260 On the Effects of Certain Physical and 



ments were repeated several times, on disconnecting and re- 

 connecting the wires, without renewing the Voltaic circuit. 



On continuing the connection for some time tlie phenomena 

 ceased. It was the discharge of the induced state, and re- 

 semhled that of the charge of a Lej'den jar, with that of its 

 residual electricity, on two successive contacts of a conductor. 



We renewed the Voltaic circuit for two minutes, we then 

 broke, remade, and again broke the circuit, with but very 

 slight effect. 



On breaking the circuit and connecting the wires we had 

 lively muscular contractions in the limbs. On connecting 

 the wires continuously these phenomena ceased ; on discon- 

 necting the wires, waiting for two minutes, and again con- 

 necting them, there was still a slight residual effect. 



We again completed the Voltaic circuit for four minutes, 

 broke the circuit, and connected the wires, with the same 

 effect as before ; we disconnected the wires, waited a minute 

 or two, and reconnected them witli a similar slight residual 

 eff'ect as before. 



It was observed that the phenomena were similar when- 

 ever the wires were brought into contact, whether the circuit 

 was complete or not ; and that, when the circuit was com- 

 plete, by the accidental contact of the zinc and silver in one 

 of the two Voltaic cells, the same phenomenon was produced. 



In none of these experiments were there any energetic 

 spasmodic movements. These occurred, however, on raising 

 and insulating the nerves, and then completing the circuit for 

 a time, and breaking it. The moisture produces a gradual, 

 and prevents the uninterrupted discharge, with its attendant 

 tetanoid effect. 



I may here make a remark which I shall have to repeat ; 

 that the difference of effect on the muscles, of making and 

 breaking the Voltaic circuit, and of connecting the wires be- 

 fore or after breaking that circuit, is quite extraordinary. 



It is plain that the fact involves some principle of Galvan- 

 ism or Voltaism not yet fully investigated. 



E.r. 3. We prepared the frog and experiment as repre- 

 sented in fig. 4. Having attached portions of platinum plate 

 to the extremities of the platinum wires, proceeding from two 



