[ 40i ] 
or negatively ; or as the conductor, from which it 
charged, is electrified. Tab. xiv. fig. 5. letter A. 
fhews fuch a bottle, charging negatively, at a con- 
ductor, loaded with pofitive electricity. Letter B. 
fhews the fame bottle, charging positively , at the 
fame conductor. 
Tab. xiv. fig. 6. letter C. fhews the bottle 
charging pojitively at a conductor, electrified nega- 
tively ; or at the infulated rubber. Letter D. fhews 
the fame bottle, charging negatively at the fame 
conductor. 
SECTION THIRD. 
Of the lateral explosion in the difeharge of the leyden 
BOTTLE. 
EXPERIMENT I. 
H AVING made a double circuit, the firft by an 
iron bar, one inch and an half in diameter, and 
half an inch thick ; the fecond, by four feet and an 
half of fmall chain ; on difeharging ajar, containing 
five hundred fquare inches of coated furface, the 
eleCtricity palfed in both circuits, fparks being vi- 
fible on the fmall chain in many places. On 
making the difeharge of three jars, containing 
together fixteen fquare feet of coated furface, 
through three different chains at the fame time , 
tab. xiii. fig. 7. bright fparks were vifible in 
them all ; and I have not the leaft doubt, but it 
would have been vifible in as many more. The 
chains were of iron and brafs, of very different 
lengths; the fhortefl ten, or twelve inches, the 
Vol. LXIV. Fff longeft. 
