﻿Charge 
  of 
  the 
  Ions 
  emitted 
  hy 
  Hot 
  Bodies, 
  765 
  

  

  for 
  the 
  following 
  series 
  of 
  values 
  of 
  the 
  constants 
  : 
  — 
  

   a 
  = 
  -006 
  cm., 
  b 
  = 
  '606 
  cm., 
  V 
  = 
  3'65xl0 
  10 
  E.M. 
  units, 
  

   H 
  = 
  4800, 
  w 
  2 
  = 
  8 
  X 
  10 
  8 
  cm.'Vsec. 
  2 
  , 
  e/m 
  = 
  250 
  E.M. 
  units. 
  The 
  

   ratio 
  of 
  the 
  two 
  values 
  of 
  x 
  is 
  found 
  to 
  be 
  1*25, 
  that 
  for 
  the 
  

   plates 
  being 
  the 
  greater. 
  

  

  In 
  working 
  out 
  our 
  results 
  we 
  have 
  assumed 
  that 
  the 
  

   conditions 
  for 
  parallel 
  plates 
  held 
  ; 
  whereas 
  the 
  actual 
  

   conditions 
  are 
  probably 
  somewhere 
  between 
  the 
  two 
  cases. 
  

   The 
  actual 
  displacements 
  are 
  smaller 
  than 
  they 
  should 
  be 
  

   according 
  to 
  the 
  simple 
  theory 
  of 
  parallel 
  planes, 
  so 
  that 
  the 
  

   values 
  of 
  ejm 
  calculated 
  from 
  the 
  measurements 
  will 
  be 
  too 
  

   small. 
  Since 
  ejm 
  varies 
  very 
  nearly 
  as 
  x 
  x 
  2 
  it 
  follows 
  from 
  

   the 
  calculations 
  first 
  given 
  that 
  the 
  values 
  which 
  have 
  been 
  

   obtained 
  will 
  have 
  to 
  be 
  increased 
  by 
  a 
  factor 
  lving 
  between 
  

   1 
  and 
  1*625. 
  We 
  may 
  use 
  the 
  experiments 
  on 
  the 
  negative 
  

   ions, 
  for 
  which 
  ejm 
  is 
  known, 
  to 
  determine 
  this 
  factor, 
  

   approximately 
  at 
  any 
  rate. 
  Using 
  1'88 
  x 
  10 
  7 
  as 
  the 
  correct 
  

   value 
  of 
  ejm 
  for 
  the 
  electrons 
  we 
  get 
  for 
  the 
  correction 
  factor 
  

   a 
  : 
  for 
  platinum 
  a 
  = 
  l*30, 
  and 
  for 
  carbon 
  a 
  = 
  l*26, 
  both 
  of 
  

   which 
  lie 
  between 
  the 
  assigned 
  limits. 
  Using 
  these 
  values 
  

   to 
  correct 
  the 
  numbers 
  previously 
  given 
  for 
  ejm 
  and 
  w/H 
  for 
  

   the 
  positive 
  ions 
  we 
  find 
  the 
  mean 
  values 
  

  

  For 
  Platinum... 
  <?/m=384, 
  m/H 
  = 
  25*7. 
  

   „ 
  Carbon 
  ... 
  e/m 
  = 
  353, 
  m/H 
  = 
  27'6. 
  

  

  This 
  method 
  of 
  applying 
  the 
  correction 
  is 
  somewhat 
  

   unsatisfactory 
  on 
  account 
  of 
  the 
  great 
  disparity 
  between 
  the 
  

   values 
  of 
  ejm 
  for 
  the 
  positive 
  and 
  negative 
  ions. 
  It 
  is 
  clear, 
  

   however, 
  from 
  the 
  nature 
  of 
  the 
  two 
  integrals, 
  that 
  with 
  the 
  

   values 
  of 
  the 
  constants 
  which 
  were 
  used 
  the 
  corrections 
  will 
  

   be 
  about 
  the 
  same 
  for 
  both 
  kinds 
  of 
  ions. 
  

  

  § 
  6. 
  Conclusion. 
  

  

  The 
  constitution 
  or 
  material 
  structure 
  of 
  the 
  positive 
  ions 
  

   given 
  out 
  by 
  hot 
  bodies 
  is 
  a 
  matter 
  of 
  great 
  interest. 
  It 
  is 
  a 
  

   significant 
  fact 
  that 
  the 
  mean 
  corrected 
  ratio 
  of 
  the 
  mass 
  to 
  

   that 
  of 
  the 
  hydrogen 
  atom 
  is 
  so 
  nearly 
  the 
  same 
  for 
  the 
  ions 
  

   from 
  both 
  carbon 
  and 
  platinum, 
  and 
  so 
  nearly 
  equal 
  to 
  

   the 
  corresponding 
  quantity 
  found 
  by 
  J. 
  J. 
  Thomson 
  for 
  

   iron. 
  The 
  values 
  under 
  consideration 
  are 
  : 
  for 
  platinum 
  

   m/H 
  = 
  25*7, 
  for 
  carbon 
  ra/H 
  = 
  27'6, 
  and 
  for 
  iron 
  ??i/H 
  = 
  about 
  

   24. 
  It 
  is 
  difficult 
  to 
  say 
  what 
  the 
  ions 
  are, 
  but 
  it 
  is 
  evident 
  

   that 
  the 
  values 
  which 
  have 
  been 
  found 
  enable 
  certain 
  definite 
  

   assertions 
  to 
  be 
  made 
  as 
  to 
  what 
  they 
  are 
  not. 
  They 
  are 
  

  

  