The works of the Honourable Robert Boyle, Esq., epitomiz'd by Richard Boulton ... ; illustrated with copper plates.

CHAP. I. Of the Original and Virtue of Gems.

* 1.1THO' I am far from believing, that Gems are endowed with so many Me∣dicinal Virtues as are usually ascribed to them; yet I believe they may have considerable Effects on Humane Bodies, which Virtues they may receive from the Intermix∣ture of Mineral and Metalline Parts, whilst they were in a fluid form. And that preci∣ous Stones have once been in a fluid form, may be argued hence, viz.

• First, from their Di∣aphaneity;

• fluid Bodies being more apt to have their Parts ranged in an order requisite to transparency, than solid Bodies; as Silver dis∣solved in Aqua Fortis, and Lead in Spirit of Vinegar, not only become transparent, but may form Diaphanous Crystals.
• Secondly, from their External figure; it being usual for Bo∣dies to form more regularly and curiously sha∣ped Crystals when in a fluid, than a solid Am∣bient substance; for which Reason, if a Glass-Bottle be filled with a Solution of Nitre, and the Water hath been pretty well consumed by boiling, the Salt will shoot into a Mass, whose side next the Glass answers the form of it, but that next the Water will be set with Prismatical Crystals of a Nitrous figure: And I have seen Indian Granates taken out of a lump of Heterogeneous matter, some of whose Surfaces were Triangles, others Paralellograms, &c. ac∣cording the figures of the Cells they were con∣tained in.

And I have seen not only Bristol Stones, but Cornish Diamonds curiously shaped like Crystals of salt Petre: And I have like∣wise seen Rubies very Geometrically shaped; and amongst other Rarities, a Diamond whose Sur∣face consisted of several Triangular Planes, which contained several lesser within them, which for the most part met at a Point, and formed an obtuse solid Angle. And I have observed, that most Diamonds have angular and determinate shapes.

And in favour of the Hypothesis already laid down, I shall add, that precious Stones be∣ing dissolved in a Particular Menstruum, they shoot into Crystals like those of Nitre, but

insipid. And I have observed, that tho' Bristol Stones have on the upper part, six smooth sides which were so cut as to represent six smooth Triangles, which terminate like those of a Pyramid in a Virtex, yet the lower Part which was next the matter it adhered to, made it appear less transparent, and conformable in figure to the Cavity of its womb, this is more remarkably evident, when clusters of these Crystals grow out of one Mineral lump. And to this I shall further add, that I have seen a Mass which consisted of two flat Parallel Cakes, which seemed to be composed of a dirty kind of Crystalline substance; and out of each Cake there grew towards the other a great number of Stones, which having a little space about them, were regularly shaped, and of the co∣lour of a German Amethyst. And I have a Stone which consists of four Parts, the lowest being like a flake of coarse Stone, only adorned here and there with very minute glittering Particles, as if of a Metalline Nature; over this is spread a thin white Opacous bed, and the third is made up of a long series of Crystals thick set, and which look whitish; and upon these which are not much thicker than a Barly-Corn, lyes another made up of Crystals like Amethysts, some higher tinged than others, and more elevated where they had most Room to shoot; those that were most elevated being hard e∣nough to grate lines upon Glass. And I have found in the Cavities of concreted Stones Cry∣stals which were set round the sides of them, and seemed to be formed of a Lapidescent Juice, which was Percolated through the substance of

the Stones, and formed curiously shaped Cry∣stals. And I am told by a digger, that he hath observed several clusters of these Crystals which stuck to no part of the Rock, but seem∣ed to be hastily formed in a soft Mould.

But thirdly, not only the External but their Internal Texture favours our Hypothesis; since it seems to imitate that of those Bodies which have been formerly fluids: For it hath been observed, that several Particles of Salt sticking together have not only formed large lumps, but Sal-Gem and lumps of the Isle of Mayow Salt be∣ing broke seemed to be made up of the like Parts. And tho a solution of Silver usually shoots into thin Plates, yet it may be so orde∣red, that several of these joining together may form larger Crystals, whose outsides may be finely shaped like some peculiar kind of Vitriol. And tho' transparent Bodies are usually thought to be of an uniform Texture, yet I have obser∣ved, that a thin Muscovy Glass Plate, which was so thin as to be scarce visible, might be fur∣ther divided into Plates; and the like hath been observed in other Stones; and to this I shall add, that I have been able to perceive the grain of a large Grizolette with my Eye, as well as in Hyacinths and Saphirs; and English Gra∣nates when they are broke, appear mani∣festly to be made up of flakes or Plates; and so do even Diamonds themselves, which are observed to cleave much more easily with the grain than against it, as Wood is observed to do, which is made up of an assimilated Juice which was first fluid: But it is observed in some Diamonds, that the flakes are not wholly

Parallel, but in the substance of the Stone, sometimes make Angles; for which reason some of them break in pieces before they will cleave through.

Fourthly, it seems requisite, that these Stones should have been in solutis Principiis, that they might be tinged with Mineral Juices. Which proposition suggests several Observations; and First, That most Gems lose their colour, or have it altered by the fire, and tho' it may be suggested, that the loss of a colour may be effected without the addition of a Pigment, by a change of the superficial Texture of a Body; (as when red Ink is beaten into a froth, or when Crystal receives several flaws in its Surface, by being suddenly cooled in Water, and becomes white, or in Cochinele, and puts on a pleasing colour, by the insinuation of the Tincture into the cracks and flaws) yet Indian Granates are observed to change their redish for a dark and dirty Iron colour, and Agats being kept a competent time in the fire be∣came white, except where Mineral Veins ran, where it was observed, that the colour was not destroyed but changed, and became a deep red, tho' I suspected that a more lasting fire would have turned them white, and the like change of colour hath been observed in Pebbles, and other Stones, some of which losing their Transparency by Ignition, acquired a deeper colour upon their Extinction in Water. And to countenance what I have laid down, it may be further offered, that Gems are generally found near Mines, or Mineral Veins; and tho' they are not sufficiently skilled in digging

Mines to discover what they otherwise pro∣bably might, yet I have seen several Amethysts which were taken out of Ground abounding with Iron and Tin Ores; and those softer Gems called by Mineralists Fluores, are often to be found in or near Metalline Veins, finely tinged with Mineral Juices, which were they in hot Countries and sufficiently hardened with the Sun, they might pass for Emaralds, &c. And I remember, that I once prepared a Menstruum no more corrosive than white Wine, which being poured upon well coloured Granates ex∣tracted a lovely Tincture from them. And Benvenuto Cellini tells us, that he saw a Rubie which was not of the usual colour but white, as also he acquaints us, that he hath seen Berils, Topazes, and Amethysts of the same colour; and Rubies and Saphirs have been observed to be of the same degree of hardness, so that they were looked upon to be the same kind of Stone tho' differently tinged; and that the same kind of Stone may be differently tinged appears, since Diamonds have been observed to be yellowish, more yellow and perfectly yellow, bluish, greenish, and some as green as Emaralds. And one who lived near the River Siam or Pegu in the East-Indies told me, he had seen Stones taken out of the Water partly void of colour, and partly of the colour of a Rubie. And besides what I have obser∣ved in Agats and Opacous Gems, as to the differing colours of the same Stone; I wear a Sardoinx in a Ring, the uppermost part of which is black, the middlemost of a Chesnut, and the other of a blue colour, almost like

a Turquois, and each of these of an uniform breadth and Parallel to each other, and even amongst Saphirs tho' they are commonly azure, yet a white Stone hath been called by the same name, because of the same degree of hard∣ness. And to these I shall add, that in Italy I have seen a large piece of Crystal, whose Py∣ramidal part was of a trnsparent green; the Vertex being richly tinged like an Emerald; but the further the colour spread from the Vertex, the more dilute and pale it grew, so that the Base was transparent and like ordina∣ry Crystal; agreeable to which Josephus Acosta says, that Emeralds seem to grow in Stones like Crystals, and by little and little to thicken and refine. He likewise says, he hath seen some half white and half green; others all white, and some green and very perfect. And I have seen a Saphir so odly tinged with Mineral fumes, that it might well be taken for a Chalcedonian, tho' of the hardness of a Saphir.

And to shew further, that solid Gems may include Heterogeneous matter in them; I shall add, that not only I but others have perceived something in the Body of Rock-Crystal, which by varying the posture of that Stone might be rendered visible; and the like hath been seen in Grisolets brought from the East-Indies: And in a hard Stone brought from thence, and designedly broke, I found several clear and transparent Crystals, which had their Points in∣wards, and were Arguments that they had swam in some Liquors, whose incoagulable Parts were either imbibed by the Ambient matter or penetrated it. And to illustrate

what I have said I shall add, that I have not only seen a Fly in shape and size much like a Grass-hopper, enclosed in solid Amber, but variously and curiously coloured with his wings displayed. And I have seen white Amethists in which there appeared to be several lines, some of a brownish and some of a reddish colour, which looked like hairs, some lying Parallel to each other, and others more inclin∣ing; and I am apt to believe, that even Dia∣monds are not void of Particles of Heteroge∣neous matter, which is countenanced not only by odd Clouds which I have seen in a great many of them, but the different specifick Gra∣vity of those of the same Water, the difference amounting to a Carrat betwixt Diamonds of the size of two ordinary Pease.

But, besides what hath been already offered, to prove that Gems have been once in a fluid form, it may be further alledged, that the Mineral Particles which they are so uniformly tinged with are convincing Arguments, since it is inconceivable how they should otherwise be so impregnated. And to what hath been already delivered; I shall further add, what is delivered by a French Author, viz. That the Stones which are found in the Earth have their Water coloured by the Earth, whether it be fat and black, or abounds with black or red Sand, and in some the Gems have been obser∣ved to be black or yellow; but tho' this Au∣thor hath said thus much which countenances our Hypothesis, yet I must not omit to adver∣tise, that tho' he asserts Diamonds to be not only the hardest but heaviest of Stones, I must yet

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say, that they are not the heaviest as may be Hydrostatically discovered.

But perhaps against what we have said, It may be urged, first that the figures of these Crystals are so curious, that a Plastick or Se∣minal Power seems requisite to the forming of them; which were it requisite, it might be an∣swered, that that Plastick Power may be lodged in fluid as well as solid substances, since the so∣lid Parts of Animal Bodies as well as Plants are formed of liquid substances; but that the figures of these Crystals may be owing to an apt convension and coalition of fluid Particles may be argued hence, viz. Since common Salt, by the help of Oyl of Sulphur or of Vitri∣ol and Water, will shoot into Crystals with Points like Diamonds, and not unlike native Crystal in shape and transparency; but if the Quality or proportion of the Oyl of Vitriol be varyed, they will shoot into Crystals some∣times of one shape and sometimes of another, for the most part fiuely figured. And to shew that the regular figure of Sea-salt contributes not to such figurations, I shall add, that hav∣ing dissolved some Stony Stiriae, found in Caves or Grottoes, in Spirit of Verdigrease, and e∣vaporated the clear solution in a digestive Fur∣nace after the ordinary manner, it yielded ra∣ther a coagulated Mass, than any thing like Crystals; whence it appears, that a concourse of circumstances may be sufficient to determine the figures of consistent Bodies, made of fluid ones; especially since when I allowed a longer time for the fluid to shoot in, it afforded a

good number of distinct Crystals; long, trans∣parent, and curiously shaped.

And not only the external figure of Cry∣stalized Bodies may be accounted for, without he help of a Plastick Power, but their inter∣nal Construction likewise, since divers Bodies upon a slow coalition will form Concretes, some of which will consist of streaks, and o∣thers of flakes; as lumps of Sal-Armoniack, which tho' a factitious Body, when broke will appear to be full of streaks, like those Stiriae observed in petrifying Water. And I have made artificial Concretes of Salts alone, or of Salts or Minerals, as Stones, or Antimony which look very like Talk, being white Bodies made up of a multitude of streaky Particles, lying long ways one upon another as in that Mineral, and I have not only found Concretes shaped like Rhomhus's or Lozenges, composed of a multitude of flat and extreamly thin Plates, but have imitated such by Art. And I have observed, that tho' generally Crystals of Silver form flakes seemingly simple like scales of Fish∣es, yet when they have shot leasurely they are Geometrically enough shaped, and made up of thin flakes sticking one to another. And Tin-Glass which naturally consists of a multitude of shining and polished flakes, will, tho' beaten to Powder, and melted, upon its Refrigeration form several broad and shining flakes, which lying one upon another, cross each other at various Angles, as the matter happens in several Portions to be variously refrigerated. And the like instances may be observed in some Mixtures of Copper, Iron, and other

Minerals; and very conspicuously in good Regu∣lus Martis Stellatus, whose internal structure appears upon breaking of it, to be made up of shining flakes, almost of a specular Polish. And tho' whilst we are looking on some Concretes, the Stony Stiriae in some places have a streaky and in others an angular Configuration, yet I have seen several of them made up of Parts con∣fusedly jumbled together, and if there be a due disposition in the components Parts to such Configurations, they may be brought to Con∣cretes in a far shorter time than any one would expect or believe; so that a solution of Silver being heated hot, and removed suddenly into cold Water, one might not only very easily, but plainly see the Silver shoot with ones nak∣ed Eye; but even a strong Solution of Sal-Ar∣moniack, or some Urinous Spirit, being spread upon the outside of a Glass in which a frigori∣fick Mixture is contained, will in less than a minute of an hour be coagulated into Cry∣stals of a determinate figure, according to the Nature of the Liquor that afforded it.

But if against these instances it be urged, that tho' they are taken from saline Bodies, which are for the most part disposed to con∣vene into smooth Surfaces, and Angular shapes, and are easily wrought on by External Cold, yet it may seem strange, that the figure of a Mould or Womb should alter the Internal Con∣struction of solid Minerals and Gems; but that it may is evident, since, tho' Tin-Glass con∣sists of several smooth and bright Planes, which sometimes meet, and sometimes lye a∣cross

each other, at very different Angles, yet having beaten a sufficient quantity of it to Pow∣der, and when it was melted cast it into Iron Moulds, whose Cavities were each an Inch in Diameter, it formed a Bullet, which when varily broke seemed to be made up of a multi∣tude of shining Planes, so shaped and placed that they rought every way like so many Radi∣us's of a Sphere tending from a Centre to the Circumference, so that they seemed gradually to decrease, as they were removed further and fur∣ther from the Circumference. But if the mel∣ted Tin-Glass was permitted to cool in a Cru∣cible, the hardened matter would form several Planes irregularly and confusedly associated to∣gether. And the like Experiment being tryed with Regulus of Antimony it succeded, tho' not so uniformly as with Tin-Glass: And melted Sulphur being hardened in the same Moulds, the Concreted Mass seemed when broke to consist of flakes like Straws lying Parallel to each other: But how the flakes of Tin-Glass came to be so regularly situated; and whether the outside being first condensed, the contiguous Liquor was connected by ap∣position, successively as it moved within the crusted Surface, or whether it was otherwise effected, I shall not now stay to examine; but to what I have said I shall add, that having broke several Marchasites of a peculiar sort, I found them to consist of several rows of Planes reaching from the inermost Parts to the Exter∣nal Surface; and in those which were some∣what Cylindrically shaped on the outside, these Ranks of Gold coloured Particles, in the seve∣ral

Planes of the broken Mineral seemed like Semi-Diameters issuing out from from a row of Physical Points, conceived to be placed on an Imaginary Line; lying almost like the Axes of a Cylinder between the apposite ends; as if the Wombs wherein those Marchasites were found, contained the fluid matter as in Molds, and as if it Concreted there, as Tin-Glass or Re∣gulus did in the Molds.

But tho' from hence it may appear, that tho' the figures of such Concretes be curious enough, yet they may easily be accounted for without a seminal Principle, yet I find not the uniformity of the figrue always so great as is imagined, but rather to depend on the diffe∣rent Figure and Texture of the Wombs they are contained in; for comparing American, African, and European Granats together, I found that one which weighed eleven grains and a half, tho it seemed to have been coagulated in a fluid Medium, and to consist of twelve Plains, at the concourse of two or three of which it seemed to have been broken off from the Root or Womb, yet it was not of the Do∣decahedron of Geometricians; for whereas that consists of twelve equilateral and equiangled Pentagons; almost all the Planes that made up our Granate, were quadrilateral, and not of a regular shape or Magnitude; for one of them seemed to have five sides; others resembled a Rhombus, some a Rhomboides▪ but most were a little bigger than the Trapezia But, besides the want of uniformity in these Stones, I observed amongst Cornish Diamonds, that some of them were cu∣riously and Geometrically shaped like Rock-Crystal,

having each six sides, whereof every two that were opposite were equal to each o∣ther; and tho' the Stone had a Pyramidal Ter∣mination, made up of several resembling and curiously figured Planes, that terminated in a solid Angle or Apex, yet the greatest number of the Titular Diamonds were made up of very irregularly shaped Stones; for tho' most of them had six long Planes, yet the opposite were most of them irregular and unlike; and tho' the Apex was made up of Planes apart usually Angular, yet being compared with each other they were far from being uniform; tho' it appeared that they shot in a fluid Ambient, except at the bottom where they were fastned to the Rock. And I have observed a great irregularity in the Area of the Superficial Planes, or their figures, or both, in Diamonds brought from the East-Indies.

Having shewn that the figures of Stones are far from discountenancing our conjectures of their Originals, I shall proceed to shew, that they help to confirm them; since I have seen a small Cornish Diamond so bedded in a large one, that it left a Cavity in it when separated, and on the contrary I have sometimes seen a large one so joyned to a smaller as to form a Cavity within it, which is a likely Argument, that the one being first hardened, afterwards a soft matter was collected together, and being contiguous, hardened in such a form as to con∣tain part of the other in the Cavity, which was formed whilst the one was fluid, and the other was hardened; which may be illustrated by considering, how Nitrous or Aluminous

Salts fasten themselves about pieces of sticks, and leave a Cavity proportionably to the solid contained: To which I shall add, that I have seen a Stone which was taken out of a Silver Mine, which had coagulated about the Branches of a Silver Wire, which was produced by Na∣ture in the Mine.

Another Argument of the fluid state of Gems, and their Impregnation with Mineral Stems, may be drawn from their Specifick Gravity, for whereas common Rock-Crystal is to its bulk of Water as two and almost two thirds to one, the weight of an American Granate was as four to one. And tho' by this method a tinged Gem hath not so great a difference in its proportion to Water, yet it may never∣theless be impregnated with Mineral Particles, for I found by Hydrostatically weighing Water impregnated with Iron, that it was not much heavier than common Water.

Another Argument may be drawn from the Medicinal Virtues of Stones, and the Metalline or Mineral substances, as well from Opacous Stones as Opacous Gems, &c. as the Tur∣quois, the Onyx, the Sardonix, &c. as also Cats Eyes, Opates, &c. And indeed I much question whether Diaphaneity depends on the essence of a Gem; since it may rather proceed from the Position of the Parts of a Pigment, and the scituation of the Pores in reference to the Beams of Light: But waving a further consideration of this matter, I shall rather sub∣joyn, that precious Stones and even Diamonds themselves, have sometimes great clouds, which makes them in those Parts almost Opacous, with∣out

out being less of the Nature of true Diamonds. And it is observable that Cornelians and Agats are some of them transparent, and some of them Semidiaphanous, as the Portion of the Mineral Pigment is greater or less, or as it is more or less inconveniently mixed. And I have seen even a Sardonix transparent, and on the contrary, figured Granates which were both of them Diaphanous: And I have some by me of several Countries, which tho' they are in some places Diaphanous, yet in the main they are almost as dark as ordinary Stones. And I question not, but that if the Glassy Na∣ture of Gems did not render common Men∣struums inaccessable, Mineral Particles might be extracted from them; and when they are con∣siderable, I question not but that they may be obtained from solid and transparent Gems; for having kept Granats in a hot Crucible till they changed their colour and afforded a very fine Powder, that being digested with rectifyed Spirit of Wine, afforded a curious Tincture; and burnt Granats gave Aqua Regis a Tincture, which in some measure resembled a solution of Gold; but a drop of the Liquor being put to a great many drops of Tincture of Galls, it turn∣ed them as black as Ink, if not blacker. And the like measures being taken with Granates which were looked upon by some to be Rubies, the Tincture coloured an Infusion of Galls not quite so black as the other; but a white Powder was precipitated at the same time; and by the use of an urinous Spirit a redish substance, which being dryed in the Air formed Bodies like Moss, and here and there small Mushrooms prettily

coloured. And from other Granates I obtain∣ed a Tincture, which after evaporation did in the Cold afford saline Concretions, but so small that their figures could not be determined. And probably, were tryals made, other Mineral Concretes might be wrought on by appropri∣ated Menstruums, for tho' the Spar that is found in Lead Mines next the Veins of Ore be Semi∣diaphanous, and usually breaks in smooth and Glassy Superficies, and looks like a Talck, and also for the most Part is made up of figured Particles shaped like Rhombuus's or Rhomboides, yet I found it was a more open Body than Talk, being dissolved in Spirit of Salt, without the assistance of Heat.

But I am apt to believe, that besides the methods already mentioned, there are other methods to discover the Metalline Ingredients of a Body, by Fusions and proper Additaments. And to conclude this Chapter, I shall subjoyn the following Experiment, viz. Having dissolved Stony Stiriae of petrifyed Water, in Spirit of French Verdigrease, and after a gentle Evapora∣tion, placed it in a cool place, it yielded •…•…∣stals, figured much like those of pure Nitro••, 〈◊〉〈◊〉 some of this Stony solution being mixed wi•••• a solution of Copper, they did not precipitate each other, but upon Evaporation yielded Cry∣stals transparent and colourless, and that were richly adorned with a greenish blue Tincture of the Metal.

Notes

• * 1.1

  Of the Ori∣ginal▪ of Gems.