Law of dhnded discharges 203 



in receiving its shock under water, the quantity of electricity which passes 

 through the torpedo, through my body, and through the water, are to 

 each other as NT, B, and W; the quantity of electricity which will now 

 pass through my body, when the shock is received under water, and 



D D 



out of water, will be to each other as ,=, ^r, r to 5 JT; which two 



D + \ 1 + W D + 1\ 1 



T) 



quantities differ from each other in a less proportion than - TW 



T> 



and p j,: consequently, the readier the body of the torpedo conducts, 



the greater charge will it require to give the same shock, either in water 

 or out of it ; but the less will be the difference between the strength of the 

 two shocks. It should be observed, that this alteration, so far from making 

 it less resembling the real torpedo, in all probability makes it more so; 

 for I see no reason to think, that the real torpedo is a worse conductor 

 of electricity than other animal bodies; and the human body is at least 

 as good, if not a much better conductor than this new torpedo. 



418] The event answered my expectation ; for it required about three 

 times as great a charge of the battery, to give the same shock in air, with 

 this new torpedo as with the former ; and the difference between its strength 

 when received under water and out of it, was much less than before, and 

 perhaps not greater than in the real torpedo. There is, however, a con- 

 siderable difference between the feel of it under water and in air. In air 

 it is felt chiefly in the elbows; whereas, under water, it is felt chiefly in 

 the hands, and the sensation is sharper and more disagreeable. The same 

 kind of shock, only weaker, was felt if, instead of touching the sides, I 

 held my hands under water at two or three inches distance from it. 



419] It is remarkable, that I felt a shock of the same kind, and nearly 

 of the same strength, if I touched the torpedo under water with only one 

 hand, as with both. Some gentlemen * who repeated the experiment with 

 me thought it was rather stronger. This shews, that the shock under 

 water is produced chiefly by the electricity running through one's hand 

 from one part to the other; and that but a small part passes through one's 

 body from one hand to the other. The truth of this will appear with more 

 certainty from the following circumstance ; namely, that if I held a piece 

 of metal, a large spoon for instance, in each hand, and touched the torpedo 

 with them instead of my hands, it gave me not the least shock when 

 immersed in water; though when held in air, it affected me as strongly 

 if I touched it with the spoons as with my hands. On increasing the charge, 

 indeed, its effect became sensible: and as well as I could judge, the battery 

 required to be charged about twelve times as high to give the same shock 

 when the torpedo was touched with the spoons under water as out of it. 



* [See Art. 601, 27 May, 1775. Mr Ronayne, Mr Hunter, Dr Priestley, Mr Lane, 

 Mr N[airne].] 



