﻿Homogeneous 
  Secondary 
  Rontgen 
  Radiations 
  . 
  581 
  

  

  secondary 
  homogeneous 
  radiation 
  and 
  ionization 
  by 
  the 
  

   primary 
  beam, 
  as 
  shown 
  by 
  fig. 
  2 
  for 
  the 
  copper 
  radiation. 
  

   A 
  study 
  of 
  the 
  curves 
  (fig. 
  3), 
  exhibiting 
  the 
  transparency 
  of 
  

   various 
  metals 
  to 
  homogeneous 
  rays, 
  shows 
  the 
  same 
  thing. 
  

   Thus, 
  dealing 
  with 
  the 
  radiation 
  from 
  zinc, 
  aluminium, 
  in 
  

   which 
  a 
  Zn 
  radiation 
  does 
  not 
  stimulate, 
  a 
  homogeneous 
  

  

  Kir. 
  4. 
  

  

  6000 
  

  

  5000- 
  

  

  -ma 
  

  

  4000 
  

  

  X 
  

  

  3000 
  

  

  eooo 
  

  

  -&ee 
  

  

  -4m 
  

  

  -4ee 
  

  

  -29e 
  

  

  \ 
  

  

  1000 
  

  

  60 
  65 
  

  

  Atomic 
  We/&ht 
  of 
  ffaoiATOft 
  

  

  secondary 
  radiation 
  is 
  fairly 
  transparent. 
  Iron, 
  in 
  which 
  an 
  

   intense 
  radiation 
  is 
  set 
  up 
  — 
  the 
  characteristic 
  radiation 
  from 
  

   iron 
  being 
  considerably 
  softer 
  than 
  that 
  from 
  zinc 
  — 
  is 
  very 
  

   opaque. 
  Copper 
  is 
  much 
  more 
  transparent, 
  as 
  the 
  zinc 
  

   radiation 
  being 
  only 
  a 
  little 
  more 
  penetrating, 
  is 
  only 
  able 
  to 
  

   set 
  up 
  a 
  feeble 
  radiation 
  ; 
  while 
  zinc, 
  in 
  which 
  zinc 
  radiation 
  

   is 
  unable 
  to 
  set 
  up 
  any 
  further 
  radiation, 
  is 
  more 
  transparent 
  

   still. 
  The 
  substances 
  Ag, 
  Sn, 
  and 
  Pt 
  appear 
  relatively 
  more 
  

   transparent 
  to 
  this 
  radiation 
  than 
  to 
  a 
  more 
  penetrating 
  beam*. 
  

   * 
  Also 
  Phil. 
  Mag. 
  Sept. 
  1907, 
  p. 
  416, 
  fig. 
  5. 
  

  

  