Reflexion of the fi-P articles hy Matter. 851 



foils are placed directly on top of the thin radioactive material, 

 and this is placed at some distance below the electroscope, 

 an entirely different initial portion of the curve is obtained. 

 This is clearly shown by the following experiments. Table I. 

 and the corresponding curves in fig. 1 show the results. 



Table I. 





Ionization. 





Ionization. 









Tinfoil 

 equivalent in 























EaE. 



Acta 



ThA+D. 



mms. of Al. 



EaE. 



Acta 



ThA+D. 



00000 



1000 



100-0 



1000 



000 



1000 



100-0 



1000 





0025 



100-0 



101-3 



100-1 



•04 



116-3 



121-8 



1203 





0050 



100-3 







•08 



1060 



120-5 



119-8 





010 



100-8 



103-0 



105-8 



•12 



92-0 



1140 



114-9 





020 



103-3 



1050 



105-9 



•16 



79-9 



105-4 



1091 





030 



103-7 



105-5 



1060 



•20 







95-7 



1069 





035 



102-3 







•24 







91-8 



1000 





040 





106-9 



107-0 



•28 









94-4 





045 



100-9 







•32 







73-2 







050 





107-4 



109-8 



•40 







58-8 



82-0 





059 



lbb-s 







•52 









67-4 





090 



97-1 



105-5 



101-6 



•64 









57-8 





120 



87-5 



99-0 



99-4 













150 



82-0 

















177 



71-0 

















236 





75-0 



90-6 













295 



48-] 

















354 





56-1 



79-4 











•413 



30-8 















Kar. 1. 



£ 



/ke.C. 



TMtD 



; -010 -020 -030 -010 -020 -030 -010 -020 -030 -040 

 thicm£ss,of Aluminium w cms. 



