﻿of 
  Water-Vapour 
  by 
  Electric 
  Sparks. 
  

  

  101 
  

  

  The 
  following 
  details 
  of 
  an 
  experiment 
  will 
  illustrate 
  these 
  

   observations 
  : 
  — 
  

  

  1. 
  More 
  rapid 
  current 
  through 
  cathode 
  bulb. 
  

  

  i 
  Hydrogen 
  

  

  collected 
  in 
  

  

  voltameter 
  

  

  in 
  same 
  

  

  circuit. 
  

  

  Excess 
  of 
  

   hydrogen 
  

  

  from 
  

   cathode. 
  

  

  Excess 
  of 
  hy- 
  

   drogen 
  for 
  1 
  c.c. 
  

   hydrogen 
  liber- 
  

   ated 
  in 
  volta- 
  

   meter. 
  

  

  Excess 
  of 
  

  

  oxygen 
  

  

  from 
  

  

  anode. 
  

  

  Excess 
  of 
  

   oxygen 
  for 
  1 
  c.c. 
  

   hydrogen 
  liber- 
  

   ated 
  in 
  volta- 
  

   meter. 
  

  

  ; 
  3-055 
  c.c. 
  4-529 
  c.c. 
  

  

  1-482 
  c.c. 
  

  

  2-241 
  c.c. 
  

  

  0-733 
  c.c. 
  

  

  2. 
  More 
  rapid 
  current 
  through 
  anode 
  bulb. 
  

  

  Hydrogen 
  

  

  collected 
  in 
  

  

  voltameter 
  

  

  in 
  same 
  

  

  circuit. 
  

  

  Excess 
  of 
  

  

  hydrogen 
  

  

  from 
  

  

  anode. 
  

  

  Excess 
  of 
  hy- 
  

   drogen 
  for 
  1 
  c.c. 
  

   hydrogen 
  liber- 
  

   ated 
  in 
  volta- 
  

   meter. 
  

  

  Excess 
  of 
  

  

  oxygen 
  

  

  from 
  

  

  cathode. 
  

  

  Excess 
  of 
  

   oxygen 
  for 
  1 
  c.c. 
  

   hydrogen 
  liber- 
  

   ated 
  in 
  volta- 
  

   meter. 
  

  

  2-673 
  c.c. 
  

  

  0-622 
  c.c. 
  

  

  0-232 
  c.c. 
  

  

  0-173 
  c.c. 
  

  

  0-065 
  c.c. 
  

  

  These 
  different 
  results 
  obtained 
  with 
  the 
  same 
  apparatus 
  

   are 
  easily 
  explicable 
  as 
  a 
  diffusion 
  phenomenon, 
  for 
  when 
  the 
  

   current 
  of 
  water- 
  vapour 
  which 
  passes 
  down 
  one 
  limb 
  is 
  more 
  

   rapid 
  than 
  that 
  down 
  the 
  other, 
  it 
  is 
  evident 
  that 
  there 
  is 
  

   a 
  larger 
  volume 
  of 
  gas 
  in 
  the 
  quicker 
  stream 
  into 
  which 
  the 
  

   hydrogen 
  can 
  diffuse, 
  and 
  since 
  it 
  becomes, 
  or 
  tends 
  to 
  become, 
  

   equally 
  distributed 
  throughout 
  the 
  water-vapour, 
  the 
  greater 
  

   part 
  of 
  it 
  will 
  be 
  collected 
  where 
  there 
  is 
  the 
  more 
  rapid 
  

   current. 
  The 
  oxygen 
  can 
  only 
  be 
  affected 
  to 
  an 
  extent 
  equal 
  

   to 
  one-sixteenth 
  that 
  of 
  the 
  hydrogen, 
  so 
  that 
  very 
  little 
  more 
  

   of 
  it 
  is 
  found 
  to 
  pass 
  into 
  the 
  faster 
  than 
  into 
  the 
  slower 
  

   stream. 
  

  

  A 
  consideration 
  of 
  these 
  experiments 
  leads 
  to 
  the 
  conclusion 
  

   that 
  the 
  products 
  of 
  decomposition 
  of 
  a 
  compound 
  gas 
  are 
  not 
  

   arranged 
  in 
  such 
  a 
  manner 
  that 
  one 
  constituent 
  is 
  liberated 
  

   at 
  the 
  anode 
  and 
  the 
  other 
  at 
  the 
  cathode. 
  

  

  A 
  homogeneous 
  mixture 
  is 
  first 
  formed 
  in 
  the 
  path 
  of 
  the 
  

   spark, 
  and 
  the 
  separation 
  is 
  due 
  to 
  gaseous 
  diffusion 
  against 
  

   the 
  current 
  of 
  water-vapour. 
  When 
  both 
  the 
  decomposition 
  

   products 
  diffuse 
  at 
  nearly 
  similar 
  rates, 
  there 
  is 
  no 
  perceptible 
  

   separation. 
  

  

  