Page:Philosophical Transactions - Volume 024.djvu/669

not only the Receiver and Included Glass were distinguishable by it, but Hands and Fingers on the outside were so too. It is to be observ'd, that altho the Quicksilver would give a Light upon a small motion, yet would that Light be inhanc'd by the encrease of that Motion. What farther occurr'd was, That when a pretty brisk Agitation of the Mercury was given, it would resemble Waves of Light breaking on the sides of the Glass, scattering some Species of the same Appearance towards the upper part of it. That upon the Repetition of the Experiment three or four times, the Phosphores seem'd every time to be more Vivid than other, till at last, by often shaking the Quicksilver, its surface became something solid, rendring the Light less then, than it had before. That in this, as well as in all other Mercurial Experiments, the Light Exhibited is of a very pale Colour. That the first Appearance of this Light, is, when about half the Air contain'd in the Recipient is exhausted, which still encreases with the Rarefaction; And Confirms with all the rest, the Necessity of a Rarefy'd Air to such a degree, to Produce the Mercurial Phosphore, concurring with that made by the Motion of the Quicksilver in the Weather-glass.

The Account already given of this Experiment, so far as occurr'd at the first time of making, leaves me but little room to add more. However, altho but little, 'tis too deserving to pass it by in silence: The Appearance of it being not only very surprizing, but Distinguishably the Clearest and most Vivid Light in all the Mercurial Phosphori, Produc'd in Rarefy'd Air. The Description of the Receiver, Included Glass, and Funnel, being before given, I shall directly proceed to my farther Observations on the Ex-peri-