Prof. 0. W. Richardson on Metallic Conduction. 295 



As most of the more important results are independent of 

 these terms, and their retention would lead to unnecessary 

 complications in the statement of the problem, it was thought 

 preferable to give the present analysis in its simpler form 

 pending a discussion of the correlative problems in gas 

 theory. 



The University, Sheffield, 

 Jan. 4th, "1915. 



[Note added April lst.~\ Since the above was written I 

 have, through the kindness of Dr. Bohr, had the pleasure of 

 reading his dissertation, and I find that the reference made 

 in the text to this work is hardly just. The method employed 

 by him is as stated, but it is necessitated by the far more 

 general circumstances under which he treats the problem. 

 I had not access to his work and relied on the reference 

 to it given by Enskog. Bohr's analysis is, however, rather 

 different from that here given, being based on the idea of the 

 momentum distribution rather than the velocity distribution 

 as here. 



XXVIII. Metallic Conduction. By 0. W. Richardson, 

 F.R.S., Wheat stone Professor of Physics , University of 

 London, King's College *. 



THE form of theory of metallic conduction f which has 

 recently been revived and extended by Sir J. J. 

 Thomson %, and has been strikingly successful in explaining 

 the variation of metallic conduction with temperature, 

 suggests a number of interesting questions some of which 

 are discussed in the present note* According to the theory 

 under consideration, the transference of electricity in metals 

 is due to the motion of electrons from the various atoms to 

 those immediately adjoining them. The electrons are 

 imagined to be projected, from the atoms at which they 

 originate, in directions which coincide with those of the 

 axes of electric doublets which are also supposed to be 

 present in the atoms. In the absence of an external electric 

 field the axes of the doublets are distributed uniformly in all 

 directions, so that there is no preponderance in favour of 

 any particular direction of projection and therefore no 



* Communicated by the Author. 



t J. J. Thomson, 'Corpuscular Theory of Matter,' p. 80, New York 

 (1907). 



X Phil. Mag. vol. xiii. p. 192 (1915). 



