AQUEOUS SOLUTIONS. McKAY. 329 



The mean of these ratios is .2131. This was taken as the 

 calibration constant, and by means of it the conductivities of 

 solutions measured in the first cell were expressed in Kohl- 

 rausch's units. The capacity of the second cell was determined 

 in the same manner. It will be seen that the solutions above, 

 which show the closest agreement with Kohlrausch's values, are 

 those which could be measured near the middle of the bridge, 

 viz., those of concentrations 0.5 and 5 gramme-equivalents per 

 litre. 



Observations on Simple Solutions. 



The following tables give the concentrations and the conduc- 

 tivities of the simple solutions of NaCl and BaCl 2 , by means of 

 which the curves that show the relation between the ionic con- 

 centration and dilution were drawn.* The concentrations are 

 expressed in gramme-equivalents per litre for the temperature 

 of 18C. The conductivities are expressed in terms of the 

 conductivity of mercury at 0C, multiplied by 10~ 8 , the tempera- 

 ture being also 18C. 



* See paragraph on making up of solutions. 



