﻿Energy 
  of 
  the 
  Ions 
  emitted 
  by 
  Hot 
  Bodies. 
  907 
  

  

  range 
  of 
  experimental 
  conditions 
  although 
  the 
  absolute 
  

   values 
  are 
  subject 
  to 
  the 
  same 
  kind 
  of 
  uncertainty 
  as 
  that 
  

   which 
  occurred 
  in 
  the 
  case 
  of 
  the 
  negative 
  ions. 
  The 
  daia 
  

   given 
  by 
  fig. 
  4 
  led 
  to 
  the 
  value 
  2 
  =*372 
  and 
  on 
  substituting 
  

   this, 
  and 
  the 
  values 
  already 
  given, 
  in 
  equation 
  (11) 
  we 
  find 
  

   R-=5'4:X 
  10 
  3 
  . 
  This 
  is 
  also 
  as 
  good 
  an 
  agreement 
  as 
  could 
  

   be 
  expected. 
  It 
  may 
  be 
  that 
  the 
  correction 
  is 
  somewhat 
  

   underdone 
  in 
  the 
  case 
  of 
  the 
  positive 
  ions 
  ; 
  but 
  we 
  should, 
  

   in 
  any 
  case, 
  expect 
  this 
  method 
  to 
  give 
  a 
  high 
  value 
  for 
  R, 
  

   as 
  the 
  central 
  ordinate 
  is 
  obviously 
  too 
  low, 
  owing 
  to 
  some 
  

   of 
  the 
  ions 
  having 
  been 
  shot 
  over 
  to 
  the 
  left 
  by 
  the 
  electric 
  

   field 
  in 
  the 
  manner 
  already 
  explained. 
  

  

  A 
  large 
  number 
  of 
  curves 
  were 
  obtained 
  with 
  the 
  positive 
  

   ionization 
  which 
  gave 
  values 
  comparable 
  with 
  the 
  above. 
  

   The 
  curves 
  obtained 
  after 
  the 
  strip 
  had 
  been 
  heated 
  for 
  a 
  

   long 
  time, 
  which 
  led 
  to 
  exceptional 
  results 
  when 
  treated 
  by 
  

   the 
  first 
  two 
  methods, 
  were 
  also 
  examined 
  by 
  this 
  method. 
  

   The 
  value 
  of 
  i 
  Q 
  was 
  found 
  to 
  be 
  '695 
  and 
  on 
  substituting 
  

   this 
  and 
  the 
  other 
  numbers 
  already 
  given, 
  equation 
  (11) 
  led 
  

   to 
  either 
  

  

  ne=SU 
  and 
  R 
  = 
  3'16xl0 
  3 
  , 
  

   or 
  

  

  w<? 
  = 
  -407 
  and 
  K 
  = 
  l"58xl0 
  3 
  . 
  

  

  These 
  results 
  are 
  again 
  consistent 
  with 
  those 
  given 
  by 
  the 
  

   previous 
  methods 
  when 
  applied 
  to 
  this 
  experiment. 
  

  

  The 
  results 
  obtained 
  by 
  the 
  third 
  method-, 
  with 
  an 
  appa- 
  

   ratus 
  not 
  really 
  fitted 
  for 
  applying 
  it, 
  have 
  been 
  described 
  

   in 
  detail 
  for 
  two 
  reasons. 
  In 
  the 
  first 
  place, 
  it 
  seems 
  likely 
  

   that, 
  with 
  slight 
  changes 
  in 
  the 
  apparatus 
  used, 
  this 
  method 
  

   will 
  prove 
  the 
  easiest, 
  simplest, 
  and 
  most 
  reliable 
  of 
  the 
  

   three. 
  In 
  the 
  second 
  place 
  it 
  seemed 
  of 
  great 
  importance 
  

   to 
  show 
  that, 
  after 
  making 
  due 
  allowance 
  for 
  the 
  limitations 
  

   imposed 
  by 
  the 
  construction 
  of 
  the 
  apparatus, 
  this 
  method 
  

   led 
  to 
  the 
  same 
  conclusions 
  as 
  the 
  others. 
  

  

  § 
  7. 
  All 
  the 
  results 
  which 
  have 
  been 
  obtained 
  so 
  far 
  are 
  

   consistent 
  with 
  the 
  view 
  that 
  the 
  distribution 
  of 
  the 
  com- 
  

   ponent 
  of 
  velocity 
  parallel 
  to 
  the 
  metal 
  surface, 
  among 
  both 
  

   the 
  positive 
  and 
  the 
  negative 
  ions, 
  is 
  substantially 
  that 
  given 
  

   by 
  Maxwell's 
  law 
  ; 
  and 
  that 
  the 
  mean 
  translational 
  kinetic 
  

   energy, 
  in 
  both 
  cases, 
  is 
  the 
  same 
  as 
  that 
  of 
  a 
  molecule 
  of 
  

   gas 
  at 
  the 
  temperature 
  of 
  the 
  hot 
  metal. 
  

  

  The 
  strip 
  used 
  in 
  the 
  experiments 
  on 
  the 
  negative 
  ions 
  

   had 
  previously 
  been 
  exposed 
  to 
  high 
  positive 
  potentials. 
  

   Dr. 
  Brown 
  finds 
  that 
  the 
  part 
  of 
  the 
  kinetic 
  energy 
  of 
  the 
  

  

  