Made this 27th.[a]35] of October 1663. about Mr. Clayton's Diamond.[a]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 Morning[a]37] 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.[a]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.