CONSTANT FOR ELECTROLYTES HEBB 413 



The data, as I have indicated, are taken from the second of 

 the papers referred to above. Before, however, plotting the 

 ionization-eqnivalent depression curve, I plotted in each case the 

 equivalent depression against concentiation, and drew in the. 

 smooth curve which best represented the results, so that approxi- 

 mately as many points fell on one side of the curve as on the 

 other. In drawing in this curve, however, I did not use many 

 of the observations only those of the stronger concentrations* 

 This was done in order to get rid, as much as possible, of the 

 error due to the rightward or leftward tendency of the observa- 

 tions ; for, had I plotted all the points and then drawn in the 

 smooth curve which best represented them, these latter erratic 

 points would have given a rightward or leftward tendency even 

 to the part of the curve corresponding to the stronger concentra- 

 tions. Hence, as a general thing, I discarded all but three or 

 four of the observations on the stronger concentrations. In 

 cases where I have kept more it is due to one of three things : 

 (1) because the points were close together; (2) because there was 

 very little rightward or leftward tendency to the ionization- 

 equivalent depression curve, or (3) because the ionization-equi- 

 valent depression curve for these stronger concentrations had a 

 rapid natural bend to it. The information in (2) and (3) was 

 ascertained by a preliminary plotting of ionization coefficients 

 against equivalent depressions. Having thus drawn in the 

 smooth concentration-equivalent depression curve, I read off 

 the values of the equivalent depressions corresponding to the 

 given concentrations, and have given them in brackets alongside 

 of the observations themselves. 



1 then plotted these corrected equivalent depressions against 

 their corresponding ionization coefficients, and finding by inspec- 

 tion the portion of the curve thus obtained, which was straight, 

 I drew in the straight line which I thought best represented the 

 results. In drawing in this straight line I generally gave more 

 weight to points corresponding to solutions of greater concen- 

 tration. This straight line was then 'treated as pointed out 

 above, and k and I were thus obtained. 



