304 MR. W. R. BOUSFIELD AND DR. T. M. LOWRY ON THE ELECTRICAL 



This assumption, also, does not postulate any direct proportionality between the two 

 quantities, but is sufficiently justified by the general relationships to which 

 J. J. THOMSON and NERNST have called attention. 



In order to express the variations of ionic mobility we have made use of SLOTTE'S 

 fluidity formula : 



where 17 is viscosity, t is temperature, nbc are constants, the general applicability of 

 which has been fully demonstrated by THORPE and RODGER in their Bakerian Lecture 

 ('Phil. Trans.,' A, 1894, vol. 185, pp. 397-710). To express the variations of 

 ionisation we have adopted the formula 



D = ce-", 



which is used by ABEGG and SEITZ to express the relation between the dielectric 

 constant D and the temperature t for a series of alcohols ('Zeit. Phys. Chem.,' 

 1899, vol. 29, p. 242), and which we find to be applicable also to EVERSHEIM'S values 

 for the dielectric constant of sulphur dioxide almost up to the critical temperature. 

 Combining these formulae with that given in Part VI. for the specific conductivity, 



am / I \ 

 " 1000^' 

 we get the relation 



K o Po 



for the variations of specific conductivity with temperature, and for the variations of 

 molecular conductivity 



It is to be noted that the formulae thus deduced have an empirical value which is 

 independent of the theoretical consideration that led to their construction. 



For the purpose of expressing and tabulating the experimental results it was 

 convenient to correct at once for the measured variations of concentration and to 

 work with the molecular rather than with the specific conductivity. It was further 

 convenient for the purpose of comparing the influence of temperature on the 

 conductivity of solutions of different concentrations to refer the molecular conduc- 

 tivities to those at 18 C. as unity and to tabulate only the ratios 



KO = AQ/AU, K M = A 50 /A 18 , KJOO = A 100 /A 18 , &c. 



The exponential factors in the equations given above have been taken to base 10, 

 and the form generally employed for arithmetical computation was 



log, n K = log, K +nlog(l +/>*)-. 



