Voiv. 6, 1920 
CHEMISTRY: NO YES AND MacINNES 
21 
Ag + AgCl, LiCl fe), Li in Hg, UCl (d), AgCl + Ag. 
Hg + HgO, KOH fe), K in Hg, KOH (c,), HgO + Hg. 
It is the purpose of this paper to summarize and compare the results of 
these investigations, and to state the general conclusions to which they 
lead. 
From the observed values of the electromotive forces of these cells there 
were calculated by the equation given above the products a~ of the 
activity-coefficients of the two ions at various concentrations, the value 
of the products at the lowest concentration (0.001 or 0.0035 molal) at which 
accurate measurements could be made being assumed equal to the con- 
ductance-ratio A/Ao at that concentration. These activity-coefficient 
products were plotted against the logarithm of the concentrations, and 
those corresponding to round concentrations were read off. 
The following table contains the values of the square root of the so- 
obtained products, that is, the values of the expression (a:+a~)'^^ which 
represents the geometrical mean of the activity-coefficients of the posi- 
tive and negative ions of the substance. This table also contains the corre- 
sponding values of the conductance-ratio A/Ao, multiplied by the ratio 
rj /t]o of the viscosity of the solution to that of pure water, this last serving 
to correct approximately for the frictional resistance of the medium to the 
passage of the ions through it. 
TABLE 1 
Activity-Coefficients and Conductance-Viscosity Ratios 
Mols. per 
ACTIVITY-COEFFICIENTS 
CONDUCTANCE-VISCOSITY RATIOS 
1000 g. 
water 
KCl 
LiCl 
HCl 
KOH 
KCl 
LiCl 
HCl 
KOH 
0.001 
0 
979 
0 
976 
0 
979 
0 
976 
0 
990 
0.003 
0 
943 
0 
945 
0 
990 
0 
982 
0 
968 
0 
962 
0 
986 
0.980 
0.005 
0 
923 
0 
930 
0 
965 
0 
975 
0 
956 
0 
949 
0 
981 
0.975 
0.010 
0 
890 
0 
905 
0 
932 
0 
961 
0 
941 
0 
932 
0 
972 
0.963 
0.030 
0 
823 
0 
848 
0 
880 
0 
920 
0 
914 
0 
904 
0 
957 
0.939 
0.050 
0 
790 
0 
817 
0 
855 
0 
891 
0 
889 
0 
878 
0 
944 
0.925 
0.100 
0 
745 
0 
779 
0 
823 
0 
846 
0 
860 
0 
846 
0 
925 
0.910 
0.200 
0 
700 
0 
750 
0 
796 
0 
793 
0 
827 
0 
812 
0 
909 
0.891 
0.300 
0 
673 
0 
738 
0 
783 
0 
769 
0 
807 
0 
792 
0 
903 
0.889 
0.500 
0 
638 
0 
731 
0 
773 
0 
765 
0 
779 
0 
766 
0 
890 
0.884 
0.700 
0 
618 
0 
734 
0 
789 
0 
772 
0 
761 
0 
751 
0 
874 
0.879 
1.000 
0 
593 
0 
752 
0 
829 
0 
786 
0 
742 
0 
737 
0 
845 
0.877 
2.000 
1 
040 
3.000 
1 
164 
1 
402 
The table contains the results of only the above-described researches 
carried out under our direction. It should be mentioned, however, that 
exact electromotive-force measurements from which activities can be 
derived have also been made by Jahn^ on potassium, sodium, and hy- 
