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ROYAL SOCIETY OF CANADA 



given above, deduce an approximate estimate of the ratios of the co- 

 efficient of diffusion of the active product or products into the three gases 

 at atmospheric pressure. These follow directly from the argument just 

 presented and are all given in Table VII. 



TABLE VII 



Following the same line of argument in case of the anode deposits, 

 since the maximum effects were obtained at pressures 14 mms., 17 mms., 

 and 80 mms., for carbon dioxide, air and hydrogen respectively, it 

 follows that the ratios of the coefficients of diffusion of the active pro- 

 duct concerned were as 1 : 1.31 : 5.7, i.e, the relative coefficient for air 

 was slightly lower and that for hydrogen somewhat higher than the 

 values deduced from the behaviour of the cathode deposits. 



The ratios of the coefficients of diffusion of the active product con- 

 cerned, as deduced from the cathode deposits, are practically the same 

 as some values given in a paper by Euss ^ and this agreement goes to 

 show that it is a diffusion phenomenon which is the paramount one in 

 the present investigation. 



The interpretation of the maximum effect obtained on each elec- 

 trode with the three gases, however, presents some difficulty. One should 

 have expected, with the active deposits in the experiments in which the 

 salt was placed at different distances from the electrodes, that in the case 

 of the lowest pressures a maximum value would have been obtained for 

 a certain critical distance of the salt from the plates. But, as the curves 

 in Figs. V and VI show, no such maximum values appeared. 



IX. Active Deposits in the Absence of Electric Fields. 



In the experiments described up to the present the active deposits 

 were all obtained with a potential difference of approximately 250 volts 

 between the electrodes. With these conditions, however, it was impossible 

 to draw any definite conclusion as to the relative quantities of charged 



1 Russ, Phil. Mug., March, 1909. 



