1121 



T — 290°. 





10.47 — 10.08 shi 2.4G (31.36 — jjpl) 

 1.657 — 0.749 .sin 4.5 (12 — |Xp|) 



§ 5. Gerieral remarks and co7iclusions. Referring to the existing obser- 

 vations we may make some remarks on the electron theory of metals. 



The sign of the HALL-effect shows, that the intlnence of the magnetic 

 field on the so-called "free" electrons is a complicated phenomenon. 

 The change of the resistance in the magnetic field can give us an 

 insight into the mechanism of the electric current For it has been 

 found, that the resistance change of a cr^'stal depended only on the 

 angle between the crystal axis and the field ') ; the angle between the 

 directions of the Held and of the current is of no importance, at 

 least in a first approximation. From this we may conclude, that 

 although the electrons may be "free" in passing from one molecule 

 to the other, the influence of the field on these free paths and the 

 resistance change caused by it, is negligible. Therefore theories as 

 e.g. that of J. J. Thomson, which try to calculate the phenomenon 

 from the direct effect of the field on the "free" electrons cannot 

 possibly give the right result. 



1) D. E. Roberts, loc. cit. p. 468. Table U. 



73* 



