ON THE GALVANIC CHARGE, &C. 57 



By electrical intenfity I understand the quantum of eleftri- On the galvanic 

 city multiplied by the refifting powers of the fubfiance to ad- c arge ' c ' 

 jmit it. Let us fuppofe the plates I, 2, and 3, difpofed to 

 give out electricity on every affignable point of their refpec- 

 live furfaces. A ringer applied at No, 1, Fig. 1, will abftract 

 a certain portion of electricity from the points of metal directly 

 in contact; a certain portion of electricity will immediately be 

 determined from the fquares 2, 3, 4, 5, 6, &c. from every 

 correfponding fquare on the furface of the plate, by that mo- 

 tion which Volta has well termed the moto-electrical power : 

 there is a phyfical refifiance in the tranfmiffion from thefe re- 

 fpective fquares to the firfi touched by the finger, and the 

 more remote the greater the refifiance : at whatever points 

 this phyfical refifiance (hall be equal to the capacity of the 

 iubfia nee employed, there all further tranfmiffion mufi ceafe : 

 this refifiance in plates of 2\ inches in the fquare, appears, 

 from experiment, fully adequate to the confiant fupply of fo 

 imperfect a conductor as animal fubftances, and therefore any 

 increafe of fize in the furface of the plate, will produce no 

 additional effects. 



When a certain quantify is thus abftracted from the pair 

 of plates at the extremes of the battery, in direct contact with- 

 the fingers, thefe plates and the interpofed fluid in the cells, 

 only act as conductors to the next pair, and fo on ; as the ve- 

 locity of difcharges of each fucceffive pair is fo infinitely greater 

 than the lime required for the chemical action, is the reafon 

 why the effects we experience are increafed in proportion to 

 the numbers : if we were to fuppofe that the time required for 

 the fucceffive difcharge of 50 pair of plates, fhould be pre- 

 cifely equal to the time required for the chemical action, we 

 fhould derive no increafe of power by an increafe of number, 

 which is contrary to experience. 



I have a battery formed of 600 plates, each plate only ex- 

 pofing half a fquare inch in furface : To experience equal 

 effects from this arrangement, I am obliged to paufe three or 

 four minutes between each contact; an interval of time no 

 ways requifite in larger plates. 



When fuch fuperior conductors as metals are employed, 

 the phyfical refinance of tranfmiffion from one part of the 

 plate to another, bearing no proportion with the capacity of 



the 



