Mr. cavendish on the Torpedo. 225 
touched the pofitive fide with a piece of metal held in 
the other hand, fo as to receive the fhock through the 
chain without its palling through the torpedo ; the bat- 
tery being charged to fuch a degree that the fhock w as 
confiderably ftronger than what I ufually felt in the fore- 
going experiments. I found that it the chain was not 
If retched by any additional weight, the fhock did not pafs 
at all : If it was ftretched by hanging a weight of feven 
pennyweights to the middle link, it paired, and a light 
was vifible between tome ol the links; but if fourteen 
pennyweights w r ere hung on, the fhock palTed without 
my being able to perceive the leaft light, though the room 
was quite dark; the experiment being tried at night, and 
the candle removed before the battery was difcharged. 
It appears, therefore, that if in the experiments made by 
tliefe gentlemen the fhock never palTed, except when the 
chain was fomewhat tenfe, which in all probability v r as 
the cafe, the circumflance of their not having perceived 
any light is by no means repugnant to the luppofition 
that the fhock is produced by eledfricity. 
G 
cr 
o 
Vol. LX VI. 
XIII. Ob- 
