230 CONSTITUTION OF ELECTRONS [APP. M. 



instead of merely broadening them : other types will only 

 do so when they are all similarly orientated to the in- 

 ducing magnetic field. 



The experiments of Kaufmann held out a hope that 

 we should get to know something definite about intrinsic 

 electron structure. They have proved sufficiently the 

 fundamental fact that a free electron has no independent 

 material sub-stratum : they have made it very probable 

 that it may be provisionally represented as a region of 

 electricity spherically stratified : also that convection of 

 an electron does not affect the volume relations of this 

 distribution (Bucherer); but unfortunately it has not 

 proved possible to push on the precision of the experi- 

 ment so as to get information beyond this. 



We must still be content to treat the electron as a point, 

 or at most as a spherical electric aggregate of some sort 

 whose volume does not undergo shrinkage. But the in- 

 direct evidence afforded by the entire absence of convection 

 effects of many kinds, such as the earth's motion might 

 be supposed to excite, is strongly in favour of the pro- 

 visional theory that the ultimate elements of which 

 atoms are constituted are in their dynamical relations 

 purely aethereal structures of some sort which probably 

 we cannot yet adequately imagine. 



GLASGOW : PRINTED AT THK UNIVERSITY PRESS BY ROBERT MACLEHOSE AND CO. LTD. 



