80 
PROF. H. A. WILSON ON THE ELECTRICAL CONDUCTIVITY AND 
values of 10 4 & calculated from (5), using the observed values of c. The calculations 
were done with a slide rule :— 
c. 
k (calculated). 
k (experimental). 
1 
0 
0 
2-88 
0-00326 
0-0032 
5-72 
0-0087 
0-008 
8-9 
0-0166 
0-016 
13-5 
0-0315 
0-032 
22 • 7 
0-074 
0-08 
32-8 
0-14 
0-16 
85-2 
0-81 
0-8 
282 
8-2 
8-0 
883 
79-0 
80-0 
The experimental numbers for c are probably reliable to about 5 per cent., so that 
when k is calculated from c the results may be in error by 10 per cent. 
The calculated and experimental values of k agree to less than 10 per cent, in 
nearly all cases. When the enormous variation in k, from 0'0032 to 80, is taken into 
account, it may be said that the results are in good agreement with the ionic theory. 
Since 
n _ b 
S b + ac 
we get for caesium chloride 
n _ 10 
S ~ 10 + c" 
The following table gives the percentage of the CsCl molecules, which are ionised 
in the flame according to this equation :— 
Solution sprayed 
(grammes CsCl per litre). 
-gx 100. 
0 
90-9 
0-0032 
75-6 
0-032 
41-8 
0-16 
22-0 
0-8 
10-6 
8-0 
3-5 
80-0 
1-1 
