Views of the Theory of Galvanism. 165 



under discussion were not at all favourable to the chemical 

 theory, for undoubtedly the chemical action which takes place 

 in the acid cells is, as to extent [intensity?], infinitely superior to 

 that which is going on in the water cells. There should, there- 

 fore, be a difference of currents proportionate to the difiference 

 of the extent of the chemical actions taking place in the two 

 systems. Certainly, if we do not take into account the dif- 

 ferent degree of resistance which is offered to the circulation 

 of the currents by the'two sets of cells, the equilibrium in 

 question must appear entirely at variance with the principles 

 of the chemical theory, and speak in favour of Volta's hypo- 

 thesis; but by duly appreciating the circumstance alluded 

 to, the theoretical difficulty and the anomalous character of 

 the fact can easily be removed. 



According to the theory of the voltaic pile, such as it was 

 established some time ago by M. De la Rive, the electricities 

 which are set free by chemical action at the two ends of a 

 closed compound circle unite themselves by two ways ; one of 

 which is the pile itself, the other the conductor placed be- 

 tween the poles. The quantities of the electricities recom- 

 bining within each of the two conducting mediums depend, 

 according to the same theory, upon the peculiar degree of the 

 conducting power of each medium. Now let us at first con- 

 sider only the acid cells as originating a current, and those 

 charged with water merely as a medium put between the 

 poles. It is manifest, that under such circumstances, by far 

 the larger portion of electricities being developed by the pile, 

 must reunite within the latter, and only a small quantity will 

 consequently pass through the galvanometer and the water 

 cells. If, as above stated, the latter are connected with one 

 another by the means of platina, no current whatever circu- 

 lates through the galvanometer, however violent chemical ac- 

 tion may be within the water cells; but if pieces of copper or 

 of any other readily oxidable metal are made use of instead of 

 platina, there will pass a weak current from the acid system 

 into that of water. This result is easily accounted for by the 

 well-known fact, that those metals offer much less resistance 

 to a current than platina does. From such being the case, it 

 follows, that we should always obtain a current of the descrip- 

 tion mentioned, if the pairs of zinc and copper, by means of 

 which the water cells of our arrangement are connected with 

 one another, only acted the part of conductors. We know, how- 

 ever, that they also give rise to a weak current, which current, 

 on account of the peculiarity of the arrangement, must be, as 

 to direction, opposite to that excited by the acid cells. From 

 the fact that in most cases above stated equilibrium takes 



