﻿1040 
  

  

  Mr. 
  F. 
  W. 
  Wheatley 
  on 
  Ionization 
  of 
  

  

  The 
  values 
  of" 
  a, 
  have 
  been 
  calculated 
  by 
  the 
  method 
  

   explained 
  on 
  page 
  1036 
  from 
  the 
  readings 
  at 
  '5 
  and 
  1 
  cm. 
  

  

  Fig. 
  2 
  (PL 
  XXIV.) 
  gives 
  the 
  current-electromotive 
  force 
  

   curves 
  for 
  S0 
  2 
  at 
  this 
  pressure, 
  and 
  it 
  will 
  be 
  seen 
  that 
  

   there 
  is 
  no 
  tendency 
  for 
  the 
  curves 
  to 
  cross, 
  and 
  that 
  they 
  

   diverge 
  in 
  the 
  same 
  way 
  as 
  the 
  curves 
  for 
  lower 
  pressures. 
  

  

  Barss's 
  curves 
  for 
  the 
  same 
  pressure, 
  distances, 
  and 
  field- 
  

   strengths 
  are 
  shown 
  on 
  the 
  same 
  figure 
  by 
  dotted 
  lines. 
  

  

  Table 
  II. 
  

   S0 
  2 
  . 
  Pressure 
  16 
  mm, 
  

  

  X. 
  

  

  •5 
  cm. 
  

  

  "8 
  cm. 
  

  

  *1 
  cm* 
  

  

  a. 
  

  

  a/p. 
  

  

  X/p. 
  

  

  50 
  

  

  

  

  32*37 
  

  

  

  

  

  

  80 
  

  

  21-02 
  

  

  — 
  

  

  42-07 
  

  

  •0032 
  

  

  •0002 
  

  

  5 
  

  

  100 
  

  

  — 
  

  

  32'57 
  

  

  — 
  

  

  

  

  

  160 
  

  

  21-28 
  

  

  — 
  

  

  42*65 
  

  

  •0081 
  

  

  •0005 
  

  

  10 
  

  

  200 
  

  

  — 
  

  

  3287 
  

  

  — 
  

  

  

  

  

  280 
  

  

  21-50 
  

  

  — 
  

  

  4321 
  

  

  •0190 
  

  

  •0012 
  

  

  17-5 
  

  

  420 
  

  

  21-57 
  

  

  33-08 
  

  

  43*49 
  

  

  '0307 
  

  

  •0019 
  

  

  26-25 
  

  

  560 
  

  

  21-62 
  

  

  — 
  

  

  43-77 
  

  

  •0479 
  

  

  •0030 
  

  

  35 
  

  

  750 
  

  

  22-41 
  

  

  35-84 
  

  

  — 
  

  

  

  

  

  800 
  

  

  22-81 
  

  

  36-17 
  

  

  46-76 
  

  

  •0961 
  

  

  •0060 
  

  

  50 
  

  

  845 
  

  

  2303 
  

  

  — 
  

  

  47-44 
  

  

  '1083 
  

  

  •0068 
  

  

  52-81 
  

  

  1045 
  

  

  26-88 
  

  

  — 
  

  

  56-78 
  

  

  •2133 
  

  

  0132 
  

  

  65-31 
  

  

  1056 
  

  

  — 
  

  

  43'23 
  

  

  57-31 
  

  

  

  

  

  ]200 
  

  

  32-05 
  

  

  51-85 
  

  

  73-14 
  

  

  •4972 
  

  

  •0311 
  

  

  75 
  

  

  1300 
  

  

  37-81 
  

  

  61*96 
  

  

  102-5 
  

  

  1*0758 
  

  

  •0672 
  

  

  81-25 
  

  

  1400 
  

  

  4332 
  

  

  77-16 
  

  

  139*1 
  

  

  1*5843 
  

  

  •0990 
  

  

  87-5 
  

  

  loOO 
  

  

  50-12 
  

  

  105*2 
  

  

  214 
  

  

  2*3677 
  

  

  •1480 
  

  

  93-75 
  

  

  1600 
  

  

  59-86 
  

  

  155*4 
  

  

  

  

  

  

  1700 
  

  

  . 
  77-45 
  

  

  

  

  

  

  

  1800 
  

  

  111-2 
  

  

  

  

  

  

  

  In 
  order 
  to 
  further 
  test 
  the 
  result 
  just 
  obtained 
  another 
  

   experiment 
  was 
  tried 
  with 
  S0 
  2 
  at 
  a 
  still 
  higher 
  pressure, 
  

   viz. 
  20 
  mm. 
  

  

  The 
  results 
  are 
  given 
  in 
  Table 
  III. 
  and 
  the 
  corresponding 
  

   curves 
  in 
  fig. 
  3. 
  

  

  Here 
  again 
  it 
  will 
  be 
  seen 
  that 
  there 
  is 
  no 
  tendency 
  for 
  

   the 
  curve 
  for 
  a 
  smaller 
  distance 
  between 
  the 
  plates 
  to 
  rise 
  

   more 
  abruptly 
  than 
  for 
  a 
  greater 
  distance, 
  and 
  the 
  curves 
  

   do 
  not 
  cross 
  one 
  another. 
  

  

  There 
  is, 
  therefore, 
  no 
  evidence 
  from 
  these 
  results 
  to 
  

   show 
  that 
  the 
  behaviour 
  of 
  S0 
  2 
  at 
  higher 
  pressures 
  is 
  at 
  all 
  

   inconsistent 
  with 
  the 
  theory 
  of 
  ionization 
  by 
  collision 
  as 
  

   developed 
  for 
  gases. 
  

  

  