[ *43 ] 
The permanence of either kind of eledricity \n 
the clouds, or the length of time in. which neither 
can be difcovered, is uncertain ; fometimes the fame 
eledricity has returned, and at other times has been 
fucceeded by the contrary ; whilft either generally 
came on, and went off gradually. Rut changes were 
often made, very fuddenly, by a flafli of lightning, 
efpecially if the thunder- dorm happened to be in 
the zenith. A branch of it, over-head, has fre- 
quently occafioned dronger electricity than I could 
difcover, when the g mated part of the fky had been 
overcad ; which, perhaps, might be accounted for, 
from this con fide ration, that one kind of eledricity 
ading alone, mull exert more powerful effeds than 
when counteraded by the other. 
I once obferved in a thunder-ftorm, during which 
I faw no lightning, that the balls, which hung 
from the tin tube, repelled and atiraded each other, 
very rapidly, for the fpace of ten or twelve feconds ; 
at the fame time, Mr. Canton’s eiedrometer, which 
I held at fuch a didance from the tube, as to have its 
balls opened to the didance of an inch, continued quiet 
in that date, and were not affeded convuldvely like 
the others. Hence I imagined, that the fame kind 
of eledricity went off, and came on, without being > 
changed in contrarium ; for when that circumdance 
happened, they were very evidently affeded in the 
fame manner. And here I mud obferve, that 
I have found it more eafy to difcover the kind of 
eledricity prefent in the tube, by approaching ex- 
cited wax to the balls of an eiedrometer, which I 
held at a proper didance from the tube, than by ap- 
plying it near the bails which hung from the tube ; 
for ' 
