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XXV. On the Law of Electro-chemical Equivalents. 

 By M. I. SoRKT*. 



IN a previous memoir I have shown that equal weights of" 

 copper are obtained, by submitting to the action of the 

 same current different electrolytes in which copper forms the 

 positive element, or what is called the cation. I proposed also 

 to study the different electrolytes of which hydrogen is the elec- 

 tro-positive radical, and had even commenced some experiments; 

 but I have given up this investigation, which has become useless 

 since M. Despretz published his researches upon this subject, 

 and announced his intention of pursuing them. I shall here 

 limit myself to the relation of the following observation upon 

 the decomposition of water. 



When distilled water is submitted to the action of a somewhat 

 powerful battery (sixty small Grove's elements), the gaseous 

 bubbles which are disengaged at one of the electrodes are attracted 

 by the other electrode, probably in consequence of the great dif- 

 ference of tension of the electricity at the surface of the two 

 poles. The molecules of gas, and perhaps of water, electrized 

 by their contact with one of the poles, discharge themselves upon 

 the other. 



It is possible that, by this mechanical transfer, if I may call 

 it so, there may be a passage of a certain quantity of inefficacious 

 electricity, which will necessarily be greater the nearer the elec- 

 trodes are to each other. But I do not know whether the 

 amount of this may become considerable. 



The same thing does not take place in acidulated water, the 

 conductibility of which is much greater, because the difference 

 of tension of the two electrodes is much less considerable. 



To return to the law of electro- chemical equivalents. We may, 

 I think, consider that the above-mentioned researches have de- 

 monstrated, that, in taking separately the groups of different 

 electrodes from which the current separates the same electro- 

 positive radical or cation, the law of Faraday is exact, within the 

 limits of errors of observation. Buff has proved a second point ; 

 he has shown with nitrate of silver that the point of silver sepa- 

 rated is exactly in proportion to the quantity of electricity which 

 traverses the electrolyte^ whatever may be the intensity of the 

 currentf. 



To complete the verification of Faraday's law, it is necessary 

 also to show that a similar current traversing electrolytes, the 

 electro-positive elements of which are different, separates weights 

 of these elements proportionate to their chemical equivalents. 



* From the Comptes Rendtis for August 6, 1853, p. 220. 

 t Liebig's Annalen, vol. Ixxxv. p. 1. 



