en Animal EleSlricity, 31 i 



moift condu6lors which connect the two different pieces of 

 metal. 



In the arrangement of fig. 26, the fame contact of differ- 

 ent metals, viz. brafs on the one fide, and tin on the other, 

 with the fame kind of moift condu6lor, takes place, as well 

 as in the preceding experiment of fig. 25. The addition of 

 the ele6lric fluid in the one, and the abi'traftion of i,t in the 

 other, ought therefore equally to take place, though in an in- 

 verted order, when the aftion on the fluid calls forth the 

 moving power, by this contaSl of the two metals L, E, with 

 the moift conductor between them ; and yet this is not the 

 cafe, as no figns of eletlricity are obtained even after a long 

 time, and when the machine has been caufed to make twice 

 or three times as many revolutions. The condition efl'en- 

 tially necefTary to obtain electricity is, that the different me- 

 tals muft be in contail with. each other^ which is the cafe ia 

 fig. 25, but not in fig. 26. 



When the machine has been repeatedly turned, fome- 

 thing may be obtained. This arifes either from fome fmall 

 remains of old elettricity, which could not be deftroycd or 

 diffipatcd In the time duringw hich the arrangement of fig. 26 

 was continued; or even from frefli ele£trlcity, which the 

 moveable plate may have obtained from the aimofphere or 

 vapours during the pretty confiderable time of the machine 

 being in a ftate of revolution; or fome accidental difference, 

 either between the two tin or the two brafs pieces, may be 

 the caufc of fome a£lion on the eleffrlc fluid, or of fome de- 

 rangement in regard to the equilibrium. In the laft place, 

 thf contaft of the moii't condu£tor with the tin on the one 

 fide, or with the brafs on the other, may have a different 

 a£tion, which, in my opinion, mufl be very fmall, but yet is 

 not entirely without eiFedt. 



,As it is now proved that, accor<ling to the arrangement 

 of the li.xth experiment, nothing, or almoft; nothing, is ob- 

 tained by 40, 60, and even 80 revolutions of the doubler, 

 while a great deal is obtained by that of the fifth with 20 

 X 4 or 



