2 4 8 



'Journal of Experiments, Dec. 18, 1772 



The plates were electrified, holding my finger to bottom plate, they were 

 then moved 24 inches by lifting up the weight M, and then discharged by 

 holding my little finger to lower plate and touching upper plate with brass 

 knob held in the other hand. I could feel a small pulse in little finger, having 

 tried this I electrified and discharged the plates in same manner only without 



c 



moving them first and endeavouring to preserve the same distance of time 

 between the electrification and discharge. I was not able to perceive any 

 difference in the feel. I endeavoured to ascertain the time by the vibrations 

 of a pendulum, but without much success. It seemed needless, however, as I 

 could perceive scarce any difference in the sensation whether I discharged it 

 immediately or waited as long as when the plates were moved. The usual 

 time between the electrification and discharge was about 2\". 



The experiment was also made by Richard, who did not perceive any 

 difference. 



The heavy paper electrometer was used. The bits of sealing wax between 

 the plates were those made in 1771 [Art. 457]. 



512] Whether globe included within hollow globe is overcharged by electrifying 

 outer globe*. 



It was tried whether the globe enclosed within hollow paper globe was 

 overcharged when the outer globe was electrified. 



This was first tried by making the 2 hemispheres slide on 2 sticks of glass 

 by means of 2 tin hooks and a stick of glass fixed to the back of the hemisphere. 



The wire by which it was elect, was suspended about 4 inches above the 

 hemispheres while the vials were charging. It was then let down, and it was 

 so contrived that the same motion of the hand which lifted up again the elect, 

 wire, lifted up the wire which connected the inner globe with the outer, drew 

 back the hemispheres, and drew up the pith balls fastened to a stick of glass 

 till they touched the inner globe. 



It was found that if the elect, of the hemispheres was discharged before 

 they were separated, but after the communication between them and the inner 



* [See Exp. i, Art. 218.] 



