250 ANAtYSIl Of THE OAT.VANIC FILE. 



pile, till it could move small metallic balls, in hope fhat 

 these would not stick. 

 Increase of the Two ways presented themselves to my mind for this in- 

 pile"^ l ° crease °f P ower >n a pi^; one by u\\x\g plates of a larger 

 size, the other by increasing the number of the groups. The 

 first method would have been cumbersome: but for a rea- 

 son which I shall explain, I did not expect, that it would 

 have the desired effect. However, even for the verification 

 of my conjecture, I made the following experiment. 

 Fxp. 20. Exp. 29. I procured 10 tinned iron plates 4 inches square ; 



Plates 1 of diffe- 10 otners roU nd, of only 0*5 inch diameter: and I took 10 



rent shape and . * 



size. of my plates ot l»o inch diameter. I cut pieces of Dutch 



gilt paper, the size of each of them, and compared their 

 respective effects on my condenser. The result was be- 

 yond my expectation ; I had only conjectured, that the in- 

 crease of size would not increase the divergence of the 

 gold leaves; now this was not only verified, but the largest 

 plates produced the smallest effect. However, this unex- 

 pected difference probably proceeded from some acciden- 

 tal cause, which I had no time to investigate, and I consi- 

 dered this experiment, which I have often repeated under 

 various forms, only as ascertaining the following proposition : 

 Size indifferent that for the electric motions, considered solely with respect 

 with respect to t the quantity of divergence in the electroscope, the size of 

 buMhTfrel the plates is indifferent; though, for the frequency of the 

 quency of the striking s of the little pendula, and the intensity of the ef- 

 erease ^with" ^ ects wnen the extremities of the pile are connected toge- 

 the size. ther, with the same number of groups, these effects increase 



with the size of the plates. This distinction, to which I 

 shall return in the following paper, constitutes a part of the 

 theory, which, as it made me foresee the result of the above 

 experiment, I shall now explain. 

 Volta's, con. 1 ara indebted for the ground of this theory to Sig. 

 denser does Volta ; who, when in 1782 he showed me, at Paris, his then 

 flight devia- new-invented admirable condenser, explained to me, that it 

 tions of ♦tec- CQU ld not serve to manifest minute degrees of deviation 

 bod'uL '■• from the c lectric standard, when belonging to small bodies 

 but only to bodies ©f such an extent or nature, that the 

 application of the condenser (by this taking its share of tliat 

 deviation) does not sensibly lessen it. As an example of 



the 



