41 



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4 — WWIAAAAH 



of a salt of the metal, generally the i)iti-ate. The two electrodes 

 were coiuiected by a variable resistance and an Ampèrenieter with 

 a nnmber of accumulators, so that the strength of the polarizing 

 current is easily changed and measured. To measure the tension of 

 polarisation at one of the electrodes a beakshaped bent glass tril)e 

 was br'ought into the solution, whose capillary point Was placed as 

 close as possible against the polarized electrode. In this glass tube 

 a third (auxiliary) electrode of the same metal was brought. This 

 auxiliary electrode, which is currentless, exhibits the normal potential 

 difference with respect to the solution. As theie is no loss of tension 

 in the liquid of the auxiliarj' electrode, and its point is close against 

 the polarized electrode, the potential difference between the auxiliary 



electrode and the polarized 

 electrode gives directly the 

 deviation which the potential 

 difference of the polarized 

 electrode presents from the 

 normal potential difference, 

 so the polarisation tension. 

 The measurement of this 

 potential difference took place 

 by reading the deviation 

 which was obtained by con- 

 necting the auxiliary electrode 

 and the polarized electrode 

 by means of a resistance of 

 Fig- 2. some meg. ohms with a gal- 



vanometer. The value of the scalar divisions in Volts was determined 

 by comiecting the galvanometer with a normal element. 



Silver, Copper, Lead. 



2. The investigation of different metals, undertaken in this direc- 

 tion, has shown us that as was to be expected, they i-epresent the 

 most different types. 



There are metals which in contact wiih an electrolyte, assume 

 intei-nal equilibrium very quickly ; there are those that do so very 

 slowly, and there are those that lie between these extremes. 



Beginning with the metals which quickly assume internal equili- 

 brium, we may tirst mention the metals : silver, copper and lead. 



The result of the inxestigation of these metals is found in the 

 following tables. 



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