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XXII. Experiments and Obfervations on Electricity. By Mr. 
William Nicholfon ; communicated by Sir Jofeph Banks* 
Bart . P. R. S. 
Read June 25, 1789* 
Sect, I. On the Excitation of Electricity. 
x. A GLASS cylinder was mounted, and a cufhion ap'» 
plied with a filk flap, proceeding from the edge of 
the cufhion over its furface, and thence half round the cylin- 
der. The cylinder was then excited by applying an amal- 
gamed leather in the ufual manner. The electricity was re- 
ceived by a conductor, and pafled off* in fparks to - Lane’s 
electrometer. By the frequency of thefe fparks, or by the 
number of turns required to caufe fpontaneous explofion of a 
jar, the ftrength of the excitation was afcertained. 
2. The cufhion was withdrawn about one inch from the 
cylinder, and the excitation performed by the filk only. A 
ftream of fire was feen between the cufhion and the filk ; and 
much fewer fparks pafled between the balls of the eleCtro- 
meter. 
i 
3. A roll of dry filk was interpofed, to prevent the ffream 
from pafling between the cufhion and the filk. Very few fparks 
then appeared at the electrometer* 
4. A metallic rod, not infulated, was then interpofed, in- 
ftead of the roll of filk, fo as not to touch any part of the 
apparatus. 
