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my Eyes as if 1 would look at something afar off bcyond them, therdjy t»render the Vision confused, the Froth has appeared without any other O®-lour thau Whkeneß. And what is here siid df Froth«, may easily be uoder--stood of the Paper or Metal, in the foregoing Experiments. For their par»*»Specular Bodies, like theso Bubbles; And perhaps with an excellent Micro-fcope, the Colouvs may be also soen intermixedly Reflebied from them.

In proportioning the feverally Coloured Bodies to produce theso eflccts, therrmay besome Nicenefs; and it will be more conveniant,tomake uso of theColoursof the Prilm, cast on a Wall, by whose Reflexion the Paper, Metal, Froth, andother White Substances may be illuminated. And I usoally made my tryalsthis way, because 1 could better exclude any fcattering Light from mixingwithilie Colours to dilate them.

To this way of Compounding Whitends, may be referred that other, byMixing Light aster it hath been trajected through tranlparently Colouredsiubstances. For Instance, if no Ligiit be admitted into a Room but onlythrough Coloured Olals; whose feveral parts are of feveral Colours inapretty•equal proportion ; all White tliings in the Room fhall appear White, if theybe not held too near the Olafs. And yet this Light, with whidithey are illu-minated, cannot poflibly be Uniform ; becauso, if the Rays, which at theirentrance are of divers Colours, do in their progrefs through the Room, suf-fer any alieration to be reduccd to an Uuiformity, the Olafs would not inthe remotest parts of the Room appear of the very fame Colour, which it•doth when the Spectatoris Eyc is very near it: Nor would the Rays, whentransmitted into another Dark Room through a little hole in an opposite Dooror Parrition-wall, project on a Paper the Species or Reprefentation of theGlafs in its proper Colours.

And, by the by, this feems-a very sit and cogent Instance of some otherparts of my T 'bcory, and particularly of the i jth Prcpcsition. For, in this Roomali natural Bodies wbatever appear in their proper Colours. And all thePhaenomena of Colours in Nature, made either by Refraction or without it,are here the fame as in the open Air. Now, the Light in this Room beingsocb a dillimilar Mixture,as I have desoribed in my Tbeory , the Causos of ali thefePhaenomena must be the fame that 1 have there afligned. And I see no rea-son to fuspect, that the fame Phaenomena fhould have other causos in the openAir.

The Succefs bf this Experiment, may be easily conjectured by the Ap-pcarances of things in a Chitrch or Chapel, wsiofe Windows are of ColouredGlafs ; or in the open Air, when it is illustrated with Clouds of variousColours.

There are yet other ways, by which I have produced Whitenefs ; as by Castingsoveral Colours from twoor more Prifms tipon the iame Place ; by RefractingaBeam of Light with two or three Prisins succeffively, tomake the Di verging Co-lours Converge again; by Reflecting one Colour to another; and by Lookingthrough a Prifm on an Object of many Colours; and, (which is equivalent to theabove mentioned way of mixing Colours by concave Wedges silled with Co-loured Liquors) I have obsorved the Shadows of a Painted Glafs Window to

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