﻿896 
  Prof. 
  0. 
  W. 
  Richardson 
  on 
  the 
  Kinetic 
  

  

  where 
  n 
  is 
  the 
  number 
  of 
  molecules 
  in 
  1 
  e.e. 
  of 
  a 
  gas 
  at 
  0° 
  C. 
  

   and 
  760 
  mms. 
  pressure 
  and 
  RrsnR,! 
  is 
  the 
  constant 
  in 
  the 
  

   equation 
  pv=H0, 
  referred, 
  as 
  is 
  usually 
  the 
  case, 
  to 
  a 
  cubic 
  

   centimetre 
  of 
  gas 
  under 
  standard 
  conditions. 
  If 
  the 
  change 
  

   on 
  an 
  ion 
  i^ 
  equal 
  to 
  that 
  carried 
  by 
  a 
  monovalent 
  atom 
  in 
  

   electrolysis, 
  ne 
  will 
  be 
  equal 
  to 
  the 
  quantity 
  of 
  electricity 
  

   required 
  to 
  liberate 
  half 
  a 
  cubic 
  centimetre 
  of 
  hydrogen 
  in 
  a, 
  

   water 
  voltameter 
  at 
  0° 
  C. 
  and 
  760 
  mms. 
  This 
  quantity 
  is 
  

   ■407 
  E.M. 
  units. 
  

  

  ^ 
  hen 
  tli!' 
  centre 
  of 
  the 
  -lit 
  is 
  in 
  the 
  plane 
  of 
  symmetry 
  

   ,v 
  = 
  and 
  the 
  value 
  of 
  / 
  is 
  

  

  _ 
  ?i 
  / 
  V 
  ne 
  

  

  *o= 
  

  

  tttV 
  mg? 
  w 
  

  

  The 
  fraction 
  passing 
  through 
  the 
  >lit 
  in 
  different 
  positions, 
  

   which 
  is 
  the 
  quantity 
  measured 
  experimentally, 
  may 
  there- 
  

   fore 
  he 
  expressed 
  by 
  the 
  equations, 
  

  

  or 
  

  

  i/v=< 
  *"'" 
  (7; 
  

  

  §3. 
  The 
  equations 
  (5) 
  to 
  (8) 
  point 
  out 
  a 
  number 
  of 
  

   different 
  ways 
  in 
  which 
  the 
  theory 
  may 
  be 
  subjected 
  to 
  the 
  

   tesl 
  of 
  experiment. 
  Ji 
  will 
  be 
  observed 
  that 
  the 
  apparatus 
  

   required 
  lor 
  this 
  purpose 
  is 
  the 
  same 
  in 
  general 
  design 
  as 
  

   that 
  already 
  described, 
  and 
  used 
  by 
  the 
  author* 
  to 
  measure 
  

   the 
  value 
  of 
  - 
  m 
  for 
  the 
  ions 
  emitted 
  by 
  hot 
  bodies. 
  While 
  

   that 
  investigation 
  was 
  in 
  progress 
  experiments 
  were 
  made 
  

   which 
  afford 
  a 
  preliminary 
  examination 
  of 
  the 
  ground 
  covered 
  

   by 
  the 
  theory 
  tinder 
  consideration. 
  The 
  results 
  of 
  these 
  

   experiments 
  are 
  incorporated 
  in 
  the 
  present 
  paper. 
  They 
  

   are 
  necessarily 
  somewhat 
  rough, 
  for 
  a 
  variety 
  of 
  reasons. 
  

   In 
  the 
  first 
  place, 
  the 
  apparatus 
  used 
  for 
  measuring 
  e/m 
  had 
  

   to 
  be 
  made 
  very 
  -mad 
  as 
  it 
  was 
  necessary 
  to 
  place 
  it 
  in 
  a 
  

   strong 
  uniform 
  magnetic 
  field. 
  The 
  smaller 
  the 
  apparatus 
  

   is, 
  the 
  more 
  it 
  deviates 
  from 
  the 
  condition 
  of 
  infinite 
  parallel 
  

   plane.-, 
  so 
  that 
  we 
  should 
  expect 
  an 
  error 
  due 
  to 
  the 
  electric 
  

   field 
  not 
  being 
  uniform 
  and 
  equal 
  to 
  the 
  value 
  calculated 
  

   from 
  the 
  difference 
  of 
  potential 
  between 
  the 
  plates. 
  Un- 
  

   doubtedly 
  one 
  of 
  the 
  worst 
  sources 
  of 
  error 
  in 
  these 
  experi- 
  

   ments 
  arose 
  from 
  the 
  strips 
  used 
  not 
  being 
  quite 
  plane 
  and 
  

   not 
  lying 
  accurately 
  in 
  the 
  plane 
  of 
  the 
  *• 
  upper 
  " 
  plate. 
  

  

  * 
  Phil. 
  Mag. 
  vol. 
  xvi. 
  [6] 
  p. 
  740 
  (Nov. 
  1008). 
  

  

  