130 



ANALYSIS OF THE GALVANIC PILE. 



$m. 14. 



cases here referred to is, that the circulation of the fluid^ 

 in these cases becomes too rapid, to be discovered by that 

 test. 



Exp. 14. After Exp. 12, I took off the glass tubes from 

 the pile. 



1. The electroscopes at its extremities, then free, indi- 

 cated, A, 0*0, B, neg. 0'4. 



2. I produced the communication between the two ex- 

 tremities by a brass conductor; every electric sign ceased, 

 even to the condense*. 



3. I substituted a slip of deal, which I had left a long 

 while in tvater, in order that water itself might become the 

 conductor : it produced the same effect as brass, every elec* 

 trie sign disappeared. 



4. I left this slip in the same situation, in order to ob- 

 serve the effects in the progress of drying. The water had 

 already disappeared at the surface, and no electric sign was 

 perceived, even by the condenser', after some time, the con- 

 denser manifested these signs, positive at A, and negative 

 at B ; at last the same signs became visible in the electro- 

 scopes of the pile. 



I think it now evident in general, that an actual circula- 

 tion of the electric fluid is produced, through the pile and 

 any conducting substance which connects its extremities; 

 that this circulation is naturally so rapid when the electric 

 fluid defes not undergo any retardation in the conductors^ 

 that its course cannot be manifested even by the condenser ; 

 and that when it is manifested by electric signs, these are 

 produced by some retardation. 

 Its course may Now: a retardation in the course of the electric fluid 

 be retarded by se 't in motion by thepile may proceed, either from the nature 

 the conductors °'f thi conductors, as in the above experiment; or from 

 or Haodificuti- some modification, which the electric fluid itself undergoes 

 ' in pervading the pile. The former cause of retardation of 

 the first a ten the electric fluid, manifested by the preceding experiment, 

 of theinsulat affords, as I shall show in another paper, the best and easi^ 

 in- property of egt m()thod of trying the j 7isu lating faculty of the different 



varnishes laid on glass for supports of electric apparatusses ; 

 an essential object in practical electricity; but the latter* 

 namely, the different modifications which the electric fluid 



undergo*'* 



Electric fluid 

 circulates 

 through the 

 pile. 



