160 Normal and Selective Photoelectric Effect. 



the addition of the two effects ; Tables III. and IV. cor 



respond to these figures. 



Fig, 5.— Rubidium ; unpolarized light. 





Z 24 



03 



CO 



^ 20 



O 

 i—i 



"g 16 



5-1 



| 12 

 o 



~o 8 



<D 

 ""3 



O 



Ph 

















-U 







! i 





















-3 









1 



















7 









1 

















































_/_ 





























n 









\ 









— <* 



\ 











L 









i I 















/ 



r 









1 



— ? — r~ 











\ 



\ 





r 











l\ 





















/ 











\ i 





























\l 





















■■• 











] 



3 







T 











1 









~"t 



■--1 







,W 2 



OO.um 300 



400 



600 







Wave-length. 



r 



fABLE II. Table III. Table IY. 





K-Na alloy. <£ = 60°. Solid K. £ = 60°. Solid Rb. <£ = 60°. 





No. 



Wave- 

 length 



| 



Photoelectric current, j 



No. 



Wave- 

 length 

 fill. 



Photoelectric 



current 

 10 -13 amp. 



No. 

 135 



Wave- 

 length 

 pp. 



546 



Photoelectric 



current ! 

 10 -13 amp. 



0-47 





E|l 

 10 _13 amp. 



] 



10" 



3± 



13 amp. 



11 



1... 



546 



10 







122 



546 



0-9 





2... 



436 



100-0 



8-0 



123 



436 



60 



134 



436 



22-9 





3... 



406 



1590 



12 3 



124 



406 



45 



133 



406 



9-8 





4... 



365 



138 



13-0 



125 



365 



18-4 



132 



365 



5-4 





5... 



313 



66-7 



17-1 



126 



313 



6-3 



'131 



1 



313 



9-4 





6... 



254 



36-2 



21-0 



l 127 



254 



5-8 



,129 



i 



254 



126 



There is no more difficulty in explaining the assertions 

 2, 3, 5, and 6 with the aid of the figs. 2-5. 



(2) Elster and Geitel and Braum, using visible light at an 

 oblique incidence, obtained the addition of the two effects, 

 and as the selective one is much stronger their curves had a 

 maximum in the visible part of the spectrum. 



(3) In Hallwachs's experiments the light being incident 



