138 ROYAL SOCIETY OF CANADA 
that the deflection was in the opposite direction to that produced by 
the polarization, a deflection first in one direction and then in the 
other direction resulted. The balance point was taken to be the 
exact point at which the momentary deflection in the opposite direc- 
tion to the polarization disappeared. After a little practice it was 
possible to take readings and repeat measurements of the resistance 
to 1 part in 5,000 with comparative ease. 
As a check of the accuracy of our measurements the resistance 
of one of our solutions, through the kindness of Mr. McIntosh, was 
determined by the Kohlrausch method, using the telephone instrument 
set up and in constant use by him in the McDonald Chemistry Build- 
ing. The result was in good agreement with our own on the cal- 
culation of the specific resistance, and showed, we think, that we were 
free from constant errors. Our method of; 
a. Keeping the electrolyte in motion, 
b. Reversing the direction of the main current between each 
reading, 
c. Closing the main current for only a small fraction of time 
in obtaining the readings, 
reduced the errors of the direct current method to a negligible 
amount and avoided current heating common to all methods. 
In preparing our solutions we took great care to use pure dis- 
tilled water, and to have all parts of the apparatus clean. ‘Twelve 
different concentrations were taken varying above and below the 
point in question. These solutions were first adjusted roughly with 
a hydrometer and afterwards the density obtained accurately by 
means of a pyknometer. The density varied from 1-155 to 1-019, 
representing a range in strength from 0-211 grms. per c.c. to 0-026 
grams per ©.c. 
The following table contains the results of our measurements: 






| ONCENTRATION GRAMS 
DENSITY. RESISTANCE. Concr SRE en 
1°1553 101°52 0°2119 
1 1235 113°57 01670 
11111 118°21 0°1470 
1°1031 120°44 0°1350 
1°0901 126°54 0°1200 
1;0821 | 134°65 0°1085 
10735 | 145: 56 | 0:0970 
1°0673 155° 28 0° 0888 
1°0585 175°72 0°0770 
1°0407 | 233° 88 | 0° 0536 
1°0322 | 269° 25 | 0° 0424 
1:0195 | 423° 88 | 0° 0260 

| These are plotted in fig. 2. 
