140 ROYAL SOCIETY OF CANADA 
the curve would lie along the vertical axis. It does this approxim- 
ately up to a concentration of ‘05 grms per c.c., after which more 
water is displaced by the added salt than is represented by this simple 
relation. 
A second change in relation appears to take place at a density 
of about 1:105. These points correspond approximately with the 
change in slope of the resistance curve. 
Density at which a possible change in dissociation takes place: 
Density-concentration. Density-resistance. 
1:105 1:090 
1:040 1:035 
In conclvsion we may state that we hope to examine a number 
of other salts during the coming summer. 
(Added January 1st, 1903.) We have examined the resistance 
curves of two salts, KCl and K, SO,, since the communication of this 
paper, and find that the experimental evidence is not sufficiently 
strong to justify us in assuming a form of dissociation to account 
for the discontinuity in the density curves. There appears to be 
indications of it in the case of MgCl,, supra, but this is not shown 
in our curve for K,SO,, where a very marked change in the density 
curve occurs. Our later experiments will shortly form the subject 
of a further communication. 
