Electron Theory of the Metallic state. 75i> 



which for /a=9 according to (4), (6), and (7) gives 



d£ e __ 0-17 7.1-74 26 

 rfR" 2R 2 



As further ., -.,., is the linear coefficient 7) of dilatation, 



K </T 



we have 



, 0'177.1-742e 7] , 11 rt iy microvolt , 



4 R R degree ' v ' 



where rj' = tj . 10 5 and R' = H . 10 8 are both of order one. 



We may at least for high temperatures sum up our results 

 as to the Thomson heat in the formula 



a=Ar)-Bc c , (25) 



where the second term is a sum of a x and cr 2 . A and B are 

 positive constants. This formula was deduced in an earlier 

 paper from somewhat less definite assumptions, and was 

 also shown to be well consistent with the unfortunately 

 rather few experimental facts that are known to-day about 

 thermoelectric phenomena at low temperatures. 

 For metals with /jl=9 we have 



7) -p microvolt , 



11-5, — B^ ,——. . . . (25') 



B decree v 7 



To show the possibility of this equation, I have in fig. 1 

 plotted the Thomson coefficients of a number of heavy 



i 



7) 



metals against the ratio 777- The line in the figure corre- 



71 



spon ds to a = 11 -p. The experimental values are all under 



this line, and there also seems to be a certain orientation of 

 them in this direction. Certainly the structure of the 

 metals is known to be consistent with our premises only by 

 Cu, Ag, Au, Al, Pb, and perhaps Ni ; but the other metals 

 are given because their compressibilities by means of 

 equation (8) give values for fju of the same order as those 

 of the named metals, so that it seems probable that our 

 calculations are approximately valid for them. The alkaline 

 metals, on the other hand, are excluded. The values for a 

 refer to temperatures greater than 6. They are taken from 

 measurements of a or of the thermoelectric power against Pb, 



