Experiments and Considerations Touching Colours - Couverture souple

Boyle, Robert

9781428015739: Experiments and Considerations Touching Colours

Couverture souple

ISBN 10 : 1428015736 ISBN 13 : 9781428015739

Editeur : IndyPublish, 2006

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Excerpt: ... but yet the same Vivid Colours would appear in the Displac'd part (if I may so term it) as in the other. To which I shall add, that having, by hiding the side of the Prism, obverted to the Sun with an Opacous Body, wherein only one small hole was left for the Light to pass through, reduc'd the Prismatical Iris (cast upon White Paper) into a very narrow compass, and look'd upon it througn a Microscope; the Colours appear'd the same as to kind that they did to the naked Eye. pg 194 EXPERIMENT VI. It may afford matter of Speation to the Inquisitive, such as you, Prophilus, that as the Colours of outward Objects brought into a Darken'd Room, do so much depend for their ibility upon the Dimness of the Light they are there beheld by; that the ordinary Light of the day being freely let in upon them, they immediately disappear: so our Tryals have inform'd us, that as to the Prismatical Iris painted on the Floor by the beams of the Sun Trajected through a Triangular-glass; though the Colours of it appear very Vivid ev'n at Noon-day, and in Sun shiny Weather, yet by a more Powerfull Light they may be made to disappear. For having sometimes, (in prosecution of some Conjectures of mine not now to be Insisted on, ) taken a large Metalline Concave Speum, and with it cast the converging Beams of the Sun upon a Prismatical Iris which I had caus'd to be projected upon the Floor, I found that the over-powerfull Light made the Colours of the Iris disappear. And if I so Reflected the Light as that it cross'd but the middle of the Iris, in that part only the Colours vanish'd or were made Inible; those pg 195 parts of the Iris that were on the right and left hand of the Reflected Light (which seem'd to divide them, and cut the Iris asunder) continuing to exhibit the same Colours as before. But upon this we must not now stay to Speate. EXPERIMENT VII. I have sometimes thought it worth while to take notice, whether or no the Colours of Opacous Bodies might...

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