160 Conductivities and Viscosities in Pure and in Mixed Solvents. 



Jones 1 has pointed out the following general relations deduced from 

 the study of a large number of data concerning temperature coefficients : 



1. Those ions with the largest hydrating power have the largest 

 temperature coefficients of conductivity. 



2. Those substances having equal hydrating power have approxi- 

 mately the same temperature coefficients of conductivity. 



3. At higher dilutions, the temperature coefficients of conductivity, 

 for any given substance, are greater than at lower dilutions. 



In the present investigation all of these relations have been found 

 to hold, with the few apparent exceptions noted in the above discussion. 



SUMMARY. 



1 . A brief sketch of the work done in this laboratory on the conduc- 

 tivity of aqueous solutions, together with a resume of the results 

 obtained by Jones and his co-workers, has been given. 



2. A few practical suggestions as to apparatus and methods of pro- 

 cedure are offered. 



3. Eighteen more or less unusual salts were studied with reference 

 to their conductivity, over a range of temperature from to 35. 

 Their temperature coefficients of conductivity are expressed in two sets 

 of units; and where it is possible their dissociation has been calculated. 



4. The results of this investigation are, for the most part, in accord 

 with the findings of other workers in this field. Three exceptions were 

 found to the rule that dissociation decreases with rise in temperature. 

 Two apparent exceptions to the rule that large temperature coefficients 

 of conductivity are indicative of great hydration are noted and possible 

 explanations are offered. 



. Chem. Journ., 34, 357 (1905). 



