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XLV. Experimental Researches in Electricity, — Third Series. 

 By Michael Faraday, D.C.L. F.R.S. M.R.I. Fullerian 

 Prof. Chem. Royal Institution, Corr. Mem. Royal Acad, of 

 Sciences, Paris, Petersburgh, SfC.SfC. 



[Continued from p. 171.] 



309. iii. Chemical De- HPHE chemical action of voltaic elec- 

 composition. A tricity is characteristic of that 



agent, but not more characteristic than are the laws under 

 which the bodies evolved by decomposition arrange them- 

 selves at the poles. Dr.Wollaston showed* that common elecr 

 tricity resembled it in these effects, and " that they are both 

 essentially the same ;" but he mingled with his proofs an ex- 

 periment having a resemblance, and nothing more, to a case 

 of voltaic decomposition, which however he himself partly 

 distinguished ; and this has been more frequently referred to 

 by others, on the one hand, to prove the occurrence of electro- 

 chemical decomposition, like that of the pile, and on the other, 

 to throw doubt upon the whole paper, than the more numerous 

 and decisive experiments which he has detailed. 



310. I take the liberty of describing briefly my results, and 

 of thus adding my testimony to that of Dr. Wollaston on the 

 identity of voltaic and common electricity as to chemical ac- 

 tion, not only that I may facilitate the repetition of the experi- 

 ments, but also lead to some new consequences respecting 

 electro-chemical decomposition (376. 377.). 



311. I first repeated Wollaston's fourth experiment f, in 

 which the ends of coated silver wires are immersed in a drop 

 of sulphate of copper. By passing the electricity of the ma- 

 chine through such an arrangement, that end in the drop 

 which received the electricity became coated with metallic 

 copper. One hundred turns of the machine produced an evi- 

 dent effect; two hundred turns a very sensible one. The 

 decomposing action was however very feeble. Very little cop- 

 per was precipitated, and no sensible trace of silver from the 

 other pole appeared in the solution. 



312. A much more convenient and effectual arrangement 

 for chemical decompositions by common electricity, is the fol- 

 lowing. Upon a glass plate, fig. 2, placed over, but raised 

 above a piece of white paper, so that shadows may not interfere, 

 put two pieces of tinfoil a, b ; connect one of these by an in- 

 sulated wire c, or wire and string (301.) with the machine, and 



* Phil. Trans. 1801, pp. 427, 434. f Ibid. 1801, p. 429. 



