THE PHYSICAL PROPERTIES OF AQUEOUS SOLUTIONS. 121 
and the sum of these portions gives the combined conductivity 
K — l+ K 2V2^ 2 
^(v 1+ v 2 ) • 
This, then, should be the true formula for the conductivity of mixtures of equal 
ionisation. 1 
The formula for calculating the densities of the mixture is, of course, simply 
p v.+v, ' 
In the following table are set out the observed values of the viscosities, densities 
and conductivities, together with the calculated values for the densities and 
conductivities according to the above mixture formula;. The calculated values for the 
viscosities of the mixtures are dealt with elsewhere. 
Table X.—Mixtures of Normal KC1 and NaCl Solutions. 
Vi 
(KC1). 
i 
1 
Vo 
(NaCl). 
Viscosity 
observed. 
Density. 
Difference. 
Conductivity. 
Difference. 
Observed. 
Calculated. 
Observed. 
[ 
Calculated. 
! 4 
1 3 
2 
1 
0 
0 
1 
2 
3 
4 1 
0-01037 
0-01063 
0-01088 
0-01116 
0-01143 
1-04497 
1-04354 
1-04211 
1-04068 
1-03921 
1-04353 
1-04209 
1-04065 
I 
+ 1 
+ 2 
+ 3 
0-0983 
0-0920 
0-0860 
0-0800 
0-0743 
0-0919 
0-0859 
0-0799 
b 
+ i 
(e) Hittorf Numbers a Function of the Raclions .—From equations (10) and (6) 
we see that, according to our theory, 
Vl 4 (1 +< 4 ) _ ^2 
n 2 4(1+ (f>2 ) V x 
and therefore, since n x + n 2 = 1, we have 
Hence the reciprocal of the Hittorf number should be a linear function of the ratio 
O tie radions, and the radions for the ions of a given solute are inversely proportional 
to the migration numbers of the ions. # 
The most useful way of testing this relation for KOI and NaCl, since it gives us 
certain important results and verifies the result predicted by our theory in a form 
* This simple relation leads to a different method of arriving at the radions from that which is 
followed in this paper, but it cannot be developed here. 
VOL. CCVI.—A. K 
