X-ray Electrons. 



1121 



error o£ 1 per cent. — an error which is likely to be even 

 greater in the case o£ faint lines presenting difficulty in 

 measurement. 



Experimental Results. 



Eight elements have so far been examined for X-ray 

 electrons under the action of the radiation from Rhodium 

 [45], viz.: Aluminium [13], Copper [29], Zinc [30], 

 Arsenic [33], Strontium [38], Molybdenum [42], Tung- 

 sten [74], Bismuth [83]. 



One typical photograph is shown (lower of PL XXIY.) 

 of copper. 



As noted by de Broglie, there are a number of lines or 

 rather bands coming to a more or less sharply-defined head 

 on the high-velocity side. To each band de Broglie attaches 

 a maximum v and therefore v corresponding to the pH. value 

 of the head *. This maximum value, in fact, is associated 

 with electrons escaping from the surface atoms of the material 

 with a speed unaffected by subsequent passage through or 

 near other atoms : it may, in fact, be taken to be the value 

 corresponding to emission from a free atom. 



It is these maximum values of v which have been tabulated 

 below. 



Table. 



V. 



Origin of electron. 



Agency 



of 

 ejection. 



v expected from 

 origin and agency. 







Copper (j 



metal leaf). 





r s. 



172 



L Eing 



CuK a 



CuK a -CuL=173 



8. 



i 



193 



( L Eing 



\ or 



I outer rings or free 



CuK/3 



or 

 CuK a 



CuK^-CuL =194-1 

 CuKa =195 J 



{ '• 



217 



outer rings or free 



CuK/j 



CuKp =216 



r s - 



270 



KEing 



Eh¥ a 



EhK a -CuK=273 



i '• 



287 



? 



p 





< 8. 



313 



?KKing 



EhK^ 



EhK /3 -CuK=334 



8. 



i l 



461 



L Eing 



KhK a 



EhK a -CuL=468 



502 



1* L Eing 

 \ outer or free 



EhK/3 



EhK a 



EhK j8 -CuL=529 

 EhK a =490 



552 



outer or free 



EhKp 



Kbp = 551 



* I have applied an obviously necessary correction in measurement 

 instead of pH. I use [p— d/4]H where <5=slit width. 



Phil. Mag. S. 6. Vol. 43. No. 258. June 1922. 4 



