C 3 66 ] 
hrafs rod, at the other extremity of the tube, and by 
thefe means, upon letting the electrical machine in 
motion, the longbrafs lod in the tube was e'edtrifkd. 
When the brafs plate at the bottom of this rod was 
placed near, or even at the distance of two inches 
from the plate of the other rod, the brufhes of elec- 
trical fire were feen palling from the periphery of the 
upper plate to that of the lower, and every part of 
the air-pump fnapped upon the touch of any one 
handing upon the floor, and gave the other uluai 
figns of the accumulation of eledtricity. But, as 
thefe plates were made to recede from each other, 
this effect grew lefs and lels ; fo that, when they 
were removed five or fix inches from each other, no 
fnaps could be drawn from the air-pump ; as the 
difiipation of the eledtric fluid was now as eafy from 
every part of the prime conductor, as from the upper 
brafs plate in the tube : but it is to be noted, that 
this difiance is different, as from the weather or other 
circumftances the electricity is more or lefs firong. 
Upon exhaufting this tube, and eledtrifing as be- 
fore the air-pump fiill fianding upon cakes of wax, 
the elcdtrical fire was not only feen to pafs from 
one plate to the other at the difiance of y inches, 
but the fame eftedt enfued at the greateft difiance, 
to which in the tube the brafs plates could be drawn. 
Being therefore defirous to fee a farther efiedt, and 
to avail myfelf of the whole length of this tube, I 
took from the infide of it the fhort brafs rod, to 
which the lower brafs plate was fixed, and fafien’d 
this plate at the very bottom of the tube into the 
cap. The confequence was, that the eledtricity, 
meeting with fcarce any refiftance, palled from the 
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