Experiments and Considerations Touching Colours (1664) eBook

This eBook from the Gutenberg Project consists of approximately 260 pages of information about Experiments and Considerations Touching Colours (1664).

Experiments and Considerations Touching Colours (1664) eBook

This eBook from the Gutenberg Project consists of approximately 260 pages of information about Experiments and Considerations Touching Colours (1664).

10.  In the Fifth place then, I will inform You, that (not to repeat what Gassendus observes concerning Water) I have for Curiosity sake Distill’d Quicksilver in a Cucurbit, fitted with a Capacious Glass-head, and observ’d that when the Operation was perform’d by the Degrees of Fire requisite for my purpose, there would stick to the Inside of the Alembick a multitude of Little round drops of Mercury.  And as you know that Mercury is a Specular Body, so each of these Little drops was a small round Looking-glass, and a Multitude of them lying Thick and Near one another, they did both in my Judgment, and that of those I Invited to see it, make the Glass they were fastened to, appear manifestly a White Body.  And yet as I said, this Whiteness depended upon the Minuteness and Nearness of the Little Mercurial Globuli, the Convexity of whose Surfaces fitted them to represent in a Narrow compass a Multitude of Little Lucid Images to differingly situated Beholders.  And here let me observe a thing that seems much to countenance the Notion I have been recommending:  namely, that whereas divers parts of the Sky, and especially the Milky-way, do to the naked Eye appear White, (as the name it self imports) yet the Galaxie look’d upon through the Telescope, does not shew White, but appears to be made up of a Vast multitude of Little Starrs; so that a Multitude of Lucid Bodies, if they be so Small that they cannot Singly or apart be discern’d by the Eye, and if they be sufficiently Thick set by one another, may by their confus’d beams appear to the Eye One White Body.  And why it is not possible, that the like may be done, when a Multitude of Bright and Little Corpuscles being crowded together, are made to send together Vivid beams to the Eye, though they Shine but as the Planets by a Borrow’d Light?

11.  But to return to our Experiments.  We may take notice, That the White of an Egg, though in part Transparent, yet by its power of Reflecting some Incident Rays of Light, is in some measure a Natural Speculum, being long agitated with a Whisk or Spoon, loses its Transparency, and becomes very White, by being turn’d into Froth, that is into an Aggregate of Numerous small Bubbles, whose Convex Superficies fits them to Reflect the Light every way Outwards.  And ’tis worth Noting, that when Water, for instance, is Agitated into Froth, if the Bubbles be Great and Few, the Whiteness will be but Faint, because the number of Specula within a Narrow compass is but Small, and they are not Thick set enough to Reflect so Many Little Images or Beams of the Lucid Body, as are requisite to produce a Vigorous sensation of Whiteness:  And partly least it should be said, that the Whiteness of such Globulous Particles proceeds from the Air Included in the Froth; (which to make good, it should be prov’d that the Air it self is White) and partly to illustrate the better the Notion we have propos’d of Whiteness, I shall add, that I purposely made this Experiment,

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Experiments and Considerations Touching Colours (1664) from Project Gutenberg. Public domain.