﻿Ionization 
  of 
  Electrolytic 
  Oxygen. 
  31 
  

  

  Though 
  these 
  results 
  are 
  probably 
  not 
  so 
  accurate 
  as 
  those 
  

   obtainable 
  in 
  the 
  case 
  o£ 
  an 
  electrolytic 
  fog 
  or 
  by 
  Rutherford's 
  

   method, 
  yet 
  they 
  are 
  of 
  greater 
  interest, 
  since 
  they 
  give 
  the 
  

   charges 
  on 
  ions 
  for 
  which 
  N^ 
  can 
  be 
  found 
  directly 
  where 
  N 
  

   is 
  the 
  number 
  of 
  molecules 
  in 
  a 
  cubic 
  centimetre 
  ot 
  gas. 
  The 
  

   most 
  recent 
  value 
  of 
  N^ 
  is 
  1-23 
  x 
  10^^ 
  at 
  15° 
  C. 
  * 
  Faraday's 
  

   experiments 
  show 
  that 
  1 
  c.c. 
  of 
  hydrogen 
  at 
  15° 
  C. 
  is 
  liberated 
  

   from 
  acidulated 
  water 
  by 
  2'44 
  x 
  10^^ 
  E.S. 
  units 
  of 
  electric 
  

   cnrient. 
  Now 
  1 
  c.c. 
  will 
  contain 
  2N 
  atoms, 
  and 
  hence 
  

   we 
  m;iy 
  conclude 
  that 
  N^ 
  for 
  hvdrogen 
  ions 
  in 
  solutions 
  is 
  

   1/2 
  X 
  2-44 
  X 
  101^^=1-22 
  X 
  10^^ 
  a 
  figure 
  which 
  is 
  in 
  substantial 
  

   agreement 
  with 
  Ng 
  for 
  gaseous 
  ions. 
  Hence 
  it 
  has 
  been 
  

   concluded 
  that 
  e 
  has 
  the 
  same 
  value 
  for 
  gaseous 
  as 
  for 
  

   electrolytic 
  ions. 
  

  

  If 
  we 
  assume 
  that 
  ^ 
  = 
  4*66 
  x 
  10"^^ 
  we 
  obtain 
  for 
  N 
  \\\q 
  

   value 
  2'Q'2 
  x 
  10^^ 
  which 
  may 
  be 
  compared 
  with 
  that 
  derived 
  

   from 
  other 
  considerations 
  : 
  

  

  2-61x101^ 
  Planck 
  (Theory 
  of 
  Heat 
  Radiation) 
  f. 
  

   S-OxlO^^PerrinJ. 
  

  

  The 
  last 
  value 
  is 
  of 
  especial 
  interest 
  as 
  it 
  was 
  obtained 
  by 
  the 
  

   most 
  direct 
  method. 
  The 
  numerical 
  distribution 
  of 
  particles 
  

   at 
  different 
  depths 
  in 
  a 
  colloidal 
  solution 
  was 
  obtained 
  by 
  

   direct 
  counting 
  under 
  a 
  microscope 
  ; 
  the 
  osmotic 
  pressures 
  

   calculated 
  from 
  these 
  numbers 
  gave 
  the 
  actual 
  numbers 
  of 
  

   molecules 
  corresponding 
  to 
  a 
  known 
  osmotic 
  pressure. 
  

  

  Since 
  the 
  experiments 
  here 
  described 
  did 
  not 
  yield 
  results 
  

   of 
  the 
  accuracy 
  expected, 
  owing 
  to 
  the 
  various 
  causes 
  noted 
  

   above 
  and 
  since 
  it 
  is 
  sufficiently 
  clear 
  that 
  the 
  charge 
  is 
  the 
  

   same 
  as 
  that 
  on 
  ions 
  produced 
  by 
  other 
  methods, 
  they 
  were 
  

   not 
  further 
  pursued. 
  It 
  may 
  possibly 
  be 
  found 
  that 
  the 
  

   most 
  accurate 
  method 
  of 
  finding 
  e 
  is 
  from 
  the 
  quantities 
  

   N6' 
  = 
  1'23 
  X 
  10^^ 
  and 
  N 
  ais 
  found 
  by 
  Perrin's 
  method. 
  

  

  The 
  author 
  wishes 
  to 
  acknowledge 
  his 
  indebtedness 
  to 
  

   Prof. 
  J. 
  S. 
  Townsend 
  for 
  his 
  many 
  suggestions 
  and 
  his 
  

   sympathetic 
  help 
  in 
  the 
  course 
  of 
  these 
  experiments. 
  

  

  University 
  Museum, 
  Oxford. 
  

  

  * 
  J. 
  S. 
  To^vnsend, 
  Proc. 
  Eoy. 
  Soc. 
  vols. 
  Ixxx. 
  & 
  Ixxxi, 
  (1908) 
  j 
  C. 
  E. 
  

   Haselfoot, 
  Proc. 
  Rov. 
  Soc. 
  vol. 
  Ixxxii. 
  (1909). 
  

   t 
  Wied. 
  Ann. 
  [4l 
  iv. 
  1901, 
  p. 
  504. 
  

   \ 
  Compt. 
  Rend, 
  cxlvii. 
  1908, 
  p. 
  .094. 
  

  

  