6CHLUNDT — DIELECTRIC CONSTANTS OF TURE SOLVENTS. 363 



The average of three determinations gave the value 20.4 for its 

 D. C. at 24° C. 



Valeronitrile (normal). — The sample was obtained from 

 Schnchardt. It was redistilled from calcium chloride, and the 

 portion which distilled between 137° and 139° 0., under 743 

 mm of pressure was taken for the measurements. The D. C. 

 was found to be 17.4° at 31° C. 



Iso-butylcyanide. — The sample was Schuchardt's make; it 

 was redistilled from calcium chloride, and the portion distilling 

 between 129° and 130.5° C, under a pressure of 742 mm was 

 taken for the measurements. Its D. C. was found to be 17.95 at 

 22° C. 



CapronltriJr. — The sample used was obtained from Schu- 

 chardt. It was redistilled from calcium chloride, and the por- 

 tion distilled between 153 c -154.2° C, under 743 mm pressure, 

 was taken for the measurements. Its D. C. was found to be 

 15.5 at 22° C. The higher members of the series show a slight 

 amount of absorption, but the maximum resonance is still well 

 enough denned without increasing the intensity of the oscilla- 

 tions in the secondary circuit. 



Ethylene Cyanide. — The sample of succinic acid nitrile was 

 of Schuchardt's make. It was treated with fused calcium chlor- 

 ide, filtered and redistilled twice under diminished pressure. 

 Its boiling point was 168° C. under a pressure of 28 mm. A 

 solid, almost colorless, amorphous compound was thus obtained 

 which melted at 54° C. Its D. C. was measured in the form of 

 cell used by Drude 1 for the measurement of substances at higher 

 temperatures. During the measurements the cell was kept in 

 an oil-bath of the form figured and described by Coolidge. 2 The 

 bath was attached to the ebonite slide by means of a small spring 

 clamp. The temperature was kept at 60° ± 1° during the 

 measurements of the liquid ethylene cyanide. The average of 

 three determinations gave the value 61.2 for its D. C. The D. 

 C. of the solid compound was also determined. Three determi- 



i See Fig. 7, p. 285, Zeit. phys. Chein. 23. (1897). 

 8 Wied. Ann. 69, 133. (1899). 



