﻿Homogeneous 
  Secondary 
  Rontgen 
  Radiation, 
  

   Table 
  IV. 
  

   Radiation 
  from 
  Copper 
  (thick 
  sheet). 
  

  

  561 
  

  

  I. 
  

  

  Percentage 
  Absorption 
  

  

  byCu 
  

  

  previous 
  to 
  absorption 
  

  

  by 
  Cu, 
  Zn, 
  or 
  Al. 
  

  

  II. 
  

  

  Percentage 
  Absorption 
  by 
  Cu, 
  Zn, 
  and 
  Al 
  

   after 
  absorption 
  in 
  column 
  I. 
  

  

  Cu 
  00295 
  cm. 
  

  

  Zn 
  -00262 
  cm. 
  

  

  Al 
  -0104 
  cm. 
  

  

  

  

  98-3 
  

  

  74 
  

   70 
  

  

  69-7 
  

  

  m 
  

  

  72 
  

   68 
  

  

  Radiation 
  from 
  Iron 
  (thick 
  sheet). 
  

  

  i. 
  

  

  Percentage 
  Absorption 
  

  

  byFe 
  

  

  previous 
  to 
  absorption 
  

  

  by 
  Fe, 
  Cu, 
  or 
  Al. 
  

  

  II. 
  

  

  Percentage 
  Absorption 
  by 
  Fe, 
  Cu, 
  and 
  Al 
  

   after 
  absorption 
  in 
  column 
  I. 
  

  

  Fe 
  00313 
  cm. 
  

  

  Cu 
  00296 
  cm. 
  

  

  Al 
  0104 
  cm. 
  

  

  

  

  80 
  

   96 
  

  

  80-5 
  

   79-8 
  

   76-9 
  

  

  91-5 
  

  

  91 
  

  

  86 
  

  

  90 
  

  

  89-5 
  

   83-5 
  

  

  There 
  was 
  thus 
  evidence 
  of 
  a 
  slight 
  heterogeneity 
  even 
  in 
  

   these 
  radiations. 
  

  

  Scattered 
  Rays. 
  — 
  To 
  test 
  if 
  this 
  heterogeneity 
  could 
  be 
  

   accounted 
  for 
  by 
  the 
  mixture 
  of 
  a 
  scattered 
  radiation, 
  like 
  

   that 
  from 
  light 
  atoms, 
  with 
  the 
  homogeneous 
  radiation, 
  a 
  

   direct 
  comparison 
  was 
  made 
  between 
  the 
  ionization 
  produced 
  

   by 
  the 
  secondary 
  beams 
  from 
  thin 
  sheets 
  of 
  copper 
  ['00067 
  

   cm.] 
  and 
  paper, 
  subject 
  to 
  the 
  same 
  primary 
  radiation. 
  The 
  

   paper 
  which 
  was 
  used 
  had 
  ten 
  times 
  the 
  mass 
  of 
  the 
  thin 
  

   copper, 
  yet 
  the 
  ionization 
  produced 
  by 
  the 
  secondary 
  rays 
  

   from 
  the 
  copper 
  was 
  19*5 
  times 
  that 
  produced 
  by 
  the 
  

   secondary 
  rays 
  from 
  paper 
  even 
  though 
  a 
  greater 
  proportion 
  

   of 
  the 
  radiation 
  from 
  copper 
  was 
  absorbed 
  by 
  the 
  copper 
  

   itself 
  than 
  that 
  from 
  the 
  paper 
  in 
  the 
  paper. 
  As 
  sheet 
  after 
  

   sheet 
  of 
  aluminium 
  was 
  placed 
  in 
  the 
  path 
  of 
  the 
  two 
  

   secondary 
  beams, 
  the 
  copper 
  radiation 
  was 
  absorbed 
  to 
  a 
  

   much 
  greater 
  extent 
  than 
  the 
  radiation 
  from 
  paper; 
  thus 
  

   34 
  per 
  cent, 
  of 
  the 
  radiation 
  from 
  paper 
  was 
  transmitted 
  

  

  Phil. 
  Mag. 
  S. 
  6. 
  Vol. 
  16. 
  No. 
  94. 
  Oct, 
  1908. 
  2 
  P 
  

  

  