Thus (for Instance) Black and White differingly mix'd, make a Vast company of Lighter and Darker Grays.

Blew and Yellow make a huge Variety of Greens.

Red and Yellow make Orange Tawny.

Red with a little White makes a Carnation.

Red with an Eye of Blew, makes a Purple; and by these simple Compositions again Compounded among themselves, the Skilfull Painter can produce what kind of Colour he pleases, and a great many more than we have yet Names for. But, as I intimated above, 'tis not my Design

to prosecute this Subject, though I thought it not unfit to take some Notice of it, because we may hereafter have occasion to make use of what has been now deliver'd, to illustrate the Generation of Intermediate Colours; concerning which we must yet subjoyn this Caution, that to make the Rules about the Emergency of Colours, fit to be Relied upon, the Corpuscles whereof the Pigments consist must be such as do not Destroy one anothers Texture, for in case they do, the produced Colour may be very Different from that which would Result from the Mixture of other harmless Pigments of the same Colours, as I shall have Occasion to shew ere long.

EXPERIMENT XIII.

It may also give much light to an Enquirer into the Nature of Colours, to know that not only in Green, but in many (if not all) other Colours, the Light of the Sun passing through Diaphanous Bodies of differing Hues may be tinged of the same Compound Colour, as if it came from some Painters Colours of the same Denomination, though this later be exhibited by Reflection, and be (as the

former Experiment declares) manifestly Compounded of material Pigments. Wherefore to try the Composition of Colours by Trajection, we provided several Plates of Tinged Glass, which being laid two at a time one on the top of another, the Object look'd upon through them both, appear'd of a Compounded Colour, which agrees well with what we have observ'd in the second Experiment, of Looking against the Light through differingly Colour'd Papers. But we thought the Experiment would be more Satisfactory, if we procur'd the Sun-beams to be so Ting'd in their passage through Plates of Glass, as to exhibit the Compounded Colour upon a Sheet of White Paper. And though by reason of the Thickness of the Glasses, the Effect was but Faint, even when the Sun was High and Shin'd forth clear, yet, we easily remedied that by Contracting the Beams we cast on them by means of a Convex Burning-glass, which where it made the Beams much converge Increas'd the Light enough to make the Compounded Colour very manifest upon the Paper. By this means we observ'd, that the Beams trajected through Blew and Yellow compos'd a Green, that an intense and moderate Red did with Yellow make differing

degrees of Saffron, and Orange Tawny Colours, that Green and Blew made a Colour partaking of both, such as that which some Latin Writers call Pavonaceus, that Red and Blew made a Purple, to which we might add other Colours, that we produc'd by the Combinations of Glasses differingly Ting'd, but that I want proper Words to express them in our Language, and had not when we made the Tryals, the Opportunity of consulting with a Painter, who perchance might have Suppli'd me with some of the terms I wanted.