112 ON THE CALCULATION OF THE CONDUCTIVITY OF 
in the case of each salt in terms of reciprocals of powers of V. 
In obtaining these formule, I made use of Kohlrausch’s data 
only, Kohlrausch and Grotrian’s data not being at the time 
available to me. As the experimental data from which the 
formule were obtained, applied to a much greater range of 
dilution than that of the parts of the curves in the drawing of 
which these formulz were used, I did not think it necessary to 
re-determine the formule when Kohlrausch and Grotrian’s 
observations came into my hands. The following tables shew 
the accuracy with which the formule reproduced the experi- 
mental data on which they were founded : 
CONCENTRATION OF IONS (a/V) 
CALCULATED FROM 
DILUTION (Y). : 
KOHLRAUSCH’S | 
OBSERVATIONS. | FORMULA. 
NaCl SOLUTIONS. 
10 0.08414 0.08413998 
2 0.3682 0.3681999 
lee 0.6761 0.6760998 
Ole 1.5418 1.541798 
0.2 1.9360 1.936008 
KCl SOLUTIONS. 
10 0.08610 0.086099 
2 0.3939 0.393900 
1 thaws 0.7558 0.755802 
0.3 2.0409 2.04088 
As the formule, owing to the narrow range of their applica- 
bility, are of no permanent value, they need not be given here. 
The consistency of the results of the calculations based on them, 
as given in the table below, would seem to show that they were 
sufficiently accurate for the purpose in hand. 
As Bender measured the specific gravities of both his simple 
solutions and his mixtures, his paper affords the necessary data 
for determining the change of volume on mixing. Such change 
