388 



BULLETIN OP THE UNIVERSITY OF WISCONSIN. 



Table XIV. 



Substance. 



Acetonitrile . 

 Propionitrile 

 Butyronitrile 

 Valeronitrile 

 Capronitrile . 



L. H. 



D. C. 



4.77 

 5.07 

 5.48 

 5.51 

 5.68 



The ratios can hardly be said to be constant although the 

 values obtained for the nitriles show as close an agreement as 

 the values Obach had in hand when he indicated the relation 

 between dielectric constant and heat of vaporization, as will 

 appear from the following table which has been selected for 



comparison 



.i 



Table XV. 



Substance. 



Methyl formate — 



Ethyl formate 



Propyl formate 



Iso-butyl formate. 

 Amyl formate (iso) 



Ratio. 



10.7 



10.1 



9.3 



9.0 



9.2 



Conclusion. 



The principal points in the foregoing presentation may be 

 summarized in the following general statements : 



1. The values of the dielectric constants for the homologous 

 series of compounds examined decrease with increase of molec- 

 ular weight. 



2. The introduction of the cyanogen group in a compound 

 causes a marked increase in the value of the dielectric constant. 

 In this respect the cyanogen radical produces a greater effect 

 than all other radicals which have hitherto been systematically 

 studied. 



1 Phil. Mag. 3«, p. J17, (1891). 



