BY MIXTURES OF ELECTROLYTES. BARNES. 149 



acid, were prepared and their conductivities measured at 18 

 and at 0. The conductivity of the water used in the prepara- 

 tion of these solutions was measured at both temperatures, and 

 its value substracted in each case from the conductivity of the 

 solution. Considerable care was required with these dilute 

 solutions to obtain good results. The electrodes were thoroughly 

 washed with a portion of the solution before placing them in 

 the cell. Both the solutions and the water used were exposed 

 as little as possible to the air, and the measurements were taken 

 immediately after a solution was made. The measurements 

 were repeated three times, and the mean of the values obtained 

 was taken as the most probable value. 



The following Table I gives the values thus obtained, and the 

 ratio , where ^ 8 and JM O are the specific molecular con- 



1*18 



ductivities at 18 and respectively. The concentrations are 

 expressed in gramme-molecules per litre at 0, and the specific 

 molecular conductivities in terms of this unit and of 10~ 4 times 

 Kohlrausch's new unit of conductivity. 



