21.0 " Transfer-Resistance" in Electrolytic Cells. [Mar. 19, 



varies largely in amount with different metals in the same solution, 

 and with the same metals in different solutions ; in dilute solutions of 

 mineral acids of different strengths, or of different temperatures, and 

 is usually small with easily corrodible metals which form quickly 

 soluble salts, and large with those which are net corroded ; and is dis- 

 guised in the case of those which by corrosion form insoluble salts. 



The results of the experiments also show that the same voltaic 

 current was " resisted " in different degrees by every different metal 

 when employed as an anode, and when used as a cathode ; also by 

 the same metal when used as an anode and cathode respectively ; and 

 that the proportions of such "resistance" at an anode and cathode 

 of the same metal, varied with every different metal in every different 

 electrolyte (and strength of electrolyte), and at every different tem- 

 perature ; and that the resistance at the anode was usually smaller 

 than that at the cathode ; in some cases, however, where a film was 

 formed upon the anode, an apparently reverse effect occurred ; that 

 •a current from a given positive plate of a voltaic cell was differently 

 resisted by every different metal used as a negative plate in that cell ; 

 and that by rise of temperature "transfer-resistance" was usually 

 and considerably reduced. 



They further show that this species of " resistance " was largely 

 reduced by increasing the strength of current ; and was thus con- 

 spicuously distinguished from ordinary conduction-resistance of the 

 electrolyte. In consequence of this effect, " transfer-resistance " was 

 greatly influenced by every circumstance which altered the ordinary 

 resistance, and thereby the strength of current. The usual effect of 

 diminishing the density of current alone, by enlarging both the elec- 

 trodes and keeping the strength constant, was to diminish the 

 u transfer-resistance ;" and of enlarging one only, was to diminish it 

 at that electrode and increase it at the other, the effect being greatest 

 at the altered electrode ; but the influence of density was very much 

 smaller than that of strength of current. The current was usually less 

 " resisted," and larger with a small positive plate and a large nega- 

 tive one, than with those sizes reversed. Alterations of size or kind 

 of metal at one plate of an electrolytic or voltaic cell affected the 

 transfer-resistance " at the other, by altering the strength and 

 density of the current. 



" Transfer- resistance," therefore, appears to vary, not only with 

 •every physical and chemical change in the metals and liquids, but 

 also with every alteration in the current. Such " resistance " throws 

 light upon the relative functions of the positive and negative plates 

 of voltaic cells, and illustrates the comparatively small influence of the 

 negative one in producing strength of current. Nearly all these con- 

 clusions are based upon results represented by average numbers 

 obtained by series of experiments. 



