668 BELL SYSTEM TECHNICAL JOURNAL 



a the radius of a polar molecule, assumed to'be spherical, 

 h the radius of a colloidal particle, 



d the thickness of a conducting skin on the particle of radius b, 

 r a frictional resistance coefficient of unspecified origin, 

 / an elastic restoring force coefficient of unspecified origin, 

 n the number per unit volume of elementary charged particles 



subject to certain specified conditions, 

 p the ratio of the volume occupied by the spherical particles 



in (3c, d, e) to the total volume, 

 Ci the capacity of the blocking layer of (3&), Table I, 

 R the resistance of the dielectric, exclusive of the blocking 



layer. 



The following list contains the definitions of quantities which appear 

 in other parts of the article. 



CO is 2-K times the frequency of alternation of the applied field, 

 V the applied voltage, 

 E the intensity of the applied field, 



P the polarization per unit volume induced by a field E, 

 F the internal or local field, 

 p the density of the dielectric, 

 M the molecular weight of the material of which the dielectric is 



composed, 

 m the mass of a molecule ; in another context, the mass of any charged 



particle considered in the discussion, 

 N is Avogadro's number, 6.06 X 10-^ molecules per mole, 

 s the displacement of a charged particle from an equilibrium position 



by an applied field, 

 i; the velocity of the charged particle in the applied field, 

 s the acceleration of the particle in the applied field. 



References Relating to Table I 



1. P. Debye, "Polar Molecules," New York (1929). 



2. P. Drude, Ann. d. Physik, 64, 131 (1898); L. Decombe, J. d. Physique (5) 3, 215 



(1912); and the present article. 



3. K. W. Wagner, Chap. I of Schering's "Die Isolierstoffe der Elektrotechnik," 



Springer, Berlin (1934). 



4. A. Joffe, "The Physics of Crystals," New York (1928). 



5. K. W. Wagner, Arch. f. Elektrotechnik, 2, 371 (1914). 



6. J. B. Miles and H. P. Robertson, Phys. Rev., 40, 583 (1932). 



7. A. Gemant, "Die Elektrophysik der Isolierstoffe," Berlin (1930). 



General reviews of the theory of dielectric behavior as it concerns dispersion for 

 power and radio frequencies are included in the following places, among others: 



1. E. Schrodinger, "Dielektrizitat," Graetz, Handb. d. Elek. u. d. Magn., Leipzig 

 (1918), pp. 157-229. 



