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;[a]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.
[a]1] L. Annæ Senecæ Natur. Queſt. l. 6. c. 5.
[a]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.
[a]3] See the Diſcourſe of the Nature of Whiteneſs and Blackneſs.