ncident green
Light, will cause those Rays to abound so much in the reflected Light,
as to draw the Colour from red towards their Colour. And because the red
Lead reflects the red-making Rays most copiously in proportion to their
number, and next after them the orange-making and yellow-making Rays;
these Rays in the reflected Light will be more in proportion to the
Light than they were in the incident green Light, and thereby will draw
the reflected Light from green towards their Colour. And therefore the
red Lead will appear neither red nor green, but of a Colour between
both.

In transparently colour'd Liquors 'tis observable, that their Colour
uses to vary with their thickness. Thus, for instance, a red Liquor in a
conical Glass held between the Light and the Eye, looks of a pale and
dilute yellow at the bottom where 'tis thin, and a little higher where
'tis thicker grows orange, and where 'tis still thicker becomes red, and
where 'tis thickest the red is deepest and darkest. For it is to be
conceiv'd that such a Liquor stops the indigo-making and violet-making
Rays most easily, the blue-making Rays more difficultly, the
green-making Rays still more difficultly, and the red-making most
difficultly: And that if the thickness of the Liquor be only so much as
suffices to stop a competent number of the violet-making and
indigo-making Rays, without diminishing much the number of the rest, the
rest must (by _Prop._ 6. _Part_ 2.) compound a pale yellow. But if the
Liquor be so much thicker as to stop also a great number of the
blue-making Rays, and some of the green-making, the rest must compound
an orange; and where it is so thick as to stop also a great number of
the green-making and a considerable number of the yellow-making, the
rest must begin to compound a red, and this red must grow deeper and
darker as the yellow-making and orange-making Rays are more and more
stopp'd by increasing the thickness of the Liquor, so that few Rays
besides the red-making can get through.

Of this kind is an Experiment lately related to me by Mr. _Halley_, who,
in diving deep into the Sea in a diving Vessel, found in a clear
Sun-shine Day, that when he was sunk many Fathoms deep into the Water
the upper part of his Hand on which the Sun shone directly through the
Water and through a small Glass Window in the Vessel appeared of a red
Colour, like that of a Damask Rose, and the Water below and the under
part of his Hand illuminated by Lig