THE 



PHILOSOPHICAL MAGAZINE 

 AND JOURNAL. 



31 st DECEMBER 1824. 



LXX. On the Electro-motive Actions of Water and Liquids 

 in general on Metals ; and of the electric Effects which take 

 •place—first, in the Contact of certain Flames and Metals ,« 

 secondly, in Combustion. By M. Becquerel, Ancien Chef 

 de Bataillon du Genie* 



Electro-motive Actions of Water on Metals. 



"V1/"E have formerly been occupied in reducing to the smallest 

 possible number the causes which produce electric phse- 

 nomena, whether in the contact of bodies, or at the instant 

 when these bodies enter into combination with each other. 

 Constantly guided by this view of the subject, we have had to 

 submit to experiment, simple bodies, as much as circumstances 

 would permit. Researches of this kind require that the means 

 of experiment be continually modified ; for as we quit one of 

 the causes which concurs to the production of a phenomenon, 

 we often diminish its intensity to such a point that a more sen- 

 sible apparatus is then necessary, in order to observe it. 



For some time we had sought to determine the electro- 

 motive action of water on a metal ; but our first attempts were 

 not satisfactory: first, the condenser had not sensibility enough; 

 and lastly, the mode of experiment itself was not suitable. 

 We placed on the upper plate of the condenser a band of pa- 

 per, and above the vessel of metal into which we poured some 

 water. We found afterwards that this band of paper did not 

 prevent electro-motive actions between it and the metals ; after 

 that, it became impossible to collect the very weak electricity 

 which the vessel of metal acquired during its contact with the 

 water. 



We subsequently recollected that Coulomb had found that 

 electricity escaped very rapidly by the glass and wood sup- 

 porters, when they were slightly damp; a property which 



* From the Annates de Ckimie ct tie Phk'ique, torn, xxvii. p. K 

 Vol. 64. No. 320. Dec. 1824. 3 E M. Rous- 



