﻿Homogeneous 
  Secondary 
  Rontrjen 
  Radiations. 
  579 
  

  

  radiation, 
  while 
  it 
  is 
  very 
  similar 
  to 
  that 
  obtained 
  by 
  experi- 
  

   ments 
  on 
  a 
  beam 
  o£ 
  Rontgen 
  rays 
  *. 
  

  

  The 
  special 
  powers 
  of 
  penetrating 
  certain 
  substances 
  are 
  

   such 
  as 
  have 
  not 
  been 
  observed 
  and 
  are 
  difficult 
  to 
  conceive 
  

   of 
  on 
  any 
  corpuscular 
  theory. 
  

  

  Neither 
  electrostatic 
  nor 
  magnetic 
  deflexion 
  of 
  these 
  rays 
  

   has 
  been 
  observed. 
  

  

  Finally, 
  the 
  fact 
  that 
  the 
  homogeneous 
  rays 
  are 
  invariably 
  

   produced 
  by 
  primary 
  rays 
  of 
  more 
  penetrating 
  type, 
  yet 
  not 
  

   necessarily 
  more 
  than 
  just 
  on 
  the 
  more 
  penetrating 
  side, 
  

   appears 
  some 
  of 
  the 
  strongest 
  evidence 
  in 
  favour 
  of 
  similarity 
  

   in 
  type 
  between 
  the 
  primary 
  and 
  secondary 
  rays. 
  If 
  the 
  

   natures 
  were 
  different; 
  the 
  penetrating 
  powers 
  would 
  represent 
  

   totally 
  different 
  physical 
  facts, 
  and 
  such 
  connexion 
  between 
  

   them 
  would 
  be 
  inconceivable. 
  We 
  can 
  only 
  conclude 
  from 
  

   consideration 
  of 
  this 
  evidence 
  that 
  the 
  nature 
  of 
  the 
  homo- 
  

   geneous 
  rays 
  is 
  similar 
  to 
  that 
  of 
  the 
  primary 
  X-rays. 
  

  

  As 
  the 
  homogeneous 
  rays 
  are 
  of 
  the 
  nature 
  of 
  Rontgen 
  

   rays, 
  we 
  must 
  conclude 
  that 
  the 
  radiation 
  is 
  set 
  up 
  by 
  distur- 
  

   bance 
  of 
  electrons 
  produced 
  directly 
  or 
  indirectly 
  by 
  the 
  

   passage 
  of 
  the 
  primary 
  pulses. 
  That 
  this 
  motion 
  of 
  electrons 
  

   is 
  not 
  controlled 
  by 
  the 
  electric 
  forces 
  in 
  the 
  primary 
  pulses, 
  

   is 
  proved 
  by 
  the 
  equality 
  of 
  the 
  intensities 
  of 
  radiation 
  in 
  a 
  

   direction 
  approximately 
  opposite 
  to 
  that 
  of 
  primary 
  propa- 
  

   gation 
  and 
  one 
  at 
  right 
  angles, 
  by 
  the 
  absence 
  of 
  evidence 
  

   from 
  the 
  secondary 
  rays 
  of 
  polarization 
  of 
  a 
  primary 
  beam 
  

   in 
  which 
  such 
  polarization 
  exists, 
  and 
  by 
  the 
  absence 
  of 
  

   dependence 
  of 
  the 
  penetrating 
  power 
  of 
  the 
  secondary 
  beam 
  

   on 
  that 
  of 
  the 
  primary. 
  

  

  The 
  forces 
  called 
  into 
  play 
  which 
  produce 
  the 
  accelerations 
  

   resulting 
  in 
  radiation 
  cannot 
  then 
  be 
  directly 
  due 
  to 
  the 
  

   electric 
  displacement 
  in 
  the 
  primary 
  pulses, 
  but 
  must 
  be 
  those 
  

   called 
  into 
  play 
  in 
  the 
  atom 
  itself. 
  The 
  two 
  possibilities 
  that 
  

   suggest 
  themselves 
  are 
  that 
  the 
  radiations 
  result 
  from 
  a 
  dis- 
  

   tur 
  bance 
  of 
  the 
  atom, 
  which 
  quickly 
  recovers 
  its 
  normal 
  

   configuration, 
  or 
  that 
  it 
  is 
  produced 
  when 
  the 
  equilibrium 
  of 
  

   an 
  atomic 
  system 
  is 
  destroyed 
  and 
  forces 
  of 
  unusual 
  magnitude 
  

   are 
  called 
  into 
  play. 
  

  

  The 
  homogeneity 
  of 
  the 
  radiation 
  and 
  its 
  independence 
  of 
  

   the 
  primary 
  rays 
  suggest 
  a 
  regularity 
  in 
  the 
  motion 
  which 
  is 
  

   characteristic 
  simply 
  of 
  the 
  atom 
  ; 
  and 
  although 
  the 
  relation 
  

   between 
  intensity 
  of 
  secondary 
  radiation 
  from 
  copper 
  and 
  

   ionization 
  produced 
  by 
  the 
  primary 
  in 
  air 
  is 
  striking, 
  it 
  does 
  

   not 
  follow 
  that 
  the 
  radiation 
  is 
  due 
  to 
  ionization 
  in 
  the 
  

   * 
  Details 
  of 
  these 
  experiments 
  have 
  not 
  been 
  given. 
  

  

  2Q2 
  

  

  