewhere recite upon my own Observation; but in transparent ones they are very great Rarities; and therefore it will not, I presume, be thought strange, if I mention but a few.

First then on this occasion I remem­ber, that a very ingenious and qualify'd Lady, who had accompany'd her Hus­band in an Embassy to a great Monarch, assur'd me, that she brought thence a­mong several Rich Presents and other Rarities, (some whereof she shew'd me,) a piece of Christal, in the midd'st of which there was a drop of Water, which by its motion might be very easi­ly observ'd, especially when the Chry­stal was made to change its posture. And, if my memory deceive me not, [Page 44] I have in some pieces of Rock-Chrystal taken notice of things that seem to ar­gue, that somewhat or other was in­tercepted within the Body of the Stone.

A curious person, that traded much and was very skilful in Indian-Gems, particularly Grisolets, which he got from the Indies, and whereof he shew'd me the largest I have yet seen, being ask'd by me, whether he had ever found in them any Heterogeneous substance, which something, I had observ'd, made me suspect that some of them might harbour notwithstanding their hardness; he averr'd to me, that among divers rough ones, that were brought from the Indies, he had with wonder seen one that was about the bigness of a Filberd, in the Solid substance whereof there was a Cavity with a certain Li­quor in it; which by changing the po­sture of the Stone might be made to move to and fro in the Cavity: And when the drop was settled, it was of the bigness of a round Pearl that he shew'd me, which wanted somewhat of a mo­derate [Page 45] size for a Neck-lace. And when he had answer'd the Questions I pro­pos'd him to clear my Doubts, he ad­ded, that this Rarity made the Stone, which was otherwise of a small Value, priz'd at an hundred Pound. And I have my self seen a monstrous Gem, if I may so call it, and little less a Rarity then the former, that an acquaintance of mine had bought, (as I afterwards learnt,) from this Relatour; whose Narrative about the Grisolet, I think the more Credible, because, that ha­ving had the curiosity to break a Stone, that was brought as a Rarity from the East-Indies, where Gems are often har­bour'd in such Stones, I found in the So­lid substance of it (which was so hard as to strike fire like a Flint, and in its little flakes was at least Semediapha­nous) a Cavity wherein were coagula­ted very minute but polish'd and Chry­ [...]talline Stones, which seem'd to have their points inwards, which argued, that there had been some Liquor, in which these glistering particles had shot, though in process of time the remaining [Page 46] and incoagulable part of it may have been imbibed by the Ambient Matter if not have escap'd thorough it, by Vir­tue of some peculiar congruity of it with the Pores of the Stone. Which need not be thought impossible, since experience has assured us, that some solid Stones and even Gems may be (though slowly) penetrated or have their Tex­ture altered by common Water. No [...] are these the only Heterogeneous sub­stances I found included in this Stone.

And if, as Amber is reckon'd among Gems, and is sometimes of a greater hardness than one would expect, so I could reckon it among true Stones, 'twere easie for me to borrow thence a great confirmation of what I have been saying; and how ever it will afford [...] an Illustration of it. For, not to men­tion many things, of what I elsewhere recite my self to have seen in Amber▪ I have now by me a fine piece of cler [...] and Solid Amber, (presented me by a Person no less extraordinary than it) in which is included a large intire fly, in shape and size much like a Grass-hop­per, [Page 47] but variously and curiously co­lour'd, with his Wings displayed.

To these Observations I shall add only this, That I have had my self, and shewn to others, one of that sort of pale Amethysts, that some call white Amethysts; which had been cut to be set in a Ring, or turn'd into a Seal, and was like that sort of Gems so hard, that I could readily cut Glass with it; and yet in the Body of this Stone there ap­pear'd to be a considerable number of things that look'd just as if they had been hairs, some of them lying parallel, and others inclining to one another; and having contemplated them as well by Day-light as Candle-light, and in di­vers positions in reference to the Light and the Eye, some of them seem'd at times to be of a lovely reddish Colour, but reflecting the Light, as if they were well fill'd either with Air or Water: But for the most part they did, as I was saying, seem to be hairs of a Brownish Colour, which made the Stone not a little wonder'd at even by curious and skilful Men. I leave you to judge, [Page 48] Whether 'twill be fit here to add, that I have sometimes suspected, that even in Diamonds themselves there may pos­sibly be found intercepted, or mingled with a pure Lapidescent substance, some Particles of Heterogeneous Matter. And that in this suspition I was somewhat confirm'd, as by the odd Clouds I had observ'd in an extraordinary Diamond, and by some Hydrostatical, and other Observations I made about those Stones; (some of which I found heavier than either Chrystal or white Marble,) so by my having purposely demanded of an ancient Cutter of Diamonds of great Practice and Experience, whether he observ'd not a sensible difference of weight among Diamonds of the same place: For to this he reply'd, that he had; especially in those that were cloudy or foul: Insomuch that shewing me a Diamond that seem'd to me to be about the bigness of two ordinary pease or less; he affirmed that he sometimes found in Diamonds of that bigness, about a Carrat (which is by common estimati­on four Grains) difference in point of weight.

[Page 49]Sixthly, The last Argument I shall imploy to shew, That the Matter of di­vers Gems may have once been fluid, may be taken from the Proofs you will meet with (in the following part of this Tract) of the Second Member of our Hypothesis. For if it shall ap­pear, that several even of the transpa­rent Gems have metalline or other ex­traneous Mineral Bodies mingled with them, per minima, it will be very agre­able to reason to suppose, that such a mixture was made, when the mingled Bodies were in a fluid form; since, beside that one may well ask, how else the Metalline Corpuscles came to be convey'd into such compact and hard Bodies as Gems, 'tis very easie to con­ceive, if our Hypothesis be admitted, and very hard otherwise to apprehend, how among Bodies that differ toto ge­nere, as Metals and Stones, there should be made mixtures so exquisite as many of these appear to be, partly by the Uniform Coloration of the Gem, and partly by the Diaphaneity retain'd not­withstanding this dispersion of Mineral [Page 50] Pigments through the whole Mass; and in many Instances also by the Curious Figuration that we have lately been discoursing of.

Post-script. To all the foregoing Cir­cumstances, I can now add something, that I met with, since I thought to con­clude with the Last of them, and that tends highly to the Confirmation of our Hypothesis. In a Tract that makes part of a small Book freshly Publish'd in French, principally to acquaint Men with the waies of estimating Gems ac­cording to the Rates of Modern Jewel­lers, the Anonymus, but Curious Au­thor, takes occasion, to give us, from the Mouth, as he affirms, of the Famous late Travellers he convers'd with in di­vers places, (and whose Relations are indeed the recentest I have seen is Print) an account of the Number, and Names of the places, where Diamonds and Rubies are found in the Indies, ad­ding some Circumstances and Particu­larities about the Qualities of the Soil in those places that I have not elsewhere met with. This Author then speaking [Page 51] of the first of those three Diamond-Mines, which he makes to be the only ones in the East-Indies, having told us that the Stones are there found some in the ground and some in the Rock, sub­joyns, that those that are drawn from the Rock, or the neighbouring parts, have ordinarily a good Water; but for those which are drawn out of the Ground, Note: Que's ilya quelque sable n [...]ir ou rouge parmi la terr [...], le Diamant aussi en aura quelqu' un Pag. 9. their Wa­ter partakes of the Co­lour or Soil wherein they are found. So that if the Earth be clean and somewhat San­dy, the Diamonds will be of a good Water; but if it be fat or black, or of another colour, they will have some tincture of it. Nay he immediately annexes, that if there be some black or red Sand among the Earth, the Diamond will also have some grain of it. And elsewhere mentioning the Second Mine of Diamonds, which the Natives call Gems, he admonishes his Reader, that in this, as in the Mine of Visapour, (which is that formerly mention'd) the Stones partake of the Quality of the Soil where [Page 52] they are found; so that if that be bog­gy or moist, the stone will incline to Blackness, and if it be reddish, 'twill have an Eye of that Colour. Elsewhere he tells us, that of late Years there were found in the Kingdom of Golcond [...] store of Diamonds, which were brought to the Nababe, or first Minister of State, who forbad the making any further search after them, Note: Page 18.19. finding not one in the whole number to have a good Water, all of them being Black or Yellow. But by the way, Note: Page 37. whereas this Author affirms it as a clear Truth, that as Gold is the heaviest and most precious of Metals, so Diamonds are the hardest, and hea­viest of all Stones, he must excuse me if I declare, that what he asserts agrees not with my experience, who having try'd the weight of an uncut Diamond Hydrostatically, have taken such a course to estimate its specifick Gravity, as I find not to have been yet taken by any other, and which you will easily grant to be more exact than any other of the known wayes can be.

[Page 53]The Argument that hath detain'd us all this while, comprised so great a vari­ety of Matter, and may, I hope, per­form so great a part of my task in this Discourse, that, though I shall not much apologize for having dwelt so long up­on it, yet I should think my self obli­ged to make some amends for my past prolixity by being succinct in the re­maining part of this Treatise, and there­fore, having left off with an intimated promise to shew more fully, that divers Gems contain Metalline or other Mi­neral substances in them, I should im­mediately connect those Arguments to what hath been lately said, but that I think it altogether requisite, to make way for what is to follow, by first ta­king notice of a main Objection, that may be urged against the Doctrine we have been proposing.

This is taken from the Figuration of some Gems (and especially the Prisma­tical one of Christal) and seems the more fit to be urg'd against us, because we our selves have, in the Second of the above-recited Arguments, given se­veral [Page 54] Instances of it. For it seems scarce possible, that so curious a shape should be so Uniformly produc'd in such a multitude of Christals, great and small, unless there were some seminal and plastick power to fashion the mat­ter after so regular and Geometrical a manner.

But he that shall attentively consider, what I elsewhere say concerning the Figuration of Salts and of Metal­line and other Magisteries dissolv'd by, and concoagulated with Salts, may be very much assisted to discover the Invalidity of this Objection. But yet, because I confess 'tis very speci­ous, if not important, I am content here to consider it a little more parti­cularly.

To this plausible Objection then, I have two or three things to answer; First, That there is no absurdity to con­ceive, that if there be a Seminal and plastick power in Mineral Bodies, it may be harboured in Liquid Principles, as well as otherwhere. For we see that the Seed of Animals, which oftentimes, [Page 55] as in Elephants, Rhinocerots, &c. pro­duces hard and solid Bones, Teeth, and Horns, is at first but a Liquid substance; and the Formative power in some Trees and their Fruits does convert the Ali­mental Juice into Woods, Shells, and other Bodies very Solid and ponde­rous.

But Secondly, I elsewhere shew, that ev'n in the Figures of Allom, Vitriol, Note: See the Origine of Forms and Qua­lities now publish [...]d by the Author. and other Salts, that are so curiously and Geometri­cally shap'd, there is no necessity to fly to a distinct Architectonick principle; but that those Bodies themselves may receive their shapes from the Coalition of such singly invisible Corpuscles, as by the Motion of the Fluid, wherein they did swim, and by divers assistant Circumstances, are determin'd to stick together rather in that manner than in another. That this may be apply'd also to other Bodies, I shall need to shew in this place by no other Instance than that of the Salt, that (in this or some other paper) I formerly told you I made [Page 56] of common Salt, only by the help of Oyl of Sulphur or of Vitriol and Water. For though it be manifefestly a factitious Body compounded of Salt and Sulphur, and such a Body that therein the Sea-Salt, whereof 'twas chiefly made, has had its own Nature destroy'd; yet by reason of the Figure of the resultant Corpuscles, and their fitness to convene when dissolv'd in Water, into curiously shap'd Bodies, this factitious Salt, when I have rightly prepar'd it, did sundry times shoot into long Christals with points like Diamonds, that did emulate native Christal as well in the regularness of the shape, as in the transparency of the substance. And to make it the more evident, That 'twas partly the Figure, that happen'd to result from the operation of the Oyl of Vitriol up­on the Sea-Salt, and partly other Cir­cumstances, that determin'd the shape of the Christals; I shall add, that usu­ally, when the Quality or proportion of the Oyl of Vitriol was other than it should have been, or an errour was committed in some (important) Circum­stance [Page 57] or other of the Operation, the Saline Concretions, though they did not shoot at all like Cubes, as the Sea-Salt, which they were made of, would alone have done; yet they did not shoot any thing at all like Rock-Chri­stal, as did those formerly mentioned; and for all this did, by reason of the cu­rious Shapes of the Corpuscles, they consisted of, shoot into Christals for the most part finely Figur'd; though some­times of one shape and sometimes of a­nother. And that you may not have any suspition as if the regular Figure, which Sea-Salt is naturally of, is any way necessary to such figurations, I will add an Experiment that I devis'd to shew, That even out of a petrescent Juice such curiously figur'd Bodies may be made. I took then some Stony Sti­riae, elsewhere mention'd to have been found in Caves or Grottoes where pe­trescent Liquors coagulated before they have time to fall down, and having dis­solv'd them in Spirit of Verdigrease, I put the clear Solution to evaporate in a Digestive Furnace after the ordinary [Page 58] manner; by which means, though I made the Experiment more than once, I had rather a coagulated Mass than any thing like Christals. Whereby you may learn the truth of what I was say­ing, That a Concourse of divers cir­cumstances may be requisite to deter­mine the figuration of consistent Bodies, made out of fluid ones: since here, for want of time for making occursions enough for the Particles to concrete i [...] after the most convenient manner, the Experiment succeeded not: Wherefore it being agreeable to my notions, that some sorts of Bodies may require a lon­ger time to make such a Convention in, than others, I allow'd many daies to a­nother solution of Stiriae made in the same Menstruum; after which there shot, as I desir'd, about the sides and bottom of the Glass a number of di­stinct Christals, long, transparent, and curiously shap'd, most of which, I think, I can yet shew you.

Perhaps 'twill be said, that the pe­trescent Juice, when broken, does of­tentimes appear to abound, within, [Page 59] with stiriae or narrow streaks like those of Antimony, and that I my self observe some Gems to be made up of thin flakes or plates; which internal figuration seems to be much more difficult to be accounted for without a Plastick Form, than the External.

I will not reply to this, that, for ought I know, divers known Salts would, when broken, appear to be Geometri­cally figur'd ev'n in the lesser Corpus­cles as well as they are evidently so in their entire bulk, if we had eyes quick enough to discern the Shapes of the minuter as well as of the bigger Bodies. And we have great Inducements to think, that whether or no Cartesius do rightly make the invisible particles, of which the smallest visible Grains of Sea-Salt are made up, to be long and rigid [...]ike sticks; the minute visible concre­ [...]ions, of which the bigger Grains of Salt consist, are as well as themselves of [...] Cubical figure; I will not, I say, insist on this reply, but proceed to alledge, That there are divers Bodies so luckily [...]hap'd, that upon a slow Coalition, they [Page 60] will convene into a multitude of mani­fest Concretions; some of which will consist of streaks, and others be made up of Flakes; as in the Sal-armoniack, commonly sold in the Shops (for I speak not of the native, that is said to come from Armenia,) though it be avowedly a Factitious Body, you may often observe, upon breaking the big­ger Masses, great multitudes of streaks, like those we may usually observe in the broken stiriae of petrifying Water. And I have more than once seen, and also made, artificial Concretions (of whose preparation I elsewhere speak) some of which consisted of Salts alone, and others of Salts and Minerals, as Stones or Antimony, which look very like Talk, being white Bodies, made up of a multitude of very slender strea­ky Particles lying long-wayes one upon another, as in that Mineral. And as I have taken out of Earth many Con­cretions, which as they were for the most part outwardly shap'd like Rho [...] ­bus's or Lozenges, were compos'd of a multitude of flat and extreamly thi [...] [Page 61] plates; so I have sometimes taken plea­sure to imitate such Concretions by Art. And though a Solution of Silver in purify'd Aqua Fortis does usually af­ford only a great company of small, thin and seemingly simple Flakes, like Scales of Fish, because Men have not any design like ours in procuring the Concretion; yet having dissolv'd a good quantity of the Metal together, and suffer'd it to shoot leasurely and with due Circumstances, I have obtain'd sundry Christals, which both were Geo­metrically figur'd without, and consi­sted of a multitude of exceeding thin Flakes orderly sticking to one another. And I remember, That whilst the Ob­jection, I am answering, was in my thoughts, I pitch'd upon a yet more pregnant Experiment for the clearing of it. For considering, how Tin-Glass, though a compact and ponderous Body, does naturally consist of a multitude of shining polish'd Flakes, (which may be easily perceiv'd and di­stinguish'd by breaking a Lump of it into three or four pieces;) I found by [Page 62] tryal what I expected, That though a mass of this Mineral were beaten to Powder, yet if it were melted and suffer'd to cool of it self, the disposition of the Component Particles would determine them to stick to one another in broad and shining Flakes, whereof many will be incumbent one upon ano­ther, and some cross to one another at various Angles, according as the matter happen'd in its several Portions to be diversly refrigerated. And some Factitious Bodies may afford us the like Instances, as I have observ'd in some mixtures of Copper, Iron, and other Minerals; and very conspicuously in good Regulus Martis. Stellatus, whose Internal Configuration may be found by breaking it; by which way I have observ'd with pleasure, That the Regulus abounded with flat and shining Flakes of an almost specular Polish.

If it be urg'd, to confirm the former Objection, That some Lapidescent Jui­ces, ev'n of those we mention'd in these Discourses, do concrete even whilst Men are looking on; and yet our Stony [Page 63] Stiriae, often mention'd (which proba­bly may be also hastily Coagulated) have in some places a Streaky and in other places an Angular Configuration of parts; I answer First, That I have seen divers of that kind of Concretions, which as far as the eye took notice of, were made up of parts confusedly jum­bled together. And next, That (to consider now those whose Texture is more uniform) I have found by Tryals, that, if there be a due disposition in the component Corpuscles of Bodies to such Configurations, they may be brought to concrete accordingly in a far shorter time, than almost any, that have not try'd, would expect, not to say, believe. Having sometimes for Curiosity's sake warm'd six or seven Oun­ces of Aqua Fortis, glutted with fine Silver, 'till the mixture was all brought into a transparent Liquor; and having then put the clear but strong Glass, that contain'd it, into cold Water, that the Menstruum might be the more hastily Refrigerated, I observ'd, That when once the dissolv'd Metal began to shoot, [Page 64] the Coagulation into figur'd Christals proceeded so fast, that a naked Eye could see the progress of it. And ha­ving sometimes put a quantity of Salt and Snow, or of some other strongly Refrigerating mixture, into a conveni­ent Glass, and wetted the outside with a strong Solution of Sal Armoniack or some Urinous Spirit, though in less than a Minute of an Hour it would be Coa­gulated; yet the Salt, into which it shot, had usually a curious and deter­minate Figure according to the Nature of the Liquor that afforded it; as I have often shew'n the Curious.

Perhaps you will say, that these In­stances are taken from Saline Bodies, which are for the most part dispos'd to convene in smooth Surfaces, and angu­lar Shapes, and easie enough to be wrought on by the External cold; and it may yet seem strange to Philosophers themselves, what in some Cases must have happen'd, if our Hypothesis be admitted, namely, that external Cir­cumstances and Accidents, such as the Figure of a Mold or Womb, the cold­ness [Page 65] of the Ambient, &c. should visi­bly, and sometimes not a little, diver­sify even the internal figuration of close and solid Minerals and Gems, without excluding all those that are supposed to be of a quicker Concretion.

Wherefore to clear this difficulty, it may not be a miss to subjoin an Experi­ment, that I devised to shew, that if the Corpuscles of a Body be so shap'd as to be fitted by their coalition, to constitute smooth (and if I may so speak) glossy Planes, though they be variously shuffled and discomposed as to their Pristine order, yet if they be but a little while kept in a state of flui­dity, that they may the fitlier place themselves or be placed by other Agents, they will presently be brought to con­vene into smooth and shining Planes, and the Situation of those Planes, in reference to one another, will be more Uniform and Regular, than almost any one would expect in a Concretion so hastily made; notwithstanding which, their internal contexture will be much diversified by circumstances, as parti­cularly [Page 66] the figure of the Vessel or Mold wherein the fluid Matter concretes.

Considering then, that (according to what I noted already) if we break Tinn-Glass (taken for the Bismuth of the Ancient Mineralists) as 'tis wont to be sold in Lumps in the Shops, it will discover a great many smooth and bright Planes, (larger, or lesser, according to the bigness of the Lump;) which sometimes meet, and sometimes cross one another at very differing Angles: considering this (I say) I thought it pro­bable, that a Body, that had already been melted, and was apt to convene into such Planes, not onely would do so upon another fusion, but might have the order and bigness of those Planes, diversified by the Figure and capa­city of the Vessel, I should think fit for my purpos [...]. Wherefore having bea­ten a sufficient quantity of it to powder, and, when 'twas well melted, cast it in­to a good pair of Iron-Molds, whose Cavity was an Inch in Diameter, we had a Bullet, which, being warily bro­ken, did, as we expected, seem to be, [Page 67] as it were, made up of a Multitude of little shining Planes, so shaped and plac'd, that they seem'd orderly to de­crease more and more as they were fur­ther and further removed from the Su­perficies of the Globe; And they were so rank'd, that they seem'd to consist of a multitude of these rows of Planes reaching every way, almost like so many radious's of a Sphere from the Centre or middle part, to the Circumference: Whereas if we melt Tinn-Glass in a Crucible and let it cool there, the Mat­ter being taken out and broken, will ap­pear indeed full of smooth Planes, but (as was lately intimated) very irre­gularly and confusedly associated or plac'd.

I will not now stay to enquire, whe­ther the orderly composition of the Planes in our Bullet (which some curi­ous Persons, that I shew'd it to, look'd on, as a not unpleasant sight,) may be deriv'd from this, that the Matter was coold first on the outside, by the con­tact of the cold Iron Mold, and the neighborhood of the Ambient Air, and [Page 68] that the coagulation being once thus begun, the parts of the remaining fluid, as they happen'd to pass by this already coold Matter, with a motion, which, by reason of their removal from the Fire, was now slacken'd, they were easily fastened against the already stable parts, (as may be illustrated by the concretion of dissolv'd Nitre and Allom, both a­bout the injected sticks, and the Grains that first concrete against the sides of the Vessel,) and the refrigeration still reaching further inwards, till it came last of all to the middle of the Globe, that being the remotest part from the refrigerating Agents; the apposition was successively and orderly made, till the whole Matter was concreted. But, (as I was saying) I must not now stay to inquire, whether the figuration of our Bullet may be explain'd after this or some such way: or whether we are not to take in some subtle or all pervading matter, or some other Catholique A­gent? For though such points may be well worth discussing, and we may possibly elsewhere say something of [Page 69] them; yet here it may suffice to say, that we have varied the foregoing Try­al by casting Bullets of some other Bo­dies, (and particularly the simple Re­gulus of Antimony) wherein it succee­ded well enough, though the produc'd contexture were not so Uniform as in Tinn-Glass. And I also try'd, that ha­ving cast melted Sulphur it self into a Globous Body of about five or six In­ches in Diameter, and warily broken it, though one would think it an unlikely Mineral to make any other than a con­fus'd Concretion, it presented me great Fibres almost like little strawes, whose number and (in great part) orderly si­tuation afforded me a much less unfit Instance for my present purpose than one would have lightly expected. But what I came from saying, may serve to make out what I propounded to my self; which having named already I need not here repeat.

But one thing more there is, that may be pertinent on this occasion, namely, That I have broken divers Marchasites of a peculiar sort, that were either of [Page 70] a roundish, or of an almost Cylindrical Figure, to observe their internal Stru­cture and Qualifications; whereupon, I found in more than one of them (for I remember not that I did in all) a great many rowes of little Planes or glistering Corpuscles, reaching from the inner­most parts to the External Surface, and in those that were somewhat Cylindri­cally shap'd on the outside; these ranks of Gold-colour'd particles in the seve­ral Planes of the broken Mineral, seem'd like Semi-Diameters ishuing out from a row of Physical Points, conceived to be plac'd on an imaginary Line, lying al­most like the Axis of a Cylinder be­tween the opposite ends, (though I do not well remember how near it reach'd to them:) As if the Cavities of the Chalk or Clay, wherein these Marcha­sites were found, had made the Soil like a Mold, wherein the Matter of the Mar­chasite being detained whil'st 'twas in a Fluid form, did afterwards concrete much after the manner that the Bullets of Tinn-Glass, Regulus, &c. did in our Molds. But the prosecution of this [Page 71] Conjecture belongs to another Dis­course.

I shall therefore now proceed to a further Answer to the formerly raised Objection: Wherefore as to the exqui­site uniformity of Shape, which is so admir'd in Gems, and is thought to demonstrate their being form'd by a Seminal and Geometrizing Principle; though I have, in the Second of the above mention'd Arguments, ascrib'd to them such curious Figures, as argue their having been generated after the way propos'd in our Hypothesis; and though also I willingly allow their shapes to deserve from us a delightful Wonder at the curiousness of Nature's, (or rather her Author's) Workmanship; yet upon a more attentive surveying of them, I do not find the Uniformity to be near so great as is wont to be ima­gin'd; but have rather met with such Diversities as agree well with our Hy­pothesis about their Figuration.

In several transparent Gems, it seem'd manifest enough to me, (as I lately also noted) that the Shape was, in great part, [Page 72] due to the Figure of the Womb, or Mold, wherein the matter, whilst liquid or soft, happen'd to settle. In some o­ther transparent and well figur'd Gems of the same kind or Denomination, and sometimes growing very near one ano­ther, by a diligent Inspection I found a manifest and sometimes very considera­ble Difference in their shapes, either as to the Number, or the Figures, or the bigness of the Sides or Planes that made up the respective Gems; or as to two, or all, of these; comparing these devi­ating Particulars with what would have been in a Stone of that kind or Deno­mination, that were perfectly figur'd. This I had opportunity to take notice of, particularly in two sorts of Stones; the first Granats, of which I had a consi­derable number brought me out of America growing in one Lump of Mat­ter; but in distinct parts of it, and without touching one another: Among which I took notice of a manifest dis­parity of shape, and so I did in some Affrican ones, that were presented me; as also in others that were European, one [Page 73] which, that was of an extraordinarily large size for a figur'd Gem of a transpa­rent kind, (for it weigh'd above Eleven Drachms and a half,) I consider'd with a particular attention, and found, that, though it seem'd to have been coagu­lated in a Fluid Medium, and to consist of Twelve Planes, at the concourse of two or three of which it seem'd to have been broken off from the Womb or Root; yet it was very far from the Dodecahedron of Geometricians: For, whereas that consists of Twelve aequi­lateral and aequiangled pentagons, al­most all the Planes, that made up our Granat, were quadrilateral and very different from what regularly they should have been, not only in magni­tude, but in shape: for one of them seem'd to have five Sides, and of the rest, some were most of kinn to a Rhom­bus, others to a Rhomboeides; but the most were but little better figur'd than those that the Geometricians call the Trapezia. And thus much for the first sort of Gems whose shapes I observed to be not regular. The Second consists of [Page 74] those Christalline Stones, which they call Cornish Diamonds, and which are some of them much harder than the Bristol Diamonds, or perhaps than Rock-Cristal it self; it being easie to write upon Glass with them. Of these Stones having procur'd a good number (many of which I have yet by me,) I took notice, by comparing them heedfully together, that though some of them were Geometrically and curiously shap'd like Rock-Cristal, having each six sides, whereof every two, that were opposite, were throughly like and equal enough to one another; and though the Stone had a Pyramidal termination, made up by several resembling and cu­riously figur'd Planes, that terminated in a solid Angle or Apex; yet the grea­test number, by much, of these Titular Diamonds was made up of Stones, far from being so exactly and uniformly shap'd, as those newly describ'd. For though most of them had six long Planes; yet oftentimes the opposite ones (besides that they were not so pa­rallel to one another, as they should [Page 75] have been) were unlike and exceeding unequal; and those Planes, that went to make up the Apex, though a part, they were usually angular; yet being com­par'd to one another, or to the Regular Patterns above mention'd, their Figures, their Bignesses, and their manner of concurring (which was sometimes not in a Point or Apex, but in a Line,) was so remote from being uniform, that this great diversity and irregularity agreed far better with our Hypothesis, than with its Rival. And yet in these Stones, the want of room to coagulate freely in, could not with probability be pre­tended; for they seem'd to have been form'd separately in a fluid Ambient, save at the bottom, where they were fasten'd to the Rock, as appear'd by an opacous Root, if I may so call it, which still adher'd to most of them. And, if I much misremember not, I have more than once in Diamonds, newly brought from the Indies, and some of them very fair ones, observed a great want of Uniformity in the Area's of the Superficial Planes, or in their Figures, [Page 76] or both; and sometimes too in the very number as well as Situation of their Solid Angles or Corners: about which I hope to recover some Notes And so I have done with the first part of my Answer to the above mention'd Objection; whereby it may appear, that there is no such regular and con­stant Uniformity in the Shapes of Gems, but that their Real Likeness may be reconcil'd to our Hypothesis.

But now in the Second part of my An­swer, I shall endeavour to shew, that the Figuration of Gems may not only con­sist with our Conjectures, but confirm them. For, I have more than once ta­ken notice in the Cornish Diamonds I have been mentioning, that sometimes a small Stone of the same kind, has made up, as it were, one Body with a greater; so as that the lesser Stone did not only adhere closely to the other, but was, if I may so speake, Set or Bedded in it. So that when the Separation was made, there remain'd in the greater Stone a Cavity, whose Figure did curiously an­swer that of as much of the smaller [Page 77] Stone, as chanc'd to be harbour'd there. And, as sometimes I observ'd, that there was such an adnascency, (if you will pardon the Word,) of a Lesser Stone to a much Greater; so at other times, I met with the like of a Greater to a much Lesser, with a Cavity in the Les­ser, answerable to that part of the Greater that had been lodg'd in it. Which, for ought I know, allows us with high probability to conjecture, that the Stone, to which the other grew, was first form'd and harden'd; since it re­tain'd its own shape, and that, whilst this remain'd adherent to the Rock or Soil, some more Liquor, either that came af­terwards by chance into the same Cavi­ty, or (in case 'twere there before,) that was less dispos'd to an early Concretion, began to coagulate by fastening it self against the Solid Body that was already concreted: Upon which account these two Diamonds must stick close together, and yet be but Contiguous, and a Ca­vity, such as I freshly mention'd, must be left in the last concreted Gem. Which may be illustrated by putting in­to [Page 78] a strong solution of pure Nitre, or Rock-Allom, some little sticks of Wood or any solid Body, that may be kept steadily in the same posture; for you will see many coagulations begin to be made against them, and the Cristals thus concreted will necessarily have their Figures incompleat, and have in them Cavities correspondent to those Parts of the Stick, whereto the Saline Corpuscles fasten'd themselves. To which I shall only add, that though I have given Instances of the adnascency of figur'd Stones only in Cornish Dia­monds, yet they are not the only tran­sparent Minerals, wherein I have been able to observe it. And particularly I remember, that I observed among some Minerals left by a Gold-Smith to his Widow, a Fine transparent and neatly figur'd Stone, which seem'd to be pure Cristal, but was coagulated a­bout a kind of branching Wire, where­of a good part was inclosed by the Stone, that seem'd to grow out of a piece of Ore, that look'd like Silver-Ore, and which the Woman, that was [Page 79] a curious Person, upon the strict Inqui­ry that I made, affirm'd to be, together with the above-mention'd branch, good Silver, produc'd by Nature in that form, (which I thought the more credible, be­cause of the odd and almost hairlike shape wherein I have seen Silver-Ore to have as it were grown;) which will excellently agree with the Resem­blance, I was just now proposing be­twixt the coagulation of dissolved Salts and the liquid matter of Gems, about Stable Bodies partly immers'd in those fluids.

The very many Circumstances be­longing to our First Argument, and the [...]ast answer'd Objection, have so long [...]etain'd us, that I doubt, you now think [...]t more than time I should advance to, [...]nd dispatch the Second of those Grand Considerations, whereon I at first inti­ [...]ated our Hypothesis was founded; And this is built upon the Weight of [...]ome Gems, which being greater than [...]hat which seems to belong to them [...]s hard and transparent Stones, I think [...]e may probably derive it from Metal­ [...]ine or Mineral Mixtures.

[Page 80]I question not, but as you will think this allegation new, so you will be apt to question, how I come to know the Truth of what I here deliver; since, though Gems are wont to be estimated by Lapidaries, as they weigh such or such a Number of Carrats, or of Grains, yet they compare only the weight of this and that Stone of the same kind in reference to one another, as the greater or lesser weight argues the greater or lesser Bulk, without looking after or knowing how to discover the Specifick Gravity of several Gems which depends not on the greater or lesser Bulk; as (if you know it not already) you will gather from what I am now going to relate.

Considering then with my self, that for my purpose, it was requisite to have a Gem as free as I could get from the Metalline Mixtures, that I suspected ma­ny pretious Stones to have; and re­membring, that Rock-Cristal, as it is by Mineralists reckon'd among Gems, so it is hard enough, as I try'd, both to cut Glass, and to strike fire, and that its [Page 81] having so great a transparency, and its being devoid of Colour, makes it ex­ceeding likely to be free from adven­titious mixtures; I pitch'd upon it as the Standard whereby to make a proba­ble estimate of the weight of Gems; and having Hydrostatically and with a tender Ballance examin'd the weight of it, first in the Air, and then in Water, I found its weight to be to that of Water of equal Bulk as two and almost two thirds to one: Which, by the way, shews us, how groundlessly many Learned Men, as well Ancient as Modern, make Crystal to be but Ice extraordinarily harden'd by a long and vehement Cold; whereas Ice is bulk for bulk lighter than Water, (and therefore swims upon it) and (to add that Objection against the vulgar error) Madagascar and other Countreys in the Torrid Zone abound with Crystal.

Having thus found the Ponderous­ness of Crystal in reference to Water, when I met with a colour'd Gem, whose Specifick Gravity I ghess'd to be sensi­bly greater; I sometimes gave my self [Page 82] the trouble (for a trouble 'tis) to weigh them in the Air and in the Water, and so discover, whether I conjectur'd aright. And if its Specifick Gravity did much exceed that of Cristal, I thought it a probable Argument, that there might be some Metalline or Mineral Corpuscles mingled with the stony Ones of the Gems, and that also it may probably derive its Tincture thence. I will not tell you, that I then found many sorts of transparent Stones much heavier than Cristal: For, besides that the Tryals were troublesome enough to make, I chanc'd to fall upon them in a place, where I had not any store and variety of Gems to examine. But one Instance among those that occurr'd to me, I shall here set down, because being so notable, it may suffice to shew, that, as to some Gems at least, my opinion of their ha­ving an Adventitious Gravity, and con­sequently Ingredient, is very probable. I had some American Granats, which I had a great and peculiar Reason to be­li [...]ve had been once Liquid Bodies, and therefore thought them the more wor­thy [Page 83] to be examin'd; and finding their Colour to be so deep, that they were almost opacous, and judging by my hand, that they were much heavier than pieces of Cristal of the same Bulk would be, I weigh'd them in a pair of nice Scales in the Air and in the Water, and found them, as I expected, to be almost four times as heavy as Water of the same Bulk, and consequently heavier by about a third part than pieces of Cristal, e­qualling them in bigness, would be. Whence so great an accession of pon­derousness proceeded, I shall tell you, when I come to my next Argument; to which I shall advance, as soon as I have noted, that though, when colour'd Gems have a greater Gravity than Cristal, 'tis a probable Argument, that they have some Metalline Pigment or other Mine­ral substance mingled with them; yet if such Gems have no such surplusage of weight, it will not follow that their Co­lour cannot proceed from any Mineral Tincture; since 'tis not unreasonable to conceive, that a Mineral Substance may be present in a Liquor (such as the [Page 84] Lapidescent Juice,) that we suppose Gems to be made of, even when it adds no manifest weight to the Body that harbours it; since I have observ'd (what is odd,) That a Mineral Water, which by its Tast, its Effects, and the Colour it would strike, appear'd to be richly im­pregnated with Iron, being carefully by me examin'd Hydrostatically, did appear very little, (if at all) sensibly heavier than Common Water.

The Third and last Argument, I shall now make use of, is taken from hence; That out of divers Medicinal Stones, and ev'n out of some fine Gems, real and Corporeal Metals, or other Mineral sub­stances, may be extracted.

Of this Argument I shall at present say the less, because the further prose­cution of it will be more proper in the Second Part of this Discourse, where I shall be oblig'd to handle it with refe­rence to opacous Gems, in which its force will best appear. And therefore I shall desire you to take notice, when you arrive at that Part of the subsequent Discourse, of those particulars, that [Page 85] may serve to strengthen the newly pro­pos'd Argument: And if it be ob­jected, that the Bodies, there treated of, are opacous Stones, not Gems, I have these things to answer.

First, that divers Stones, that are reckon'd amongst precious ones, are opacous too; as the Turquois, the Onyx, the Sardonix, &c. not to mention di­vers others, as Cats-Eyes, Opales, &c. which are as it were Semi-opacous. Be­sides I much question, whether Diapha­neity be absolutely necessary to the Essence, though it be to the Beauty, of those precious Stones, wherein 'tis usually found. And I might here make it probable by discourse, that transpa­rency and opacity oftentimes depend but upon the manner of the Pigmen's dispersion thorough the stony matter of the Gem, and the convenient or incon­venient situation of the pores in refe­rence to the beams of Light. But wa­ving this speculative Argument, I shall rather take notice, that several precious Stones, and even Diamonds themselves, have sometimes great clouds, which [Page 86] make them in those parts almost (if not quite) opacous, without being thereby hinder'd from being true Diamonds or Gems, of this or that kind, to which their hardness, colour, &c. makes them appertain: And not to mention Corne­lions, Agats, and some other Stones that we may observe to be (as the tinging Corpuscles happen to be in a due or an over great proportion mix'd with the petrescent matter, and to be Uni­formly or inconveniently mingled with it,) some of them transparent and some of them semi-diaphanous; I have seen worn in a Ring a Sa [...]dmix it self that was transparent, as unlikely a Gem as that is to be so. And as for Granats, though you know, that both of them are Diaphanous; yet I have had some figur'd ones, that seem'd quite opacous: and I have others by me of several Countreys, (where of one very remar­kable for its large size and Geometri­cal shape,) that are in some places Dia­phanous, but as to the main bulk of their Bodies appear at least almost as dark as ordinary Stones.

[Page 87]I further add, that I little doubt, but that experiments, not unlike those, I shall hereafter tell you, I try'd to ob­tain Mineral or Metalline substances from Load stones, native Cinaber, Blood-stones, &c. might succeed in several other of the more ponderous Gems, if it were not that the Glassy Na­ture, or exceeding compactness of many of them, makes the Mineral Corpuseles, that are harbour'd in the stony and in­soluble parts, to be inaccessible to our Common Menstruums. And when the Metalline and Mineral ingredient is very abundant, and the Tincture of the stony parts not so very close, I question not, but even from transparent Gems the adventitious Ingredient may, in part at least, be dissolv'd. And to satisfie you about this matter, I shall now inform you, that having by the ponderousness of the lately mention'd kind of Granats been induc'd to conclude them impreg­nated with somewhat Metalline, and for that reason to think it fit to try, whether I could separate it from them, or other­wise discover it in them; I kept some of [Page 88] them (in a crucible) for a competent time in the fire, and found, that they had exchang'd their Colour, for one not unlike that of unbrightned Iron; and having reduc'd them to very fine powder, and digested some acid Men­struums and particularly rectifi'd Spirit of Salt upon them, they afforded me a rich Tincture: Encourag'd by which, I hop'd, that, without their being pre­viously burnt, they would in Aqua Regis afford a Tincture, and accordingly I obtain'd from crude Granats, (only reduc'd to very fine powder) a rich So­lution, which though in colour it some­what emulated a Solution of Gold; yet partly by the Colour of the burn'd Gra­nats and partly by the Tast of this So­lution, I suppos'd, that another Metal was likelier than Gold to be the pre­dominant Mineral; and having gently evaporated part of that Menstruum, I obtain'd from some of the rest certain Cristals, whose shape, by reason of their smallness and disorderly coagulation, I could not well determin; and touching with the Tip of my little Finger the [Page 89] uncoagulated portion of the Liquor, this part of a drop, being put to a great many drops of the Infusion of Gall, did so immediately turn it into a sub­stance that seem'd full as black, if not blacker than Ink, as you would, I think, have been somewhat surpriz'd to behold.

Which tryal I made to examin the conjectures I had, that one Mineral (for perhaps 'twas not the only, that help'd to constitute these Granats, was of a Martial nature; which, if it were, I suppos'd it would, like other Bodies that participate of Iron, afford with Galls an Inky colour. I tryed also with a parcel of small and red transpa­rent Stones, which some ghessed to be Granats; others, more probably, Ru­bies, that being finely powder'd, they would in an appropriated Menstruum, (made extraordinary strong) give a Co­lour like that of dissolv'd Gold. And that there were really some parts of the Gem dissolved in the Menstruum, ap­pear'd not only by the above mentioned colour, but by these two indications: The one, that having put some of this [Page 90] Liquor to some of the same solution of Galls, I just now spoke of, it produced indeed, at the very first, a dark Colour, but not neer so black as that of the Granats, and in a trice let fall a copious precipitate that was almost white: The other, that I was able to precipitate from it, by an urinous Spirit, a reddish substance, which being suffer'd to dry in Air, seem'd to grow into Bodies, in shape not unlike Moss, and here and there small Mushrons, all of them pret­tily colour'd. And from certain Granats that were in some places opacous, as well as in others Diaphanous, I obtain'd a Solution from whence the superfluous Liquor being abstracted, the residue, which was deeply coloured, did in the cold afford me a kind of saline concre­tions, which yet were not large enough to inable one to determin their Fi­gures.

And on this occasion I hold it not un­fit to intimate, that perhaps, if Men had curiosity enough to make tryals, there would be other transparent Minerals found capable of being wrought on by [Page 91] appropriated Menstruums. For, I do not think, that every seemingly glassy contexture of a Mineral makes it unsit to be wrought on: For though the clear Spar, which in most of our Western Lead-Mines in England is sound next to the Metalline Veins, be at least Semi­diaphanous, and be of so glassy a contex­ture, that it usually breaks into smooth and glossy Superficies, and looks like a Talk, and also for the most part is made up of and presently reducible into Geo­metrically figur'd Bodies, shap'd like Rhombus's or Rhomboides; yet some other Tryals, that I have made with this Spar inducing me to suspect, that 'twas not indeed a Talk, but a Body of a much more open Texture, I found, I could dissolve it in several Liquors, and particularly in good Spirit of Salt, which would presently work upon it, even whil'st it was in Lumps, and that without the assistance of Heat; which Observation may perhaps give some incouragement to such a curiosity as yours.

But by what I have said of the use­fulness [Page 92] of Menstruums, I would not have you think, that they are the only Instruments, wherewith something Me­talline may be obatin'd from some Gems: For in an other Paper of mine (to which such tryals more properly belong) you may find an account of some attempts of that kind by fusions and appropria­ted additaments. And however such Tryals may succeed with you that aim at separating from a Gem a Metalline or Mineral Body of a determinate Spe­cies; I can teach you an easie way, where­by I have (by the help of fusion) more than once manifested in the General, that there may be substances, partaking of a Metalline nature, in some kinds e­ven of transparent Gems. And partly by the same way, and partly by some others, I have been able to determin probably enough, in some cases, that the Mineral substance is predominant in it.

And here, before I dismiss the first part of our Essay, I think I may possibly somewhat illustrate our Hypothesis, if I briefly mention to you an experiment, [Page 93] I remember I once made to that pur­pose. And it was this: I reduc'd to powder some of those Stiriae, that I have often spoken of, of water petrified, as it were, spontaneously: I also consi­der'd with my self, that I had found Spirit of Verdigreas, (which I make without the tedious preparations, that Bafilius and others prescribe, by barely distilling without additaments good French Verdigreas, and rectifying the ob­tained liquor) I had, (I say) found this Menstruum to be not only (as I else­where observe) a good solvent for many Bodies, but also to be distillable from many of them, without leaving near so much of it self behind, as other Saline Solvents are wont to do: Consi­dering this, I say, I dissolved the stony stiriae in this Liquor, and having suffer'd some of it to evaporate away, and put the rest into a cool place, I obtained, as I expected, store of small but finely figur'd and transparent Cristals, that shot much after the fashion of those of the purer sort of Nitre. With some part also of the stony solution I mixed, in a conve­nient [Page 94] proportion, a high colour'd solu­tion of Copper, made likewise in Spirit of Verdigreas; and these two solutions being made with the same Menstruum, and warily enough put together, did not precipitate one another, but affor­ded me, upon the evaporation of the superfluous moisture, among divers Cristals that were transparent and co­lourless, some that were richly adorned with a greenish blew Tincture of the dissolved Metal. What tryals I made by this way, little varied, to imitate nature by associating into transparent Bodies stony and metalline Substances, I cannot now give you a full account of; since I neither have by me the Notes, I set down about those tryals, nor think it fit to make this first part of our Dis­course more prolix, than I now perceive it to be already.

SECT. II. Containing a Conjecture about the Causes of the Virtues of GEMS.

WHat has been hitherto deli­ver'd in the first part of our Discourse, will, I suppose, make it allowable for me to be more succinct in the Second. I shall now therefore proceed to those other considerations, which, being assisted by what has been already said, may, I hope, suffice, to keep our conjecture about the Cause of the Virtues of Gems from seeming unreasonable.

And my first Observation shall be, that not only there is in the Earth a great number and variety of Minerals, alrea­dy [Page 96] known by particular Names; but probably there are very many others that are not yet known to us.

The former part of this proposition will not be doubted by those, that con­sider, how great a multitude of Metal­line Ores, Marchasites of several sorts, Antimonies, Tinn'd-glass, Fluores, Talks of various Kinds, Spars, Sul­phurs, Salts, Bitumens, &c. are men­tion'd partly by Chymists, and other Mineralists, and partly by those that have given us accounts of Musaeums and other collections of natural Rarities; insomuch that of only one Kind of Fossils, the diligence of some modern Writers hath reckoned up between two hundred and two hundred and fifty; besides Animal Stones, as Lapis Bezoar, Lapis Manati, Oculus Cancri, Lapis Por­cinus, &c.

And as for the Second Part of our proposition or observation, you will scarce deny it, though you consider with me but these two things.

The first is the small and inconsidera­ble proportion, that the perpendicular [Page 97] depth, that the generality of Mines bears, to the Semidiameter of the Earth, reckon'd to be above 3500 Miles; so that, though our Globe were inha­bited by some hundreds of millions of men more than now it is, and they had curiosity enough to dig Mines every where, and consequently there were Millions of inquisitive and laborious men more than really there are, their Spades and Pickaxes would, except here and there, penetrate so little a way into the Earth, that a vast multitude of Fossils might, by lying deeper in the bowels of it, continue undiscover'd.

And to this First Observation I shall subjoin this Second, that, as far as I have observed, almost every Region affords Minerals of its own, differing from those that are taken notice of in other Regions. And in particular Countryes, as in some Shires of England, a curious and heedful Eye may, I doubt not, observe several that are not taken notice of by the inhabitants themselves, especially if well-made borers were diligently and skilfully imploy'd to [Page 102] pierce the ground, and bring up Sim­ples of divers Fossils that lye hidden under it. But having elsewhere dis­coursed of this matter, I shall here only tell you, in general, that in some parts of England, where I had more oppor­tunity than in others, to exercise some Curiosity about Minerals, I met some­times in a small compass of ground, with a much greater variety than I ex­pected, and several of them undescrib'd, that I know of, by any Writer; of which sort I have received divers others from several parts both of the old world and the new.

In the next place I consider, that Na­ture has furnished the Earth with Men­struums and others Liquors of several sorts, and indowed it with divers quali­ties. This I have already manifested in the discourse of subterraneal Men­struums, whereto I shall therefore refer you; only taking notice in this place, that whereas water is abundantly to be met wi [...]h under ground, and for the most part very copiously in Mines, by which it is capable to be variously im­pregnated; [Page 103] this liquor it self, especially being thus alter'd, may in some cases act the part of no despicable M [...]nstruum, and on some occasions otherwise con­cur to the production of Mineral Bo­dies.

I further observe, that the subterrane­al Liquors, upon one account or other, (for we need not now particularly de­termin it) are qualified to work either as Corrosive Menstruums, or as other Solvents, upon many of the Medicinal Earths and other Minerals they meet with under ground: which Minerals, having never been exposed to our sires, have their Texture more open, and their parts more soluble than those, that have been melted by the violent heats of our furnaces.

And that even Common water will suffice to dissolve, and impregnate it self both with the Saline and oftentimes with Metalline parts, that it meets with in its passage, is obvious enough in the differing tasts and other qualities of liquors, that all pass for common water, whereof some is found better and some [Page 100] worse than others, to Brue, some to wash Linnen, some to Dye Scarlet, or other determinate Colours; some to temper Steel, and some for other uses.

But others unquestionably more emi­nent instances, are given us by the Mi­neral Springs, whether Thermae or Aci­dul [...], as Authors distinguish those that are actually hot, (as at Bath) and those that are Saline and for the most part sowrish (like those at Tunbridge and the [...]ork-shire Spaw;) of which two sorts good store are enumerated by Physiti­ans and Geographers; and of which a far greater number would be disco­ver'd, if men wanted neither skill nor diligence. And here I shall desire you to take notice, that, though common water do the most readily dissolve the Salts more properly so called, though not altogether pure, it meets with in the bowels of the Earth, as we see it happens in those Salt-Springs that come not from the Sea; yet there are also many others subterraneal Bodies, which upon the score of their abounding with Saline particles, will be dissolved by [Page 101] water, though they be of a compoun­ded nature, and contain very differing substances; as 'tis plain in those waters of Hungary and other Regions, which by the evaporation of their super­fluous moisture, will yield Vitriol, a Mineral not only compounded but decompounded, as containing in it a Saline, a Sulphureous, a Metaline and an Earthly part, (which it self I have found to be none of the simplest Bo­dies;) every one of which may be made distinctly to appear.

Lastly, I consider, that the Petrifie Juice or Spirit coming to be in a suffi­cient proportion mingled with these im­pregnated waters, so as to coagulate them, and concoagulate with them; from their coalition may result those precious Stones that we call transparent Gems. For 'tis certain, that Bodies, that were a while before in the form of waters, may coagulate into stony stiriae, of whose odorousness and reducible­ness into lime, I have already given an account in my discourses of Lapides­cent Juices; of which you may com­mand [Page 98] a sight. And that even Diamonds themselves, the hardest of Gems, were once fluid substances, the first part of thi [...] Discourse has, I hope, evinced.

To which I shall now add, that pro­cu [...]ing some petrified Bodies to be brought me from a place in England, which I could not be admitted to, I found, that the Petrific Juice or Spirit, that abounded in the Earth of that spot of ground, was so penetrating, and so operative, that it made some of the vegetable substances, that were found in it, in their pristine shape, and, for ought I could perceive, bigness, hard enough to cut Glass as well as grave▪ on I [...]on. And 'twas among these rarities (if I much mis-remember not) that I pick'd up a (moderately) transparent Body (which I think I have yet by me) that, by the shape and other Circum­stances I judg'd to have been a diapha­nous Gum, belonging to one of the pie­ces of petrified wood, that had been brought me, and was hardened to a de­gree that made it capable of scratching Glass.

[Page 99]And now to bring home these things to my present subject, I conceive, that some (at least,) of the Real Virtues of divers Gems may be derived from this, That whilst they were in a fluid form, (or at least not yet Hard'ned,) the Pe­trescent substance was mingled with some mineral solution or tincture, or with some other impregnated liquor, and that these were afterwards Concoa­gulated, or united and hardened, into one Gem, as a Diamond, a Saphir, a Granat, an Onyx, a Blood-stone, &c. And as divers of the Virtues of Gems may be in a general way deduc'd from the commixture of these Mineral Corpu­scles; so the greatness of those Virtues and the variety of those properties in particular, may be ascribed to the pe­culiar nature of the impregnating li­quors, to the diversity of them, and to the greater and lesser proportions, wherein they are mixt with the Petres­cent juice.

To render this conjecture (for I pro­pose it as no other,) thus summarily and briefly express'd, the more probable; [Page 104] 'twill be fit to recall to mind the Argu­ments, whereby we have already shewn, both that Gems were once fluid or soft Bodies, and that divers of them were not simple concretions of a Petrescent liquor, but consisted also of other Mi­neral adventitious Corpuscles: Which may appear, partly by the separableness of such substances from some Gems; (as we exemplified in Granats) partly by the specific gravity of others, and partly by the differing tinctures (where­of one at least may well be supposed adventitious,) to be met with in Gems of the same species, as Rubies, Saphirs, Granats and even (the hardest stones, that we yet know of,) Dia­monds themselves; of which (as is be­fore noted) I have seen some Yellow (and that to a great degree,) some of other colours, but not so vivid, and some Green, almost like Emeraulds.

Now since there may be in Gems, and in some of them abundantly such adven­titious Corpuscles; and since there is cause to think, that some may be indow­ed with divers properties and Medical [Page 105] Virtues; since also there is a great dif­ference among these impregnating par­ticles and probably of a greater va­riety of them, than is known to us; since lastly divers Gems are not sparingly but richly impregnated with these innobling Corpuscles, I see no sufficient reason, why some of the Virtues of divers Gems are not more likely to proceed thence, than from those unintelligible and pre­carious substantial Forms, to which they are wont to be referr'd.

But because there are some difficul­ties, that the objections of others or my own thoughts have suggested against our Hypothesis; though I neither have time, nor do think it very necessary, to discourse amply of them: Yet to clear the way for what I am afterwards to re­present, I shall (though I can but briefly do it) say something to each, that may perhaps appear no insufficient answer; especially after I have declared, as I here do once for all, that I speak of the True and Medical Virtues that belong to Gems; and that, as to those Magical and other Extravagant properties, that [Page 110] either notoriously fabulous, or other credulous Writers have made bold to deliver, I am so far from pretending to afford them an Explication, that I do not allow them the least degree of Assent.

This premis'd, let us consider the chief difficulties themselves; among which I doubt not but it will be object­ed, That it is not credible, that the Mi­neral Substances, wherewith our Hypothe­sis would have Gems to be impregnated, should have any Medical operation at all on the human body, in regard that they are so lock'd up that they can commu­nicate nothing to it, especially being indigestable and unconquerable by so small a heat as that of the Stomach and other parts of the Body.

But to this specious Objection I have several things to return by way of An­swer. And first of all; had there yet never been any actual Tryal made, whereby to know, whether a Gem be capable of having any Medical Virtues, I confess I should find probability e­nough in the Objection to suspend my [Page 111] Judgement, till experience should de­termine the Question. But since upon the very credible Testimony of eminent Physitians and Patients themselves of my own acquaintance, I find much less cause to disbelieve, than to assent to some matters of Fact about the opera­tions of Gems; and since such matters of Fact do strongly argue in the gene­ral, that a Precious Stone may have Medical Virtues; I think, the Obje­ction, as 'tis propos'd in general, is suf­ficiently enervated by such particular instances, and ought not to keep us from believing upon Experience the possibility of the thing denyed; espe­cially since there are other things be­sides, that may be alledg'd in favour of our Hypothesis.

For it may be consider'd in the next place, that vigorous Load-stones emit copious and very plentiful Effluvia; and yet, besides that ordinary Magnets are usually a very hard sort of Stones, I have met with some Load-stones much harder than ordinary ones, and possibly than divers Gems. And 'tis [Page 108] farther considerable, that there are Load-stones, (some of which I can shew you,) which do not only work upon Iron and other Magnetical Bodies, but have a manifest and inconvenient ope­ration upon Human Bodies, by being worn in mens Pockets or long held in their Hands; as those, that have resent­ed such operations themselves, and ob­served them in others, have complain'd to me; which I might confirm by some analogous observations, if I had time to relate them.

But now I proceed to observe, that among transparent Pebles, some of which, you know, are by being barely well Cut and Set, made to counterfeit Diamonds, I have found several, that may be brought in a trice to emit co­pious and even strongly sented streams. And if you allow the opinion of the ge­nerality of Modern Philosophers, who ascribe Electrical attractions to the [...] ­ [...]a of bodies excited by rubbing, you will, I presume, allow me to infer, that very light alterations may suffice to pro­cure Expirations even from transparent [Page 109] Gems: Many of which are Electrical, and so are the hardest of them, Dia­monds themselves; one of which I keep by me, that upon a little friction at­tracts, vigorously enough to be won­der'd at by the Spectators.

And as to that part of the Objection I am answering, which contends, that Gems are not to be digested or con­quered by the heat of the Stomach; I will not stay to examine, whether and how far the digestion of things in the Stomach be to be ascribed to Heat, con­tenting my self to say at present, that, to make the Objection valid, it should be first proved, that such Bodies can­not have any operation upon the human body as pass thorough it, without any sensible change of bulk, figure, &c. as Gems that are swallowed down are supposed to do. For, we know, that some Chymists make Bullets of the Re­gulus of Antimony (which we also have made, and observ'd something odd a­bout them) which they call Pisulae per­petuae, because when they have per­formed their operation in the Body; [Page 107] and have been ejected with the Excre­ments, they are by some more thrifty than cleanly persons, washed and em­ploy'd again and again to the former purposes. Nor do we know, what A­nalogie there may be between some Juices in the Body, and some of the Mi­neral substances that impregnate Gem [...] with their Virtues.

For, though the Oculus mundi be reckon'd by Classic Authors among the rare Gems, (as indeed good ones may be justly accounted Rarities;) yet i [...] one of the best sort be but a while kept in common Water, it will, as Experience assures me, receive an alteration obvi­ous to the Eye. I might here alledge the concurrent Authority of many, and the common Practice of most Physiti­ans, who in their publick Dispensatorie [...] as well as private Prescriptions, ordai [...] the Fragments of precious Stones to b [...] taken inwardly, upon the score of the Cordial and other Virtues they ascrib [...] to them. But I shall rather make u [...] of less question'd Arguments, and with­out insisting on the manifest operation [Page 106] that the Juices of the Body have not only on the Chalibeat preparations, where the Metal is presum'd to be o­pen'd, but upon crude Steel it self; or urging the Examples of Lazarus Vitri-V [...]rax, or the devourers of Stones, as be­ing rare [...]; I shall proceed to acquaint you, that with a faint Liquor, distill'd from a Vegetable substance, as temperately qualified and as plentifully eaten as Bread, I have obtain'd, and that without Heat, from divers hard Bodies, and amongst them from a tran­sparent sort of Gems, a manifest Tin­cture. And whether some Juices of the Body, assisted by the Natural Heat of it, may not, in reference to some Gems, serve for extracting Menstruums, though it may well be, more then either I or the Objectors certainly know, yet the Instance, I come from alledging, fa­vours our Hypothesis more than theirs.

And even the Natural Heat of a hu­man Stomach, nay perhaps the outward parts of the Body, may be able, though not to digest precious Stones, yet to soli­cite out some of their Virtues; since I [Page 112] am sure it makes a sensible alteration in the hardest sort of them. For I have a Diamond, whose Electrical faculty may be excited not only by rubbing, but, without it, by a languid degree of ad­ventitious heat. And I have had in my keeping a Diamond, which by Water, made a little more than Luke-warm, I could bring to shine in the dark.

Object. If it be further alledged, that, though some Virtues may be conceded to Gems upon the account of the Mi­nerals that impregnate them, yet it will be no way likely, that their Virtues should be so Various and Great, as even the modester sort of Authors pretend. If this, I say, be alledged, I shall readily acknowledge, that I do not think others or my self obliged to believe all the strange things, that even some Learned Writers do sometimes ascribe to Gems: And if any man will think, that some of them are fabulous, and more of them Hyperbolical, he may sooner find me his Associate than his Adversary in that point. For the Rarity of transparent Gems, their Lustre, and the great Value, [Page 113] which their Scarceness and mens Folly sets upon them, imboldens some to say, and inclines others to believe, that such rare and noble Productions of Nature must be endowed with proportionable, and consequently with extraordinary Qualities.

But this being freely granted, I an­swer to the Objection; First, that 'tis not improbable, that there may be in the Earth a much greater Variety of Minerals dissoluble by the subterraneal Menstruums, and capable of concoagu­lation with Petrescent Juices, then Au­thors have yet taken notice of: To which conjecture divers subterraneal productions, that I have met with, doe strongly incline me. And from the number and various mixtures of these may proceed not only a great Variety of operative particles in precious Stones, but a high degree of Energy in some of them.

And next I consider, that the Effi­cacy of those Mineral Tinctures or So­lutions, that are already known to us and may be concoagulated with the [Page 114] Petrescent Juice, may be reasonably presum'd to be much greater in some Gems, whereof they became Ingredi­ents, whil'st they were (as Chymists speak) in solutis principiis, than may be expected in our Shops or Laborato­ries from the vulgar Solutions of the same Metals or Minerals, after they have by vehement Fires been reduced into Gold or Silver, or Lead, or Antimony, &c. For, whereas in these vehement Fusions, requisite to bring Metalline or other Ores into such substances, the vo­latile and spirituous parts are wont to be driven away, and the remaining Body becomes more hard and compact, and has his Virtues as it were locked up: In the state of Fluidity those subtle and efficacious parts are preserved, and uni­ted to the other Ingredients of the Gems, whence some Emanations of them may be easily enough drawn out: As in the instance I not long since mentioned, of the easie eduction of strongly sented Steams from Pibbles so hard, that I found them more disposed to strik [...] Fire, than Flints themselves, that are [Page 115] used in Guns. And from the greater or less plenty, and natural activity of the impregnating particles in this or that Gem, may problably be deduced the difference in Colour of some, and in Virtue of other Stones of the same de­nomination: Of which we have in a Learned Writer or two, emi­nent Examples given us, Note: See Ʋnzerus de N [...]phritide. of the great Virtue of some, and the inefficacy of other, that Expe­rience has discovered, among those Stones that go under the Title of Lapis Nephriticus. For, though they be not properly transparent Gems, yet the A­nalogy betwixt them and those that are, seems sufficient to warrant the mention­ing of them on this occasion.

And here we may subjoin two things, in favour of both the foregoing answers: the First, that for ought we know, the Petrescent Juices themselves may have all that is requisite to make them such, and yet have distinct Natures, and be in­dowed with peculiar qualities, abstract­ing from those which they acquire upon the score of their coalitions with adven­titious [Page 116] Liquors. This I cannot stay to make probable by the differences I have observed in Petrescent fluids, and there­fore I hasten to the Second.

The next thing which I would repre­sent, is, that having observed Petrific Liquors or Spirits to pervade and give a high degree of hardness to bodies, that chanced to lie within their reach, though one would have thought them sufficient­ly indispos'd to receive such an indura­tion; I see no absurdity in supposing, that sometimes such a Liquor may in­vade, permeate and subdue transparent Minerals, abounding in Saline, Sulphu­reous, and Bituminous particles; which consequently being duly excited, may be made to emit their more subtle and more active parts. And as I have cause to think, that subterraneal Fires and Menstruums do divers times make va­rious compositions and decompositions in the Earth, (as 'twere not hard for me to shew, if I had leisure;) so 'tis not impossible, but that the Spirit, we have been speaking of, supervening, may mingle it self with such Bodies and pe­trifie [Page 117] them together with it self into Gems. On which occasion, I remember, that I have had Salt, made by nature in the bowels of the Earth, just like that which Chymists compound by Art on the surface of it. And I have some­times made by an easie operation and a moderate degree of Fire a certain com­position of volatile particles of Salt and Sulphurs (some of which I have yet by me) which after distillation did in a fluid Medium shoot into Crystals transpa­rent, and more curiously figured than I have seen divers natural Gems to be. So that, if either beneath or upon the surface of the Earth, such kind of sub­stance happen to be pervaded and sub­dued, by a clear petrifying Liquor; we may well presume that the resulting concretions may be indued with Qua­lities, as well uncommon for the Kind, as considerable for the degree.

Objection. If it be yet objected, that it is very unlikely, that Gems should part with any Eflluvia or portions of themselves, since they lose not of their weight, and some of them are very [Page 118] little heavier than Crystal it self, and consequently are not like to have much adventitious substance to part with: I might leave the answering of one part of the Objection to Physitians and Chy­mists, who teach, that the Antimonial Glass and Cup imbue Wine and other Liquors with a strong emetic quality without any sensible loss of weight. But having elsewhere spoken of those things; I shall rather here demand, whether the Objectors have tryed the truth of what their Argument supposes by any way sufficiently accurate? For I much doubt, that that has neither been attempted, nor would be found easie to be performed. And till due tryal be made, let me represent, that though they will not allow common Water to be a Menstruum fit to draw any thing with from such a Body as Mercury, which is wont to mock the Chymists Aqua Fortis and Aqua Regis; yet both Helmont and others inform us, that Mercury kept for a day or two in common Water, or boiled a while in it, though it be taken out without any [Page 119] sensible diminution of weight or bulk, will have imbued a considerable quan­tity of Water with a Virtue of killing Worms; for which purpose 'tis much used, and often with good success in a great Hospital in London, as the Chief Physitian of it (a very judicious and experienced man,) has more than once informed me.

And as for the lightness, that is object­ed against some Gems, besides that it may safely be granted, that caeteris pa­ribus such may have fewer or more lan­guid Virtues than others of the same kind; it may also be answered, that the adventitious substance that impregnates the Petrescent Juice, may be of so small specific gravity, as not to make the Gem at all heavier in specie than Crystal it self. For this, (as we have formerly observed,) being about two times and a half heavier than common Water of the same bulk, I have hydrostatically found, that divers Salts and some other Mineral substances are of less specific gravity; and consequently, if they were concoagulated with the Petrescent [Page 120] Juice that hardens into Crystal, need not increase the ponderousness of it, and yet may imbue it with considerable Vertues: Nor is it necessary (to add that in transitu on this occasion) that, not to alter even the colourlesness of Crystal or the colour of another Gem, the adventitious substance should be purely Saline: For I have divers times made Bodies, which, though transpa­rent and colourless like Crystal, and sometimes curiously and regularly fi­gur'd, were yet of a compounded Na­ture, and particularly abounded with an easily separable and strongly sented Sulphur. But to give yet a farther and more direct answer to the Objection; I shall add, that though, when a Gem has much more specific gravity then Cry­stal, or will suffer an adventitious Mi­neral to be separated from it, 'tis a very probable Argument, that the Petrescent Juice is that Body compounded with an adventitious substance; yet it will not necessarily follow, that, when neither of these Signes appear, the Gem is quite devoid of any such substance. For, [Page 121] (according to what I elsewhere de­clare,) the Petrescent Liquor, it mainly consists of, may be impregnated not with the grosser substance, but with the finer and more spirituous part of the Mi­neral, without having the specific gravity sensibly increas'd. Of which I remem­ber I shew'd a notable Instance to some curious persons, at a Mineral Spring, which many were then drinking of by the Advise of Learned Physitians for several Diseases. For though this Wa­ter both by it's Inky taste, by it's black­ing the Excrements of those that drank it, and by other Signs appear'd to par­ticipate richly enough of Iron; yet the ferruginous particles, it abounded with, were so light and spirituous, that not only they would, as I tryed, be easily lost, if the Liquor were kept too negli­gently stopt; but when I came whilst the Spirits were yet there, (it being but newly taken from the Spring it self) to examine it hydrostatically with very good Scales and much diligence, I con­vinc'd the Virtuosi that assisted, that this ferruginous Water was very little, if at [Page 122] all, heavier in specie than other Water, which was brought as common Water to be compared with it, and examin'd with the same Scales and after the same manner.

And now, if you recall to mind what I have elsewhere said partly of the Atmosphers of solid Bodies, and partly of the great Efficacy of Effluviums; I hope, you will not think it absurd to conjecture, both that some precious Stones may have Medical Virtues, and that divers of these may be ascribed to the Mineral substances, whereof they participate or consist; and especially to those, which are best fitted to exert their powers by the copious Effluxions of their more agile and subtle parts.

And by this time it may be seasonable to tell you, that though, what I have hitherto discours'd do chiefly belong to transparent Gems; yet divers of the things already deliver'd may, with no great alteration, be applied to opacous Gems: of which I shall speak much more briefly, not only for the reason just now given, but because, if we have [Page 123] shewn (as I hope we have) that even Diaphanous Gems may be indowed with Virtues by the Mineral substances they contain or are in part made up of; the Arguments will hold more strongly as to opacous Gems: both because these are for the most part much less hard than the others, and because 'tis far more easie to shew by their specific gravity, and the compoundedness of divers of them, that the dark ones, than 'tis that the clear ones, may partly, and sometimes plentifully, consist of Mineral substances, imbodyed with, and hard­ned by Petrescent Juices or Petrific Spirits.

In favour of this Doctrine, I shall endeavour in the first place to shew, that what has been deliver'd is possible; and afterwards set down some particulars to make it very probable.

The first part of my Task might be easily performed, or perhaps would be needless, if I were sure, you had no need to be told of any thing I have written about Lapidescent Juices. But for greater security I shall in this place [Page 124] briefly intimate, that among the Kinds of those Liquors, I have observed a sort that is of so fine a substance, and yet of so Petrifying a Virtue, that it will pe­netrate and petrifie Bodies of very dif­fering Kindes, and yet scarce, if at all, visibly increase their bulk, or change their shape or colour. To which pur­pose, I remember, that I have seen di­vers Animal and Vegetable substances so petrified, as scarce at all to be ta­ken notice of, by their appearance, to have been alter'd by the operation of the Petrescent Liquor. I have with pleasure seen a thin Cream-Cheese turn'd into Stone, where the Size, Shape, and Colour even of the Wrinkles, and the blewish Mold (which it seems it began to have when the Liquor invaded it) were so well preserv'd, that an hungry man would not have scrupled to have fallen upon it for a good Bit. And as for the hardness, that this Petrescent Juice can give to the Body that it pene­trates, I shall now only remind you of what I lately told you: That I have had, (and I think yet have in another place) [Page 125] a pretty quantity of Wood petrified in England, which retaining its former figure, and grain, and scarce at all vi­sibly increas'd in bulk, was so very hard, that I could make Impressions with it upon Iron, and Glass it self, and make it strike Fire like an excellent Flint. To which I shall here add, that the stony parts did not suffer the Wood, which they had penetrated, to be reduced in the Fire, either to Ashes or Charcoal. And I have by me a lump of Mineral Substances, wherein a Petrescent Li­quor, that fills the large intervalls be­tween them, is transparent enough, and harder than most Stones, as far as we could guess by some tryal of it made by a skilful Ingraver of Gems.

And to these instances might be ad­ded many others, if it did not by these few sufficiently appear, that Petrifick Agents may insinuate themselves into the pores of various Bodies, and turn them into Stone, without otherwise destroying their pristine Nature, or so much as their former Figure.

Wherefore having in general shewn [Page 126] our Hypothesis to be possible, we may now descend to four or five particular Arguments, that 'tis hoped may help to render it very probable. And these I shall fetch partly from the great specific gravity of divers opacous and medici­nal Stones; partly from the fitness of our Hypothesis to render a reason of di­vers Phaenomena relating thereunto, some of them scarce at all, and others much less probably to be accounted for without it; partly from the Metalline substances to be manifestly separated or obtained from the Stones we are treat­ing of; and partly from the Nature of the Bodies whereof Medicinal Stones seem to be compounded.

Arg. I. That the specific gravity of divers opacous Stones, whereunto Me­dicinal properties are ascribed, is very considerable, is a Truth, which, if those that have writ ten of such concretions had been vers'd in Hydrostaticks, & had had the curiosity to examine them that way, they might have easily discover'd; as will quickly appear by particular Examples: Before the mention where­of, [Page 127] of, it will be fit for me take notice to you, that considering with my self that white Marble is generally allowed to be a pure and solid Stone, and upon the score of its whiteness is likelier than most others to be free from Mineral mixtures, I thought, I might at least as well pitch upon that as on any other for the standard of the specifick gravity of opacous Stones, as they are meerly such. And accordingly having weigh'd a piece of white Marble in Air and Water, I found it to be in weight to an equal bulk of that Liquor very near 2 12/100 to I, or, (that the proportion with very little errour may be the better re­membred,) as two and seven tenths to one. And to make trial in a Stone un­coloured, but, because harder, suppos'd to be of a closer Texture, we examin'd a fine white Pible, which we found to be to an equal magnitude of Water as two and above six Tenths to one. This being determin'd, 'twas not difficult for me to think, both that divers Bodies, that commonly past for meer Stones, are more ponderous than white Marble of [Page 128] the same bulk; and that, if there were any such great surplusage of specific weight, as I ghest, many will be found to have above that of Marble, it might proceed from some Metalline Body, though not visibly, yet really, and per­haps plentifully mingled with the Pe­trescent matter of these Stones. The later part of this Conjecture will here­after be confirm'd in the third Argu­ment; which makes it unnecessary for me to give you now of the former more than a few instances: which I shall soon dispatch by telling you, that I quickly found by weighing the following Mi­nerals, first in the Air and then in the Water, that a Blood-stone (bought at the Druggist) was in weight to Water of the same bulk as 5 7/10 to 1; The Load­stone, I then tried, (for all are not e­equally heavy in specie) as 4 and 6ths / 10, to 1; L [...]pis Calaminaris, us'd for Rheums in the Eyes, and to turn Cop­per into Brass, as 4 7/16 to one; Lapis Tutiae, as they call it, which is also much imploy'd in Rheumatick Eyes, as very near 5 to 1.

[Page 129]But here I must advertise you, that I have not found the proportion of each of these bodies and water to be any thing near constantly the same, but sometimes to differ very much in par­ticular Stones of the same kind; which agrees very well with our Hypothesis. For, according to that, those particular Stones, that happen to partake more plentifully of Mineral substances hea­vier in specie than Stone as such needs to be, ought to be more ponderous than others of the same kind that are not so qualified: I said, heavier in specie than a Stone, as such need to be, because there are substances that are reckon'd among Minerals, and are ca­pable of endowing the stony matter, wherewith they are coagulated, with Medical Virtues, and yet those substan­ces may make the Stone or aggregate, whereof they are made, not to be heavier but lighter in specie. From Jet, which in some parts of Europe being found in Quarries of Mines is indeed a fossile, which is wont to be reckon'd among Stones, and by many worn as [Page 130] a Gem; I obtain'd no inconsiderable proportion of oil: and having weigh'd choice Jet it self in water, I found it to be bulk for bulk to that Liquor but as 1 22/10 [...] to 1. And there are some other fossils, hard as Stone and pollishable as Marble, from which I have by distil­lation obtain'd two kinds of Oil, where­of one was lighter than common water; which shews, that even bituminous and light substances may be ingredients of a Stone: And that Salts, which are most of them less heavy in specie than white Marble, may plentifully concurr to the making up of Stones; I shall have oc­casion to manifest at the close of this Discourse by those Stones, whereof we in England use to make Vitriol. The foregoing Reflection I have here touched upon, because I would inti­mate to you, that Stones that are light­e [...] in specie than white Marble may be compounded of fossils whence they may derive peculiar Qualities, at the same time when I tell you that in my opinion such Stones as are considerably more heavy in specie than Marble may [Page 131] afford us a strong presumption of their owing their gravity to the mixture of Metalline or Mineral substances. And this may suffice for our first Argument.

Arg. II. The next shall be taken from the consideration of some Phaeno­mena, (relating to Medicinal Stones) which agree very well with our Hypo­thesis, and will scarcely be very well explicated without it.

And 1. As to Transparent Gems themselves, I have learn'd by inquiry of Travellers, that have visited those parts of the East Indies, where they grow, that sometimes one sort of Gems, sometimes another, and sometimes also Diamonds themselves are found inclu­ded in the Rocks where they are digg'd for, or in the midst of hard loose Stones, which must be broken in pieces, to take out the Diamond or other in­closed Gem: Which Phaenomenon will be hard to be accounted for, unless by our Hypothesis; according to which it may rationally be supposed, that the Gem was first formed either in Earth or some other soft and easily permeable [Page 132] substance, which being afterwards per­vaded by some Petrific juice or Spirit, was turn'd into Rock or loose Stones, ac­cording as the Earth and other ambient matter chanc'd to be an intire and co­herent mass, or divided into clods & o­ther portions. And I remember, that the Governour of an American Colony, having sent me among other Rarities, digg'd up in his Countrey, an odd kind of Mineral, that seem'd more pon­derous than at first sight it promis'd, I had the curiosity to break it, and found in it, here and there, several Gems, which by their figuration and some other circumstances were conclu­ded to have been form'd there, be­fore the ambient Mineral had obtain'd the nature it then appear'd to be of. And in Opacous stones it may hence happen, that a great lump of Medicinal Earth may be invaded and petrified af­ter the newly mention'd manner; so that it may not be thought incredible, that some of these Medicinal Stones should be very large in comparison of others: As I remember, that an inge­nious [Page 133] Physitian told me of a Spleen­stone, as they call them, in the hands of an acquaintance of his (where I might have seen it, if my occasions had permitted,) amounting to about four­score pound weight. And on this oc­casion, I also remember that even in a Medicinal Stone, much harder and hea­vier than Marble, and whereof I have seen lumps far greater than I could lift, I remember, I say, that having had the curiosity to cause a pretty big piece, violently broken off from the mass whereto it belong'd, to be sawn asun­der, that I might consider the internal Textures, as far as 'twas visible; I found several empty Cavities of differing sizes and figures in the solid substance of the Stone, (which I think I have not yet lost:) which seems to argue, that this compact and ponderous Body was made of a stony nature by the supervening of some Petrescent Liquor▪ or Spirit, upon porous Earth or some other consistent substance. For if it had been a meer Liquor wherein those Cavities must have been so many aerial bubbles; 'tis [Page 134] not like that some of them should have such irregular shapes, and that all should have continued without emerging to the top.

2. Our Hypothesis will also help to render a reason of what seems exceed­ing difficult to be explicated; namely, How some Gems, that seem to be in­tire Stones, are in part of one co­lour, and in that, which is contiguous to it, of a quite differing: Of which sort we have the Sardonix, and some other opacous Gems. And I have observ'd the like, though very rarely, in dia­phanous ones. For, according to our Hypothesis, it may be said, that a por­tion of matter, imbued with one of the Tinctures of the parti-colour'd Gem, was first form'd, and afterwards, some Petrescent Juice, endowed with ano­ther colour, came to settle contiguous­ly to it, and so by accretion made up one Stone with it. I might illustrate this by telling you, that though Fire do make a far greater agitation of Bo­dies melted by it, than need be sup­posed in cold Petrescent Liquors, yet I [Page 135] have found in making Artificial Gems, that by some mischance or error in the operation, the Mineral pigment has richly tinged one part of the transpa­rent mass, without at all imparting that colour to the very next part to it; so that if I should shew one of those I I have yet by me, you would judge it to consist of two differing Gems sub­tlely glewed or fasten'd together, un­less you should in vain try as others have done, to discover by the Eye or otherwise some naked commissure, which may keep those so differingly colour'd Bodies from making up one intire mass.

But let us leave these Artificial Gems, and add to what I was saying about our Natural Ones, that the Union of parts in these Resulting Stones (if I may so call them) I was speaking of before, might be the more perfect, if the super­vening matter found not the first form'd Stone to have attain'd to its full indu­ration: Though, for ought I know, even in this case, the apposition may be so close, and the two matters so near of [Page 136] kin, that both may pass for one Stone, and be polish'd both together without any blemishing discontinuity of surface at those parts, where one would expect commissures. For I have by me a lump, wherein there plainly appear Stones of colours very different from each other, that were once distinct and incoherent; but by some petrescent Liquor have had all their intervals so exqui­sitely filled up, that neither the touch nor the Artificers Tool, the lump be­ing now sawen asunder, discovered any Commissures; but the whole Mass bears an uniform Polish, and is harder than divers Gems that are worn in Rings, readily enough striking Fire with a Steel. And to confirm this the more, I shall add, that in a place where a pry­ing person of my acquaintance lighted on this portion of petrified matter, he found not only other lumps, but divers loose Stones, that seem'd altogether of the same nature with those, that by the supervention of the Petrescent Liquor were united into stony masses. I have also had a curious Agat so form'd, that [Page 137] it seem'd highly probable, that the opa­cous parts of its matter had been some thin, but not altogether contiguous, Beds of fine Clay, or Earth, lying almost parallel to each other (but not to the Horizon,) which by some Petrescent Liquor, that chanc'd to settle there, was reduced to coagulate with it into a partly opacous and partly diaphanous Stone. And of such Clays or Mineral Earths, I have sometimes with pleasure observed more than one or two, which, though distinct and perhaps of differ­ing colours, were so very thin, that the thickness of them all did scarce exceed an inch, nor did they always lie flat or horizontally, but in differing postures both in reference to the Horizon, and one an other, and now and then the exterior ones did successively almost surround the interior: And of these thin Couches or Layers of Earth, I remem­ber, I have observ'd a considerable number, within a very small compass of ground. I must not in this place stay to shew, how probable 'tis, that much after the same way may be expli­cated [Page 138] the production of divers other Gems besides Agats, as Chalcedonians and Jaspers, which are for the most part opacous, but oftentimes have some parts that are not so. But I am content, before I go further, to mind you on this occasion of what I else­where deliver, That by purposely cal­cining, without breaking, some of these Stones, whose greater part was diaphanous, I found, that the transpa­rent parts turn'd white; and that some of the thin Layers or Couches of Mi­neral Earth had retain'd their co­lour as well as position, and had it much heighten'd; so that one of these Layers after calcination was of a very rich and permanent Red. And this difference of Colours I observ'd not only in Layers, but in the Specks and ir­regularly shap'd Clouds (if I may so call them) of other Colours (as Green­ish, Blewish, &c.) I might here add, that I have found shining Marchasites, not only in other solid Stones, but in Marbles; as also Flints themselves, in­closed in great masses of Marble, and [Page 139] likewise Wood; in strong Stones im­ploy'd to build a Wall, and Shells (at least as was judg'd by their shapes and sizes;) in a great mass of Stone that I met with almost on the top of a Hill remote from the Sea, together with divers other such Phaenomena, which I think may probably be accounted for by our Hypothesis and scarce without it. But being willing to dispatch this Discourse, and unwilling to intrench upon the Discourse of the Effects of the Petrescent Juice, (to which the consideration of these and divers other Phaenomena, to be met with about the Generation of Stones and petrified Bodies, especially in Wombs or Molds, more properly belongs;) I shall in this place only point back to one Observation, and answer one Objection; because both of them are pertinent to our present Discourse.

The Observation is this: That even in transparent Gems, and which is more, of the self same Species, I have sometimes taken notice of such an Aggeneration or Accretion of Stones to one another, as argues their having [Page 140] been produc'd at several times. For proof of this, I need no more than re­ferr you to what I have not long since, Note: Page, 76, 77, & 78. related about those Cornish Diamonds, wherein somet [...]mes a lesser Stone, though Geometrically shap'd, was found in good part inclos'd in a greater, as well as in part also extant above it. Whence I argued, that the production of this aggregate of two Crystalline Bodies was not made all at once, but successively, and that the lesser was first form'd, which I shall now confirm by this Consideration. That if the greater Stone had been first harden'd, the matter of the lesser must only have exteriourly stuck to it, and been as it were imbost upon it; but could not have made it self in the sub­stance of the greater a Bed or Mold, especially of such a Geometrical figure as it self had not yet received.

And though this successive Genera­tion of the parts of (seemingly) intire Gems may appear to you somewhat new and strange, yet that its fitness and requisiteness to explain the foregoing [Page 141] Phaenomena and others, to be hereafter mentioned, may the more recommend it to you; I shall add, that perhaps you may be assisted to conceive, if not in­vited to admit it by a Mechanical illu­stration. For we see in divers Chymical Solutions, as of Salts and other Bodies, that there are certain stages or periods of coagulation; so that, when such a quantity of the superfluous moisture is exhal'd, especially upon any conside­rable refrigeration or other favourable circumstance, those particles that are most dispos'd to coagulation will con­vene and shoot into Crystals, after which no more will do so, till a farther and more considerable evaporation of the water or other Menstruum be made; upon which will ensue a new Crystalli­zation of the parts. And I can shew you the productions of a metalline, but uncommon Solution, that I so made in an appropriated Liquor, that the first shooting afforded me a Layer or Bed of curiously figur'd Crystals, and the fol­lowing, another Layer of fine Crystalline Bodies, that have fasten'd themselves [Page 142] to the former, but differ notably from them both in shape and posture. And in this Experiment, the dissolv'd Body was but one, as the menstruum but one; but if there be a diversity of nature in the Liquors that make up a menstruum, or in the Bodies that are dissolved in it; some of the Corpuscles may convene either a part with those of the same Na­ture, or mingled with those of a differ­ing Nature; but yet at the same time and so make up Crystals of a compoun­ded Nature, and some of them may convene with homogeneous particles, but at differing times; and so miss of such uniformity as might else appear in their concretions. Which may be illu­strated by what I have elsewhere re­lated concerning the Crystallizations of Salt-Peter and Sea-Salt, dissolv'd together in ordinary water; where most commonly grains of Salt of result­ing figures are produc'd; and also a considerable part of the Sea-salt coagu­lates in the form of imperfect Cubes about the bottom, before the nitrous Corpuscles shoot into Crystals of their [Page 143] own (almost prismatical) shape. And I might further add, that it matters not, whether the superfluous water be wast­ed by Exhalation, or by being drained by a body fit to soak it up; as we have had occasion to observe in accelerating the Crystallization of some Bodies, where I was not willing to imploy the heat of the fire, by placing, underneath the Solution, dry'd Earth, or some other porous and soaking body.

With some Analogy to such instances as these, we may conceive, that where there are Petrescent Liquors, mingled with common water, there may, by di­vers accidents, and particularly an hot Summer, a sufficient discharge be made of the superfluous moisture, to make the more disposed parts of the Petre­scent Liquor to coagulate, and after­wards the coagulation may be suspend­ed, either by the supervening of a cold­er season, as Winter; or even in Sum­mer it self, by a plentiful rain, or the effect of it, a Land-flood, which might check the progress of coalitions by o­vermuch diluteing the Liquor, that [Page 144] might else have turn'd into Stone. Not to mention, that trial hath assured me, that there are Bodies, and those of very differing kinds, which will in tract of time, especially if their coalition be fur­ther'd by cold weather, coagulate, after they have long remained in a fluidform, though the water or other menstruum, by being inclos'd in stopt Glasses, be kept from wasting. And since the Earth harbors differing kinds of these Liquors (as I have elsewhere shewn) and di­vers of them may be copiously impreg­nated, some of them with one sort of Mineral, and some with another; we may conceive, that they may have di­stinct periods for their respective coali­tions, and yet may stick close to one another; in regard that, though in our Chymical Crystallizations the Artists are wont to take out of the vessel what shoots the first time, before they make a fresh exhalation of the water for a new Crystallization, and by this means have the coagulated Bodies, that they ob­tain at one time, more uniformly shap'd; yet in the hollow Receptacles, that the [Page 145] Earth affords to Petrescent Liquors, the Vessels continuing the same from first to last, the Uniformity of the Bodies pro­duc'd by coalitions made at several times must be less regular, and the ma­nifest accretions or aggregates of coa­lescent Bodies must in all likelihood be more frequent. And accordingly ha­ving suffer'd the exhaling of some Li­quors to be continued in the same Ves­sel, I had coalitions of very differing Bodies at the bottom.

What I was not long since saying, makes me remember, that in order to a satisfaction (which the Event gave me) of the conjectures I had about the suc­cessive concretions of some solid Fire-stones, that were not suspected to be other than intire and uniform masses, I caus'd two or three that I thought likely and of very different sizes and shapes, and brought from distant places, to be warily broken: Which Tryal gave me the pleasure of observing, that the internal Texture of the least of these Mi­nerals, which was almost spherical, was very differing from that of the more [Page 146] internal part of the substance of the Stone. And that in the other and greatest Mineral there was a little glo­bulous Stone, that manifestly was not of the same piece with the invironing mass, differing from it not only in Texture, but here and there by a discernable Commissure: though in most places their Adhaesion was so strict, that we could not make any separation of the two Minerals by the help of this Com­missure. The greatest part of this double Fire-stone I keep by me, and shall say nothing of what I further ob­serv'd in it, having mention'd what I said already but upon the by.

I might add, that in some Circum­stances, even in those Vessels, and therefore without any manifest exha­lation of the water or other Menstruum, and sometimes where the dissolv'd Bo­dy was homogeneous, I have in process of time had coagulations, where the last form'd Crystals seem'd plainly to have been generated by way of accre­tion to the first.

Difficulty. Having now done with [Page 147] my Observation, I shall endeavour to clear a grand Difficulty, which I fore­see may be objected against our Hypo­thesis, namely, That these Aggenerations (if I may so call them) of Medicinal and other Stones are sometimes found in places, where there are no petrifying Springs, and perhaps no Springs or other Waters at all, nay little or nothing but Quarries or other masses of Stone.

But to this I answer, First, that if we admit of the Relations, that I elsewhere mention out of approved Authors con­cerning Men and Beasts turn'd into Stone by a petrifying Spirit, that sud­denly invaded them, it will not be ab­solutely necessary that there should be any Petrescent Springs or other like water to produce such Minerals, as we are now discoursing of.

Secondly, for ought has yet been shewn to the contrary, we may suppose that Rain-water does sometimes bring along with it such petrifying particles as may serve our turn. In confirmation whereof I shall add, that having of a learned and judicious person inquired [Page 148] after divers particulars relating to a fa­mous Bath, by him visited in Hungary, whose Water abounds very much with Pet [...]escent particles, over which there is very high Building erected, I learn'd by his answers, among other remarkable things, that to the Roof or upper part of this tall Structure there were fasten­ed many long stony concretions, (like those wont to be imploy'd to adorn Groto's;) which he affirmed to be from time to time generated there, not, as I at first suspected, by the dashing up of any drops of water; (which he averr'd could not reach any thing near so high,) but by the copious petrific steams, that being there checked in their ascent, did, according to their natural propensity, coagulate into Stone. Whether this Relation may warrant me to guess, that in some places Stones may be generated, without the help either of Rain or Springs, by the ascent of Petrific par­ticles in the form of exhalations from some lower parts of the Earth; which exhalations, suffering the lighter steams that accompanied them to exhale, may [Page 149] operate upon some disposed materials that they find in their way, and turn them into Stone: whether, I say, this narrative may well suggest this conje­cture, I shall not now stay to examine, though the Earthy and sometimes Sul­phureous sediments that have been ob­serv'd at the bottom of Rain waters, suffer'd to settle in clean vessels, may seem to favour it; and though also I might illustrate it by what I observ'd in a Bottle of distill'd Liquor, whereof no part would naturally ascend in a dry form: for having kept this Viol well stop'd in a safe and quiet place for a year or two, I observ'd that the ascend­ing steams had quite pervaded the Cork, and had formed at the top of it numerous whitish stiriae, slender, but of a length that surprized me.

Thirdly, there is no necessitie, that in all soils, where petrific waters are to be met with, there should be petrifying Springs, at least above ground. For I have caused to be digg'd store of fi­gur'd and transparent Stones in a cer­tain Earth, that lay upon the upper part [Page 150] of a Rock, and seem'd to be a very dry Soil: Perhaps you will allow me to tell you, that I have by pouring a solu­tion of stony stiriae, made with Spirit of Verdigrease, on a convenient quantitie of Bolus Armenus, and suffering the soft mixture to remain in a Glass in the open Air, till the superfluous moisture was exhal'd; I have, I say, by this means imitated in a little, what I have been now relating, and found small but un­ting'd and figur'd Crystals dispersed through the little Cavities of the Red Earth. But 'twill be more considerable to our present purpse to add, that the fairest and hardest petrifying Wood, that I ever had or tryed, was taken up by an Ingenious person I imployed in a Plot of Sandy ground, where he could not find any petrifying or so much as any other Spring. To which I know not whether I should add, that supposing the ground to have been once moisten­ed with a Lapidescent Liquor, whether brought thither by Springs, or any other way; one may in our Hypothesis well enough account for this difficult Phaeno­menon, [Page 151] that now and then, not only in the surface of the ground, and perhaps upon Rocks themselves there are found Aggregates of figur'd Stones, that seem to grow upwards, as it were from a Root; which much puzzle men to know how they came there, and may incline them to their opinion, who ascribe Vegetations to Stones. But to this may be answered, that many of the Concretions, we are speaking of, may have been formed in wombs that lay, though not deep, yet under ground, or in shallow cavities in the surface of it, and that, after their formation, the looser Earth that surrounded them, may have been washed off by Rains, blown off by Winds, or otherwise remov'd, leaving behind them these Stones that adher'd firmly to a solid Body. Besides, if I had time, I think it were very pos­sible for me to shew, that stony Con­cretions might be produc'd by the Me­chanical action of the Air upon the stony particles that successively apply themselves to the matter, that first be­gins to coagulate, when they are ready [Page 152] to be forsaken by the moisture that ac­companied those particles, and was ne­cessary to their due application to the casual rudiments (which pass for Roots) in imitation whereof I have more than once obtained both from saline and stony Solutions, dry tufts of prettily figur'd, and diaphanous or white, but very slender, stiriae, (if I may so call them) that seemed to grow out of the solid Glass, and made men wonder how they came thither, no Water or other Liquor appearing near them.

Fourthly, It may very well happen, that the Petrescent Liquor may be so mingled and dilated with ordinary wa­ter, as not to be distinguished from it by the generality of men, nor to be capable of disclosing it-self by its ef­fects, till either by the copious exha­lation of the common water, or by some peculiar advantages, it has to operate upon Bodies, it has opportunity to dis­cover it self. On which occasion I shall add, that there is a Lake in the North of Ireland, wherein I could never hear but that Fishes lived as well as in other [Page 153] Lakes, and yet there are some Rocks near the bottom of it, to which there fasten themselves divers masses and o­ther pieces of a finely figured substance, and transparent as Crystal; of which an eminent person, the chief Owner of the Lake, presented me with some, and promised me more. Now if we sup­pose, that either by Springs of Petre­scent water, or by Rains, or by sub­terraneal steams, or otherwise, waters, resting in any hollow place, though upon the top of Rocks and Moun­tains, shall be sufficiently impregnated with Petrific particles; and that after­wards in process of time the meerly aqueous parts shall be, by degrees, by the heat of the Sun, the soaking of the grounds, the winds, or the continual action of the Air, brought to exhale away in the form of Vapors, the Petrific particles, which are not so volatile, will turn the Soil beneath them and on the sides of them, as far as the Sphere of their activity reaches, into Stone harder or softer, of this or that kind, accord­ing to the particular nature of the Pe­trescent [Page 154] Liquors, and the Structure and other dipositions of the Soil they in­vade: In which Soil, if there chance to be lodged Bodies heterogeneous to it, whether vegetable substances, as Roots, pieces of Wood, Gums, &c. or the whole Bodies of Animals, as Toads, Frogs, Serpents, Fishes, &c. or their parts, as Shells, Bones, &c. or Minerals of an open Texture, as Boles, unripe Ores; or else Gems or Stones of an­other kind already form'd; any of these things or any other that shall chance to be lodged there, must be found either petrified or inclosed in Stone, when this changed and harden­ed Soil shall come to be broken up. Nor is it at all necessary, that this petre­faction of the extraneous Bodies, and of the Soil or Bed, be made at once: For, it may well be made successively at se­veral times, according as some parts of the Petrescent Juice happen to be more copious and penetrant, and consequently more fit to be soaked in further than other. For, as the porousness happens to be greater in one part of the Soil [Page 155] than in another; or as the Texture and disposition of particular Bodies, lodged in the Earth, gives advantage to the Pe­trific particles to work on some of them sooner, or in a differing manner than in others; so the Induration of the per­vaded matters may be very unequal­ly made in point of time, as well as in other circumstances. So that (to omit many other things explicable by it) we may, from what hath been already de­liver'd, conceive, how it may happen, that Medical Stones of very differing Colours, Consistencies, and Operations (of which I have several by me, that I had from the same Mineral mass,) may be generated and seem intire Bodies, though (as in some that I found,) the difference is so great, that one part of the Medical Stone is dark, heavy, and o­pacous, and the other much lighter, tran­sparent, and quite otherwise colour'd. And upon the same Principle may be explained, what I lately mentioned to you about the finding of Diamonds in­closed in loose Stones and even in Rocks; of which we have credible [Page 156] Testimony: which seems not more strange to me than a Stone, which I have by me, which being a kind of Pible, contains in it a perfectly shap'd Serpent, coild up, but without a head, which appears to have been formed be­fore the Stone, in regard that in the upper and lower parts of the solid Stone there are cavities left, which together make up one Cavitie, just of the size and shape of the contained body; to which as it was easie for the matter of the Stone, whilst 'twas yet a soft body, to accommodate it self exactly; so 'tis scarse conceivable, how, if the Pible had been first form'd, the inclosed ani­mal, if it were one, or the matter where­of the seeming animal afterwards was formed, should not only get in, but find a cavity so curiously shap'd and so fitted to its bulk. And that this variety was produced at several times, might be further argued from this, that the seem­ing Serpent is plainly of another and clearer kind of Stone than that of the Mold, that incompasses it; and of the Mold it self, one part, contiguous to the [Page 157] included body, is whitish, and abounds in shining grains or flakes; in both which, it differs from the other and far greater part. And now it will be time to hasten to the

Fifth consideration, which is, that for ought we know, in those very pla­ces, where now there is nothing to be seen but loose Stones, and perhaps beds of Stone themselves, that in those very places (I say) there may in times past have been Petrescent Liquors, whether stagnant or running. For, I *In an Exa­men of an Ex­periment urged for the Mag­netism of the Earth. elsewhere shew, (to an other purpose) that Earth­quakes, Inundations of Seas and Rivers, sinkings of ground, incroachments of the Land on the Water, fiery Erup­tions and other such Accidents, (some related by Authentick Authors, and others happening in our own times, in places, some of which I had the curiosi­tie to see,) have among other odd ef­fects been able to dry or choak up Pools and Lakes, and to stop and quite divert the course not only of Springs, [Page 158] but of Rivers, so as to leave no foot­steps of them, where they plentifully flow'd before. Upon the score of which transpositions of notable quanti­ties of terrestrial matter and other great changes of the structure and dis­position of the Soil in divers places, it may well be suspected, that the stony Wombs or Molds, wherein the above mentioned Bodies were found, were heretofore at sometime or other, of a muddy or earthy Nature, and were re­ceptacles of Petrescent Liquors, which at several times turn'd the whole mass of the Soil into Stone, before the Springs or other Waters, containing the Petri­fic Liquors or Spirits, were quite con­sumed, or had their course altogether diverted. But though I could say much more to confirm and apply this, and the preceding considerations; yet ha­ving spent so much of my time already, I shall not only leave all that unsaid, but, to make some amends for having staid so long in clearing this difficulty, I shall do little more than name the two remaining Arguments.

[Page 159] Arg. III. It agrees very well with what we were formerly saying (in the first Argument) about the great specific gravity of such as the newly mention'd Stones, in comparison of that of white Marble or transparent Pibles, that it should be possible, out of those Mine­rals to extract some of that substance, whether Metalline or of kin to it, upon whose account I told you I supposed them to be so ponderous. And accord­ingly we have by appropriated Men­struums obtained, from the foremen­tioned Bodies, (and not from those only,) Solutions or Tinctures, which, besides that, by their colour or taste, they discover themselves, did, upon their being dropt upon a Solution of Galls or some other convenient Liquor, or upon their being examin'd by other proper ways, produce such changes of colour or such determinate Phaenomena, as argued them to abound with Metal­line or Mineral particles, (which, for the most part of them I observ'd to be of a Vitriolate nature;) so I found, that the Solution of a Blood-stone, which [Page 160] tasted very rough upon the Tongue, would with the infusion of Galls make an Inky mixture; and the like would also be made with Load-stone, Emery, Marchasites, &c. open'd with corrosive Menstruums. But the Solution of Lapis Calaminaris, which was of a golden colour, did not operate like the rest on the infusion of Galls; but yet by its tast, as well as colour, sufficiently discovered it self to have copiously impregnated the Menstruum. And now the mention of Lapis Calaminaris minds me to take thence an instance of what I lately intimated, that there may be other ways, besides that of dissolutions in proper Menstruums, to shew, that some Medicinal Stones participate of Metalline and Mineral substances. For it is by melting Lapis Calaminaris with Copper, and keeping them together for a competent while in fusion, that Brass is made; wherein the red colour of the Copper is changed into a golden one, and the absolute weight (for I speak not of the specific gravity) considerably increased. Nor [Page 161] is this the only Mineral Stone, from which I have, by a way quite differing from those I have yet mentioned, name­ly with running Mercury, obtained a Metalline substance. And though na­tive Cinaber, used by eminent Physi­tians both inwardly and outwardly, be looked upon by the Vulgar as only a red Stone; yet 'tis known, in the Quick-Silver Mines of Friuli, and some other places where it abounds, that it is a Mercurial Ore, whence by vehe­ment fires they distill running Mercury, which we by moderate ones have some­times done.

But here perhaps it may not be im­proper to tell you, that though, before any admonition given men of the ex­pediency of examining stones Hydrosta­tically, I could not receive from others, yet I made against my self the following Objection, That there are some Stones, to which useful Qualities are ascribed, which are either not at all heavier in specie than is requisite for a Stone, as such, to be; or so little heavier, that 'tis no way likely, that Metals or any [Page 162] such ponderous Minerals should contri­bute either to their Productions or their Virtues.

In answer whereunto I thought it may be said in the first place, that our Hypothesis does no way oblige us to de­ny, that there may be such Stones. For though it ascribes the Virtues of most Gems and Metalline Stones to the me­talline and ponderous Mineral substan­ces they partake of, yet the concession agrees very well with our Doctrine; which, (as will in the Fourth Argument be more manifested) speaks in general, when it teaches, that the Virtues of Stones may, in many cases, depend upon their consisting not of a pure petrescent substance, but a substance impregnated with other Minerals, which, though most commonly they prove specifically heavier than the Petrescent matter, as such, without being the less, but rather in some cases the more operative and communicative of their Virtues; yet in divers stony concretions, the adven­titious ingredients may be specifically lighter than the genuine matter of the [Page 163] Stone; as may be easily gathered from some passages of the foregoing Dis­course. For, not here to urge, that divers Bodies, that pass for Stones, do abound in particles of Salt, which may be much less heavy than pure Stone of the like bulk, I have observ'd, that some other hard Fossils abound with a kind of Bitumen, which, when by di­stillation brought to an Oyl, is much less heavie than a Stone of the same bulk. And, as I remember, I have had some portions of such Oil, that would swim even upon common water: and lest this should be ascribed to the subtiliza­tion, the Bitumen received from the fire; I will add, that, having Hydro­statically weighed a piece of good Asphaltum, we found it to be to water of the same bulk, but as 1 and somewhat less than 4/10 to 1. Which was within a Tenth of the proportion to water of a stony, though a bituminous, Fossile, commonly call'd in England Scotch-Coal. And because Sulphur as well as Bitumen, is very apt, (and indeed more apt than before tryal I expected) [Page 164] by even a moderate heat or attrition to diffuse its steams, (usually ranck sented enough;) I shall add, that there are Variety of hard Stones, which abound in Sulphur: (witness that in some places they obtain their common Brimstone by sublimation thence) and yet having weigh'd a Role of Brimstone in Fire and Water, I found it to be but a fra­ction scarce worth mentioning above double its weight to the Liquor; which shews it to be much lighter in specie than Crystal it self.

An improvement of this first Answer may furnish me with the second. For hence we may argue, that 'tis not im­possible, that the principal virtue of a light Medical Stone should be due to some mixture of a Metalline or the like ponderous substance; since, if some of the ingredients, that are plentifully mix'd with the true stony matter, be of the lighter sort, though there be also some Metalline or other heavie Mineral particles mingled with the same matter, yet the specific Levity of the one, in comparison of this matter, may com­pensate [Page 165] the specific Gravity of the o­ther, and they may all compose a Stone, either less, or not more, ponderous than white Marble. On which occasion, I re­member, not only that I found a black­ish East-Indian Flint, and likewise a Black English one, to have to water not full the proportion of 2 6/10 to one, but that one of the first pieces of black Marble that I examin'd Hydrostatical­ly, was found, notwithstanding the darkness of its colour, to be to water of the same bulk scarce any thing more than 2 7/10 to 1. which you may remem­ber was the proportion I found between white Marble & water, unless we should say, that this blackness of colour pro­ceeded, not so much from any gross Bi­tuminous matter, imbodied with that of the Stone, but from some Mineral smoak that had pervaded it. And this puts me in mind of speaking something in this place about what might properly enough have been discoursed of long ago.

Wherefore I shall subjoin in the Third place, that it seems not impossible, [Page 166] that the matter which Medical Stones are made of, may, before it comes to be hardened, derive various colours and be imbued with Virtues by subterrra­neal Exhalations and other steams. This I fear you will think somewhat strange, and therefore I shall briefly en­deavour to confirm it by the mention of two or three particulars.

That then many places of the lower part of the Earth emit copious exhala­tions into the upper, and even into the Air it self; I presume you will grant, and I have elsewhere proved it. That also such subterraneal steams will easily mingle with Liquors, and imbue them with their own Qualities, may be in­ferr'd from the Experiment of mixing the Gas, (as the Helmontians call it) or the scarce coagulable fumes of kindled and extinquished Brimstone, with Wine, which is thereby long preserved. And I have elsewhere mentioned, how I have incorporated this Smoak with other Liquors, wherein I observed its operations o be notable.

That beneath the surface of the [Page 167] Earth there may be sulphureous and other steams, that may be plentifully mix'd with water, and there in likeli­hood with Lapidescent Li­quors, I have also manife­sted in another *Of Subterta­neal Steams. Dicourse.

That Quick-silver may be in part re­solved into Fumes by less fires than many of those that burn under ground, will be readily acknowledged by Chy­mists and Gilders, and is obvious in the Fumigations imployed in the Cure of the Lues Venerea. And that Mercury may in the bowels of the Earth be so disguised, and well mixed with stony matter, as to suffer the whole concre­tion to pass for Stone, may be observed in some kind of native Cinaber.

That Sal Armoniac, of which in some places there is to be dug up store, will, with a moderate fire, be made to ascend in form of exhalations, is vulgarly known, as to the factitious Salt of that name, and I have found it to hold in the native. That common Sal A [...]mo­niac, Sulphur, Mercury and Tin will be sublimed into a Gold-like substance, that [Page 168] participates of most, if not of all the Ingredients, may appear by the account I have elsewhere given of the way, I us'd in making Aurum Musicum: And that even Gold it self, the heaviest and sixest of the bodies we know, may by no great proportion of Additament, and that with but a moderate fire, be made to ascend in the form of Fumes or even of Flame, I have several times tryed, by wayes elsewhere deliver'd. And that Mineral Exhalations may be met with in the bowels of the Earth, is wit­nessed by the Relations of divers Cre­dible persons, conversant about Mine­rals, that affirm themselves to testifie what they write upon their own Ob­servation to which; some things that I had seen my self did the more incline me to give credit. And this copious ascension of Mineral fumes and even of Metalline ones, may be much confirmed not only by what is written by profes­sed Chymists, but by the Learned and curious Johannes Kentmannus, who, in the useful Catalogue of the Misnian Fossils he had collected, amongst the Pyritae or [Page 169] fire-stones, reckons one, whose title is Pu­micosus, & ab exhalatione ardenti nigro colore tinctus; and another, whose inscrip­tion is Coloris argenti, qui ab exhalatione virosa colore cinereo est tinctus. The same may be further confirmed by what I have some where met with as related in terminis by the Learned Cabaeus, that he found in the Territory of Modena.

To bring this home to our purpose, since there are Mineral Exhalations of very differing kinds, dispersed in divers places under ground, and since there are several volatile Minerals, as Arsenic, Orpiment, Sandarach, &c. that are very actively hurtful; there may be others indowed with Medicinal Qua­lities, and the Exhalations of such Mi­nerals either alone or mix'd with Pe­trescent Liquors, pervading duly dis­posed Earths and Bolusses, and other fluid, soft, or open substances, before their induration, may endow them with Medicinal and other Qualities.

Nay, when I recall to mind the old Phae­nomena that I have partly observed, and partly received from credible testimony, [Page 170] about the coalitions, mixtures, tinctures, and the emanations, as 'twere, of those Tinctures, in metalline, stony, and other fossile concretions; I dare not perem­ptorily deny, but that, even after sub­terraneal bodies have obtained a consi­derable degree of induration, and per­haps great enough to make them pass for stony ones, there may be subterra­neal steams subtle enough to penetrate, tinge, and otherwise impregnate them. Which you would think the less impos­sible, if you reflect upon what I just now related out of Kentman; and espe­cially if I had time to add here, what I remember, I elsewhere deliver about my tryals to tinge native Crystal with differing colours by the fumes of vola­tile Minerals. And that a very small proportion of a Metalline substance, re­solved into minute particles, may suffice to impart a tincture to a greater quan­tity of other matter duly disposed, may appear by those factitious Gems, where­in with three or four grains of a skilful­ly calcin'd Metal, or some such Mineral pigment, we may give the colour of a [Page 171] natural Gem to a whole Ounce or more of vitrified matter. And I remember, that in subtiler fluids, I have made the instance by vast odds more conspicuous, having ting'd with one grain or less of a prepared Metal (as Gold or Copper) as much successively generated phlegm, as, if it could have been all preserved, would have amounted to a bulky lump of deeply coloured matter.

But your allowing the hesitancy I have expressed in this last Paragraph, is not necessary to my present purpose, where­fore I shall not borrow any thing to countenance it from another Paper, but pass on to what remains.

Arg. IV. The last thing, that I shall represent to shew, that the Virtues of opacous Gems and Medicinal stones may be more easily, than those of trans­parent ones, accounted for in our Hypo­thesis, is this, That the main Ingredients, whereof many such opacous Stones con­sist, were complete Mineral bodies be­fore they became Stones; some of them having been Medicinal Bolusses, or the like Earths; some, Earths abounding [Page 172] with Metalline or Mineral Juices; some, Ores of Metals, or Minerals of kin to, Metals; and some, in fine, Bodies of other sorts or natures differing from these and one an other. For, all these several kinds of fossils may, by the supervening and pervasion of Petrific Spirits, be turn'd into Stone, and consequently retain many of the Virtues, they were indow­ed with by the Mineral Corpuscles, that had copiously, either under the form of Liquors, or Exhalations, im­pregnated them, whilst they were yet Earths, or other bodies of a more open or Penetrable Texture.

I might illustrate this by the way I elsewhere mention, whereby I made such mixtures even of Stony and Metalline Ingredients, that notwithstanding their coalition were transparent, though you will grant that to be more difficult, than to compound such concretions when one is allowed to make them opacous.

But here I must [...]oviate an objection, which I foresee may be made against our present Fourth Argument, unto which even what I have been now say­ing [Page 173] may afford a rise. For since it seems by our Doctrine, that Gems may be but Magisteries, and consequently but such compositions, as though made in the bowels of the Earth, might be made or imitated by humane skill, it may seem very improbable to many, that bodies so near of kin to Artificial ones, should be endowed with such pe­culiar and some of them with such strange Virtues as are ascribed to divers Gems, and are thought to be capable of flowing only from certain Substantial forms and those very noble ones too.

To this I might reply, that I admit not any such imaginary Beings as the Peripatetic Forms, which I fear they will never be able to demonstrate. But to avoid unnecessary disputes, I will rather answer in short, that such com­positions as are call'd Artificial, may, for all that, be indowed with great Virtues, and such as are call'd Specific; witness the Virtues of many Chymical Preparations, even of those that are used by Physitians of all sorts. And lest you should think, I need to fly to [Page 174] Chymistry, of which some Learned Men are pleased to have a great distast, I will name a couple of instances out of Galen himself; The one is the Ashes of Crafish, to which, notwithstanding the destruction that has been made of the pristine Body by fire, he gives a greater commendation against the, as strange, as fatal poyson infus'd by the biting of a mad Dog, than he does either to the Fish it self unburn'd, or to any medi­cine of Natures own providing; and I hope you will grant a Virtue of that kind and degree to be specific enough. My other Instance shall be taken from Treacle, which though allowedly a factitious body, and consisting of I know not how many Ingredients shuffled together, was yet in the dayes of Galen (to whom a Book is attributed about it) and ever since has been the fa­mousest Antidote in these parts of the world, and has been celebrated not only for its Alexipharmacal Virtues, which alone are sufficient to intitle it to specific ones, but for divers others which are generally ascribed to it, some [Page 175] indeed upon the score of Manifest, but others also upon that of Occult Qua­lities.

The objection being thus dispatch'd, we may return to our Medicinal Stones, about which I shall venture to add, that according to our way of Explicating the production of them, a not impos­sible Solution may be offer'd of this difficult Phaenomenon. That sometimes Stones, that are thought without scru­ple to be of the same kind (as hath been particularly observed by Learned men of the Lapis Nephriticus) are of such different qualifications, Note: See Ʋnzerus de Nophrit. that some of them prove very considerable Remedies in cases where others prove almost utterly ineffectual. And I have observ'd also, though very rarely, that a Medical Stone may have Virtues, that are taught to be the properties of Stones of another kind. For, according to our Hypothesis, when the stony matter is impregnated as it ought to be with those Minerals, that in the ordinary course of nature belong to that species, [Page 176] its Virtue will be such as it should be for kind, but for degree may be very various, answerable to the plenty, pu­rity, subtlety, &c. of the Mineral that impregnates it. But if the stony mat­ter chance to be inbued with some o­ther substance of a contrary nature, though perhaps the proportion of it may be so small, and the colour of it such, as not to make an alteration in the Stone obvious to sense, and great enough to make it judged to be of an other species; yet it may so vitiate the matter wherein its expected Quality resides, or check and infringe its ope­rations, as not to leave the Stone any considerable degree of Virtue. And on the other side, if it happen that the Mineral Corpuscles, that are wont to impart a certain Virtue to the stony matter of one Gem, should, by some lucky hit, be so united with that of an other sort of Gems (of which case I formerly gave an Instance in green Diamonds,) though the quantity of this unusual Ingredient may be but very small, yet, if it's efficacy be great, [Page 177] it may innoble the Stone with a notable degree of some such Virtue, as is sup­posed not to belong to that Species, but to an other.

And on this occasion I shall add, that I know a Gentleman (a professed Scholar) who to the Eye seems to be of a Complexion extraordinarily San­guin: This person was for a long time so troubled with excessive bleedings at the Nose, that, notwithstanding all the Remedies he could procure in an Aca­demy of Physick, where he lived, he was divers times brought to Death's door, till at length his Case growing very famous, there was sent him by an antient Gentlewoman a Blood-stone, about the bigness of a Pigeons Egg, with an assurance that it had done scarce credible Cures in his Disease, by being worn about the Patients Neck. Upon the use of this Stone he quickly recovered his Health, and had long in­joyed it when I convers'd with him, but yet so, that when he left it off any considerable time, his distemper would return. And when I seem'd to suspect [Page 178] that imagination might have an interest in the efficacy of this Remedy, he an­swer'd, that he was very well satified of the negative; and particularly upon this tryal, that he had, by the hands of a third person that liv'd not far off, and whom he nam'd to me, stop'd a Hae­morrogie in a neighbouring Gentle­woman, whom the violence of the Di­stemper kept from knowing that any thing had been applyed to her, till a pretty while after the Blood was stan­ched. I shall not here mention other Instances, though very remarkable, of the efficacy of this Stone, which I had both from the Gentleman himself, and an intimate Friend of his, who is a very Learned Man and a Physitian; because I have said enough to make it seasonable for me to tell you, that notwithstanding all the odd operations of this Stone, when I came to look upon it, 'twas so differing in Colour and Texture from what I expected, that I should have taken it much rather for a Gem of some other species than a Blood-stone.

To confirm some of the Particulars [Page 179] comprized in this our Fourth Argu­ment, and shew the variety and some­times great plenty of Mineral and other subterraneal matters, that may concur to the composition of Bodies that pass for Stones; I shall observe, that the subtilty and penetrancy of some Li­quors, if duly consider'd, may evince it to be possible, that such Bodies should be petrified by them and with them, as may in part consist of Animal and Ve­getable substances, as in petrified Skulls, Bones, and pieces of wood: And we see, that soft Stone, which is plentifully found near Naples, and com­monly call'd the Lapis Lyncurius, being rubb'd a little and mostened with wa­ter, and then expos'd to the Sun in a due season of the year, will, in a very short time, (as Eye-witnesses have as­sured me,) produce Mushroms fit to be eaten; as if even the seminal Principles and Rudiments of Vegetables may be so preserved in a petrified Earth, as to be able to disclose themselves when they find an opportunity. To which agrees well, what an eminent person, [Page 180] Master of some of these Stones, informs me, That they now and then find them of a vast bigness, as if whole masses of Earth, pregnant with the prolific Prin­ciples of Mushroms, were, by some super­vening but not very potently hardening Petrescent Liquor, turn'd into Stone.

And not only there may be Bolsu­ses, seal'd Earths, and such like fossils, that are commonly known to be Me­dicinal, harden'd into Stone by petri­fying Agents; but also other Earths, subject to be petrified, may have Medi­cinal and subtle particles of such a kind in them, as scarce any body would ex­pect. But to omit Instances, belonging to another Paper, I have visited a cer­tain Clay-pit in a wast piece of ground, in which at a condsierable depth from the surface of the Earth there lay a bed of Clay, which by distillation yielded some acquaintances of mine a Salt so volatile and strong, and so differing from other subterraneal Salts, that my Examens did not discover the manifest qualities of it without some wonder; and the owners of it (persons curious [Page 182] and rich) did themselves use it as well as give it in Physic, and cryed it up for an excellent Cordial, and a great open­ing and Diaphoretic Medicine.

That sublimable Salts, Sulphurs, Bi­tumens, (Bodies that communicate enough of their Virtues,) may be met with in the bowels of the Earth; I have elsewhere shewn: And that such substances may be found in bodies that pass for Stones, I have been induced to think by the Chymical Examen, that I purposely made of some such concre­tions, particularly of that solid and heavie one, that is commonly call'd Scotch-Coal, from whence I obtained by distillation, (wherein I somewhat won­der'd, other mens Curiosity did not, as far as I knew, prevent me;) a good proportion of Oil or liquid Bitumen, and no small number of Saline particles that seem'd to be of an uncommon nature.

That Metalline particles may con­curr to make up a Body, that pas­ses for a Medicinal Stone, may ap­pear by native Sulphur which is it self a compounded body, besides [Page 183] a good proportion of Mineral Earth.

I had thoughts not to make an end of this Discourse, without mention­ing to you some attempts, that I partly design'd, and partly made, to illustrate some passages of it by purposely con­triv'd Experiments, whereof some were unprosperously and others not altoge­ther unsuccessfully try'd. But not ha­ving the Minutes of them by me, and not daring to trust my single memory in Experiments so nice, and so long since made, as those were, I shall here put an end to your trouble, especially since at length I perceive, that the forgetful­ness of my first intended brevity has misled me so far beyond the bounds of it into Excursions, whereinto the un­foreseen connexion of things unawar's engag'd me, that I stand in need both of your pardon and my own: Of yours, for having exercis'd your Patience with a prolix Discourse; and of my own, for having receded from my Cu­stome, by contributing to that proli­xity, and by expatiating upon Conje­ctures; to which, the more I conform [Page 184] to my own Practise, the less I am indul­gent: Though these may be the more pardonable, because I have proposed them but as Guesses, not peremptory Assertions, much less Physical Demon­strations. And if Aristotle himself, where he gives an account of Phaeno­mena appearing above the surface of the Earth, scrupled not to think, he had done enough, if he had shewn, how such things may be produc'd; I hope, it may be tolerable in me, who treat of things, that Nature does pri­vately in her dark and subterraneal Recesses, to have offer'd Accounts, that are possible, if not probable. And yet I should have spent much less of my Discourse upon Conjectures, if I had not seen, that they gave me Rises to bring in more of Natural History, than I could else decently do. But after all this I confess to you, (though you may think it a Paradox) that one of the main causes of the Prolixity of these Papers was my Hast, and that Experience hath taught me, on this Occasion (as well as on some others) [Page 185] that there may be more Truth than there is Likelihood in the gentile Conceipt of a French Secretary, that said, He had written his Friend a long Letter, be­cause he had not Leisure to write him a short One.