Page:Philosophical Transactions - Volume 024.djvu/666

A tall Receiver being provided about 21 Inches high, to whose upper Orifice was screw'd a Glass, resembling those now commonly us'd for Cupping, having an open Passage through the Neck of it; in which Passage was Cemented a piece of small Tube, drawn taper to one end by the flame of a Candle, which with the Cup then made an entire Funnel. The small Aperture of which was stopt with a round piece of a Stick as a Plug, to prevent the Mercuries entring the Receiver before its time. Within this tall Recipient was included a Glass about the height of 17 Inches, with a Round Crown like a Shade, (as they generally call such as are put o're Images to keep them from Dust.) In this manner (see Fig. 2.) being plac'd on the Pump, and about a pound and a half of Quicksilver put into the Funnel, (presuming now to call it so,) the Air was began to be withdrawn, and in two minutes of time was sufficient to exhibit the Phænomenon. For then Loosning the Plug that stopt the Funnel, the Mercury, by the Pressure of the Air, was driven violently into the Receiver, striking strongly on the Crown of the Included Glass, which broke the Quicksilver into small Particles, descending all around the Expos'd sides of both the Glasses, appearing like a Shower of Fire in a very surprizing manner. The form of the Receiver, as well as the Included Glass, was very distinguishable by its light, and continu'd so till all the Mercury had entred thro the Funnel. What more occurr'd to my Observation was, That the Descending Mercury did more resemble the falling of Snow, by the slowness of its motion, than that of Rain. That none of it appear'd luminous but what descended Contiguous to the sides of the Glasses. That the Globules of Mercury de-scended