8CHLUNDT — DIELECTRIC CONSTANTS OP PURE SOLVENTS. 389 



3. The cyanogen (CN), amido (NH) 2 , or nitric acii 

 (N0 3 ) radicals when present in compounds do not cause anom- 

 alous absorption as Drude found for the hydroxy 1 (OH) group. 



4. A number of new examples have been given which follow 

 the Nernst-Thomson rule. 



5. Some striking exceptions to the !NTernst-Thomson rule have 

 been pointed out from which it has been argued that the rule 

 is inadequate. The exceptions indicate that the nature of the 

 solvent as well as the dissolved substance are of prime impor- 

 tance in determining whether a solution will conduct electricity. 



6. Obach's law holds only approximately for the nitriles. 



This investigation was made in the Laboratory of Physical 

 Chemistry of the University of Wisconsin. It was undertaken 

 at the suggestion of Professor Kahlenberg and carried on un- 

 der his supervision. As before stated, I am indebted to him 

 for placing at my disposal many of the solvents used for these 

 measurements, and I am under many obligations to him for his 

 helpful suggestions and for the active interest he has always 

 shown in my work ; and I am glad to have this opportunity of 

 acknowledging it. 



A portion of the results of the work on the nitriles has previ- 

 ously been published in a preliminary article in the Journal of 

 Physical Chemistry 5, 157, (1901). For the sake of complete- 

 ness the results have also been incorporated in the present 

 paper. 



Laboratory of Physical Chemistry, 

 University of Wisconsin, 



Madison, May, 1901. 



