TABLE 435 (continued}. 

 DIELECTRIC CONSTANTS OF LIQUIDS. 



A wave-length greater than 10000 centimeters is designated by oo 



Addenda to Table 440, p. 361, Dielectric Constant of Rochelle Salt: 



The polarization of the Rochelle salt dielectric in an electric field is somewhat analagous to the behavior of the mag- 

 netization of iron in a magnetic field, showing both saturation and hysteresis. The dielectric constant D depends on 

 the initial and final fields and the hysteresis. 



Initial field, 765 v/cm.; Final field, 690 v/cm.; Average D (23 C), 40 



765 153 205 



765 -765 157 



o 880 86 



The last value may be fair value for ordinary purposes. The electrodes were tinfoil attached with shellac. The fieJd 

 was applied perpendicular to the a axis. Like piezoelectric properties, the dielectric constant varies with different 

 crystals. It depends on the temperature as follows : (field o to 880 v/cm) 



-70 C, D = 12; - 40 , 14; -20, 48; o, 174 ; +20, 88; +30, 52. 

 (Data from Valesek, University of Minnesota, 1921.) 

 SMITHSONIAN TABLES. 



