to or from the Light; whereas (whether it be what an Artificer would call
Over-doing, or Burning, or else the imploying the Silver Crude that makes
the Difference,) we have found more than once, that some Pieces of Glass
prepar'd as we have related, though held against the Light they appear'd of
a Transparent Yellow, yet look'd on with ones back turn'd to the Light they
exhibited an Untransparent Blew.

_EXPERIMENT XII._

If you will allow me, _Pyrophilus_, for the avoiding of Ambiguity, to
imploy the Word Pigments, to signifie such prepared materials (as
Cochinele, Vermilion, Orpiment,) as Painters, Dyers and other Artificers
make use of to impart or imitate particular Colours, I shall be the better
understood in divers passages of the following papers, and particularly
when I tell you, That the mixing of Pigments being no inconsiderable part
of the Painters Art, it may seem an Incroachment in me to meddle with it.
But I think I may easily be excus'd (though I do not altogether pass it by)
if I restrain my self to the making of a Transient mention of some few of
their Practices about this matter; and that only so far forth, as may
warrant me to observe to you, that there are but few Simple and Primary
Colours (if I may so call them) from whose Various Compositions all the
rest do as it were Result. For though Painters can imitate the Hues (though
not always the Splendor) of those almost Numberless differing Colours that
are to be met with in the Works of Nature, and of Art, I have not yet
found, that to exhibit this strange Variety they need imploy any more than
_White_, and _Black_, and _Red_, and _Blew_, and _Yellow_; these _five_,
Variously _Compounded_, and (if I may so speak) _Decompounded_, being
sufficient to exhibit a Variety and Number of Colours, such, as those that
are altogether Strangers to the Painters Pallets, can hardly imagine.

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