84 HISTORY OF GALVANISM. 



them affected, sometimes only the positive electri- 

 city is visible, sometimes only the negative, while 

 at other times both of them are perceptible. He 

 conceives that, from various causes, the electric 

 fluid passes through the apparatus with different 

 velocity at different times, or through its different 

 parts at the same time, so as to produce a partial 

 accumulation or deficiency : it seems to be always 

 retarded when it passes from the point of the wire 

 into water. He observes, that the expressions po- 

 sitive and negative, as applied to the ends of the 

 pile, or to the wires in the interrupted circuit, can 

 only be regarded as comparative terms, because 

 the chemical action of the pile goes on as usual in 

 the decomposition of water, although the whole in- 

 strument be rendered positive or negative, by at- 

 taching it to the prime conductor, or to the rubber 

 of the electrical machine. This experiment is ad- 

 duced to prove, that the action of the pile is not 

 necessarily connected with the electric energy of 

 the substances that enter into its composition. 

 The pile, when dissected in the first way, with the 

 fluid interposed between the two metals, acts in 

 the same manner as if the parts were continuous, 

 except that the effect is rather less powerful. 

 Second dis- De Luc then examined the action of the pile, 

 section. w jj en dissected according to the second arrange- 

 ment, where the metals were placed together, and 

 the wet cloth in contact with the zinc, or the most 

 oxidable of the metals ; the ternary groups being 

 separated from each other by the wire frames. 



