DEPRESSIONS FOR ELECTROLYTES—MACGREGOR. Pa 5 
current is to be regarded as being the same as when the current 
is not flowing. But as it has been shown that electrically deter- 
mined coefficients enable us to predict within the limit of error 
of observation, not only the conductivity and the results of 
electrolysis* of moderately dilute complex solutions, but also their 
density, viscosity, and other non-electrical properties,> it would 
appear to be probable that for moderately dilute and very dilute 
solutions, electrically determined coefficients are approximately 
exact, not only for a solution through which a current is passing, 
but generally. 
The available data as to ionization coefficients at 0°, are 
unfortunately few. Whethamt has recently published some 
most valuable determinations, having measured the conductivity 
at US, of series of solutions down to extreme dilution, with what 
one may call apparei de luxe, and found the ratio of the equiv- 
alent conductivity to the maximum equivalent conductivity. For 
neutral salts, his coefficients must inspire great confidence. But 
in the case of the acids, they seem to me to be probably too high. 
For the maximum equivalent conductivity of an acid is probably 
lower than it would be, were it not for the disturbing influence 
whatever it is, which makes the equivalent-conductivity-con- 
centration curve not only reach, but pass through a maximum 
point. 
Archibald and Barnes,} working in my laboratory, measured 
the conductivity at 0° and 18° for series of solutions, down to 
dilutions, at which the ratio of the two conductivities beeame 
constant; and assuming that the same ratio would hold at 
extreme dilution, they calculated the equivalent conductivity at 
extreme dilution for 0° from Kohlrausch’s values for 18°. They 
used this method only because appliances were not available, 
with which observations at extreme dilution could be made. If 
* MacGregor: Trans. Roy. Soc. Can. (2), 4, Sec. 3, 117, 1898. 
+ MacGregor: Trans. N.S. Inst. Sci. 9, 219. 1895-7, and Phil. Mag. (5), 43, 46 and 
99, 1897. Also Archibald: Trans. N.S. Inst. Sci, 9,335, 1897-8, and Barnes: Jbid., 10, 49, 
and 113, 1899-1900. 
+ Ztschr. f. phys. Chem., 33, 344, 1900. 
t Archibald: Trans. N.S. Inst. Sci., 10. 33, 1898-9. Barnes: Jbid., 10, 139, 1899- 
1900, and Trans. Roy. Soc. Canada, (2), 6, —, 1900. 
