IV.—ON THE CALCULATION OF THE CONDUCTIVITY. OF AQUEOUS 
SOLUTIONS CONTAINING THE CHLORIDES OF SopIuM 
AND Barium. — By T. C. McKay, B.A., Dalhousie 
College, Halifax, N. S. 
(Read ith. March 1898.) 
The object of this research was to test the possibility of 
calculating the conductivity of mixtures of solutions of the 
chlorides of sodium and barium by means of the dissociation 
theory of electrolytic conduction. It was undertaken at the 
suggestion of Prof. J. G. MacGregor, and was conducted in the 
Physical and Chemical Laboratories of Dalhousie College. 
The method of calculation is fully described in one of Prof. 
MacGregor’s papers.* It may suffice here to state that by a 
graphical treatment of the dilutions and ionic concentrations of 
series of simple solutions of the two electrolytes, the magnitude 
of the dilution of each salt, in the portion or region of a 
mixture which it may be supposed to occupy, can be found, 
together with the common value of the concentration of ions of 
the electrolytes in their respective regions. These having been 
found, their products give the ionization coefficients in the 
mixture, and the conductivity of the mixture is then obtained 
from the expression of the dissociation theory for the conduc- 
tivity, viz. :— 
maGcon Ny Vy flo, +4, Ny Valley) 
where the «’s represent the ionization coefficients of the electro- 
lytes in the mixture, the n’s the concentrations of the constituent 
solutions (in gramme-equivalents per litre), the v’s the volumes 
of the constituent solutions, the p’s the specific molecular con- 
ductivities (7. ¢., per gramme-equivalent) at infinite dilution, of 
the electrolytes in the mixture, and p the ratio of the volume of 
the mixture to the sum of the volumes of the constituent solu- 
*N.S. Inst. of Sci., Trasactions, Vol. rx, p. 101. 
(321) 
