THE TORPEDO. 267 



hands applied to the torpedo, instead of holding each 

 other's left hands, plunged a pointed piece of metal into 

 a drop of water placed upon an insulating body. 



12. " By substituting flame in place of a drop of 

 water, no sensation was experienced till the two pointed 

 pieces of metal came in contact with the flame. 



13. " No shock will be experienced either in air or 

 below water, unless the body of the electric fish is im- 

 mediately touched. The torpedo is unable to commu- 

 nicate its shock through a layer of water, however thin. 



14. " The least injury done to the brain of the 

 animal, prevents its electric action." 



Spallanzani made a number of experiments upon this 

 singular animal, the most remarkable results of which 

 were that the back of the torpedo always gives a 

 shock when irritated, whether it be in air or in water, 

 but that the action of the breast is neither so uniform 

 nor so violent ; that when both surfaces are irritated at 

 the same time, the back gives a shock and the breast 

 not ; that when the animal is about to expire, the shocks 

 become more feeble, but are repeated so fast, that 

 about forty-five are given in a minute, and that the 

 sensation which they occasion is very similar to that 

 produced by the pulsations of a heart or an artery ; 

 that the shocks are always most powerful when the 

 torpedo is laid upon glass ; and that the young, if fully 

 formed, are capable of giving shocks even before they 

 have quitted the eggs. 



The difference between the electric action of the 

 torpedo, and that of a jar or battery in the common 

 electric apparatus, was explained by Cavendish, who 

 showed, by very satisfactory experiments, that the 



