CQMPOUND ELECTRICAL INSTRUMENT. ^3 



difcliarged by a flight touch with the finger, the lever was then On the fpon- 

 moved backwards and forwards about fourteen times, and the tjjcjty of this 

 ele<5trometer diverged with negative ele6lricity. This was re- inftrument, 

 peated feveral times with the fame effeft. 



The lever was then put in fuch a petition that the plates, 

 could not be fuppofed to a€t as condenfers, one pair more than 

 another, and the whole was left untouched for twenty-four 

 hours. It was then tried, and with twenty motions of the 

 lever the electrometer diverged with pofitive electricity. 



It was then left untouched for eighteen hours more, and on 

 trial the eledlrometer diverged with pofitive electricity. The 

 inftrument was next difcharged with the metal point as before, 

 and the eledlrometer made to diverge with negative eledlricity, 

 which was difcharged by a flight touch of the finger. The 

 lever was now worked, and with nine motions of the elec- 

 trometer diverged with pofitive electricity. It was then dif- 

 charged and left untouched for fixteen hours, after which it 

 diverged with pofitive ele6tricity after a few motions of the 

 lever. It was then left untouched for five days, after that 

 time it gave pofitive eieCli icity when the lever was worked, 

 Thefe experiments I have repeated a great many times with 

 the fame e(fe£t. 



As it appeared from the foregoing experiments that the re- 

 fiduum on the eledlrometer was infufficient to overcome the 

 efl^eCt of the refiduum on the plates, I was induced to charge 

 the whole infirument with the efFe6t of the eleCtricity, I would 

 wifti to communicate to it, and this I did by making the elec- 

 trometer diverge with the defired eleCtricity, and while it was 

 divergent I began working the lever, to communicate the ef- 

 fed to all the plates. I charged the inftrument with negative 

 electricity firft, and difcharged it with the metal point. The 

 lever was then worked, and in eight motions the eleClroraeter 

 diverged with negative eleClricity. It was then left untouched 

 for five days, when eighteen motions of the lever made the 

 electrometer diverge with pofitive eleClricity. This has been 

 often repeated with the fame effeCl. 



The inftrument was next charged with pofitive eleClricity, 

 and difcharged as before, after which, fix motions of the 

 lever made the eleClrometer diverge with pofitive eleCtricity, 

 It was left untouched for twenty-four hours, when the elec- 

 trometer 



