Electron Theory of the Metallic State. 747 



Stark*, Lindemunn t 3 and others to propose separately 

 very radical alterations in tho fundamental assumptions 

 of: the electron theory of the metallic state. The present 

 writer, too, has made an attempt in this direction. Last 

 year I treated in three communications J the thermoelectric 

 phenomena, the thermal and electric conduction and the 

 magnetic and galvanomagnetic phenomena from new funda- 

 mental assumptions. I here wish to give an abstract and a 

 revision of these papers. Especially the work published 

 during the past year by Madelung § and Born and Lande ||, 

 on the electrostatic forces in the atomic space-lattices in 

 connexion with some results of X-ray analysis of metals, 

 makes it possible for me now to treat some of the phe- 

 nomena in a more concise manner. 



§ 2. Number and Arrangement of the Conducting Electrons. 



We will, as a general assumption, suppose the metallic 

 state to be to a certain extent comparable to the state of 

 a halogen salt according to the modern space-lattice theory, 

 the negative ions of the salt being replaced by electrons. 

 The great dissimilarity in the behaviour of metals and 

 salts is then chiefly due to the greater mobility of the 

 electrons, caused by the diminutiveness of their mass 

 compared with that of the ions. We thus, as will be 

 seen in § 4 for a simple case, at once get an under- 

 standing of the way in which the statical equilibrium of 

 the metallic space-lattice is built up by electric forces in 

 full conformity with the theory of Born and Lande. 



In the simplest case the metal would be of the type 

 NaCl, a simple cubic lattice with alternating Na and 

 CI atoms. The figure of symmetry for one of the com- 

 ponents must then be a " face-centred cube " — that is, 

 an atom at each corner of a cube and one in the centre 

 of each of its sides. And, indeed, this symmetry is found 

 by the X-ray analysis IF for a great part of the examined 

 metals belonging to the regular crystal system, namely, 



* I. Stark, Jahr. d. Bad. ix. p. 188 (1912). 



t F. A. Lindemann, Phil. Mag. vol. xxix. p. 126 (1915). 



t Gh Borelius, Ann. d. Phys. lvii. pp. 231 & 278 (1918), and lviii. 

 p. 489 (1919). 



§ E. Madelung, Phys. Zeitschr. xix. p. 524 (1918). 



|| M. Born and A. Lande, Berl. Ber. 1918, p. 1048 ; Verh. d. deutsch. 

 Phys. Ges. xx. pp. 202 & 210 (1918). 



1j W. L. Bragg, Phil. Mag. vol. xxviii. p. 355 (1914) (Cu). L. Vegard 

 Phil. Mag. vol. xxxi. p. 83 (1916) (Ag), and vol. xxxii. p. 65 (1916) 

 ( \u, Pb)f P. Scherrer, Phys. Zeitschr. xix. p. 23 (1918) (Al). A. W. 

 Hull, Phys. Rev. vol. x. p. 661 (1917) (Pb ; Fe, Ni, Na, Li, Mg, and 

 others). 



3 a 2 



