﻿Homogeneous 
  Secondary 
  Rontgen 
  Radiations. 
  577 
  

  

  The 
  law 
  of 
  intensity 
  of 
  these 
  scattered 
  rays 
  which 
  holds 
  

   for 
  elements 
  of 
  the 
  H-S 
  group 
  — 
  that 
  the 
  intensity 
  of 
  radiation 
  

   from 
  an 
  atom 
  is 
  proportional 
  to 
  its 
  atomic 
  weight 
  — 
  cannot 
  

   be 
  extended 
  to 
  include 
  the 
  elements 
  of 
  higher 
  atomic 
  weight. 
  

   From 
  some 
  elements 
  at 
  least 
  the 
  intensity 
  is 
  greater 
  than 
  

   would 
  be 
  given 
  by 
  this 
  law. 
  

  

  The 
  scattered 
  radiation 
  from 
  some 
  elements 
  whose 
  charac- 
  

   teristic 
  homogeneous 
  radiation 
  is 
  of 
  comparatively 
  penetrating- 
  

   type 
  has 
  been 
  obtained 
  free 
  from 
  admixture 
  with 
  this 
  

   homogeneous 
  radiation 
  by 
  the 
  use 
  of 
  a 
  primary 
  beam 
  

   consisting 
  of 
  less 
  penetrating 
  rays 
  than 
  the 
  characteristic 
  

   secondary. 
  

  

  Those 
  scattered 
  radiations 
  not 
  thus 
  isolated 
  have 
  been 
  

   accompanied 
  by 
  a 
  homogeneous 
  radiation 
  more 
  easily 
  absorbed 
  

   than 
  the 
  primary 
  radiation 
  producing 
  them. 
  

  

  We 
  have 
  obtained 
  no 
  conclusive 
  evidence 
  that 
  the 
  relative 
  

   intensity 
  of 
  secondary 
  scattered 
  and 
  primary 
  radiations 
  

   changes 
  with 
  the 
  penetrating 
  power 
  of 
  the 
  primary 
  rays. 
  

  

  All 
  elements 
  of 
  atomic 
  weight 
  greater 
  than 
  that 
  of 
  sulphur 
  

   which 
  have 
  been 
  examined 
  emit 
  a 
  homogeneous 
  secondary 
  

   radiation 
  when 
  subject 
  to 
  a 
  primary 
  beam 
  of 
  X-rays 
  of 
  

   ordinary 
  penetrating 
  power. 
  Or, 
  Fe, 
  Co, 
  Ni, 
  Cu, 
  Zn, 
  Ag, 
  

   have 
  been 
  examined. 
  All 
  other 
  elements 
  whose 
  secondary 
  

   radiations 
  have 
  been 
  examined 
  less 
  minutely 
  appear 
  similar 
  

   in 
  this 
  respect. 
  

  

  The 
  penetrating 
  power 
  of 
  this 
  radiation 
  from 
  each 
  element 
  

   examined 
  has 
  been 
  found 
  independent 
  of 
  the 
  intensity 
  or 
  the 
  

   penetrating 
  power 
  of 
  the 
  primary 
  radiation 
  producing 
  it 
  ; 
  it 
  

   is 
  characteristic 
  of 
  the 
  element 
  emitting 
  it. 
  

  

  The 
  penetrating 
  power 
  of 
  this 
  radiation 
  is 
  a 
  periodic 
  

   function 
  of 
  the 
  atomic 
  weight 
  of 
  the 
  radiating 
  element 
  (e). 
  

  

  The 
  ionizing 
  power 
  of 
  this 
  radiation 
  and 
  almost 
  certainly 
  

   its 
  energy 
  is 
  usually 
  very 
  much 
  greater 
  than 
  that 
  of 
  the 
  

   scattered 
  radiation. 
  

  

  The 
  homogeneous 
  radiation 
  has 
  invariably 
  been 
  found 
  more 
  

   easily 
  absorbed 
  than 
  the 
  primary 
  radiation 
  producing 
  it. 
  

  

  In 
  all 
  cases, 
  when 
  a 
  primary 
  was 
  used 
  which 
  was 
  softer 
  

   than 
  the 
  characteristic 
  homogeneous 
  radiation, 
  this 
  radiation 
  

   was 
  not 
  emitted. 
  Also 
  there 
  is 
  reason 
  (from 
  the 
  curve 
  con- 
  

   necting 
  absorbability 
  of 
  a 
  secondary 
  radiation 
  and 
  the 
  atomic 
  

   weight 
  of 
  a 
  radiator) 
  for 
  believing 
  that 
  those 
  elements 
  H-S 
  

   which 
  do 
  not 
  under 
  ordinary 
  circumstances 
  emit 
  such 
  

   radiation, 
  possess 
  a 
  characteristic 
  radiation 
  which 
  is 
  more 
  

   penetrating 
  than 
  any 
  primary 
  beam 
  used. 
  

  

  The 
  intensity 
  of 
  this 
  homogeneous 
  radiation 
  from 
  copper 
  

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

  

  