﻿910 
  

  

  Mr. 
  C. 
  D. 
  Child 
  on 
  Line 
  Spectrum 
  

  

  region. 
  If 
  it 
  pushed 
  one 
  kind 
  back 
  towards 
  the 
  arc, 
  it 
  

   would 
  draw 
  the 
  other 
  away 
  from 
  it. 
  Hence 
  the 
  addition 
  of 
  

   the 
  field 
  does 
  not 
  intensify 
  the 
  light 
  in 
  any 
  region. 
  

  

  It 
  might 
  seem 
  possible 
  that 
  there 
  is 
  a 
  spontaneous 
  kind 
  of 
  

   ionization 
  occurring 
  immediately 
  after 
  the 
  recombination, 
  

   that 
  some 
  of 
  the 
  molecules 
  are 
  so 
  violently 
  agitated 
  by 
  the 
  

   recombination 
  that 
  they 
  fly 
  apart 
  again 
  into 
  ions 
  and 
  that 
  

   this 
  ionization 
  is 
  the 
  cause 
  of 
  the 
  light. 
  But 
  if 
  the 
  electron 
  

   gets 
  so 
  far 
  from 
  the 
  positive 
  ion 
  as 
  to 
  have 
  no 
  effect 
  on 
  it, 
  

   there 
  is 
  the 
  same 
  energy 
  given 
  to 
  the 
  positive 
  and 
  negative 
  

   parts 
  in 
  separating 
  as 
  they 
  gave 
  up 
  in 
  coming 
  together, 
  and 
  

   yet 
  during 
  this 
  action 
  vibrations 
  are 
  started 
  which 
  give 
  out 
  

   energy 
  in 
  the 
  form 
  of 
  light. 
  This 
  would 
  be 
  a 
  creation 
  of 
  

   energy. 
  If 
  the 
  electron 
  is 
  not 
  separated, 
  so 
  as 
  to 
  move 
  

   beyond 
  the 
  sphere 
  of 
  action 
  of 
  the 
  positive 
  ion, 
  the 
  two 
  are 
  

   still 
  combined 
  and 
  it 
  is 
  not 
  an 
  ion 
  which 
  is 
  vibrating, 
  but 
  a 
  

   recombined 
  molecule. 
  

  

  Further 
  Experiments 
  on 
  the 
  Luminous 
  Vapour. 
  

  

  The 
  experiment 
  was 
  modified 
  by 
  using 
  two 
  electrodes 
  in 
  

   the 
  place 
  of 
  F, 
  and 
  by 
  using 
  a 
  magnetic 
  field 
  in 
  the 
  place 
  of 
  

   an 
  electric 
  one 
  to 
  remove 
  the 
  ions. 
  The 
  wire 
  gauze 
  was 
  

   removed 
  and 
  two 
  electrodes 
  were 
  put 
  in 
  its 
  place, 
  one 
  on 
  

   each 
  side 
  of 
  the 
  upper 
  tube. 
  These 
  were 
  part 
  of 
  a 
  cylinder 
  

   cut 
  in 
  such 
  a 
  way 
  as 
  to 
  fill 
  the 
  sides 
  of 
  the 
  tube 
  and 
  compel 
  

   the 
  vapour 
  to 
  pass 
  between 
  them. 
  A 
  cross-section 
  of 
  the 
  

   tube 
  and 
  the 
  electrodes 
  is 
  shown 
  in 
  fig. 
  2. 
  They 
  were 
  

  

  Fig. 
  2. 
  

  

  connected 
  by 
  the 
  wires 
  at 
  a 
  and 
  b 
  to 
  a 
  separate 
  E.M.F. 
  

   The 
  length 
  of 
  these 
  electrodes 
  was 
  5 
  cm., 
  and 
  the 
  distance 
  

   between 
  them 
  was 
  approximately 
  7 
  mm. 
  They 
  were 
  made 
  

   of 
  copper. 
  Although 
  this 
  forms 
  an 
  amalgam 
  with 
  the 
  

   mercury, 
  it 
  was 
  used 
  in 
  order 
  not 
  to 
  distort 
  the 
  magnetic 
  

   field 
  which 
  was 
  used 
  in 
  part 
  of 
  the 
  experiment. 
  

  

  When 
  the 
  electrodes 
  were 
  connected 
  with 
  an 
  E.M.F. 
  

   distinct 
  from 
  the 
  arc, 
  there 
  was 
  a 
  dark 
  region 
  near 
  the 
  

   negative 
  electrode. 
  When 
  the 
  potential 
  difference 
  between 
  

  

  