( 1 1 ] 1 ) 
# tice, That the Light produc’d upon the Attrition r 
Exhaufted Tube, appear’d wholly within it ; and t 
which was difcover’d upon the Affrication of it unex- 
haufted, feem'd to be altogether on its outfide, 
\ 
Pofifcript . 
S ince this Account was wrote, I procur’d a folid Tube, 
about the bignefs and of the ' fame Metal with the 
other ; but upon tryal of it find no great Difference in its 
Operations, in comparifon with the other, only its E/» 
fluvium feem’d to continue a little longer, but attracts not 
at a greater diftance than the other that I cafi difcover. 
With this new Tube I made the following Experiment, 
I took a little Lamp black, and having dry’d it on a Pa- 
per before the Fire, and the Tube being- rubb’d till it 
was warm, then being held near the Lamp black, it was 
not without pleafure to behold the Brisk Agitation of a 
number of the Little Bodies, feeming promifcuoufly Amend- 
ing and Defcending with great velocity : And it was ad- 
mirable to fee, that Bodies fo light in fpecie, which by 
their own Gravity falling on Paper would make no fence- 
able noife, yet th£ fame return’d with fuch force from 
the Tube, that their ftriking the Paper was very au- 
dible. 
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