﻿Radium 
  Emanation 
  in 
  the 
  Atmosphere. 
  609 
  

  

  Table 
  IX. 
  

  

  Date. 
  

  

  Air, 
  

   70 
  litres. 
  

  

  Air 
  4- 
  Solution. 
  

   70 
  litres 
  and 
  2^-hrs. 
  

  

  March 
  23 
  

  

  •1 
  

  

  To" 
  

   •9 
  

   G 
  

  

  "'•7t 
  

   •3t 
  

  

  •2 
  

  

  50 
  

  

  "4 
  : 
  5 
  

  

  „ 
  24 
  

  

  „ 
  26 
  

  

  „ 
  30 
  

  

  „ 
  31 
  

  

  April 
  2 
  

  

  „ 
  3 
  

  

  „ 
  4 
  

  

  ., 
  7 
  

  

  „ 
  8 
  

  

  „ 
  9 
  

  

  Means 
  

  

  •7 
  

  

  50 
  

  

  t 
  See 
  footnote 
  

  

  The 
  air 
  results 
  vary 
  very 
  much 
  among 
  themselves, 
  much 
  

   more 
  can 
  be 
  accounted 
  for 
  by 
  errors 
  of 
  experiment. 
  This 
  

   shows 
  that 
  there 
  are 
  large 
  actual 
  changes 
  in 
  the 
  amount 
  of 
  

   emanation 
  in 
  the 
  air. 
  In 
  taking 
  the 
  mean 
  the 
  anomalous 
  

   results 
  of 
  April 
  4 
  and 
  7 
  were 
  neglected. 
  

  

  The 
  results 
  of 
  the 
  air 
  and 
  solution 
  also 
  vary 
  largely, 
  but 
  

   the 
  agreement 
  is 
  better 
  than 
  in 
  the 
  case 
  of 
  the 
  air 
  alone. 
  

  

  Method 
  II. 
  as 
  well 
  as 
  Method 
  I. 
  is 
  comparative, 
  and 
  the 
  

   calculations 
  only 
  hold 
  provided 
  that, 
  the 
  same 
  proportion 
  of 
  

   the 
  amount 
  of 
  emanation 
  sent 
  through 
  is 
  condensed 
  in 
  

   each 
  case. 
  

  

  Assuming 
  that 
  such 
  is 
  the 
  case 
  we 
  have, 
  therefore, 
  that 
  

   70 
  litres 
  of 
  air 
  contain 
  an 
  amount 
  of 
  emanation 
  represented 
  

   by 
  *7 
  and 
  2 
  J 
  hours 
  of 
  the 
  solution 
  and 
  70 
  litres 
  of 
  air 
  give 
  

   an 
  amount 
  represented 
  on 
  the 
  same 
  scale 
  by 
  5*0. 
  By 
  sub- 
  

   traction 
  we 
  find 
  that 
  on 
  the 
  same 
  scale 
  2\ 
  hours 
  of 
  the 
  

   solution 
  gives 
  us 
  an 
  amount 
  represented 
  by 
  4*3. 
  

  

  We 
  can 
  now 
  calculate 
  the 
  mean 
  emanation 
  content 
  of 
  the 
  

   air, 
  and 
  we 
  find 
  that 
  1 
  cub. 
  metre 
  of 
  the 
  air 
  contains 
  the 
  

   emanation 
  (when 
  in 
  radioactive 
  equilibrium) 
  from 
  

  

  1000 
  

   70 
  

  

  7 
  3-14xl0- 
  9 
  im 
  1A 
  __ 
  

  

  X 
  ^— 
  or 
  140 
  x 
  10~ 
  12 
  grm. 
  Radium. 
  

  

  4-3 
  

  

  51 
  

  

  PHI 
  Mag. 
  Ser. 
  6. 
  Vol. 
  10. 
  No. 
  94. 
  Oct. 
  1908. 
  2 
  S 
  

  

  