340 ON THE SURFACE TENSION AND 
The ionization coeflicients of the salts in the mixture were 
determined by Professor MacGregor’s* graphical method. The 
above table contains all the data required for finding them, as 
Specific gravity measurements showed that even for the strongest 
solutions the change of volume on mixing was negligible. 
Determination of Ionization Constants. 
In determining the ionization constants (A and / in expression 
(1) ) for any salt, and for either property, the data for the six 
weakest solutions examined were in all cases employed; and the 
values of the constants were found from these data by the 
method of least squares. 
The values thus found were employed in calculating the 
values of the properties of the various mixtures. 
Results of the Caculations.—Simple Solutions. 
The following table contains the values of the ionization 
constants for the various salts and for the two properties investi- 
gated, with the values of the properties calculated by means of 
these constants, and the differences between observed and ealu- 
lated values. Concentrations of solutions are expressed in terms 
of the same units as in Table I. 
TABLE I1.—SurFACE TENSION AT 15°C, (Rother’s Observations ). 
Concen- |Observed| Calculated | Differ- || Concen- |Observed| Calculated | Differ 
tration. | Value. Value. ences. tration. | Value. Value. ences. 
+ K2gSO4.—(k=0.09627 ; 7=0.18001). x NagSO4.—(k=0.11146 ; 7=0.14223). 
2341 7.392 7.392 0.000 .2041 | 7.393 7.094 |+0.001 
| Estero} & 7.414 7.413 - |l 4796 7.418 7.418 0 
946 7.A15 7.414 - Jl “7104 7.450 7.450 0 
3966 7.415 7.415 0 1.008 7.481 7.482 | + 1 
8976 7.415 7.415 0 4773 7.418 7.418 0 
.6088 7.442 7.443 + 1 4827 7.421 7418 | - 3 
S131 7.473 7.472 - 1 .9995 7.471 7.481 |+ 10 
1.244 7.537 7.543 + 6 |, 1.557 7.541 7.552 |+ 11 
* Trans. N.S. Inst. Science, IX (1896), p. 101. 
