754 Dr. G. Borelius on the 



polarization would correspond a maximal current density, 



i m — nev, (12) 



if all the electrons travelled in a direction opposite the 

 electric force. If now the current density i is throughout 

 proportional to P, we must have 



P^ 

 P. 



(13) 



Inserting (11) and (12) in (13), and as v = 2v8 = vU v'8, 

 we get for the specific conductivity at high temperatures, 



P' 



e 2 \/S nvW 



and because of (10) 

 P 



?'3 s/im'v'T 



(14) 



(14') 



We thus get the conductivity inversely proportional 

 to the absolute temperature, in good agreement with experi- 

 mental results. Further, if our premises are valid, the 



constants — , which can be calculated from (15), must be of 



P 

 order one. The values in the following table are simply 



calculated from the conductivities at 0° C, though that 



temperature cannot, for all metals, be looked upon as a 



rather high one. We see that the predictions of our 



theory are fulfilled very precisely for the best conductors 



in the first group of the periodic system. - is here nearly 



equal to one. Passing to the right side of the system, 

 this constant becomes gradually greater up to about ten for 

 the metals in group VIII. : — 



I. 



Na 1'5 

 K 11 

 Ou 1-6 



Ag 11 

 Au 1-5 



II. 



III. 



IV. 



V. 



VIII. 



Mg 2-2 



Al 19 



Sn 3-6 



(Sb 15) 



Fe 70 



Zn 4-5 





Pb V8 



(Bi 38) 



Cm 9-7 



Cd 3-8 









Eh 4-8 

 Ir 4-2 

 Ni 7-5 



Pd 8-2 

 Pt 81 



