﻿Radium 
  Emanation 
  in 
  the 
  Atmosphere. 
  593 
  

  

  experiment 
  proper. 
  I 
  usually 
  ran 
  an 
  air-current 
  through 
  

   the 
  solution 
  for 
  three 
  or 
  four 
  hours, 
  and 
  hoped 
  that 
  the 
  solu- 
  

   tion 
  would 
  have 
  then 
  got 
  into 
  a 
  steady 
  state. 
  The 
  solution 
  

   was 
  then 
  connected 
  up 
  as 
  follows 
  : 
  — 
  

  

  Outside 
  air«»— 
  >-Dust 
  tube*— 
  »-Radium 
  solution^*— 
  *-Calciuni 
  chloride 
  tube 
  

   —^-Charcoal 
  tube=>— 
  *-Gauge— 
  ^Pump. 
  

  

  Air 
  was 
  drawn 
  through 
  the 
  solution 
  for 
  a 
  known 
  time 
  and 
  

   at 
  the 
  same 
  rate 
  as 
  in 
  the 
  air 
  experiment. 
  The 
  tube 
  was 
  

   then 
  heated 
  and 
  the 
  emanation 
  collected 
  in 
  the 
  two 
  aspirators 
  

   and 
  the 
  leaks 
  due 
  to 
  it 
  measured. 
  The 
  result 
  gives 
  the 
  leak 
  

   due 
  to 
  the 
  sum 
  of 
  the 
  emanation 
  due 
  to 
  the 
  known 
  volume 
  of 
  

   air 
  drawn 
  through, 
  and 
  the 
  emanation 
  generated 
  by 
  the 
  

   solution 
  in 
  the 
  given 
  time. 
  

  

  Since 
  the 
  amount 
  of 
  emanation 
  in 
  the 
  air 
  may 
  be 
  subject 
  

   to 
  considerable 
  variation, 
  it 
  was 
  thought 
  well 
  to 
  carry 
  out 
  

   the 
  two 
  experiments 
  at 
  the 
  same 
  time, 
  so 
  that 
  the 
  emanation 
  

   due 
  to 
  the 
  air 
  would 
  be 
  the 
  same 
  in 
  both 
  tubes. 
  To 
  do 
  this 
  

   the 
  tube 
  from 
  the 
  outside 
  air 
  was 
  connected 
  to 
  a 
  bottle 
  which 
  

   1 
  shall 
  call 
  a 
  " 
  distributing 
  " 
  bottle, 
  from 
  which 
  two 
  tubes 
  led, 
  

   and 
  the 
  two 
  tubes 
  from 
  the 
  two 
  gauges 
  led, 
  as 
  before 
  men- 
  

   tioned, 
  into 
  one 
  bottle, 
  a 
  '* 
  collecting 
  " 
  bottle, 
  from 
  which 
  one 
  

   tube 
  led 
  to 
  the 
  pump 
  thus 
  : 
  — 
  

  

  /-^~"\~— 
  CaCl 
  2 
  —* 
  Charcoal 
  tube 
  A 
  — 
  -*> 
  Gauge 
  A 
  — 
  Pum 
  P 
  

   ^ 
  V_y 
  -^ 
  Rad 
  - 
  sol.*— 
  CaCl 
  2 
  *— 
  ^Char. 
  tube 
  B~Gauge 
  B— 
  \J 
  ~~* 
  

  

  If 
  the 
  same 
  volume 
  of 
  air 
  goes 
  along 
  each 
  path, 
  then 
  by 
  

   subtraction 
  we 
  can 
  get 
  the 
  value 
  of 
  

  

  emanation 
  in 
  a 
  known 
  volume 
  of 
  air 
  

   emanation 
  generated 
  in 
  the 
  solution 
  in 
  a 
  known 
  time 
  

  

  The 
  method 
  being 
  a 
  comparative 
  one, 
  gives 
  true 
  results 
  

   only 
  if 
  all 
  the 
  emanation 
  is 
  absorbed, 
  or 
  if 
  the 
  amounts 
  

   absorbed 
  are 
  the 
  same 
  fractions 
  of 
  the 
  total 
  amounts 
  what- 
  

   ever 
  be 
  those 
  total 
  amounts. 
  Experiments 
  made 
  to 
  test 
  this 
  

   proportionality 
  with 
  solutions 
  giving 
  about 
  the 
  same 
  amounts 
  

   of 
  emanation 
  as 
  those 
  obtained 
  in 
  the 
  experiments 
  gave 
  fairly 
  

   satisfactory 
  results. 
  

  

  Phil. 
  Mag. 
  S. 
  6. 
  Vol. 
  16. 
  No. 
  94. 
  Oct. 
  1908. 
  2 
  R 
  

  

  