[mail Quantities of Electricity. j ^ 
length of time that a quantity of electricity will remain upon 
a body. 
Hav ing conftruCfced a gold-leaf eleClrometer in the niceft 
manner I could, and which, on account of the non-conducting 
nature and conftruCtion of its upper part, could remain fenfibly 
eleCtrified for feveral hours together, I communicated fome 
eleCtricity to it, which cauled the flips of gold-leaf to diverge 
with a certain angle; and as the eleCtricity was gradually dilli- 
pated, the divergency diminiflied in the lame proportion. 
Now, whilfl: this diminution of divergency was going on, I 
looked through a fmall telefcope, and by means of a micro- 
meter meafured the chords of the angles of divergency, bet- 
ting down the time elapfed between each pair of contiguous 
obfervations j and as the chord of the angle of divarication is 
in the direCt Ample proportion of the denfity of the eleCtric 
fluid *, I could by this means know how much eleCtric fluid 
was loft by the electrometer in a certain time, and of courfe 
what portion of the eleCtricity firfl: communicated to the elec- 
trometer ftill remained in it. Let us make the chord of the 
angle of divarication on firfl: electrifying the eleCtrometer, or 
rather when firfl: obferved, equal to 16 ; or let us conceive that 
quantity of eleCtricity to be divifible into 1 6 equal parts. 
I obferved, that when the chord of the angle became equal 
to eight, the time elapfed between this and the firfl: obfervation 
was one minute ; when the chord became equal to four, the 
time elapfed between this point and the preceeding obfervation 
was f 3 Q,/ > when the chord became equal to two, the 
time elapfed fince the preceding obfervation was i f j and 
when the chord became equal to one, the time elapfed fince the 
* This propofition was full afeertained hy F. Beccaria. See Philofphical 
Tranfa Options, Vol. LVI. 
D 2 preceding 
