the Conductivity of Mixtures of Electrolytes. 283 



of KC1 and NaOl and those for solutions of the same strength 

 contained in Kohlrausch's tables of interpolated values, ascri- 

 bing them (1) to his own observations being the results of 

 actual measurement, and (2) to the different temperatures at 

 which their respective solutions had the specified strengths. 

 These differences are shown in the following table : — 



Salt in 

 Solution. 



Conductivity. 



Difference. 



Bender. 



Koblrausch. 





NaCl 



KOI 



388 380 



478 471 



702 698 



916 911 



977 974 



1217 1209 



1362 1328 



1425 1412 



1594 1584 



1741 1728 



1745 1728 



1845 1846 



2106 2112 



2484 2480 



2820 2822 



+ 8 

 + 7 

 + 4 

 + 5 

 + 3 

 4- 8 

 +34 

 4-13 

 + 10 

 + 13 

 +17 



- 1 



- 6 

 + 4 



- 2 



NaCl 



KOI 



NaCl 



NaCl 



KOI 



NaCl 



NaCl 



KC1 



NaCl 



NaCl 



KC1 



KC1 



KC1 









Again, it will be noticed that the differences are all of the 

 same sign up to conductivities of about 1800, and nearly all of 

 the opposite sign for higher conductivities: also that for any 

 given conductivity the difference is of the same sign and 

 order of magnitude for solutions of both salts. If they were 

 due to the first of the above assigned causes, since Kohl- 

 rausch's interpolated values agree well with his observations, 

 we should expect much more alternation of sign : if to the 

 second, there should be no change of sign : if to both, there 

 should be greater and more irregular variation in magnitude. 

 The fact that the differences are practically the same for both 

 electrolytes at any given value of the conductivity, would 

 seem to show that the cause of the differences — a defect in the 

 apparatus possibly or in the distilled water — was operative in 

 the measurements of both sets of simple solutions, and there- 

 fore probably in the measurements of the mixtures. Hence, 

 to render the results of calculations based on Kohlrausch's 

 data for the simple solutions comparable with Bender's results 

 for mixtures, we must determine what the conductivities of 

 Bender's mixtures would have been found to be if Kohlrausch 

 had prepared and measured them. To find this out as nearly 

 as possible, I have plotted the data of the above table with 

 Bender's conductivities as abscissae and the differences between 



