﻿of 
  Water- 
  Vapour 
  by 
  Electric 
  Sparks. 
  103 
  

  

  under 
  the 
  influence 
  o£ 
  the 
  spark 
  discharge, 
  and 
  the 
  amount 
  

   of 
  metal 
  shot 
  off 
  increases 
  with 
  rise 
  of 
  temperature. 
  

  

  Fisr. 
  o. 
  

  

  "i 
  

  

  "TO 
  CONDENSED 
  

   AND 
  TWHT 
  

  

  s 
  / 
  

  

  \B 
  CONDENSE* 
  

   AND 
  TWMT> 
  

  

  /\ 
  

  

  A 
  

  

  B 
  

  

  The 
  stream 
  of 
  water-vapour 
  at 
  about 
  12 
  mm. 
  pressure 
  

   entered 
  the 
  tubes 
  at 
  C, 
  and 
  after 
  being 
  decomposed 
  by 
  the 
  

   spark 
  passed 
  out 
  at 
  D 
  to 
  a 
  condenser 
  surrounded 
  by 
  a 
  freezing- 
  

   mixture 
  whence 
  the 
  electrolytic 
  gas 
  was 
  removed 
  by 
  a 
  pump, 
  

   and 
  estimated 
  by 
  explosion. 
  The 
  electrode 
  at 
  C 
  or 
  J) 
  could 
  be 
  

   made 
  anode 
  or 
  cathode 
  at 
  will 
  by 
  simply 
  reversing 
  the 
  current. 
  

  

  The 
  experiments 
  were 
  carried 
  out 
  as 
  follows 
  : 
  — 
  

  

  The 
  whole 
  apparatus 
  being 
  completely 
  evacuated, 
  a 
  current 
  

   of 
  water- 
  vapour, 
  the 
  velocity 
  of 
  which 
  was 
  measured 
  by 
  the 
  

   volume 
  of 
  water 
  collected 
  in 
  the 
  condenser 
  per 
  hour, 
  was 
  

   passed 
  through 
  the 
  spark-tube, 
  and 
  C 
  was 
  made 
  the 
  cathode. 
  

  

  After 
  ten 
  minutes' 
  continuous 
  sparking 
  the 
  current 
  was 
  

   switched 
  off 
  and 
  the 
  electrolytic 
  gas 
  produced 
  was 
  removed 
  

   by 
  the 
  pump 
  and 
  estimated. 
  D 
  was 
  then 
  made 
  the 
  cathode, 
  

   and 
  sparks 
  were 
  passed 
  for 
  another 
  ten 
  minutes, 
  when 
  the 
  

   resulting 
  oxygen 
  and 
  hydrogen 
  were 
  pumped 
  off 
  and 
  esti- 
  

   mated 
  as 
  before. 
  The 
  ratio 
  of 
  the 
  amount 
  of 
  the 
  electrolytic 
  

   gas 
  obtained 
  when 
  the 
  cathode 
  was 
  at 
  C 
  to 
  that 
  when 
  it 
  was 
  

   at 
  D 
  could 
  then 
  be 
  calculated. 
  

  

  The 
  two 
  observations 
  were 
  made 
  as 
  rapidly 
  as 
  possible 
  so 
  

   that 
  the 
  rate 
  of 
  the 
  stream 
  of 
  water-vapour 
  might 
  be 
  assumed 
  

   to 
  be 
  the 
  same 
  in 
  each 
  case. 
  No 
  voltameter 
  was 
  placed 
  in 
  

  

  