130 ON THE CALCULATION OF THE CONDUCTIVITY 
is given, according to the dissociation theory, by the equa- 
tion : 
(fa isco PRESET seas may ean) (A) 
’ p(v, +0,) (7 Om eatarecon 2 Yo 2 Hara) os 
where v,, v, are the volumes, and ”,,”, the concentrations of 
the solutions mixed, p,,,, 4, the specific molecular conductivi- 
vities of simple solutions of the electrolytes at infinite dilution, 
a, and a, the ionization co-efficients of the respective electro- 
lytes in the mixture, and p the ratio of the volume of the 
mixture to the sum of the volumes of the constituent solutions. 
? Prof. MacGregor has shown that the ionization coefficients 
in a mixture of this kind may be found by the solution of four 
equations, and I have pointed out in a former paper? that by 
throwing these equations into other forms and applying a 
graphical method they may be solved with little trouble, even 
in cases in which but few observations of the conductivity of 
simple solutions of the electrolytes in the mixtures are avail- 
able. The forms of the equations referred to are as follows: 
May 
reese 5 | 
Moo 9 
Ni ek aie) 
(Or Ce 
ky =F, (@)), 
kv a Is (Cy). 
where the k’s and C’s are the regional conductivities and 
regional concentrations, and the N’s the concentrations of the 
mixture, with respect to the electrolytes 1 and 2 respectively. 
By the regional conductivity and the regional concentration of 
an electrolyte in a mixture are meant the conductivity and con- 
centration of the portion or region of the mixture which the one 
electrolyte may be supposed to occupy to the exclusion of the 
other. If there is no change of volume on mixing, they are the 
conductivities and concentrations of the isohydric constituents 
of the mixture. 
1 Trans. N.S. Inst. Sci., 10, 68, 1898-9. 
? Trans. N. S. Inst. Sci., 10, 113, 1899-1900. 
