364 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



nations averaged 65 . 3 at 23° C. No sudden change in the D. C. 

 was observed at the melting point. The absorption of the solid 

 ethylene cyanide was very slight ; but the liquid sample did not 

 show a well defined maximum, which was found to be due to its 

 greater conductivity. The qualitative measurements of its re- 

 sistance show that the temperature has a great influence on the 

 resistance. At room temperatures the resistance is about twenty 

 times as great as it is at 60° C. ; but no sudden change in the 

 resistance was observed at the melting point. 



Toluoniirile (ortho.). — Schuchardt's preparation was redis- 

 tilled from calcium chloride. A straw colored distillate, boiling 

 at 200° — 201° C. under a pressure of 733 mm. was thus ob- 

 tained. It D. C. was found to be 18.5 at 23° C. It showed 

 slight absorption. 



a-Naphthonitrile. — Schuchardt's preparation was redis- 

 tilled under diminished pressure. Its melting point was 37° C. ; 

 but it is easily kept in a liquid state at 20° C. when the solid 

 phase is not present. Its dielectric constant was determined in 

 the form of cell adapted for measurements at higher tempera- 

 tures, and the following values were found for the liquid sample. 



D. C. = 16.0 at 70° C. 

 D. C. = 17.9 at 42° C. 

 D. C. = 19.2at22° C. 



The position for maximum resonance was about as well de- 

 fined as for nitro-benzene whose absorption index Drude 1 places 

 at 0.05. The D. C. of the solid sample was found to be 6.3 at 

 21° C. ; but this value is only approximate, for the position for 

 maximum resonance was not well defined. 



0-Naphthonitrile. — Thes ample used for the measurements 

 was obtained by distilling Schuchardt's preparation under di- 

 minished pressure. Its boiling point was 190° C. under 35 mm. 

 of pressure, and its melting point was 64° C. The D. C. of the 

 liquid was found to be 16 . 9 at 70° C, and for the solid the value 

 4.3 at 23° C. was obtained, the position for maximum resonance 

 being well defined in both the solid and the liquid samples. 



i Zeit. phys. Chem. 23, 309. (1897). 



