A SHORT
ACCOUNT
OF
SOME
OBSERVATIONS
Made by Mr. BOYLE
About a Diamond that Shines in the
Dark.
Firſt encloſed in a Letter written to
a Friend,
And now together with it annexed to the Foregoing
Treatiſe, upon
the ſcore of the
Affinity Betwixt
Light and Colours.
LONDON,
Printed for Henry Herringman. 1664
A COPY
OF THE
LETTER
That Mr. Boyle wrote to Sir Robert Morray,
to accompany
the Obſervations touching
the Shining Diamond.
SIR,
Hough Sir Robert Morray and Monſieur Zulichem be Perſons that have deſerv'd ſo well of the Commonwealth of Learning, that I ſhould think my ſelf unworthy to be look'd upon as a Member of it, if I declin'd to Obey them, or to Serve them; yet I ſhould not without Reluctancy ſend you the Notes, you deſire for him, if I did not hope that you will tranſmit together with them, ſome Account why they are not leſs unworthy of his peruſal; which, that you may do; I muſt inform you, how the writing of them was Occaſion'd, which in ſhort was thus. As I was juſt going out of Town, hearing that an Ingenious Gentleman of my Acquaintance, lately return'd from Italy, had a Diamond, that being rubb'd, would ſhine in the Dark, and that he was not far off, I ſnatch'd time from my Occaſions to make him a Viſit, but finding him ready to go abroad, and having in vain try'd to make the Stone yield any Light in the Day time, I borrow'd it of him for that Night, upon condition to reſtore it him within a Day or two at furtheſt, at Greſham College, where we appointed to attend the meeting of the Society, that was then to be at that place. And hereupon I haſted that Evening out of Town, and finding after Supper that the Stone which in the Day time would afford no diſcernable Light, was really Conſpicuous in the Dark, I was ſo taken with the Novelty, and ſo deſirous to make ſome uſe of an opportunity that was like to laſt ſo little a while, that though at that time I had no body to aſſiſt me but a Foot-Boy, yet ſitting up late, I made a ſhift that Night to try a pretty number of ſuch of the things that then came into my thoughts, as were not in that place and time unpracticable. And the next Day being otherwiſe imploy'd, I was fain to make uſe of a drowſie part of the Night to ſet down haſtily in Writing what I had obſerv'd, and without having the time in the Morning, to ſtay the tranſcribing of it, I order'd the Obſervations to be brought after me to Greſham College, where you may remember, that they were together with the Stone it ſelf ſhown to the Royal Society, by which they had the good Fortune not to be diſlik'd, though ſeveral things were through haſt omitted, ſome of which you will find in the Margin of the incloſed Paper. The ſubſtance of this ſhort Narrative I hope you will let Monſieur Zulichem know, that he may be kept from expecting any thing of finiſh'd in the Obſervations, and be diſpos'd to excuſe the want of it. But ſuch as they are, I hope they will prove (without a Clinch) Luciferous Experiments, by ſetting the Speculations of the Curious on work, in a diligent Inquiry after the Nature of Light, towards the diſcovery of which, perhaps they have not yet met with ſo conſiderable an Experiment, ſince here we ſee Light produc'd in a dead and opacous Body, and that not as in rotten Wood, or in Fiſhes, or as in the Bolonian Stone, by a Natural Corruption, or by a Violent Deſtruction of the Texture of the Body, but by ſo ſlight a Mechanical operation upon its Texture, as we ſeem to know what it is, and as is immediately perform'd, and that ſeveral wayes without at all prejudicing the Body, or making any ſenſible alterations in its Manifeſt Qualities. And I am the more willing to expoſe my haſty Tryals to Monſieur Zulichem, and to You, becauſe, he being upon the Conſideration of Dioptricks, ſo odd a Phœnomemon relateing to the Subject, as probably he treats of, Light will, I hope, excite a perſon to conſider it, that is wont to conſider things he treats of very well. And for you Sir, I hope you will both recrute and perfect the Obſervations you receive, For you know that I cannot add to them, having a good while ſince reſtor'd to Mr. Clayton the Stone, which though it be now in the hands of a Prince that ſo highly deſerves, by underſtanding them, the greateſt Curioſities; yet he vouchſafes you that acceſs to him as keeps me from doubting, you may eaſily obtain leave to make further Tryals with it, of ſuch a Monarch as ours, that is not more inquiſitive himſelf, than a favourer of them that are ſo. I doubt not but theſe Notes will put you in mind of the Motion you made to the Society, to impoſe upon me the Task of bringing in, what I had on other occaſions obſerv'd concerning ſhining Bodies. But though I deny not, that I ſometimes made obſervations about the Bolonian Stone, and try'd ſome Experiments about ſome other ſhining Bodies; Yet the ſame Reaſons that reduc'd me then to be unwilling to receive ev'n their commands, muſt now be my Apology for not anſwering your Expectations, Namely the abſtruſe nature of Light, and my being already over-burden'd, and but too much kept imploy'd by the Urgency of the Preſs, as well as by more concerning and diſtracting Occaſions. But yet I will tell you ſome part of what I have met with in reference to the Stone, of which I ſend you an account. Becauſe I find on the one ſide, that a great many think it no Rarity upon a miſtaken perſwaſion, that not only there are ſtore of Carbuncles, of which this is one; but that all Diamonds and other Gliſtering Jewels ſhine in the Dark. Whereas on the other ſide there are very Learn'd Men, who (plauſibly enough) deny that there are any Carbuncles or ſhining Stones at all.
And certainly, thoſe Judicious men have much more to ſay for themſelves, than the others commonly Plead, and therefore did deſervedly look upon Mr. Clayton's Diamond as a great Rarity. For not only Boetius de Boot, who is judg'd the beſt Author on this Subject, aſcribes no ſuch Virtue to Diamonds, but begins what he delivers of Carbuncles, with this paſſage.26 Magna fama est Carbunculi. Is vulgo putatur in tenebris Carbonis inſtar lucere; fortaſſis quia Pyropus ſeu Anthrax appellatus a veteribus fuit. Verum hactenus nemo nunquam verè aſſerere auſus fuit, ſe gemmam noctu lucentem vidiſſe. Garcias ab Horto proregis Indiæ Medicus, refert ſe allocutum fuiſſe, qui ſe vidiſſe affirmarent. Sed iis fidem non habuit. And a later Author, the Diligent and Judicious Johannes de Laet in his Chapter of Carbuncles and of Rubies, has this paſſage. Quia autem Carbunculi, Pyropi & Anthraces a veteribus nominantur, vulgo creditum fuit, Carbonis instar in tenebris lucere, quod tamen nullâ gemmâ hastenus deprehenſum, licet à quibuſdam temerè jactetur. And the recenteſt Writer I have met with on this Subject, Olaus Wormius, in his Account of his well furniſh'd Musæum, do's, where he treats of Rubies, concurr with the former Writers by theſe Words.27 Sunt qui Rubinum veterum Carbunculum eſſe existimant, ſed deeſt una illa nota, quod in tenebris inſtar Anthracis non luceat: Aſt talem Carbunculum in rerum naturâ non inveniri major pars Authoram exiſtimant. Licet unum aut alterum in India apud Magnates quoſdam reperiri ſcribant, cum tamen ex aliorum relatione id habeant ſaltem, ſed ipſi non viderint. In confirmation of which I ſhall only add, that hearing of a Rubie, ſo very Vivid, that the Jewellers themſelves have ſeveral times begg'd leave of the fair Lady to whom it belong'd, that they might try their choiceſt Rubies by comparing them with That, I had the Opportunity by the Favour of this Lady and her Huſband, (both which I have the Honour to be acquainted with) to make a Trial of this famous Rubie in the Night, and in a Room well Darkn'd, but not only could not diſcern any thing of Light, by looking on the Stone before any thing had been done to it, but could not by all my Rubbing bring it to afford the leaſt Glimmering of Light.
But, Sir, though I be very backward to admit ſtrange things for truths, yet I am not very forward to reject them as impoſſibilities, and therefore I would not diſcourage any from making further Inquiry, whether or no there be Really in Rerum natura, any ſuch thing as a true Carbuncle or Stone that without Rubbing will ſhine in the Dark. For if ſuch a thing can be found, it may afford no ſmall Aſſiſtance to the Curious in the Inveſtigation of Light, beſides the Nobleneſs and Rarity of the thing it ſelfe. And though Vartomannus was not an Eye witneſs of what he relates, that the King of Pegu, one of the Chief Kings of the East-Indies, had a true Carbuncle of that Bigneſs and Splendour, that it ſhin'd very Gloriouſly in the Dark, and though Garcias ab Horto, the Indian Vice-Roys Phyſician, ſpeaks of another Carbuncle, only upon the Report of one, that he Diſcours'd with, who affirmed himſelf to have ſeen it; yet as we are not ſure that theſe Men that gave themſelves out to be Eye-witneſſes ſpeak true, yet they may have done ſo for ought we know to the contrary. And I could preſent you with a much conſiderabler Teſtimony to the ſame purpoſe, if I had the permiſſion of a Perſon concern'd, without whoſe leave I muſt not do it. I might tell you that Marcus Paulus Venetus28 (whoſe ſuppos'd Fables, divers of our later Travellours and Navigatours have ſince found to be truths) ſpeaking of the King of Zeilan that then was, tells us, that he was ſaid to have the beſt Rubie in the World, a Palm long and as big as a mans Arm, without ſpot, ſhining like a Fire, and he ſubjoyns, that the Great Cham, under whom Paulus was a conſiderable Officer, ſent and offer'd the value of a City for it; But the King anſwer'd, he would not give it for the treaſure of the World, nor part with it, having been his Anceſtours. And I could add, that in the Relation made by two Ruſſian Coſſacks of their Journey into Catay29, written to their Emperour, they mention'd their having been told by the people of thoſe parts, that their King had a Stone, which Lights as the Sun both Day and Night, call'd in their Language Sarra, which thoſe Coſſacks interpret a Ruby. But theſe Relations are too uncertain for me to build any thing upon, and therefore I ſhall proceed to tell you, that there came hither about two years ſince out of America, the Governour of one of the Principal Colonies there, an Ancient Virtuoſo, and one that has the Honour to be a member of the Royal Society; this Gentleman finding ſome of the chief Affairs of his Country committed to another and me, made me divers Viſits, and in one of them when I enquir'd what Rare Stones they had in thoſe parts of the Indies he belong'd to, he told me, that the Indians had a Tradition that in a certain hardly acceſſible Hill, a pretty way up in the Country, there was a Stone which in the Night time ſhin'd very vividly, and to a great diſtance, and he aſſur'd me, that though he thought it not fit to venture himſelf ſo far among thoſe Savages, yet he purpoſely ſent thither a bold Engliſhman, with ſome Natives to be his guides, and that this Meſſenger brought him back word, that at a diſtance from the Hillock he had plainly perceiv'd ſuch a ſhining Subſtance as the Indians Tradition mention'd, and being ſtimulated by Curioſity, had ſlighted thoſe Superſtitious Fears of the Inhabitants, and with much ado by reaſon of the Difficulty of the way, had made a ſhift to clamber up to that part of the Hill, where, by a very heedful Obſervation, he ſuppos'd himſelf to have ſeen the Light: but whether 'twere that he had miſtaken the place, or for ſome other Reaſon, he could not find it there, though when he was return'd to his former Station, he did agen ſee the Light ſhining in the ſame place where it ſhone before. A further Account of this Light I expect from the Gentleman that gave me this, who lately ſent me the news of his being landed in that Country. And though I reſerve to my ſelf a full Liberty of Believing no more than I ſee cauſe; yet I do the leſs ſcruple to relate this, becauſe a good part of it agrees well enough with another Story that I ſhall in the next place have occaſion to ſubjoyn, in order whereunto I ſhall tell you, that though the Learned Authors I formerly mention'd, tell us, that no Writer has affirm'd his having himſelf ſeen a real Carbuncle, yet, conſidering the Light of Mr. Claytons Diamond, it recall'd into my mind, that ſome years before, when I was Inquiſitive about Stones, I had met with an old Italian Book highly extoll'd to me by very competent Judges, and that though the Book were very ſcarce, I had purchas'd it at a dear Rate, for the ſake of a few conſiderable paſſages I met with in it, and particularly one, which being very remarkable in it ſelf, and pertinent to our preſent Argument, I ſhall put it for you, though not word for word, which I fear I have forgot to do, yet as to the Senſe, into Engliſh.
Having promis'd (Says our Author)30 to ſay ſomething of that moſt precious ſort of Jewels, Carbuncles, becauſe they are very rarely to be met with, we ſhall briefly deliver what we know of them. In Clement the ſeventh's time, I happen'd to ſee one of them at a certain Raguſian Merchants, nam'd Beigoio di Bona, This was a Carbuncle white, of that kind of whiteneſs which we ſaid was to be found in thoſe Rubies of which we made mention a little above, (where he had ſaid that thoſe Rubies had a kind of Livid Whiteneſs or Paleneſs like that of a Calcidonian) but it had in it a Luſtre ſo pleaſing and ſo marveilous, that it ſhin'd in the Dark, but not as much as colour'd Carbuncles, though it be true, that in an exceeding Dark place I ſaw it ſhine in the manner of fire almoſt gone out. But as for colour'd Carbuncles, it has not been my Fortune to have ſeen any, wherefore I will onely ſet down what I Learn'd about them Diſcourſing in my Youth with a Roman Gentleman of antient Experience in matters of Jewels, who told me, That one Jacopo Cola being by Night in a Vineyard of his, and eſpying ſomething in the midſt of it, that ſhin'd like a little glowing Coal, at the foot of a Vine, went near towards the place where he thought himſelf to have ſeen that fire, but not finding it, he ſaid, that being return'd to the ſame place, whence he had firſt deſcry'd it, and perceiving there the ſame ſplendor as before, he mark'd it ſo heedfully, that he came at length to it, where he took up a very little Stone, which he carry'd away with Tranſports and Joy. And the next day carrying it about to ſhow it divers of his Friends, whilſt he was relating after what manner he found it, there caſually interven'd a Venetian Embaſſadour, exceedingly expert in Jewels, who preſently knowing it to be a Carbuncle, did craftily before he and the ſaid Jacopo parted (ſo that there was no Body preſent that underſtood the Worth of ſo Precious a Gemm) purchaſe it for the Value of 10. Crowns, and the next day left Rome to ſhun the being neceſſitated to reſtore it, and (as he affirm'd) it was known within ſome while after that the ſaid Venetian Gentleman did in Conſtantinople ſell that Carbuncle to the then Grand Seignior, newly come to the Empire, for a hundred thouſand Crowns. And this is what I can ſay concerning Carbuncles, and this is not a little at leaſt as to the firſt part of this account, where our Cellini affirms himſelf to have ſeen a Real Carbuncle with his own Eyes, eſpecially ſince this Author appears wary in what he delivers, and is inclin'd rather to leſſen, than increaſe the wonder of it. And his Teſtimony is the more conſiderable, becauſe though he were born a Subject neither to the Pope nor the then King of France (that Royal Virtuoſo Francis the firſt) yet both the one and the other of thoſe Princes imploy'd him much about making of their Nobleſt Jewels. What is now reported concerning a Shining Subſtance to be ſeen in one of the Iſlands about Scotland, were very improper for me to mention to Sr. Robert Morray, to whom the firſt Information was Originally brought, and from whom I expect a farther (for I ſcarce dare expect a convincing) account of it. But I muſt not omit that ſome Virtuoſo queſtioning me the other day at White-Hall about Mr. Claytons Diamond, and meeting amongſt them an Ingenious Dutch Gentleman, whoſe Father was long Embaſſador for the Netherlands in England, I Learn'd of him, that, he is acquainted with a perſon, whoſe Name he told (but I do not well remember it) who was Admiral of the Dutch in the Eaſt-Indies, and who aſſur'd this Gentleman Monſieur Boreel, that at his return from thence he brought back with him into Holland a Stone, which though it look'd but like a Pale Dull Diamond, ſuch as he ſaw Mr. Claytons to be, yet was it a Real Carbuncle, and did without rubbing ſhine ſo much, that when the Admiral had occaſion to open a Cheſt which he kept under Deck in a Dark place, where 'twas forbidden to bring Candles for fear of Miſchances, as ſoon as he open'd the Trunck, the Stone would by its Native Light, ſhine ſo as to Illuſtrate a great part of it, and this Gentleman having very civilly and readily granted me the requeſt I made him, to Write to the Admiral, who is yet alive in Holland, (and probably may ſtill have the Jewel by him,) for a particular account of this Stone, I hope ere long to receive it, which will be the more welcome to me, not onely becauſe ſo unlikely a thing needs a cleer evidence, but becauſe I have had ſome ſuſpition of that (ſuppoſing the truth of the thing) what may be a ſhining Stone in a very hot Countrey as the Eaſt-Indies, may perhaps ceaſe to be ſo (at leaſt in certain ſeaſons,) in one as cold as Holland. For I obſerv'd in the Diamond I ſend you an account of, that not onely rubbing but a very moderate degree of warmth, though excited by other wayes, would make it ſhine a little. And 'tis not impoſſible that there may be Stones as much more ſuſceptible than that, of the Alterations requiſite to make a Diamond ſhine, as that appeares to be more ſuſceptible of them, than ordinary Diamonds. And I confeſs to you, that this is not the only odd ſuſpition (for they are not ſo much as conjectures) that what I try'd upon this Diamond ſuggeſted to me. For not here to entertain you with the changes I think may be effected ev'n in harder ſorts of Stones, by wayes not vulgar, nor very promiſing, becauſe I may elſewhere have occaſion to ſpeak of them, and this Letter is but too Prolix already, that which I ſhall now acknowledge to you is, That I began to doubt whether there may not in ſome Caſes be ſome Truth in what is ſaid of the right Turquois, that it often changes Colour as the wearer is Sick or Well, and manifeſtly loſes its ſplendor at his Death. For when I found that ev'n the warmth of an Affriction that laſted not above a quarter of a minute, Nay, that of my Body, (whoſe Conſtitution you know is none of the hotteſt) would make a manifeſt change in the ſolideſt of Stones a Diamond, it ſeem'd not impoſſible, that certain warm and Saline ſteams iſſuing from the Body of a living man, may by their plenty or paucity, or by their peculiar Nature, or by the total abſence of them, diverſifie the Colour, and the ſplendor of ſo ſoft a Stone as the Turquois. And though I admir'd to ſee, that I know not how many Men otherwiſe Learn'd, ſhould confidently aſcribe to Jewels ſuch Virtues as ſeem no way competible to Inanimate Agents, if to any Corporeal ones at all, yet as to what is affirm'd concerning the Turquois's changing Colour, I know not well how to reject the Affirmation of ſo Learned (and which in this caſe is much more conſiderable) ſo Judicious a Lapidary as Boetius de Boot31, who upon his own particular and repeated Experience delivers ſo memorable a Narrative of the Turquois's changing Colour, that I cannot but think it worth your Peruſal, eſpecially ſince a much later and very Experienc'd Author, Olaus Wormius,32 where he treats of that Stone, Confirms it with this Teſtimony. Imprimis memorandum exemplum quod Anſhelmus Boetius de ſeipſo refert, tam mutati Coloris, quam à caſu preſervationis. Cui & ipſe haud diſſimile adferre poſsum, niſi ex Anſhelmo petitum quis putaret. I remember that I ſaw two or three years ſince a Turcois (worn in a Ring) wherein there were ſome ſmall ſpots, which the Virtuoſo whoſe it was aſur'd me he had obſerv'd to grow ſometimes greater ſometimes leſs, and to be ſometimes in one part of the Stone, ſometimes in another. And I having encourag'd to make Pictures from time to time of the Stone, and of the Situation of the cloudy parts, thatſo their Motion may be more indiſputable, and better obſerv'd, he came to me about the midle of this very week, and aſſur'd me that he had, as I wiſh'd, made from time to time Schemes or Pictures of the differing parts of the Stone, whereby the ſeveral Removes and motions of the above mentioned Clouds are very manifeſt, though the cauſe ſeem'd to him very occult: theſe Pictures he has promis'd to ſhow me, and is very ready to put the Stone it ſelf into my hands. But the ring having been the other day caſually broken upon his finger, unleſs it can be taken out, and ſet again without any conſiderable heat, he is loath to have it medled with, for fear its peculiarity ſhould be thereby deſtroy'd. And poſſibly his apprehenſion would have been ſtrengthen'd, if I had had opportunity to tell him what is related by the Learned Wormius33 of an acquaintance of his, that had a Nephritick ſtone, of whoſe eminent Virtues he had often Experience ev'n in himſelf, and for that cauſe wore it ſtill about his Wriſt; and yet going upon a time into a Bath of fair Water only, wherein certain Herbs had been boyl'd, the Stone by being wetted with this decoction, was depriv'd of all his Virtue, whence Wormius takes Occaſion to advertiſe the ſick, to lay by ſuch ſtones whenſoever they make uſe of a Bath. And we might expect to find Turcos likewiſe, eaſily to be wrought upon in point of Colour, if that were true, which the curious Antonio Neri, in his ingenious Arte Vetraria34 teaches of it, namely, That Turcois's diſcolour'd and grown white, will regain and acquire an excellent Colour, if you but keep them two or three days at moſt cover'd with Oyl of ſweet Almonds kept in a temperate heat by warm aſhes, I ſay if it were true, becauſe I doubt whether it be ſo, and have not as yet had opportunity to ſatisfie my ſelf by Tryals, becauſe I find by the confeſſion of the moſt Skilfull Perſons among whom I have laid out for Turcoiſes, that the true ones are great rarities, though others be not at all ſo. And therefore I ſhall now only mind you of one thing that you know as well as I, namely, that the rare Stone which is called Oculus Mundi, if it be good in its Kind, will have ſo great a change made in its Texture by being barely left a while in the Languideſt of Liquors, common Waters, that from Opacous it will become Tranſparent, and acquire a Luſtre of which it will again be depriv'd, without uſing any other Art or Violence, by leaving it a while in the Air. And before experience had ſatisfy'd us of the truth of this, it ſeem'd as unlikely that common Water or Air, ſhould work ſuch great changes in that Gemm, as it now ſeems that the Effluviums of a human Body ſhould effect leſſer changes in a Turcois, eſpecially if more ſuſceptible of them, than other Stones of the ſame kind. But both my Watch and my Eyes tell me that 'tis now high time to think of going to ſleep, matters of this Nature, will be better, as well as more eaſily, clear'd by Conference, than Writing. And therefore ſince I think you know me too well to make it needfull for me to diſclame Credulity, notwithſtanding my having entertain'd you with all theſe Extravagancies; for you know well, how wide a difference I am wont to put betwixt things that barely may be, and things that are, and between thoſe Relations that are but not unworthy to be inquir'd into, and thoſe that are not worthy to be actually believ'd; without making Apologies for my Ravings, I ſhall readily comply with the drowſineſs that calls upon me to releaſe You, and the rather, becauſe Monſieur Zulichem being concern'd in your deſire to know the few things I have obſerved about the ſhining Stone. To entertain thoſe with Suſpicions that are accuſtomed not to acquieſce but in Demonſtrations, were a thing that cannot be look'd upon as other than very improper by,
SIR,
Your most Affectionate
and
most Faithfull Servant,
RO. BOYLE.
OBSERVATIONS
Made this 27th.35 of October 1663. about Mr. Clayton's Diamond.36
Being look'd on in the Day time, though in a Bed, whoſe Curtains were carefully drawn, I could not diſcern it to Shine at all, though well Rubb'd, but about a little after Sun-ſet, whilſt the Twilight yet laſted, Nay, this Morning37 a pretty while after Sun-riſing, (but before I had been abroad in the more freely inlightned Air of the Chamber) I could upon a light Affriction eaſily perceive the Stone to Shine.
Secondly, The Candles being removed, I could not in a Dark place diſcern the Stone to have any Light, when I looked on it, without having Rubb'd or otherwiſe prepar'd it.
Thirdly, By two white Pibbles though hard Rubb'd one againſt another, nor by the long and vehement Affriction of Rock Cryſtal againſt a piece of Red cloath, nor yet by Rubbing two Diamonds ſet in Ring, as I had Rubb'd this Stone, I could produce any ſenſible degree of Light.
Fourthly, I found this Diamond hard enough, not only to enable me to write readily with it upon Glaſs, but to Grave on Rock Cryſtal it ſelf.
Fifthly, I found this to have like other Diamonds, an Electrical faculty.38
Sixthly, Being rubb'd upon my Cloaths, as is uſual for the exciting of Amber, Wax, and other Electrical Bodies, it did in the Dark manifeſtly ſhine like Rotten Wood, or the Scales of Whitings, or other putrified Fiſh.
Seventhly, But this Conſpicuouſneſs was Fainter than that of the Scales, and Slabber (if I may ſo call it) of Whitings, and much Fainter than the Light of a Glow-worm, by which I have been ſometimes able to Read a ſhort Word, whereas after an ordinary Affriction of this Diamond I was not able to diſcern diſtinctly by the Light of it any of the neareſt Bodies: And this Glimmering alſo did very manifeſtly and conſiderably Decay preſently upon the ceaſing of the Affriction, though the Stone continued Viſible ſome while after.
Eighthly, But if it were Rubb'd upon a convenient Body for a pretty while, and Briskly enough, I found the Light would be for ſome moments much more conſiderable, almoſt like the Light of a Glow-worm, inſomuch after I ceaſed Rubbing, I could with the Chaf'd ſtone exhibit a little Luminous Circle, like that, but not ſo bright as that which Children make by moving a ſtick Fir'd at the end, and in this caſe it would continue Viſible about ſeven or eight times as long as I had been in Rubbing it.
Ninthly, I found that holding it a while near39 the Flame of a Candle, (from which yet I was carefull to avert my Eyes) and being immediately remov'd into the Dark, it diſcloſed ſome faint Glimmering, but inferiour to that, it was wont to acquire by Rubbing. And afterward holding it near a Fire that had but little Flame, I found the Stone to be rather leſs than more excited, than it had been by the Candle.
Tenthly, I likewiſe indeavour'd to make it Shine, by holding it a pretty while in a very Dark place, over a thick piece of Iron, that was well Heated, but not to that Degree as to be Viſibly ſo. And though at length I found, that by this way alſo, the Stone acquired ſome Glimmering, yet it was leſs than by either of the other ways above mention'd.
Eleventhly, I alſo brought it to ſome kind of Glimmering Light, by taking it into Bed with me, and holding it a good while upon a warm part of my Naked Body.
Twelfthly, To ſatisfie my ſelf, whether the Motion introduc'd into the Stone did generate the Light upon the account of its producing Heat there, I held it near the Flame of a Candle, till it was qualify'd to ſhine pretty well in the Dark, and then immediately I apply'd a ſlender Hair to try whether it would attract it, but found not that it did ſo; though if it were made to ſhine by Rubbing, it was as I formerly noted Electrical. And for further Confirmation, though I once purpoſedly kept it ſo near the hot Iron I juſt now mention'd, as to make it ſenſibly Warm, yet it ſhin'd more Dimly than it had done by Affriction or the Flame of a Candle, though by both thoſe ways it had not acquir'd any warmth that was ſenſible.
Thirteenthly, Having purpoſely rubb'd it upon ſeveral Bodies differing as to Colour, and as to Texture, there ſeem'd to be ſome little Diſparity in the excitation (if I may ſo call it) of Light. Upon White and Red Cloths it ſeem'd to ſucceed beſt, eſpecially in compariſon of Black ones.
Fourteenthly, But to try what it would do rubb'd upon Bodies more hard, and leſs apt to yield Heat upon a light Affriction, than Cloath, I firſt rubb'd it upon a white wooden Box, by which it was excited, and afterwards upon a piece of purely Glazed Earth, which ſeem'd during the Attrition to make it Shine better than any of the other Bodies had done, without excepting the White ones, which I add, leſt the Effect ſhould be wholly aſcrib'd to the diſpoſition White Bodies are wont to have to Reflect much Light.
Fifteenthly, Having well excited the Stone, I nimbly plung'd it under Water40, that I had provided for that purpoſe, and perceiv'd it to Shine whilſt it was beneath the Surface of that Liquor, and this I did divers times. But when I indeavour'd to produce a Light by rubbing it upon the lately mentioned Cover of the Box, the Stone and it being both held beneath the Surface of the Water, I did not well ſatisfie my ſelf in the Event of the Trial; But this I found, if I took the Stone out, and Rubb'd it upon a piece of Cloath, it would not as elſe it was wont to do, preſently acquire a Luminouſneſs, but needed to be rubb'd manifeſtly much longer before the deſired Effect was found.
Sixteenthly, I alſo try'd ſeveral times, that by covering it with my warm Spittle (having no warm Water at hand) it did not loſe his Light.41
Seventeenthly, Finding that by Rubbing the Stone with the Flat ſide downwards, I did by reaſon of the Opacity of the Ring; and the ſudden Decay of Light upon the ceaſing of the Attrition, probably loſe the ſight of the Stones greateſt Vividneſs; and ſuppoſing that the Commotion made in one part of the ſtone will be eaſily propagated all over, I ſometimes held the piece of Cloath upon which I rubb'd it, ſo, that one ſide of the Stone was expoſed to my Eye, whilſt I was rubbing the other, whereby it appear'd more Vivid than formerly, and to make Luminous Tracts by its Motions too and fro. And ſometimes holding the Stone upwards, I rubb'd its Broad ſide with a fine ſmooth piece of Tranſparent Horn, by which means the Light through that Diaphanous Subſtance, did whilſt I was actually rubbing the Stone, appear ſo Brisk that ſometimes and in ſome places it ſeem'd to have little Sparks of fire.
Eighteenthly, I took alſo a piece of flat Blew Glaſs, and having rubb'd the Diamond well upon a Cloath, and nimbly clapt the Glaſs upon it, to try whether in caſe the Light could peirce it, it would by appearing Green, or of ſome other Colour than Blew, aſſiſt me to gueſs whether it ſelf were ſincere or no. But finding the Glaſs impervious to ſo faint a Light, I then thought it fit to try whether that hard Bodies would not by Attrition increaſe the Diamonds Light ſo as to become penetrable thereby, and accordingly when I rubb'd the Glaſs briskly upon the Stone, I found the Light to be Conſpicuous enough, and ſomewhat Dy'd in its paſſage, but found it not eaſie to give a Name to the Colour it exhibited.
Laſtly, To comply with the Suſpition I had upon the whole Matter, that the chief manifeſt Change wrought in the Stone, was by Compreſſion of its parts, rather than Incaleſcence, I took a piece of white Tile well Glaz'd, and if I preſs'd the Stone hard againſt it, it ſeem'd though I did not rub it to and fro, to ſhine at the Sides: And however it did both very manifeſtly and vigorouſly Shine, if whilſt I ſo preſs'd it, I mov'd it any way upon the Surface of the Tile, though I did not make it draw a Line of above a quarter of an Inch long, or thereabouts. And though I made it not move to and fro, but only from one end of the ſhort Line to the other, without any return or Lateral motion. Nay, after it had been often rubb'd, and ſuffer'd to loſe its Light again, not only it ſeem'd more eaſie to be excited than at the beginning of the Night; but if I did preſs hard upon it with my Finger, at the very inſtant that I drew it briskly off, it would diſcloſe a very Vivid but exceeding ſhort Liv'd Splendour, not to call it a little Coruſcation.42 So that a Carteſian would ſcarce ſcruple to think he had found in this Stone no ſlight Confirmation of his Ingenious Maſters Hypotheſis, touching the Generation of Light in Sublunary Bodies, not ſenſibly Hot.
A Poſtſcript.
Annexed ſome Hours after the
Obſervations were Written.
So many particulars taken notice of in one Night, may make this Stone appear a kind of Prodigie, and the rather, becauſe having try'd as I formerly noted, not only a fine Artificial Cryſtal, and ſome alſo that is Natural, but a Ruby and two Diamonds, I did not find that any of theſe diſclos'd the like Glimmering of Light;43 yet after all, perceiving by the Hardneſs, and the Teſtimony of a Skilfull Goldſmith, that this was rather a Natural than Artificial Stone; for fear leſt there might be ſome difference in the way of Setting, or in the ſhape of the Diamonds I made uſe of, neither of which was like this, a flat Table-ſtone, I thought fit to make a farther Trial of my own Diamonds, by ſuch a brisk and aſſiduous Affriction as might make amends for the Diſadvantages above-mention'd, in caſe they were the cauſe of the unſucceſsfulneſs of the former Attempts: And accordingly I found, that by this way I could eaſily bring a Diamond I wore on my Finger to diſcloſe a Light, that was ſenſible enough, and continued ſo though I cover'd it with Spittle, and us'd ſome other trials about it. And this will much leſſen the wonder of all the formerly mention'd Obſervations, by ſhewing that the properties that are ſo ſtrange are not peculiar to one Diamond, but may be found in others alſo, and perhaps in divers other hard and Diaphanous Stones. Yet I hope that what this Diſcovery takes away from the Wonder of theſe Obſervations, it will add to the Inſtructiveneſs of them, by affording pregnants Hints, towards the Inveſtigation of the Nature of Light.
FINIS.
Notes.
1 L. Annæ Senecæ Natur. Queſt. l. 6. c. 5.
2 He that deſires more inſtances of this kind and matter, that according to this doctrine may much help the Theory of colours, and particularly the force both of Sulphureous and volatile, is likewiſe of Alcalizate and Acid Salts, and in what particulars, Colours likely depend not in the cauſation from any Salt at all, may beg his information from M. Boyle who hath ſome while ſince honoured me with the ſight of his papers concerning this ſubject, containing many excellent experiments, made by him for the Elucidation of this doctrine, &c Dr. R. Sharrock in his ingenious and uſefull Hiſtory of the Propagation and Improvement of Vegetables, publiſhed in the yeare 1660.
3 See the Diſcourſe of the Nature of Whiteneſs and Blackneſs.
4 Since for his eminent Qualities and Loyalty Grac'd, by his Majeſty, with the Honour of Knighthood.
5 Exercitat. 325 Parag. 4
6 Album quippe & agrum, hoc quidem aſperum eſſe dicit, hoc vero læve. de Senſu & Senſib. 3. 3.
7 Epist. 2. pag. 45.
8 Gent. Septen. Hiſtor. lib. 4 cap. 13.
9 Hiſt. Anatom. Cent. 3. Hiſt. 44.
10 Olearius Voyage de Moſco. et de Perſe liv. 3.
11 Piſo Nat. & Med. Hiſt. Braſil. lib 1. in fine.
12 Purchas Pilgrim. Second part, Seventh Book 3. Chap. Sect 5.
13 Purchas. Ibid.
14 Purchas Ibid. in fin
15 See Scaliger Exercit. 325. Sect. 9.
16 Nicolaus Monardes lib ſimplic. ex India allatis, cap. 27.
17 Kircher. Art. Mag. lucis & umbræ, lib. 1. part. 3.
18 Herbariſts are wont to call this Plant Cyanus vulgaris minor.
19 Paracelſus de Mineral. tract. 1. pag. m. 243
20 See Parkinſon Th. Boran. Trib. 9. cap. 26.
21 Parkinſon, Thea. Bot. Trib. 4 cap. 12.
22 Beguinus, Tyr. Chy. Lib. 2º. Cap. 13º.
23 Libr. 2do Cap. 34.
24 See the latter end of the fiftieth Experiment.
25 The Curious Reader that deſires further Information concerning Lakes, may Reſort to the 7th Book of Neri's Art of Glaſs, Engliſhed (6 or 7 years ſince the Writing of this 49th Experiment) and Illuſtrated with Learned Obſervations, by the Inquiſitive and experienc'd Dr. Charles Merret.
26 Boetius de Boot. Gem. & Lapid. Hiſtor. Lib. 3. Cap. 8.
27 Musæi Wormiani. Cap. 17.
28 Purchas's Pilgrim. lib. 1. cap. 4. pag. 104.
29 In the year 1619.
30 Benvonuto Cellini nell Arte del Gioiellare, Lib. 1. pag. 10.
31 The Narrative in the Authors own words, is this. Ego (ſayes he) ſanctè affirmare poſſum me unam aureo Annulo incluſam perpetuo geſtare, cujus facultatem (ſi gemmæ eſt) nunquam ſatis admirari potui. Geſtaverat enim ante Triginta annos Hiſpanus quidam non procula puternis ædibus habitans. Is cum vitâ functus eſſet, & ipſius ſuſpellex (ut moris apud nos eſt) venum expoſita eſſet, inter cætera etiam Turcois exponebatur. Verum nemo (licet complures eo concurriſſent, ut eam propter Coloris Elegantiam, quam vivo Domino habuerat emerent) ſibi emptam voluit, priſtinum enim nitorem & Colorem prorſus amiſerat, ut potius Malachites, quam Turcois videretur. Aderat tum temporis gemmæ habendæ deſiderio etiam parens & frater meus, qui antea sæpius gratiam & elegantiam ipſius viderant, mirabundi eam nunc tam eſſe deformem, Emit eam nihilominus pater, ſatiſque vili pretio, qua omnibus contemptui erat, ac preſentes non eam eſſe quam Hiſpanus geſtarat, arbitrarentur. Domum reverſus Pater, qui tam turpem Gemmam geſtare ſibi indecorum putabat, eam mihi dono dat, inquiens; Quandoquidem, fili mi, vulgi fama eſt, Turcoidem, ut facultates ſuas exercere poſſit, dono dari debere tibi eam devoveo, ego acceptam Gemmam ſculptori trado, at gentilitia mea inſignia illi, quamadmodum fieri ſolet, in Jaſpide Chalcedono, aliiſque Ignobilioribus Gemmis, inſculperat. Turpe enim exiſtimabam, hujuſmodi Gemmâ ornatus gratia, dum gratiam nullam haberet, uti. Paret Sculptor redditque Gemmam, quam geſto pro annulo Signatorio. Vix per menſem geſtaram, redit illi priſtinus color, ſed non ita nitens propter Sculpturam, ac inæqualem ſuperficiem. Miramur omnes gemmam, atque id præcipuè quod color indies pulchrior fieret. Id quià obſervabam, nunquam fere eam à manu depoſui, ita ut nunc adhuc candem geſtem.
32 Olaus Wormius, in Musæ. 18º pag. 186.
33 Musæ. Worm. pag. 99.
34 Arte Vetraria, lib. 7 cap. 102.
35 Theſe were brought in and Read before the Royal Society, (the Day following) Oct. 28. 1663.
36 The Stone it ſelf being to be ſhown to the Royal Society, when the Obſervations were deliver'd, I was willing (being in haſte) to omit the Deſcription of it, which is in ſhort, That it was a Flat or Table Diamond, of about a third part of an Inch in length, and ſomewhat leſs in breadth, that it was a Dull Stone, and of a very bad Water, having in the Day time very little of the Vividneſs of ev'n ordinary Diamonds, and being Blemiſhed with a whitiſh Cloud about the middle of it, which covered near a third part of the Stone.
37 Haſt made me forget to take notice that I went abroad the ſame Morning, the Sun ſhining forth clear enough, to look upon the Diamond though a Microſcope, that I might try whether by that Magnifying Glaſs any thing of peculiar could be diſcern'd in the Texture of the Stone, and eſpecially of the whitiſh Cloud that poſſeſt a good part of it. But for all my attention I could not diſcover any peculiarity worth mentioning.
38 V. For it drew light Bodies like Amber, Jet, and other Concretes that are noted to do ſo; But its attractive power ſeem'd inferiour to theirs.
39 IX. We durſt not hold it in the Flame of a Candle, no more than put it into a naked Fire; For fear too Violent a Heat (which has been obſerv'd to ſpoil many other precious Stones) ſhould vitiate and impair a Jewel, that was but borrow'd, and was ſuppos'd to be the only one of its Kind.
40 XV. We likewiſe Plung'd it as ſoon as we had excited it, under Liquors of ſeveral ſorts, as Spirit of Wine, Oyl both Chymical and expreſs'd, an Acid Spirit, and as I remember an Alcalizate Solution, and found not any of thoſe various Liquors to deſtroy its Shining property.
41 XVI. Having found by this Obſervation, that a warm Liquor would not extinguiſh Light in the Diamond, I thought fit to try, whether by reaſon of its warmth it would not excite it, and divers times I found, that if it were kept therein, till the Water had leiſure to communicate ſome of its Heat to it, it would often ſhine as ſoon as it was taken out, and probably we ſhould have ſeen it Shine more, whilſt it was in the Water, if ſome degree of Opacity which heated Water is wont to acquire, upon the ſcore of the Numerous little Bubbles generated in it, had not kept us from diſcerning the Luſtre of the Stone.
42 I after bethought my ſelf of imploying a way, which produc'd the deſir'd Effect both ſooner and better. For holding betwixt my Fingers a Steel Bodkin, near the Lower part of it, I preſs'd the point hard againſt the Surface of the Diamond, and much more if I ſtruck the point againſt it, the Coruſcation would be extremely ſuddain, and very Vivid, though very Vaniſhing too, and this way which commonly much ſurpris'd and pleas'd the Spectators, ſeem'd far more proper than the other, to ſhow that preſſure alone, if forcible enough, though it were ſo ſuddain, and ſhort, that it could not well be ſuppos'd to give the Stone any thing near a ſenſible degree of Warmth, as may be ſuſpected of Rubbing, yet 'tis ſufficient to generate a very Vivid Light.
43 We afterwards, try'd precious Stones, as Diamonds, Rubies, Saphires, and Emeralls, &c. but found not any of them to Shine except ſome Diamonds, and of theſe we were not upon ſo little practice, able to fore-tell before hand, which would be brought to Shine, and which would not; For ſeveral very good Diamonds, either would not Shine at all, or much leſs than others that were farr inferiour to them. And yet thoſe Ingenious Men are miſtaken, that think a Diamond muſt be foul and cloudy, as Mr. Claytons was, to be fit for Shining; for as we could bring ſome ſuch to afford a Glimmering Light, ſo with ſome clear and excellent Diamonds, we could do the like. But none of thoſe many that we try'd of all Kinds, were equal to the Diamond on which the Obſervations were made, not only conſidering the degree of Light it afforded, but the eaſineſs wherewith it was excited, and the Comparatively great duration of its Shining.