LEWIS AND WHEELER. — CONDUCTIVITY OP SOLUTIONS. 



427 



M 



dilute solutions we have shown to be negative, becomes numerically 

 smaller with increasing concentration, is zero when C is a little less than 

 3.0 and for stronger solu- 

 tions becomes positive. The 

 conductivity curve for any 

 other neighboring tempera- 

 ture is therefore very simi- 

 lar to the one for 140°, but 

 crosses that curve at a con- 

 centration of about 3. The 

 change in sign of the tem- 

 perature coefficient might 

 perhaps have been predicted, 

 for with increasing con- 

 centration the substance 

 approaches more and more 

 nearly the condition of a 

 pure molten salt and all 

 salts which have been hith- 

 erto studied have large posi- 

 tive temperature coefficients. 



Table V gives the percentage change in the conductivity, per degree, 

 at several concentrations. 



TABLE V. 



Figure 2. 



Discussion of the Conductivity Curve- 



Assuming that the whole of the conductivity is electrolytic in char- 

 acter, let us consider from this point of view, the curves of Figures 2 



