324 Conductivity of Aqueous Solutions. Part XI. 



The fifth contains the actual conductance X 10 8 ; the sixth, the difference 

 between this value and the initial conductance X 10 8 as given at the end 

 of section 112;* the seventh, the corresponding change in content of the 

 whole portion, expressed in 10 -7 equivalents, obtained by multiplying this 

 difference by the conductance-capacity of the vessel (0.3956), dividing 

 by the equivalent conductance values 382.1 for HN0 3 and 385.8 for 

 HCl,f and multiplying by the volume of the portion (obtained from its 

 weight by multiplying it by 1.0018) ; and the eighth, the total change of 

 content or the sum of the changes in the electrode portion and the adjoin- 

 ing portion. The ninth column contains the milligrams of silver deposited 

 in the coulometers ; and the tenth, the transference number for the 

 anion X 10 3 . 



115. SUMMARY OF THE TRANSFERENCE NUMBERS. 



The following table contains a summary of the transference numbers 

 derived from the preceding experiments together with the means derived 

 therefrom. In finding the separate means of the cathode and anode 

 values a few abnormally high or low values (designated by an asterisk) 

 have been omitted. $ To these means in the case of the two most concen- 

 trated solutions a correction has been applied to remove a small error 

 introduced by the method used for the calculation of the separate values, 

 and the results are designated "corrected means." These cathode and 

 anode means have then been combined in the case of the three stronger 

 nitric acid solutions under the assumption that each has a weight inversely 

 proportional to the square of its average deviation (A. D.). Since 

 the cathode values show in all three cases much greater variations, this 

 procedure gives to the anode values a much greater weight, which would 

 be a priori desirable since they are not subject to the possible error arising 



*These initial values are: 2142 for HNO-, Solution No. 6; 2094 for HN0 3 Solu- 

 tion No. 7; 1975 for HC1 Solution No. 1, and 2136 for HC1 Solution No. 2. 



fThese values are those of dh/dC at 0.002 normal, where L represents the speci- 

 fic conductance and C the equivalent concentration. We derived them through a 

 careful consideration of all the results obtained by Goodwin and Haskell with both 

 acids at 18 between the concentrations of 0.001 and 0.005 normal. The values were 

 first derived at 18 and were found to be 370.0 for HN0 3 and 373.5 for HC1, and 

 these were then increased with the help of Deguisne's coefficients so as to make 

 them correspond to 20. It is scarcely possible that the errors in these values exceed 

 0.3 per cent. 



ijThe high cathode values in experiments 2, 3, and 4 were probably due to reduc- 

 tion by the electrolytic hydrogen, which was proved to have taken place in experi- 

 ment 2. The cathode value in experiment 22 was omitted since the middle portion 

 showed a large change in content. 



Namely, in calculating the original content the total weight of the electrode por- 

 tion was simply multiplied by the initial content per gram. That weight had, how- 

 ever, been increased, over what it would have been originally, at the anode by the 

 weight of the transferred nitric acid and had been decreased by the electrolysis out 



