Thus much I find in our above mention’d Collections, among which there are also some Notes concerning the Production of Compounded Colours, by Reflection from Bodyes differingly Colour’d. And these Notes we intended should supply us with what we should mention as our second Experiment: but having lost the Paper that contain’d the Particulars, and remembring onely in General, that if the Objects which Reflected the Light were not Strongly Colour’d and somewhat Glossy, the Reflected Beams would not manifestly make a Compounded Colour upon the Wall, and even then but very Faintly, we shall now say no more of that Matter, only reserving our selves to mention hereafter the Composition of a Green, which we still retain in Memory.
EXPERIMENT II.
We may add, Pyrophilus, on this Occasion, that though a Darken’d Room be Generally thought requisite to make the Colour of a Body appear by Reflection from another Body, that is not one of those that are commonly agreed upon to be Specular (as Polish’d Metall, Quick silver, Glass, Water, &c.) Yet I have often observ’d that when I wore Doublets Lin’d with some silken Stuff that was very Glossy and Vividly Colour’d, especially Red, I could in an Inlightned Room plainly enough Discern the Colour, upon the Pure White Linnen that came out at my Sleeve and reach’d to my Cufs; as if that Fine White Body were more Specular, than Colour’d and Unpolish’d Bodyes are thought Capable of being.
EXPERIMENT III.
Whilst we were making the newly mention’d Experiments, we thought fit to try also what Composition of Colours might be made by Altering the Light in its Passage to the Eye by the Interposition not of Perfectly Diaphanous Bodies, (that having been already try’d by others as well as by us (as we shall soon have occasion to take notice) but of Semi-opacous Bodyes, and those such as look’d upon in an ordinary Light, and not held betwixt it and the Eye, are not wont to be Discriminated from the rest of Opacous Bodyes; of this Tryal, our mention’d Adversaria present us the following Account.
Holding these Sheets, sometimes one sometimes the other of them, before the Hole betwixt the Sun and the Eye, with the Colour’d sides obverted to the Sun; we found them single to be somewhat Transparent, and appear of the same Colour as before, onely a little alter’d by the great Light they were plac’d in; but laying two of them one over another and applying them so to the Hole, the Colours were compounded as follows.
The Blew and Yellow scarce exhibited any thing but a Darker Yellow, which we ascrib’d to the Coarseness of the Blew Papers, and its Darkness in its Kind. For applying the Blew parts of the Marbl’d Paper with the Yellow Paper after the same manner, they exhibited a good Green.
The Yellow and Red look’d upon together gave us but a Dark Red, somewhat (and but a little,) inclining to an Orange Colour.