﻿Hydrogen 
  in 
  the 
  Atmosphere. 
  421 
  

  

  The 
  results, 
  referring 
  in 
  each 
  case 
  to 
  10 
  litres 
  of 
  fresh 
  

   country 
  air, 
  are 
  as 
  follows, 
  the 
  weights 
  being 
  in 
  gms. 
  : 
  — 
  

  

  Dec. 
  6, 
  1901 
  

  

  9, 
  ,, 
  

  

  11, 
  » 
  

  

  13, 
  „ 
  

  

  14, 
  „ 
  

  

  15, 
  „ 
  

  

  17, 
  „ 
  

  

  18, 
  „ 
  

   20, 
  „ 
  

   24. 
  „ 
  

  

  + 
  •00023 
  

   + 
  '00042 
  

   + 
  •00010 
  

   + 
  •00014 
  

   + 
  •00025 
  

   -•00001 
  

   + 
  •00031 
  

   + 
  •00028 
  

   + 
  •00025 
  

   + 
  •00016 
  

  

  Mean 
  

  

  + 
  •00021 
  

  

  It 
  will 
  be 
  seen 
  that 
  the 
  mean 
  water 
  collected 
  is 
  only 
  about 
  

   one 
  seventh 
  of 
  that 
  corresponding 
  to 
  the 
  complete 
  combustion 
  

   of 
  the 
  hydrogen, 
  according 
  to 
  M. 
  Gautier's 
  estimate 
  of 
  the 
  

   amount. 
  

  

  As 
  has 
  already 
  been 
  suggested, 
  a 
  defective 
  gain 
  of 
  weight 
  

   can 
  hardly 
  be 
  explained 
  by 
  faulty 
  manipulation. 
  The 
  

   important 
  question 
  is 
  as 
  to 
  the 
  efficiency 
  of 
  the 
  copper 
  oxide. 
  

   Did 
  my 
  furnace-tube 
  allow 
  the 
  main 
  part 
  of 
  the 
  free 
  hydrogen 
  

   to 
  pass 
  unburnt? 
  The 
  question 
  is 
  one 
  that 
  can 
  hardly 
  be 
  

   answered 
  directly, 
  but 
  I 
  may 
  say 
  that 
  variations 
  of 
  tempera- 
  

   ture 
  (within 
  moderate 
  limits) 
  did 
  not 
  influence 
  the 
  result. 
  

  

  What 
  it 
  is 
  possible 
  to 
  examine 
  satisfactorily 
  is 
  the 
  effect 
  of 
  

   small 
  additions 
  of 
  hydrogen 
  to 
  the 
  air 
  as 
  collected. 
  In 
  my 
  

   later 
  experiments 
  the 
  added 
  hydrogen 
  was 
  only 
  1 
  c.c, 
  that 
  is, 
  

   10000 
  ^y 
  volume, 
  or 
  half 
  the 
  quantity 
  originally 
  present 
  

   according 
  to 
  M. 
  Gautier. 
  The 
  hydrogen 
  was 
  first 
  diluted 
  in 
  

   a 
  gas 
  pipette 
  with 
  about 
  100 
  c.c. 
  of 
  air 
  and 
  allowed 
  time 
  to 
  

   diffuse. 
  The 
  10 
  litre 
  aspirating-bottle 
  being 
  initially 
  full 
  of 
  

   water, 
  the 
  diluted 
  hydrogen 
  was 
  introduced 
  at 
  the 
  top, 
  and 
  

   was 
  followed 
  by 
  10 
  litres 
  of 
  air 
  from 
  the 
  open, 
  after 
  which 
  

   the 
  mixture 
  stood 
  over 
  night, 
  precautions 
  which 
  had 
  been 
  

   found 
  sufficient 
  to 
  ensure 
  a 
  complete 
  mixture 
  in 
  the 
  spectro- 
  

   scopic 
  work. 
  The 
  results 
  were 
  : 
  

  

  Dee. 
  19, 
  1901. 
  

  

  5, 
  ^O, 
  ,, 
  

  

  + 
  •00091 
  

   + 
  •00084 
  

   + 
  •00103 
  

  

  Mean 
  + 
  -00093 
  

  

  The 
  additional 
  gain 
  is 
  thus 
  '00072, 
  very 
  nearly 
  the 
  full 
  

  

  