﻿288 
  Messrs, 
  Gill 
  and 
  Pidduck 
  on 
  the 
  Genesis 
  of 
  Ions 
  

  

  In 
  figures 
  5 
  and 
  6, 
  V 
  and 
  a 
  x 
  X 
  are 
  shown 
  together 
  as 
  

   functions 
  of 
  px 
  a, 
  and 
  Pascben's 
  law 
  is 
  seen 
  to 
  hold. 
  The 
  

   observed 
  sparking 
  potential 
  is 
  marked 
  with 
  a 
  small 
  circle 
  and 
  

   the 
  calculated 
  value 
  with 
  a 
  cross. 
  

  

  Fio-. 
  5.— 
  Argon. 
  

  

  500 
  

  

  400 
  

  

  301 
  

  

  20C 
  

  

  

  

  

  

  

  

  

  

  

  

  

  X*a 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  / 
  

  

  / 
  

  

  

  

  

  

  

  

  V 
  

  

  / 
  

  

  

  

  s>* 
  

  

  a 
  

  

  

  

  

  

  

  12 
  3 
  4 
  5 
  6 
  7 
  

  

  Fie:. 
  6. 
  — 
  Helium. 
  

  

  9 
  10 
  

  

  £ 
  7 
  

  

  f 
  ■ 
  ■ 
  

  

  \ 
  

  

  

  

  

  

  

  

  A 
  

  

  

  \ 
  

  

  

  

  

  

  © 
  

  

  

  / 
  

  

  

  \ 
  

  

  

  

  

  

  A 
  

  

  

  

  

  

  

  

  

  

  / 
  x 
  

  

  

  

  

  e 
  

  

  ©" 
  

  

  3 
  

  

  xy 
  

  

  

  

  

  

  

  

  

  

  

  

  J>x 
  

  

  a. 
  

  

  

  5. 
  After 
  the 
  above 
  experiments 
  were 
  made 
  with 
  helium 
  

   containing 
  small 
  impurities, 
  it 
  was 
  considered 
  desirable 
  to 
  try 
  

   some 
  experiments 
  with 
  the 
  gas 
  in 
  as 
  pure 
  a 
  state 
  as 
  it 
  would 
  be 
  

   possible 
  to 
  obtain. 
  For 
  this 
  purpose 
  the 
  helium 
  was 
  purified 
  

   by 
  passing 
  it 
  into 
  a 
  tube 
  of 
  charcoal 
  surrounded 
  by 
  liquid 
  air. 
  

   The 
  tube 
  containing 
  the 
  charcoal 
  was 
  in 
  air-tight 
  connexion 
  

  

  