﻿the 
  Ions 
  in 
  Air 
  at 
  Different 
  Temperatures, 
  

  

  335 
  

  

  The 
  value 
  of 
  K 
  (namely 
  710) 
  strictly 
  applies 
  to 
  the 
  results 
  

   given 
  in 
  Table 
  II. 
  only. 
  The 
  results 
  in 
  Table 
  I. 
  were 
  obtained 
  

   with 
  the 
  radium 
  contained 
  in 
  a 
  small 
  glass 
  tube 
  which 
  it 
  only 
  

   partly 
  filled. 
  This 
  distribution, 
  it 
  is 
  reasonable 
  to 
  suppose, 
  

   leads 
  to 
  a 
  constant 
  o£ 
  different 
  value. 
  In 
  order 
  to 
  avoid 
  

   convection-currents 
  at 
  the 
  higher 
  temperatures 
  due 
  to 
  the 
  

   cooler 
  air 
  in 
  the 
  neck, 
  it 
  was 
  necessary 
  to 
  invert 
  the 
  

   chamber. 
  It 
  was 
  then 
  thought 
  best 
  to 
  transfer 
  the 
  radium 
  

   to 
  a 
  small 
  glass 
  sphere, 
  which 
  it 
  completely 
  filled. 
  Owing 
  

   to 
  the 
  thinness 
  of 
  the 
  glass 
  in 
  this 
  case 
  a 
  greater 
  ioni- 
  

   zation 
  was 
  obtained, 
  giving 
  rise 
  to 
  a 
  greater 
  value 
  

   ofQ^. 
  

  

  Observations 
  with 
  the 
  air 
  at 
  room-temperature 
  were 
  always 
  

   taken 
  before 
  the 
  temperature 
  was 
  changed. 
  The 
  results 
  

   that 
  belong 
  to 
  the 
  same 
  set 
  are 
  connected 
  by 
  brackets 
  in 
  each 
  

   of 
  the 
  Tables. 
  

  

  The 
  value 
  of 
  N 
  and 
  the 
  absolute 
  value 
  of 
  a, 
  at 
  the 
  different 
  

   temperatures, 
  are 
  given 
  in 
  Table 
  III. 
  The 
  values 
  of 
  N 
  

   obtained 
  from 
  Table 
  I. 
  were 
  reduced 
  to 
  the 
  same 
  order 
  as 
  

  

  20-78 
  

   15-0 
  

  

  the 
  ratio 
  of 
  

  

  those 
  of 
  Table 
  II., 
  the 
  ratio 
  used 
  being 
  

  

  the 
  values 
  of 
  N 
  at 
  12° 
  in 
  the 
  two 
  cases. 
  The 
  absolute 
  values 
  

   of 
  a 
  for 
  the 
  two 
  lowest 
  temperatures 
  were 
  obtained 
  by 
  using 
  

   for 
  Ki 
  the 
  value 
  0*692, 
  obtained 
  by 
  placing 
  5-03Ki 
  = 
  4-90K, 
  

   both 
  being 
  for 
  12° 
  C. 
  Q 
  was 
  found, 
  within 
  the 
  experimental 
  

   error, 
  to 
  be 
  independent 
  of 
  the 
  temperature. 
  

  

  Table 
  III. 
  

  

  Absolute 
  

   Temperature, 
  C. 
  

  

  N. 
  

  

  «. 
  

  

  94^ 
  

  

  4-28x10^' 
  

  

  2-55x10""*^ 
  

  

  205 
  

  

  4-81 
  „ 
  

  

  1-92 
  „ 
  

  

  285 
  

  

  6-10 
  „ 
  

  

  M8 
  „ 
  

  

  337 
  

  

  7-67 
  „ 
  

  

  0-785 
  „ 
  

  

  373 
  

  

  8-80 
  „ 
  

  

  0-59 
  „ 
  

  

  428 
  

  

  9-74 
  „ 
  

  

  0-47 
  

  

  These 
  results 
  are 
  shown 
  graphically 
  in 
  fig. 
  2 
  (p. 
  336) 
  

  

  