into the Cause of Voltaic Electricity, 297 



the contrary, with a different number, the diminution pre- 

 ponderates over the augmentation. The same cause produces 

 contrary effects with energies which acknowledge no regular 

 law; hence the alternations in the intensity of the current in 

 each particular case may depend upon a multitude of variable 

 circumstances ; such for example as the nature of the pairs, 

 their dimensions, the degree of acidity and conductibility of 

 the liquid employed, &c. The results of experiment are in 

 exact agreement with this. 



We shall conclude our researches by inquiring into the re- 

 sult, if, instead of active pairs, inactive pairs be added to the pile, 

 that is, homogeneous metallic arcs of zinc, copper, or platina. 

 After I had enunciated the theory of the pile for the first time, 

 in 1828, M. Marianini thought a strong objection might be 

 raised against it from the influence of inactive pairs, which he 

 had studied carefully and in detail. Interposing between the 

 active pairs of a pile, diaphragms of copper, in a greater or 

 smaller number, he found that no augmentation in the tension 

 of the two poles resulted from it, and that this interposition 

 even diminished the chemical power of the pile in the decom- 

 position of water. But, said he, by means of these dia- 

 phragms the interior conductibility of the pile is diminished, 

 and consequently so much the more electricity should pass by 

 the conductor which unites its two poles. It is perfectly true 

 that whatever diminishes the conductibility of the pile should 

 augment the tension of its poles, and the quantity of electri- 

 city which circulates in the conductor which unites them ; 

 provided at the same time that the quantity of electricity de- 

 veloped by each pair is in no degree altered. Now the manner in 

 which M. Marianini diminishes the conductibility of the pile 

 is not included in these limits. The zinc and copper of the 

 pairs between which ha places his diaphragms are no longer 

 in the same condition as those of the other pairs; in fact the 

 liquid which separates them loses a great part of its conduct- 

 ing power by the interposition of these diaphragms ; hence the 

 positive electricity accumulated on the side of the zinc, and the 

 negative carried off" by the copper reunite in much less pro- 

 portion through this liquid, which is become a worse conduct- 

 or; it is exactly as if, instead of interposing diaphragms, a 

 liquid of much less conducting power had been substituted for 

 the liquid which separates the pairs. What is the result ? 

 That the free electricity of all the other pairs diminishes in the 

 same ratio as that of the pair which we have been considering, 

 so that if, on the one hand, the two electric principles accu- 

 mulated at the two poles reunite with less facility, on the other 

 hand they are developed in smaller quantity. With regard 



Third Series, Vol. 11. No. 67. Sept, 1837. 2 Q 



