On some Chemical Jgcncies of EleciricUy. 223 



taic and other analogous instruments, seem to be the causes 

 that disturb the equilibrium, and the chemical changes the 

 causes that tend to restore the equilibrium; and the pluTuo- 

 niena most probably depend ou tlicir joint at^ency. 



In the Voltaic pile of zinc, cupper, and solution of mu- 

 riate of soda, in uhat has been called its condition ot elec- 

 trical tension, the communicating plates of copper and zinc 

 are in opposite electrical states. And with regard to elec- 

 tricities of such very low intensity, water is an insidaling 

 body : every copper-plate consequently produces by intluc- 

 tion an increase of positive electricity upon the opposite zinc 

 plate ; and every zinc plate an increase of negative elec- 

 tricity on the opposite copper-plate : and the Intensity in- 

 creases with the number, and the quantity with the extent 

 of the series. 



When a communication is made bet^vecnthe two extreme 

 points, the opposite electricities tend to annihilate e.iL-h 

 other; and if tht fluid medium could be a substance inca- 

 pable of decomposition, the equilibrium, there is every rea- 

 son to believe, would be restored, and the motion of the 

 electricity cease. But solution of muriate of S(ida being 

 composed of two series of elements possessing opposite elec- 

 trical energies, the oxvgen and the acid are altraclcd by the 

 zinc, and the hydrogen and the alkali by the copper. The 

 balance of power is momentary only ; for solution of ziuc 

 Is formed, and the hydrogen disengaged. The negative 

 energy of the copper and the posilive energy of the zinc 

 are consequently again exerted, enfeebled only by the oppo- 

 sing energy of the soda in contact with the copper, and the 

 process of electromotion continues, as long as the chemical 

 changes are capable of being carried on. 



This theory in some measure reconciles the hypothetical 

 principles of the action of the pile adopted by its illustrious 

 inventor, with the opinif)ns concerning the chemical origin 

 of Galvanism, supported by ilu' greater nuuil)er of the Bri- 

 tish philosophers, and it is ennlirmed and sueugthened by 

 manv facts and exj)eriments. 



Thus the Voltaic pile of 'JO pairs of plates of copper and 

 zinc exhibits no permanent i Icctromolive power when tin; 

 • Vol. 29. No. 11 1. y'/^ir. ISO',-. I' rontiedlng 



