306 Report to the French N^ational hijlitute 



In rco-ard to the limits of this accnmulation, it is obvious 

 that it depends on the thicknefs of the fmall llralum of gum 

 which feparates the two plates of the condenfer; for, as in 

 confequcnce of this thicknefs the cleftricity accumulated in 

 the collefting plate cannot a£t hut ;.t a diftancc on that of 

 the lower plate, it is always more confiderable than that 

 which forms an equilibrium with it in the latter; and hence 

 there refnlts in the colleAing plate a fmall tenfion, which has 

 here for its limit the tenfion exilling in the upper part of the 

 pile. 



As the eleftricity of the column is accumulated in the 

 condenfer, it will be accumulated in like manner in the in- 

 terior of a Leydcn flaflc, the exterior of which communicates 

 with the common rcfervoir; and fincc, in proportion as the 

 pile difcharges itfelf, it is recharged at the expenfe of the 

 fame refervoir, the flallc will be equally charged whatever be 

 its-capacitv; but its interior tenfion can never exceed that 

 which takes place at the fummit of the pile: if the bottle be 

 then removed it will give a (liock corrcfponding to that degree 

 of tenfion ; and this is what is confirmed by experience. 



Such muft be the ftate of things, negle6ling, as very fmall, 

 the a6tion proper to the water on the metals; fuppofing, 



lit, That the tranfmiflion of the fluid takes place from 

 one pair to the other in the infulated pile through the pieces 

 of moift paper bv which they arc feparated, even when there 

 exifi:s no communication between the two extremities of the 

 column : 



2d, That the excefs of eleftricity which the zinc takes 

 from the copper is confiant for thcfe two metals, whether 

 they are in their natural ftate or not. 



C. Volta fupports the firft propofition by an experiment 

 which we have aheady mentioned, and in which the con- 

 denfer is charged on bringing the colle6ling plate, covered 

 with a piece of moift paper, into contaft with the copper 

 extremity of a metallic plate, the other or zinc extremity of 

 which is held between the fingers. 



In regard to the lecond fuppofition, it is more fimple than 

 mit^ht be imagined ; but a feries of very nice experiments, 

 which we had not opportunity of making, would be necel- 

 fary to afcertain how far it is agreeable to nature. 



Hitherto, for the fake of prccifion, we havefuppofed the 

 pile to be compofed of copper and zinc : the fame theory, 

 however, is applicable to any two metals whatever; and the 

 eftetts of the d fierent kinds of apparatus which they will 

 terve to form, will depend on the differences of the eieftricity 



which 

 6 



