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dered it a while before I went to sleep, and found it to shine vividly.
The next morning when I awaked, though the Sun was risen, yet forbearing to draw open the Curtains of my Bed 'till I had looked upon the sealed Glass, which I had fenced with a piece of Cloth held between it and the Window, my Eyes having not yet been exposed to the day-light since the darkness they had been accustomed to during the night, made me think the Wood shined brighter than ever. And this night, after ten of the Clock, looking on it in a dark place, it appeared luminous all its length, though not so much so as in the morning.
The morning after, and the night after that, the same Wood did likewise manifestly, though not vigorously shine, especially one piece, whose light was much more vivid than the rest. And, for ought I know, I might have observed them to shine longer, if one of the sealed ends of the Glass had not been accidentally broken.
Experiment VII.
Whilst the former Trials were making, I was wishing for a good Bolonian Stone, to try what effect the withdrawing of the Air would have upon it. For though I knew it might be objected, that the Experiments of Light performable in our Engine, must be made in the night, whereas the Bolonian Stone gains its light by being exposed to the Sun-beams, yet that Objection did not hinder my wish, since the better fort of Bolonian Stones may be indued with a luminousness by the flame of Fire, or of large Candles.
I also wished for such a shining Diamond, as is now in the hands that best deserve such a Rarity, our Royal Founder's. For you may remember, that in the Observations I made of that Stone, and annexed to the conclusion of the Book of Colours, I shew how it may several ways be brought to shine; so that by one or other of those ways, especially that of external Heat, I thought it very likely I should be able to make the light continue four or five minutes, which would be long enough to try in a very small Receiver, exhaustible at a Suck or two, whether the withdrawing and reflooring the Air would have any visible Operation on it?
