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  812 
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  LXVIII. 
  The 
  Action 
  of 
  the 
  Radium 
  Emanation 
  upon 
  Water. 
  

   By 
  Prof. 
  E. 
  Rutherford, 
  F.R.S., 
  and 
  T. 
  Royds, 
  M.Sc, 
  

   1851 
  Exhibition 
  Science 
  Scholar*. 
  

  

  SINCE 
  the 
  initial 
  experiments 
  of 
  Ramsay 
  and 
  Soddy 
  in 
  

   1903, 
  the 
  production 
  of 
  helium 
  from 
  radium 
  and 
  its 
  

   emanation 
  have 
  been 
  completely 
  substantiated 
  by 
  a 
  number 
  

   of 
  independent 
  observers. 
  On 
  the 
  view 
  that 
  the 
  a 
  particle 
  is 
  

   a 
  helium 
  atom, 
  the 
  appearance 
  of 
  helium 
  from 
  radioactive 
  

   matter 
  in 
  general 
  receives 
  a 
  simple 
  and 
  satisfactory 
  

   explanation. 
  

  

  Recently 
  Mr. 
  Cameron 
  and 
  Sir 
  William 
  Ramsay 
  have 
  

   attacked 
  the 
  important 
  question 
  as 
  to 
  whether 
  the 
  radiations 
  

   from 
  a 
  large 
  quantity 
  of 
  radium 
  emanation 
  are 
  effective 
  in 
  

   transforming 
  the 
  atoms 
  of 
  ordinary 
  matter. 
  They 
  have 
  

   published 
  results 
  to 
  prove 
  that 
  under 
  the 
  influence 
  of 
  the 
  

   radium 
  emanation, 
  copper 
  is 
  transformed 
  into 
  lithium 
  and 
  

   possibly 
  into 
  sodium 
  and 
  potassium. 
  In 
  addition 
  they 
  have 
  

   given 
  evidence 
  that 
  in 
  the 
  presence 
  of 
  copper 
  solutions 
  the 
  

   emanation 
  disintegrates 
  into 
  argon, 
  and 
  in 
  the 
  presence 
  of 
  

   water 
  into 
  neon. 
  A 
  complete 
  and 
  satisfactory 
  proof 
  of 
  these 
  

   transformations 
  is 
  attended 
  by 
  great 
  experimental 
  difficulty. 
  

   In 
  a 
  recent 
  paper 
  f, 
  Cameron 
  and 
  Ramsay 
  sum 
  up 
  the 
  results 
  

   of 
  their 
  experiments 
  as 
  follows 
  : 
  — 
  " 
  In 
  carrying 
  out 
  such 
  

   work 
  it 
  is 
  extremely 
  difficult 
  to 
  prevent 
  traces 
  of 
  air 
  leaking 
  

   into 
  the 
  apparatus 
  during 
  the 
  considerable 
  length 
  of 
  time 
  

   which 
  must 
  elapse 
  before 
  an 
  experiment 
  is 
  completed. 
  Since 
  

   0*1 
  c.c. 
  of 
  atmospheric 
  nitrogen 
  contains 
  sufficient 
  argon 
  to 
  

   be 
  detected 
  spectroscopically 
  after 
  the 
  nitrogen 
  has 
  been 
  

   removed 
  by 
  sparking, 
  the 
  proof 
  that 
  the 
  presence 
  of 
  argon 
  

   is 
  due 
  to 
  some 
  other 
  cause 
  is 
  rendered 
  extremely 
  difficult. 
  

   Similarly, 
  it 
  is 
  far 
  from 
  easy 
  to 
  free 
  copper 
  solutions 
  com- 
  

   pletely 
  from 
  traces 
  of 
  lithium, 
  and 
  to 
  prove 
  convincingly 
  

   that 
  lithium 
  did 
  not 
  pre-exist 
  in 
  such 
  solution 
  treated 
  with 
  

   emanation. 
  The 
  detection 
  of 
  neon 
  is 
  open 
  to 
  no 
  such 
  ob- 
  

   jection. 
  The 
  only 
  possible 
  source, 
  other 
  than 
  transmutation, 
  

   is 
  the 
  aluminium 
  of 
  the 
  electrodes. 
  The 
  vacuum-tube 
  had 
  

   been 
  previously 
  run 
  a 
  great 
  number 
  of 
  times 
  at 
  different 
  

   pressures, 
  w 
  T 
  ashed 
  out 
  with 
  air, 
  and 
  finally 
  showed 
  traces 
  of 
  

   hydrogen, 
  and 
  hydrogen 
  alone. 
  It 
  is 
  inconceivable 
  that 
  

   neon 
  can 
  have 
  resulted 
  thus 
  by 
  chance 
  from 
  two 
  experiments 
  

   with 
  water, 
  where 
  in 
  each 
  case 
  the 
  residues 
  were 
  tested 
  

   between 
  those 
  from 
  numerous 
  similar 
  experiments 
  with 
  other 
  

   solutions 
  in 
  which 
  no 
  neon 
  was 
  detected. 
  We 
  must 
  regard 
  

  

  * 
  Communicated 
  "by 
  the 
  Authors. 
  

  

  f 
  Jouru. 
  Chem. 
  Soc. 
  June 
  1908, 
  p. 
  992. 
  

  

  