114 ON THE CALCULATION OF THE CONDUCTIVITY OF 
tained in Kohlrausch’s tables of interpolated values, ascribing 
them (1) to his own observations being the results of actual 
measurements, and (2) to the different temperatures at which 
their respective solutions had the specified strength. These 
differences are shewn in the following table :— 
CONDUCTIVITY. 
SALT IN 
DIrFERENCE. 
SOLUTION. 
BENDER. KOHLRAUSCH. 
Na Cl. 388 380 + 8 
Ke Gl: 478 471 + £7 
Na Cl. 702 698 +4 
IES CORE 916 911 +5 
Na Cl. 977 974 +3 
Na Cl. 1217 1209 + 8 
Keel 1362 1328 +34 
Na Cl. 1425 1412 +13 
Na Cl. 1594 1584 +10 
Ee (Mk 1741 1728 +13 
Na Cl. 1745 1728 +17 
Na Cl. 1845 1846 - 1 
Keel 2106 2112 -—- 6 
Ke Ck 2484 2480 +4 
Keel 2820 2822 — 2 
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 tor higher conductivities ; also, that for any given conduc- 
tivity the difference is of the same sign and of about the same 
magnitude for solutions of both salts. If they were due to the 
first of the above causes, since Kohlrausch’s interpolated values 
agree well with hisobservations we should expect 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 
the 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 
