﻿674 
  Mr. 
  C. 
  F. 
  Hooley 
  o?i 
  the 
  Header 
  

  

  in 
  the 
  apparatus, 
  and 
  the 
  mineral 
  was 
  heated 
  for 
  about 
  an 
  

   hour. 
  Any 
  hydrogen 
  was 
  taken 
  up 
  by 
  the 
  copper 
  oxide 
  and 
  

   the 
  water 
  was 
  absorbed 
  by 
  the 
  oxide 
  of 
  phosphorus. 
  The 
  

   remaining 
  gases, 
  excepting 
  the 
  inert 
  elements, 
  were 
  absorbed 
  

   by 
  the 
  sodium-potassium 
  electrodes. 
  In 
  all 
  the 
  experiments, 
  

   the 
  residual 
  gas 
  showed 
  the 
  brilliant 
  yellow 
  helium 
  glow 
  in 
  

   the 
  vacuum-tube, 
  and 
  the 
  spectroscope 
  indicated 
  little 
  or 
  no 
  

   trace 
  of 
  argon, 
  the 
  gas 
  being 
  practically 
  pure 
  helium. 
  (The 
  

   bright 
  orange 
  argon 
  line 
  could 
  be 
  distinguished 
  only 
  faintly, 
  

   whilst 
  the 
  red 
  and 
  blue 
  lines 
  were 
  invisible 
  in 
  most 
  cases.) 
  

   To 
  obtain 
  some 
  idea 
  of 
  the 
  quantity 
  of 
  argon 
  present 
  with 
  the 
  

   helium, 
  a 
  cubic 
  millimetre 
  of 
  argon 
  was 
  admitted 
  into 
  the 
  

   apparatus 
  containing 
  the 
  residual 
  gas. 
  This 
  was 
  done 
  by 
  

   admitting 
  0*1 
  c.c. 
  of 
  air 
  by 
  means 
  of 
  the 
  side 
  tube, 
  shown 
  in 
  

   fig. 
  1, 
  and 
  absorbing 
  all 
  except 
  argon 
  by 
  the 
  sodium-potassium 
  

   electrodes. 
  It 
  was 
  found 
  that 
  this 
  small 
  quantity 
  of 
  argon 
  

   gave 
  a 
  spectrum 
  extending 
  beyond 
  the 
  helium 
  spectrum 
  into 
  

   the 
  red, 
  and 
  also 
  showing 
  well 
  defined 
  lines 
  in 
  the 
  violet, 
  

   clearly 
  proving 
  that 
  the 
  quantity 
  of 
  argon 
  present 
  in 
  the 
  

   helium 
  before 
  admitting 
  the 
  air 
  was 
  much 
  less 
  than 
  1 
  cub. 
  mm. 
  

   The 
  quantity 
  of 
  mineral 
  used 
  for 
  each 
  experiment 
  was 
  

   10 
  grams, 
  and 
  at 
  the 
  end 
  of 
  the 
  experiment 
  the 
  helium 
  was 
  

   pumped 
  off 
  and 
  measured. 
  The 
  volume 
  was 
  roughly 
  0*10 
  

   c.c. 
  Thus 
  the 
  volume 
  of 
  argon 
  was 
  shown 
  to 
  be 
  less 
  than 
  one 
  

   per 
  cent, 
  of 
  that 
  of 
  the 
  helium 
  obtained 
  from 
  malacone. 
  

  

  In 
  one 
  experiment 
  the 
  helium 
  was 
  liberated 
  by 
  decomposing 
  

   the 
  mineral 
  with 
  potassium 
  bisulphate, 
  and 
  in 
  the 
  others 
  by 
  

   simple 
  heating, 
  but 
  there 
  was 
  no 
  appreciable 
  difference 
  in 
  the 
  

   results. 
  

  

  The 
  results 
  of 
  the 
  investigation 
  show 
  conclusively 
  that 
  

   argon 
  is 
  contained 
  in 
  this 
  mineral 
  in 
  only 
  minute 
  quantities 
  

   even 
  in 
  comparison 
  with 
  the 
  helium. 
  It 
  is 
  true' 
  that 
  the 
  

   gases 
  are 
  not 
  entirely 
  expelled 
  by 
  simple 
  heating, 
  but 
  this 
  

   would 
  not 
  account 
  for 
  the 
  great 
  discrepancies 
  between 
  the 
  

   results 
  of 
  the 
  various 
  experimenters, 
  and 
  can 
  scarcely 
  affect 
  

   the 
  general 
  conclusion. 
  

  

  Part 
  II. 
  Krypton 
  in 
  Fergusonite. 
  

  

  It 
  is 
  mentioned 
  in 
  a 
  paper 
  by 
  Travers, 
  Senter, 
  and 
  

   Jaquerod 
  (Phil. 
  Trans. 
  A. 
  vol. 
  200. 
  1903, 
  p. 
  174) 
  that 
  an 
  

   appreciable 
  quantity 
  of 
  krypton 
  has 
  been 
  found 
  in 
  the 
  mixed 
  

   helium 
  obtained 
  from 
  cleveite. 
  If 
  the 
  presence 
  of 
  this 
  gas 
  

   were 
  in 
  any 
  way 
  connected 
  with 
  the 
  radioactive 
  properties 
  of 
  

   the 
  mineral, 
  there 
  should 
  be 
  no 
  reason 
  to 
  suppose 
  that 
  it 
  

   would 
  be 
  present 
  in 
  one 
  strongly 
  active 
  mineral 
  rather 
  than 
  

   in 
  another. 
  The 
  mineral 
  used 
  for 
  this 
  investigation 
  was 
  

  

  