﻿Action 
  of 
  the 
  Radium 
  Emanation 
  upon 
  Water. 
  817 
  

  

  cotton- 
  wool, 
  the 
  yellow 
  line 
  of 
  helium 
  was 
  distinctly 
  brighter 
  

   than 
  the 
  yellow 
  line 
  o£ 
  neon, 
  but 
  at 
  a 
  certain 
  stage 
  o£ 
  the 
  

   warming 
  up, 
  the 
  neon 
  and 
  helium 
  spectra 
  were 
  about 
  equal 
  

   in 
  brilliancy. 
  

  

  In 
  all 
  five 
  experiments 
  were 
  made 
  by 
  this 
  method, 
  but 
  in 
  

   only 
  one 
  case 
  was 
  the 
  presence 
  of 
  neon 
  observed. 
  This 
  was 
  

   in 
  the 
  first 
  experiment 
  of 
  the 
  series. 
  In 
  order 
  to 
  see 
  whether 
  

   the 
  presence 
  of 
  neon 
  in 
  this 
  experiment 
  could 
  be 
  ascribed 
  to 
  

   a 
  leak 
  of 
  air 
  into 
  the 
  apparatus, 
  the 
  charcoal 
  was 
  warmed 
  up 
  

   and 
  the 
  gases 
  again 
  pumped 
  out 
  and 
  collected 
  in 
  a 
  burette. 
  

   The 
  oxygen 
  present 
  was 
  removed 
  by 
  melted 
  phosphorus. 
  

   About 
  Jjj 
  c.c. 
  of 
  gas 
  remained, 
  consisting 
  mainly 
  of 
  nitrogen. 
  

   Now 
  T 
  V 
  c.c. 
  of 
  nitrogen 
  corresponds 
  to 
  a 
  leakage 
  of 
  about 
  

   (^ 
  c.c. 
  of 
  air. 
  The 
  brightness 
  of 
  the 
  neon 
  yellow 
  line 
  com- 
  

   pared 
  with 
  that 
  of 
  helium 
  in 
  the 
  experiment 
  was 
  about 
  that 
  

   to 
  be 
  expected 
  if 
  this 
  quantity 
  of 
  air 
  had 
  been 
  added. 
  This 
  

   was 
  confirmed 
  by 
  the 
  observation 
  that 
  when 
  an 
  additional 
  

   yq 
  c.c. 
  of 
  air 
  was 
  added, 
  the 
  neon 
  spectrum 
  was 
  increased 
  

   notably 
  in 
  brightness. 
  

  

  Experiments 
  ivith 
  the 
  Gases 
  produced 
  from 
  the 
  

   Radium 
  Solution. 
  

  

  Cameron 
  and 
  Ramsay 
  point 
  out 
  that 
  if 
  the 
  emanation 
  

   produces 
  neon 
  in 
  the 
  presence 
  of 
  water, 
  neon 
  should 
  be 
  found 
  

   in 
  the 
  water 
  solution 
  of 
  the 
  radium 
  salt 
  from 
  which 
  the 
  

   emanation 
  is 
  pumped 
  off, 
  and 
  they 
  state 
  that 
  they 
  have 
  

   observed 
  the 
  spectrum 
  of 
  neon 
  from 
  the 
  gases 
  thus 
  obtained 
  

   from 
  the 
  radium 
  solution. 
  We 
  have 
  made 
  experiments 
  to 
  

   test 
  this 
  point. 
  The 
  radium 
  salt 
  containing 
  over 
  200 
  mgrs. 
  

   of 
  radium 
  was 
  dissolved 
  in 
  water 
  to 
  which 
  a 
  small 
  quantity 
  

   of 
  hydrochloric 
  acid 
  had 
  been 
  added. 
  The 
  emanation 
  was 
  

   allowed 
  to 
  collect 
  for 
  about 
  five 
  days, 
  and 
  was 
  then 
  pumped 
  

   off 
  with 
  about 
  30 
  c.cs. 
  of 
  hydrogen 
  and 
  oxygen. 
  These 
  gases 
  

   were 
  treated 
  as 
  before, 
  and 
  the 
  emanation 
  removed 
  by 
  con- 
  

   densation. 
  The 
  residual 
  gas, 
  mostly 
  oxygen, 
  was 
  tested, 
  by 
  

   the 
  method 
  described, 
  for 
  neon. 
  We 
  have 
  made 
  four 
  expe- 
  

   riments 
  in 
  all, 
  but 
  in 
  no 
  case 
  have 
  we 
  found 
  a 
  trace 
  of 
  neon, 
  

   although 
  a 
  brilliant 
  spectrum 
  of 
  helium 
  was 
  always 
  observed. 
  

  

  Conclusions, 
  

   From 
  the 
  rate 
  of 
  production 
  of 
  helium 
  by 
  radium 
  recently 
  

   measured 
  by 
  Sir 
  James 
  Dewar*, 
  the 
  quantity 
  of 
  helium 
  

   produced 
  by 
  a 
  known 
  quantity 
  of 
  emanation 
  can 
  be 
  readily 
  

   estimated. 
  In 
  most 
  of 
  the 
  experiments 
  with 
  water 
  a 
  quantity 
  

   of 
  emanation 
  corresponding 
  to 
  the 
  equilibrium 
  amount 
  from 
  

  

  * 
  Proc. 
  Roy. 
  Soc. 
  A. 
  lxxxi. 
  p. 
  280 
  (1908). 
  

   Phil. 
  Mag. 
  S. 
  6. 
  Vol." 
  16. 
  No. 
  95. 
  JSov. 
  1908. 
  3 
  H 
  

  

  