44 Secondary Cathode Rays produced hy X-R 



more than oik; sheei was used. As the terms in the formula 

 containing t drop out when t is equal to or greater than two 

 sheets of the metal, and as no consistent variation with the 

 thickness of the sheets was observed, the mean of all the 

 values of e/i using more than one sheet and the resulting 

 values of R are given separately in the tables following the 

 greater value of t. 









Gold. 













Radiator 

 X, in Al. 



K 



K 



3xlO- 4 . 



fxlO 5 S. 



cm. 



L hJ\ 



Se A2 <'. 





E. 



Chromium 



3G7 



0780 



00321 



700 



0-8 

 >l-6 



103 

 103 



1-07 



110 i 

 110 



1-30 

 1-34 



118 

 1-22 



Iron 

 230 



7070 



00200 



66-0 



08 101 

 >l-6 102 



105 



106 



1-07 



m 



1-24 



Zinc 

 106*3 



3438 



0-0003 



57-5 



08 1-01 

 il-0 1-01 



101 



1-02 

 102 



1-21 

 1-25 



119 



1-23 



Tin 



4-33 



Chromium 

 367 



1064 

 6095 



00004 

 00321 



107 



Sllc 

 38-0 



0-8 



>i-o 

 er. 



18 

 ' 36 



1-00 

 100 



102 



id:; 



100 



107 



100 

 100 



ion 



110 



115 



116 



1-33 



I 40 



115 

 116 



1 22 



1 27 



Iron 



239 



Zinc 



lor.-.; 



4000 



00200 



35-8 



L-8 

 >3C> 



1-8 



1-031 



1 05 



I i i-J 



108 



1 "7 



1-31 



1 21 



L830 



00093 



31-4 



1 -02 



1 01 

 L-01 



103 



I-H2 



1 -2 1 



123 

 1 -23 



1-20 



1-23 

 1-23 



I'm 



I 33 



2302 



'in 



5-75 



1-8 

 >36 



L00 



I on 

 100 



1(H) 



TOO 



If is al once apparent from the tables ilia! the ratio of 

 emergence to Incidence cathode rays <\in-^ not vary with the 

 penetrating power of the exciting \-ray> in the rang 

 penetrating power- used ; that i-. for an increase of absorba- 

 bility a- measured in aluminium o\' aboul 8000 per cent. 

 there Is no measurable variation in the ratio. 



It is interesting lo note in this connexion tlie values 



