CHEMISTRY: HARKINS, HALL AND ROBERTS 
601 
These results are in accord with Werner's theory in so far as the" num- 
ber of ions is concerned. 
When the apparent ionization values for these salts obtained by the 
conductivity and freezing-point methods are compared, it is found that 
they are closely similar, except in the case of the tetraionic salt, when 
the result calculated from the freezing-point is much the higher. The 
deviation is in such a direction as could be explained by the theory of 
Harkins^' that all salts of this and other higher types give a considerable 
80 
60 
40 
20 
7.00 
80 
5.601 \ I 1 = 1 L 
12 5 10 20 50 
percentage of intermediate ions in solutions of about 0.1 normal con- 
centration. It is of course realized that the apparent ionizations ob- 
tained by the two methods are in no cases directly comparable, since 
we do not know the variation in the activity of the different components. 
While many of the cobaltammines are unstable and hydrolyze rapidly 
at higher temperatures, at zero degrees no trouble was experienced, 
except with dinitrotetrammine cobalt chloride when it was exposed 
to a bright light, and with sodium cobaltic nitrite. 
