is more pervious to the Light in the Neck. Nay, I remember, that I once had
a Glass and a Blew Liquor (consisting chiefly (or only, if my memory
deceive me not,) of a certain Solution of Verdigrease) so fitted for my
purpose, that though in other Glasses the Experiment would not succeed, yet
when that particular Glass was fill'd with that Solution, in the Body of
the Vial it appear'd of a Lovely Blew, and in the neck, (where the Light
did more dilute the Colour,) of a manifest Green; and though I suspected
there might be some latent Yellowness in the substance of the neck of the
Glass, which might with the Blew compose that Green, yet was I not
satisfi'd my self with my Conjecture, but the thing seem'd odd to me, as
well as to divers curious persons to whom it was shown. And I lately had a
Broad piece of Glass, which being look'd on against the Light seem'd clear
enough, and held from the Light appear'd very lightly discolour'd, and yet
it was a piece knock'd off from a great lump of Glass, to which if we
rejoyn'd it, where it had been broken off, the whole Mass was as green as
Grass. And I have several times us'd Bottles and stopples that were both
made (as those, I had them from assur'd me) of the very same Metall, and
yet whilst the bottle appear'd but inclining towards a Green, the Stopple
(by reason of its great thickness) was of so deep a Colour that you would
hardly believe they could possibly be made of the same materials. But to
satisfie some Ingenious Men, on another occasion, I provided my self of a
flat Glass (which I yet have by me,) with which if I look against the Light
with the Broad side obverted to the Eye, it appeares like a good ordinary
window Glass; but if I turn the Edge of it to my Eye, and place my Eye in a
convenient posture in reference to the Light, it may contend for deepness
of Colour with an Emerald. And this Greeness puts me in mind of a certain
thickish, but not consistent Pigment I have sometimes made, and can show
you when you please, which being dropp'd on a piece of White Paper appears,
where any quantity of it is fallen, of a somewhat Crimson Colour, but being
with ones finger spread thinly on the Paper does presently exhibit a fair