[ I 59 ] 
In a Pint-Bottle of Flint-Glafs I have fome fmall 
Pieces of brafs Leaf, and the Bottle hermetically 
fealed. Upon trying whether the excited Tube would 
much affeCt the faid Leaf, I was at firfl difappointed 
in my Expectations ; for tho’ the Tube was fo well ex- 
cited, as that, upon bringing it near the Bottle, firong 
and loud Snaps were given, there was hardly any 
fenfible Motion in the brais Leaf, till I thought of 
warming the Bottle at the Fire ; and then there was 
a confiderable one, tho’ not what I expected before I 
made any Trial. But I fufpedt the Bottle to be too 
thick ; for, on trying a common Flask, which wefealed 
in the Fire, the Leaf which I had put in was very ftrongly 
both attracted and repelled a great many times. 
One odd Circumftance I will tell you, and detain 
you no longer: Upon my lifting up the Tube haftily 
by chance, I obferved the Leaf to be powerfully at- 
tracted by the Sides of the Bottle or Flask next to the 
Tube: This put me on trying purpofely what the 
Effect would be, if, when a Perfon held Either in his 
Hand Tideways, fo as the Neck was parallel with the 
Horizon ; I took the excited T ube, and moved it 
up and down towards and from the Floor, at 3 or 4 
Inches from the Bottle, fuceeffively, as faft as I could, 
without hazarding my ftriking againft it ; upon which 
the brafs Leaf was as fuceeffively attracted and repel- 
led, or feemed to follow the Motion of the Tube, 
or was affeCted, as it would have been if I had beat 
the Air upon it, tho’ in a very inferior Degree, as 
you will fuppofe ; and thus it would be, if the Tube 
was held at a greater Diftance 5 and in the Flask, I 
carried my Hand fo as that the Tube deferibed a 
Circle about it, at the Diftance of 6 or 7 Inches, the 
Whole of the Leaf would be put into a conftantj re- 
X gular 
