240 Mr Barlow, On the Osmotic Pressure of Aqueous Solutions. 



Note. Since the body of this paper was written, I have, at the 

 suggestion of Professor Thomson, examined water containing kaolin 

 for changes in its electrical conductivity. The kaolin used was 

 washing for a week in several changes of distilled water, before 

 being used for the experiment, in order to remove traces of any 

 foreign soluble matter. Finally the kaolin was filtered off and 

 washed with redistilled water. It was then placed in the outer 

 vessel which was used with cell e above, and covered to a con- 

 venient depth with redistilled water. The vessel was closed to 

 the air and placed in a water bath. The same method of taking 

 the resistance was used. The following values of the conductivity 



[ = -p ) at 14° C. were obtained, and from them the curve above is 



drawn. 



Date 



Conductivity 



Date 



Conductivity 



June 13 



» 14 



,. 17 

 „ 19 



5-20. 10- 5 

 5-43 

 5-57 

 5-60 



June 21 



July 6 



„ 8 



5-62. 10- 5 



5-71 



5-75 



