500 



L. P. Wheeler — Dispersion of Metals. 



00 (v + iA/-erw*dv) 



2 ^f — ~^~ 



(2)' 



where q is three-halves of the square of the average electronic 



Fig. 5. 





4.0 















£_-- 



^--'Sto 





3 5 













*r 





240 





3.o 



\ 









/' 



y 





2IO< 





25 



N 



\ 





s 



y 







iao 





2.0 









/'" 









150 



5.5 

 50 

 45 







1.5 









/' 











I20 



1.0 





/ 



'' 









— r 



do 



5 



*^' 



^' 





/ 









-~~__60 





t 



y 









^ 



f 









* 











J$ 



















> 



/ 



*<?s 



^^ 

















^ 



















AoJ 



*o° N 

















/ 





















1 



















f 





















O 23y<«. O 50^*. 



OOM 



Fig. 5. Cobalt. 



I.7V- 



2.00/* 2.2^"- 



velocity, <r is the electrical conductivity for steady currents, 

 and 



7rp m <r 



4NV 



(3) 



with ^ the charge, m the mass, and N the number of electrons 

 per unit volume. 



If we now expand (a/qv 2 -\-l)~ x in series and integrate term 

 by term, we get 



'='•[7 



2! 3! 



1 + ^ 



a a 





* H. A. Wilson, Phil. Mag. (6), xx, p. 835, 1910. Wilson there assumes the 

 electric force to be given by E=E cos pt, and hence his value for<7 lacks the 

 imaginary term of the above. 



