﻿Radium 
  Emanation 
  in 
  the 
  Atmosphere. 
  597 
  

  

  of 
  emanation 
  that 
  can 
  be 
  got 
  from 
  a 
  solution 
  is 
  only 
  ^, 
  the 
  

   amount 
  that 
  could 
  be 
  got 
  ° 
  

  

  (1) 
  From 
  a 
  solution 
  in 
  radioactive 
  equilibrium, 
  could 
  all 
  

   the 
  emanation 
  present 
  be 
  removed 
  at 
  once; 
  or 
  

  

  (2) 
  From 
  a 
  solution 
  were 
  the 
  removal 
  carried 
  on 
  for 
  an 
  

   infinite 
  time 
  and 
  the 
  emanation 
  given 
  off 
  collected 
  in 
  

   some 
  absorbing 
  agent. 
  

  

  As 
  an 
  example 
  of 
  the 
  method 
  by 
  which 
  the 
  radium-content 
  

   of 
  the 
  air 
  is 
  calculated, 
  the 
  mean 
  values 
  of 
  the 
  results 
  of 
  

   Table 
  IV. 
  may 
  be 
  taken. 
  It 
  is 
  there 
  shown 
  that 
  70 
  Hires 
  of 
  

   atmospheric 
  air 
  contain, 
  on 
  an 
  average, 
  an 
  amount 
  of 
  ema- 
  

   nation 
  represented, 
  say, 
  by 
  0*3, 
  while 
  my 
  solution 
  containing 
  

   3'14xl0 
  -9 
  firm, 
  of 
  radium 
  gives 
  in 
  2 
  hours 
  an 
  amount 
  of 
  

   emanation 
  represented 
  on 
  the 
  same 
  scale 
  by 
  2*5. 
  From 
  these 
  

   numbers 
  it 
  follows 
  that 
  1 
  cubic 
  metre 
  of 
  atmospheric 
  air 
  

   contains 
  an 
  amount 
  of 
  emanation 
  that 
  would 
  be 
  generated 
  by 
  

  

  x 
  r— 
  x 
  3*14 
  x 
  10~ 
  9 
  orm. 
  of 
  radium 
  in 
  2 
  hours, 
  

  

  70 
  2-5 
  

  

  i. 
  e. 
  an 
  amount 
  that 
  would 
  exist 
  in 
  radioactive 
  equilibrium 
  

   with 
  

  

  1000 
  v 
  -3 
  v 
  3-14 
  xl0~ 
  9 
  QA 
  1A 
  12 
  e 
  ,. 
  

  

  — 
  — 
  x 
  — 
  x 
  — 
  , 
  or 
  80 
  x 
  10" 
  12 
  grm. 
  of 
  radium. 
  

  

  Record 
  of 
  the 
  Tests 
  of 
  the 
  Amount 
  of 
  Radium 
  Emanation 
  

   accumulated 
  in 
  the 
  Charcoal 
  Tubes 
  when 
  left 
  to 
  themselves. 
  

  

  In 
  Table 
  III. 
  are 
  given, 
  1st 
  the 
  date 
  of 
  testing, 
  2nd 
  the 
  

   tube, 
  3rd 
  the 
  time 
  the 
  tube 
  had 
  been 
  resting 
  since 
  the 
  last 
  

   testing, 
  4th 
  the 
  amount 
  of 
  emanation 
  accumulated 
  measured 
  

   by 
  the 
  leak 
  per 
  minute 
  it 
  caused 
  when 
  passed 
  into 
  the 
  testing 
  

   vessel, 
  5th 
  the 
  amount 
  of 
  emanation 
  accumulated 
  per 
  day. 
  

   The 
  amounts 
  in 
  this 
  column 
  are 
  calculated 
  from 
  the 
  amounts 
  

   in 
  the 
  last 
  column 
  by 
  means 
  of 
  the 
  production 
  curve 
  of 
  radium 
  

   emanation 
  (fig. 
  2). 
  

  

  From 
  this 
  table 
  I 
  find 
  that 
  on 
  the 
  average 
  the 
  accumulations 
  

   of 
  A 
  and 
  JB 
  per 
  day 
  are 
  '19 
  and 
  '23 
  respectively. 
  The 
  results 
  

   agree 
  with 
  the 
  mean 
  of 
  the 
  combined 
  accumulations 
  given 
  in 
  

   the 
  last 
  two 
  rows 
  of 
  the 
  table. 
  C 
  was 
  so 
  high 
  that 
  it 
  was 
  not 
  

   used 
  in 
  the 
  following 
  experiments. 
  

  

  