ON ELECTROLYTIC CONDUCTIVITY IN CONCENTRATED SOLUTIONS. 259 



maxima are known to occur the corresponding concentration is included in the range 

 within which equation (1) is applicable. 



I am indebted to Mr G. E. Gibson for pointing out that this in turn implies that in 

 such cases the position of maximum conductivity may be calculated. 



Thus equation (l) may be written 



k = aT + bT* (3) 



dk 

 for a maximum -y= = 0. Hence by equation (3) the condition for maximum specific 



conductivity is 



« + 2&r = (4) 



Hence the concentration at which the maximum occurs is — -=- gramme equivalents per 



a 2 



kilogramme. Also by equation (3) the value of k at the maximum is T . 



46 



Kohlrausch and Holborn (page 99) state that for sulphuric acid a maximum is 

 reached " bei 30%," and for this percentage give 10 4 & = 7388 (page 156). The 

 calculated values are 30*9 per cent, and 10U* = 7414. 



The significance and importance of maximum electrolytic conductivity will be 

 discussed in a subsequent communication. This paper is intended as a review of the 

 data published hitherto. 



In conclusion I desire to thank Professor MacGregor for kind and helpful criticism, 

 and Mr Andrew King for valuable assistance in the calculations for Table A. 



Heriot Watt College. 



PRESENTED 

 J1 FEB.1907 



>J" At t5' «. 



