440 Lincoln-—Electrical Conductivity. 
in the case of the trichloride of antimony, but the variation is 
relatively less than in the case of the ferric chloride; and the 
more concentrated solutions show a molecular weight slightly 
less than the theoretical. In the case of stannic chloride the 
same general facts appear. The trichlorides of bismuth and 
phosphorus yield molecular weights that increase with the con¬ 
centration. In the more dilute solutions these values are lower 
than the theoretical. These results are of particular interest 
in connection with the high values of /x obtained in this solvent 
for solutions of ferric chloride. The conductivity is in keeping 
with the high dielectric constant of nitrobenzene; and accord¬ 
ing to Ramsay and Shields this solvent is classified among those 
whose molecules are not polymerized. The conductivity in¬ 
creases with the temperature, and reaches a limiting value. 
(See Table XX.) 
Dutoit and Aston have determined the conductivity of a num¬ 
ber of salts in propionitrile. The conductivity of various salts 
in solutions of acetonitrile and butyronitrile has been measured 
by Dutoit and Friderich. They find that nitriles yield solutions 
that conduct, and the same is true of benzonitrile. (See Table 
XXIV.) Owing to the small quantity of this solvent available, 
only a few quantitative determinations could be made; but from 
the qualitative results it will be seen that benzonitrile solutions 
conduct fairly well. The values of /x for acetonitrile solutions 
approximate closely those obtained for aqueous solutions, while 
for CNS.NH 4 and Nal, /x is about the same magnitude as for 
AgN0 3 in benzonitrile. The conductivity of the other salts in 
these solvents is rather low. The conductivity increases with 
the dilution, but in the case of Nal in butyronitrile it appears 
to be about constant. The conductivity increases with the 
temperature except in the case of solutions of Cdl 2 in aceto¬ 
nitrile, the value of /x being virtually the same at 0.2° C. as at 
37.2° C. 
According to Werner, 1 boiling point determinations indicate 
normal molecular weights of AgN0 3 in benzonitrile. The 
average of his determinations is 176, while the theory requires 
170. His values for mercuric iodide are a little above the 
1 Zeit. Anorg. Chem ., 15, 1; 1897. 
