5i 6 Mr. henly’s Experiments and 
Mr. canton informed me, that, having excited a rod of 
glafs very ftronglv, he fet it at fome diftance from the 
fire in his parlour, and found that it was electrical, after 
handing in that fituation, in dry air, twenty-four hours. 
How much longer it would have retained its electricity, 
had he let it remain there, he knew not. How long a 
large and neatly-prepared Leyden bottle will retain its 
charge, fo as to be fenfibly eleCtrical, I have never ex- 
perienced; but Dr. priestley obferves, Hiftorv of Elec- 
tricity, p.. 516, that he has more than once received fuch 
ihocks as he fhould not like to receive again from the 
refiduum of his battery, even two days after the dif- 
charge, and when papers, books, his hat, and many other 
things, had lain upon the wires the greateft part of the 
time. Even the refiduum of a refiduum , he fays, he has 
known to remain in his battery many daystw. One thing, 
however, is very remarkable in Mr. adams’s apparatus, 
viz . fuppofing the negative eleCtric to have parted with 
its electricity to the rubber ; why, when the coated board 
or plate of metal is fet upon it, and that plate is touched 
by a finger, the equilibrium is not thus prefently re- 
ftored? But, perhaps, when the eleCtric matter, naturally 
inherent in bodies, is once thoroughly excited and put in 
(a) My friend the reverend Mr. hemming, hath been fo obliging as, at 
tny requeft, to make a variety of experiments, with a view to determine this 
matter, and fhewed me a l'mall bottle, which attra&ed a thread of trial at 
one-fixteenth of an inch diftance, May 23, though the bottle had been charged 
and ftood in a cupboard in his ftudy from March 14, viz. 70 days. The 
cylinder to his electrical machine will alfo feparate the balls of Mr. canton’s 
eleCtromctcr a fortnight after uling, though a variety of methods have been 
repeatedly ufed to del to/ that power in the interval. 
aCtion, 
