﻿254 
  Prof. 
  More 
  and 
  Mr. 
  Mauchly 
  : 
  Action 
  of 
  a 
  Magnetic 
  

  

  but 
  little 
  affected 
  by 
  the 
  nature 
  of 
  the 
  gas. 
  The 
  only 
  

   variations 
  noted 
  were 
  small 
  differences 
  in 
  their 
  length 
  and 
  

   concentration 
  along 
  the 
  axis 
  ; 
  the 
  maximum 
  lengths 
  are 
  

   attained 
  at 
  pressures 
  and 
  field 
  strengths 
  which 
  were 
  different 
  

   with 
  different 
  gases. 
  The 
  important 
  variations 
  were 
  observed 
  

   in 
  the 
  induced 
  column 
  ; 
  with 
  pure 
  gases, 
  oxygen, 
  hydrogen, 
  

   nitrogen, 
  and 
  carbon 
  dioxide, 
  no 
  virtual 
  anode 
  could 
  be 
  

   located, 
  and 
  the 
  entire 
  column 
  bent 
  around 
  the 
  pole 
  of 
  the 
  

   test-magnet 
  in 
  the 
  same 
  direction. 
  The 
  column 
  was 
  also 
  

   short 
  and 
  diffuse. 
  The 
  virtual 
  anode 
  and 
  the 
  double 
  curving 
  

   of 
  the 
  column 
  was 
  found 
  only 
  with 
  air, 
  and 
  to 
  a 
  less 
  degree 
  

   with 
  artificial 
  mixtures 
  containing 
  nitrogen. 
  These 
  results 
  

   were 
  difficult 
  to 
  explain 
  by 
  Professor 
  Righi's 
  hypothesis. 
  

  

  Another 
  point 
  was 
  commented 
  upon. 
  In 
  all 
  cases, 
  the 
  

   magnetic 
  rays 
  are 
  concentrated 
  along 
  the 
  axis 
  of 
  the 
  tube 
  as 
  

   a 
  well-defined 
  cone, 
  with 
  its 
  base 
  near 
  the 
  cathode. 
  This 
  

   seems 
  to 
  be 
  quite 
  at 
  variance 
  with 
  the 
  hypothesis. 
  If 
  the 
  

   rays 
  are 
  composed 
  of 
  electrically 
  neutral 
  doublets, 
  then 
  the 
  

   only 
  motive 
  force 
  acting 
  on 
  them 
  is 
  the 
  magnetic 
  field, 
  and 
  

   the 
  rays 
  should 
  follow 
  the 
  magnetic 
  lines 
  of 
  force. 
  These 
  

   lines 
  of 
  force 
  which 
  emanate 
  from 
  the 
  pole 
  of 
  the 
  electro- 
  

   magnet 
  certainly 
  diverge, 
  so 
  it 
  is 
  difficult 
  to 
  find 
  the 
  force 
  

   which 
  makes 
  the 
  rays 
  converge. 
  

  

  Shortly 
  after 
  its 
  appearance, 
  Professor 
  Righi 
  * 
  published 
  a 
  

   criticism 
  of 
  the 
  paper. 
  His 
  opinion 
  is 
  that 
  the 
  results 
  which 
  

   were 
  observed 
  can 
  be 
  explained 
  by 
  his 
  new 
  theory, 
  if 
  it 
  be 
  

   properly 
  modified, 
  anH 
  that 
  they 
  cannot 
  be 
  understood 
  in 
  the 
  

   light 
  of 
  the 
  usual 
  explanation, 
  according 
  to 
  which 
  the 
  action 
  

   of 
  the 
  field 
  is 
  limited 
  to 
  altering 
  the 
  path 
  followed 
  by 
  the 
  

   electrons. 
  He 
  limits 
  his 
  criticism 
  to 
  the 
  newly-discovered 
  

   variations 
  in 
  the 
  induced 
  column 
  and 
  makes 
  no 
  reference 
  to 
  

   the 
  convergent 
  form 
  of 
  the 
  magnetic 
  rays, 
  although 
  that 
  

   seems 
  to 
  be 
  the 
  more 
  difficult 
  to 
  explain. 
  He 
  thinks 
  the 
  

   discovery 
  that 
  a 
  virtual 
  anode 
  does 
  not 
  exist 
  in 
  some 
  gases 
  is 
  

   not 
  prejudicial 
  to 
  his 
  theory. 
  His 
  comment 
  is 
  : 
  " 
  Instead, 
  in 
  

   this 
  case 
  it 
  happens 
  plainly, 
  that 
  the 
  virtual 
  anode 
  is 
  formed 
  

   at 
  the 
  extremity 
  of 
  the 
  magnetic 
  rays, 
  as 
  I 
  showed 
  to 
  happen, 
  

   and 
  as 
  must 
  happen, 
  also 
  with 
  air, 
  when 
  the 
  intensity 
  of 
  

   the 
  magnetic 
  field 
  is 
  relatively 
  feeble/' 
  Now 
  we 
  do 
  not 
  

   believe 
  that 
  this 
  explanation 
  is 
  correct. 
  Since 
  it 
  was 
  assumed 
  

   that 
  the 
  position 
  of 
  the 
  virtual 
  anode 
  is 
  the 
  locus 
  of 
  the 
  limit 
  

   of 
  the 
  free 
  path 
  of 
  the 
  ions 
  formed 
  from 
  the 
  dissociated 
  

   doublets, 
  we 
  can 
  say 
  confidently 
  that 
  the 
  virtual 
  anode 
  must 
  

   lie 
  at 
  least 
  some 
  distance 
  beyond 
  the 
  extremity 
  of 
  the 
  

   magnetic 
  rays, 
  and 
  that 
  this 
  distance 
  will 
  be 
  increased 
  by 
  

   * 
  'Righi, 
  Phil. 
  Mag. 
  vol. 
  xxxiv. 
  p. 
  804 
  (1912), 
  

  

  