﻿996 
  

  

  Mr. 
  H. 
  (Wen 
  

  

  the 
  

  

  c 
  l 
  and 
  c 
  2 
  . 
  Since 
  the 
  formula 
  neglects 
  diffusion, 
  it 
  will 
  be 
  

   best 
  to 
  determine 
  these 
  constants 
  from 
  that 
  part 
  which 
  is 
  

   least 
  affected 
  by 
  diffusion, 
  that 
  is, 
  from 
  the 
  part 
  corresponding 
  

   to 
  high 
  voltages. 
  When 
  c, 
  and 
  c 
  2 
  are 
  determined 
  from 
  this 
  

   part 
  of 
  the 
  curve, 
  the 
  agreement 
  between 
  the 
  theoretical 
  

   and 
  experimental 
  values 
  is 
  good 
  in 
  the 
  case 
  of 
  the 
  gases 
  

   mentioned, 
  as 
  is 
  shown 
  by 
  the 
  following 
  table 
  : 
  — 
  

  

  Carbon 
  monoxide, 
  14°'2 
  0., 
  29*5 
  cm. 
  Hg 
  pressure. 
  

  

  Theoretical 
  curve, 
  i 
  = 
  170-8 
  V 
  log 
  10 
  f.-l 
  + 
  -=- 
  J. 
  

  

  Applied 
  volts. 
  

  

  a 
  ray 
  current 
  in 
  

   arbitrary 
  units. 
  

  

  Calculated 
  current. 
  

  

  1 
  120 
  volts 
  

  

  I 
  8 
  

  

  

  

  2 
  

  

  4 
  

  

  20 
  

  

  40 
  

  

  360 
  

  

  116-4 
  

   1125 
  

  

  

   106-6 
  

   110-5 
  

   114-8 
  

   115-8 
  

   116-5 
  

  

  116-4 
  "i 
  US 
  ed 
  to 
  calcu- 
  

   li 
  2*5 
  J 
  ^ 
  e 
  e 
  V 
  C 
  2' 
  

  

  

   90-5 
  

   104 
  

   114 
  

   115-8 
  

   116-5 
  

  

  It 
  will 
  be 
  noticed 
  that 
  the 
  calculated 
  values 
  are 
  never 
  higher 
  

   in 
  this 
  case 
  than 
  the 
  observed, 
  and 
  that 
  for 
  the 
  lower 
  voltages 
  

   they 
  fall 
  below 
  the 
  observed. 
  Such 
  a 
  deviation 
  is 
  to 
  be 
  

   expected, 
  since 
  with 
  the 
  lower 
  voltages 
  the 
  time 
  for 
  gather- 
  

   ing 
  the 
  ions 
  is 
  comparatively 
  long 
  and 
  diffusion, 
  always 
  

   operative, 
  here 
  manifests 
  its 
  maximum 
  effect 
  in 
  diminishing 
  

   the 
  density 
  of 
  ions 
  within 
  the 
  column. 
  However, 
  no 
  agree- 
  

   ment 
  could 
  be 
  found 
  for 
  curves 
  for 
  C0 
  4 
  , 
  C0 
  2 
  , 
  S0 
  2 
  , 
  &c, 
  the 
  ions 
  

   of 
  which 
  seem 
  to 
  show 
  an 
  abnormal 
  tendency 
  to 
  recombine. 
  

   A 
  second 
  test 
  of 
  the 
  applicability 
  of 
  Wheelock's 
  formula 
  

   can 
  be 
  made. 
  The 
  formula 
  can 
  be 
  put 
  in 
  the 
  form 
  

  

  y= 
  — 
  = 
  — 
  log 
  e 
  I 
  1 
  + 
  J? 
  \ 
  since 
  c 
  1 
  c 
  2 
  = 
  «o 
  the 
  saturation 
  

   l 
  o 
  c 
  2 
  V 
  A/ 
  current, 
  

  

  which 
  is 
  the 
  same 
  as 
  Langevin's 
  equation 
  

  

  y=- 
  1 
  °g 
  e 
  ( 
  1 
  + 
  ^)- 
  

  

  Accordingly 
  - 
  should 
  be 
  a 
  function 
  of 
  ~ 
  only, 
  where 
  c 
  2 
  

   ?o 
  -A. 
  

  

  