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b; ought near fome gi dcd Learher lying upon the 
piimc Condudor. 1 his Exploiion was equal to that 
trom the three Glades before- mention'd, containing a 
hundred and fifty Pounds of leaden Shot; though 
icie the Weight of the Silver lining the internal 
surface of the (dials, upon which the Eledricity was 
accumulated, did not exceed thirty Grains. So 
much or the internal Surface of this Jar, as was co- 
vered with Silver, amounted, as the Surfaces of 
Cylinders are as their Length multiplied by their 
1 enphery, and allowing thirty fix fquare Inches for 
the Bottom to three hundred and fix fquare Inches, 
it tins' Exploiion was made in a dark Room, the 
Corruicaaons within the Jar, at the Inftant of the 
Expioiion, were extremely brilliant. 
When this Jar is fully elcdriled, if, indead of 
making it explode, you only bring the fhort iron 
Rod, with which the Exploiion isufually made, near 
a Piece of gilded Leather lying upon the prime Con- 
ductor, though not near enough to make the Glafs 
explode at once, you hear the Eledricity, accumu- 
nted within the Jar, efcape with a Noife very like 
Water' * lleateci iron Bar quenching in 
§ XIV. The great Exploiion from the Tar before- 
mention d, when fo little non-eledric Matter was 
included therein, has caufed me to be of Opinion, 
that the Effed of what wc call the Experiment of 
Leyden is greatly increafed, if nor principally owin<% 
not lo much to the Quantity of non-eledrical Mat- 
ter contained in the Glafs, as to the Number of Points 
of 
i. 
