﻿V 
  = 
  10'6xlO 
  s 
  , 
  

  

  Energy 
  of 
  the 
  Ions 
  emitted 
  by 
  Hot 
  -Bodies. 
  

  

  = 
  •407, 
  and 
  z=*534, 
  we 
  obtai 
  

   R 
  = 
  4-5X10 
  3 
  . 
  

  

  903 
  

  

  ne 
  

  

  am 
  

  

  This 
  agrees 
  very 
  satisfactorily 
  both 
  with 
  the 
  number 
  obtained 
  

   by 
  the 
  first 
  method 
  and 
  with 
  the 
  standard 
  value 
  o£ 
  R. 
  

  

  The 
  agreement 
  o£ 
  R 
  with 
  the 
  standard 
  value 
  shows 
  that 
  

   the 
  mean 
  sideways 
  kinetic 
  energy 
  o£ 
  the 
  negative 
  ions 
  is 
  the 
  

   same 
  as 
  that 
  o£ 
  a 
  molecule 
  o£ 
  gas 
  at 
  the 
  temperature 
  o£ 
  the 
  

   hot 
  metal 
  ; 
  whilst 
  the 
  straight 
  line 
  exhibited 
  in 
  fig. 
  5 
  shows 
  

   that 
  this 
  energy 
  is 
  distributed 
  among 
  the 
  different 
  ions 
  in 
  

   accordance 
  with 
  Maxwell's 
  law 
  of 
  distribution 
  of 
  energy 
  

   among 
  the 
  molecules 
  of 
  a 
  gas. 
  

  

  (b) 
  Positive 
  Ions. 
  — 
  The 
  numbers 
  used 
  for 
  applying 
  this 
  

   method 
  to 
  the 
  positive 
  ions 
  were 
  obtained 
  by 
  drawing 
  as 
  

   smooth 
  a 
  curve 
  as 
  possible 
  through 
  the 
  experimental 
  points 
  

   shown 
  in 
  fig. 
  4. 
  In 
  doing 
  this 
  no 
  use 
  was 
  made 
  of 
  the 
  

   theoretical 
  curve, 
  which 
  had 
  not 
  at 
  that 
  time 
  been 
  con- 
  

   structed. 
  The 
  portion 
  of 
  the 
  curve 
  to 
  the 
  left 
  hand 
  of 
  the 
  

   approximate 
  line 
  of 
  symmetry 
  was 
  rejected 
  as 
  being 
  obviously 
  

   subject 
  to 
  a 
  serious 
  instrumental 
  error. 
  Measurements 
  of 
  

   the 
  right-hand 
  portion 
  of 
  the 
  curve 
  gave 
  the 
  values 
  of 
  i 
  and 
  

   jc 
  tabulated. 
  

  

  X 
  

  

  (1 
  = 
  -00318 
  cm.). 
  

  

  i. 
  

  

  (arbitrary 
  units). 
  

  

  A< 
  2 
  

  

  (1 
  = 
  1-01 
  Xl0-5cm. 
  2 
  .) 
  

  

  log 
  10 
  i. 
  

  

  

  

  302 
  

  

  

  

  •480 
  

  

  3 
  

  

  2-85 
  

  

  9 
  

  

  •455 
  

  

  6 
  

  

  2-25 
  

  

  36 
  

  

  •352 
  

  

  9 
  

  

  1-5 
  

  

  81 
  

  

  •176 
  

  

  14 
  

  

  •75 
  

  

  196 
  

  

  1-875 
  

  

  17 
  

  

  •45 
  

  

  288 
  

  

  1-653 
  

  

  21 
  

  

  •25 
  

  

  441 
  

  

  1-398 
  

  

  27 
  

  

  •12 
  

  

  729 
  

  

  1-079 
  

  

  38-5 
  

  

  •043 
  

  

  1480 
  

  

  2-633 
  

  

  If 
  the 
  numbers 
  in 
  the 
  last 
  two 
  columns 
  are 
  plotted 
  against 
  

   each 
  other 
  the 
  first 
  five 
  points 
  will 
  be 
  found 
  to 
  Jie 
  very 
  nearly 
  

   on 
  a 
  straight 
  line, 
  from 
  which 
  the 
  others 
  show 
  a 
  gradually 
  

   increasing 
  divergence. 
  This 
  divergence 
  is 
  in 
  the 
  same 
  direc- 
  

   tion 
  as 
  that 
  observed 
  with 
  the 
  negative 
  ionization 
  for 
  large 
  

   values 
  of 
  a 
  2 
  , 
  but 
  is 
  very 
  much 
  more 
  marked. 
  It 
  indicates 
  a 
  

   great 
  excess, 
  over 
  the 
  requirements 
  of 
  the 
  theory, 
  of 
  ions 
  

   having 
  very 
  large 
  values 
  of 
  the 
  sideways 
  energy. 
  In 
  other 
  

   words 
  the 
  currents 
  through 
  the 
  slit 
  for 
  large 
  values 
  of 
  x 
  are 
  

   greatly 
  in 
  excess 
  o£ 
  theoretical 
  requirements. 
  

  

  