[ 356 ] 
other refpeCts, there appears to be fuch a refemblance 
between the Leyden phial, or the electrical pane of 
glafs, and the black hocking in conjunction with the 
white, efpecially when the one is within the other, 
that I have been induced to conlider them both in the 
fame light. In both cafes, the pojith ve eleCtricity is 
on the one fide, and the negative on the other; and 
the dockings, as well as the phial, and the pane of 
glafs, are at once electrified pojitively and negatively. 
In both cafes there is 'an accumulation of eleCtricity, 
and a retention of it, fir beyond what is to be met 
with in a fimple body, eleCtric or non*eleCtric. There 
is, however, a very remarkable difference between 
them in two refpeCts. In the phial, and in the pane 
of glafs, an explofion is always obtained by carrying 
on a communication between the two fides by the in- 
terpofi tion of a non-eleCtric ; but, in the cafe of the 
black flocking and the white, I never yet have been 
able to procure an explofion, nor fo much as a fpeedy 
difeharge, by any means I could think of, while the 
one was within the other. I have put one hand 
within the innermoft, and with my other have clafped 
the outward flocking ; nay, I have thrufl in my 
hand, and turned the dockings infide out, and, in 
that condition, have dafhed them againd the floor ; 
and all this without procuring the lead perceptible 
difeharge. On the other hand, the phial and the 
pane of glafs afford no opportunity of feparating the 
pofitive from the negative eleCtricity, fo as to fhew 
them intire and diflinCt from each other; whereas 
we need only pull the dockings afunder, and then in 
the white we find the pofitive , and in the black the 
negative eleCtricity. 
6 ®. 
