35 S Experiments on the Torpedo. 



immediate contact ; for no shock is communicated when a 

 conducting body, such as a piece of metal, is interposed 

 between the iingcr and the organs of the fish. Thus we 

 may touch tlic animal with a key, or other metallic instru- 

 ment, and experience no shock in consequence. 



6. M. Gav-Lussac having observed this important fact, 

 we placed the torpedo on a plate of metal, so that the in- 

 ferior surface of its electric organs was in contact with the 

 metal. The hand which supported the plate felt no shock, 

 althou(jh another )K'rson in a state of insulation irritated the 

 animril, and when the convulsive motions of its pectoral 

 fins plainly indicated very powerful discharges of its elep- 

 tric fluid. 



7. If on the contrary a person support the torpedo placed 

 on a metallic plate, with his left hand as in the preceding 

 experiment, and with his right touches the upper surface of 

 the electric organ, then a violent shock is felt in both arms 

 at the same moment. 



8. The same feeling is experienced when the fish is 

 placed betvvcen two plates of metal, the edges of which do 

 not touch, and the person applies a hand to each pJate at 

 the same instant. 



g. But if in the preceding experiment there exists an 

 immediate communication between the edges of the two 

 plaies, no shock is felt in the arms; for in this case the 

 chain of connection between the two surfaces of the organ 

 is formed by the plates, and the new communication esta- 

 blished bv applying the two hands to the plates becomes al- 

 together ineificient. 



10. The most delicate electrometer does not indicate the 

 state of electricity of the organs of the torpedo : it is no 

 way affected by any method which we can have recourse to, 

 either by bringing it near to the organs, or by insulating 

 the fish, covering it with a plate of metal, and then form- 

 ing a communication bv means of a wire between the plate 

 and the condenser of Volta. Nothing shows here, as in 

 the gymnotus, that the animal can modify the state of 

 electricity of surrounding bodies. 



11. As electric fish act while in a stale of health with 

 the same power under water as in the air, we examined the 

 conducting p'.onerties of this fluid. A number of persons 

 having formed a circle of connection between the upper and 

 imder surfaces of the organs of the torpedo, no shock was 

 experienced till they had moistened their hands with water. 

 The shock is equally felt when two persons who have their 

 right hands applied to the torpedo, instead of taking hold of 



$ cacU 



