﻿Investigation 
  of 
  the 
  Nature 
  of 
  y 
  Rays. 
  

  

  925 
  

  

  fays. 
  For 
  according 
  to 
  our 
  theory 
  equal 
  quantities 
  o£ 
  7 
  rays 
  

   would 
  be 
  converted 
  into 
  /3 
  rays 
  in 
  equal 
  weights 
  o£ 
  different 
  

   substances 
  ; 
  and 
  the 
  subsequent 
  emergence 
  of 
  these 
  /3 
  rays 
  

   into 
  the 
  ionization-chamber 
  would 
  be 
  governed 
  only 
  by 
  their 
  

   ability 
  to 
  penetrate 
  the 
  layers 
  intervening 
  between 
  their 
  place 
  

   •of 
  origin 
  and 
  the 
  chamber. 
  It 
  is, 
  perhaps, 
  important 
  to 
  

   observe 
  that 
  we 
  are 
  implicitly 
  making 
  another 
  assumption, 
  

   viz., 
  that 
  the 
  /3 
  rays 
  originating 
  in 
  different 
  substances 
  have 
  

   the 
  same 
  speed. 
  On 
  the 
  material 
  theory 
  of 
  the 
  7 
  rays 
  the 
  

   assumption 
  is 
  natural 
  ; 
  it 
  is 
  justified 
  by 
  the 
  general 
  nature 
  of 
  

   our 
  results, 
  and 
  by 
  special 
  experiments 
  to 
  be 
  described 
  later. 
  

  

  Since 
  the 
  absorption 
  o£ 
  /3 
  rays 
  by 
  substances 
  of 
  small 
  

   atomic 
  weight 
  is 
  much 
  less 
  than 
  in 
  the 
  case 
  o£ 
  the 
  large 
  

   atomic 
  weight, 
  weight 
  for 
  weight 
  o£ 
  screen 
  ; 
  or, 
  in 
  the 
  usual 
  

   phraseology, 
  since 
  X/p 
  is 
  smaller 
  for 
  light 
  atoms 
  than 
  for 
  

  

  

  

  

  Fig. 
  

  

  2. 
  

  

  

  

  2000 
  

  

  mo 
  

  

  i 
  

  

  \/2C0 
  

  

  i 
  

   1 
  

  

  B 
  

  

  

  

  

  

  

  

  

  

  

  3 
  

  

  NO 
  PLUG 
  

  

  

  

  

  V 
  / 
  

  

  

  

  C 
  

   A 
  \ 
  

  

  >V. 
  

  

  

  * 
  

  

  

  

  

  \\ 
  

  

  

  

  

  *s 
  

  

  C 
  

   2 
  05 
  CM. 
  Zn 
  

  

  A 
  

  

  I 
  6/CM 
  P6 
  

  

  

  

  

  ■ 
  — 
  : 
  — 
  -. 
  

  

  '* 
  

  

  

  

  

  

  

  ATOMIC 
  WEIGHT 
  OF 
  SCfi£EIV— 
  S 
  ' 
  

  

  120 
  /> 
  

  

  160 
  

  

  heavy 
  atoms, 
  we 
  expected 
  the 
  emergence 
  radiations 
  o£ 
  C 
  and 
  

   Al 
  to 
  be 
  much 
  greater 
  than 
  those 
  of, 
  say, 
  W 
  and 
  Pb. 
  Fig. 
  2 
  

   shows 
  that 
  this 
  expectation 
  was 
  realized 
  ; 
  the 
  results 
  

   shown 
  graphically 
  along 
  the 
  curve 
  AA. 
  

  

  are 
  

  

  