: f, - 
( ttfO ') 
liave a Motion given them y but without Compari- 
fon to what it did when the Experiment was made 
with it unexhaufted of its Air. Befides, I jdoubt not 
but fome fmall quantity of Air might be left in the 
Tube, and fo the Attraction to continue in proportion to 
the .Quantity of the remaining Air. Or the Heat that is 
produc'd upon the fmart Attrition of it, may as well in 
this (I think) as in other Experiments, fupply the EffeCt 
and Space of fuch a quantity of • that Element : Upon 
letting in the Air again, it was worth taking notice. 
That before any new attrition was given the T ube, or 
was remov’d from {be Pofition and Diffance it vitas held 
in when in Vacuo, that feveral of the premention’d Bodies 
at Rdf, ( as to fence ) began fuddenly to move, . and 
were fome of them attracted to the Tube, which, upon 
a frefh attrition, its EleCtrical Quality recover’d as vigo- 
rous as at firft. Thus far the firft part of the Experi- 
ment. 
Now the Attrition of the Tube being made in the 
dark, it was very obfervable, that when the Glafs be- 
came warm, a Light would continually follow the Mo- 
tion of the Hand, backward and forward 5 and at the 
fame time, if another Hand was held near the Tube, a 
Light would be feen to break from it with noife, much 
like that of a Green Leaf in the Fire, for fmartnefs, but 
nothing fo loud : Altho when the Experiment has been 
very filently made, I have heard feveral Cracks at j or 8 
feet diffance, or more $ if any thing elfe as well as the 
Hand . was brought near it, a Light would fix upon it, 
notwithffanding it touched it not, as I have fry’d with 
Gold, Silver, Brafs, Ivory, Wood, &c. giving much 
. the fame appearance as the Hand. But after the Glafs 
came to be exhaufted of its Air, then upon the firft At- 
trition of it, a much larger did enfue 5 but the quality of 
giving a Light to a Body approacht near it, feem’d to be 
quite loft. I conclude this Experiment with taking no- 
tice, 
