70 IONIZATION OF COMPLEX 
obtained from the few available observations. In some cases 
also Kohlrausch’s! observation may be utilised, viz., that the 
curves obtained by plotting equivalent conductivity against 
linear concentration (7.e¢., the cube root of the concentration), 
are for univalent salts, through considerable ranges, practically 
rectilinear. 
The dilution-ionic-concentration curves, having been drawn 
for the simple solutions (curve A for electrolyte 1, and B for 2, 
in the figures below), the problem resolve itself into finding two 
points, one on each curve, having, according to equation (1), the 
same abscissa, and having ordinates which satisfy the condition 
of equation (2). This may be done of course by inspection, 
but more accurately, and usually more quickly, by one or other 
of several graphical processes. 
(1.) Plot a new curve 
C (Fig. 1) with the 
same abscisse as A 
and B, but with ordi- 
nates equal to the sum 
of N, times the ordi- 
nates of A and N, 
times the ordinates of 
B. Then draw the 
straight line F G par- 
ofy allel to the axis of 
: ionic concentrations 
Pig. L. and at a _ distance 
unity from it (I assume for simplicity that the dilutions and 
ionic concentrations have been plotted to the scale unity). Let 
FG cut C in G; and through G draw the straight line GJ_ par- 
allel to the axis of dilutions and cutting A and B in I and H 
respectively. I and H are the two points required. For they 
have the same abscissa OJ, and their ordinates, 1 J and HJ, 
are such that 
N,- lJ 4+N,.HI=GJ=1. 
Then a, =OJ.IJ, anda, =OJ.HJ. 
1Wied. Ann., 26, 201, 1885. 
