﻿Properties 
  of 
  Newly 
  Prepared 
  Gases, 
  147 
  

  

  t 
  x 
  the 
  time 
  in 
  minutes 
  required 
  to 
  admit 
  the 
  charge 
  ; 
  h 
  L 
  the 
  

   maximum 
  height 
  in 
  centimetres 
  that 
  the 
  sulphuric 
  acid 
  rises 
  

   in 
  U 
  after 
  the 
  tube 
  T 
  is 
  closed 
  ; 
  t 
  2 
  the 
  time 
  that 
  elapses 
  while 
  the 
  

   manometer 
  falls 
  from 
  A 
  x 
  to 
  h 
  2 
  ; 
  and 
  n 
  2 
  the 
  charge 
  that 
  is 
  

   blown 
  out 
  of 
  P. 
  The 
  current 
  through 
  the 
  electrolyte 
  was 
  in 
  

   each 
  case 
  fourteen 
  amperes. 
  

  

  In 
  the 
  last 
  experiment 
  the 
  charge 
  on 
  the 
  gas 
  was 
  reduced 
  

   by 
  passing 
  it 
  through 
  a 
  tube 
  of 
  phosphorus 
  pentoxide 
  before 
  

   it 
  entered 
  T. 
  

  

  We 
  thus 
  see 
  that 
  the 
  carriers 
  of 
  the 
  electricity 
  in 
  the 
  

   charged 
  hydrogen 
  can 
  with 
  ease 
  be 
  transferred 
  to 
  an 
  atmo- 
  

   sphere 
  of 
  any 
  other 
  gas 
  by 
  diffusion. 
  Also, 
  by 
  continuing 
  

   the 
  stream 
  of 
  hydrogen 
  into 
  P, 
  the 
  density 
  of 
  the 
  charge 
  in 
  

   P 
  increases, 
  so 
  that 
  diffusion 
  not 
  only 
  affords 
  a 
  method 
  of 
  

   removing 
  a 
  charge 
  from 
  a 
  gas, 
  but 
  also 
  gives 
  us 
  a 
  means 
  of 
  

   increasing 
  the 
  electrification 
  per 
  unit 
  volume. 
  

  

  Experiments 
  with 
  Hydrochloric 
  Acid. 
  

  

  24. 
  When 
  gases 
  are 
  given 
  off 
  by 
  electrolysis 
  both 
  the 
  

   quantity 
  and 
  sign 
  of 
  the 
  electricity 
  which 
  they 
  carry 
  are 
  

   affected 
  by 
  various 
  causes. 
  These 
  changes 
  which 
  the 
  charge 
  

   undergoes 
  are 
  well 
  illustrated 
  by 
  a 
  series 
  of 
  experiments 
  which 
  

   were 
  performed 
  with 
  a 
  twenty-per-cent. 
  solution 
  of 
  hydro- 
  

   chloric 
  acid. 
  

  

  The 
  electric 
  state 
  of 
  the 
  gases 
  was 
  examined 
  by 
  leading 
  

   them 
  into 
  an 
  insulated 
  inductor, 
  connected 
  to 
  one 
  pair 
  of 
  

   quadrants 
  of 
  an 
  electrometer. 
  The 
  other 
  pair 
  of 
  quadrants, 
  

   the 
  case 
  of 
  the 
  electrometer, 
  and 
  the 
  screen 
  inside 
  which 
  the 
  

   inductor 
  was 
  placed, 
  were 
  connected 
  to 
  earth. 
  

  

  The 
  hydrogen 
  was 
  bubbled 
  through 
  a 
  strong 
  solution 
  of 
  

   caustic 
  potash 
  and 
  the 
  chlorine 
  through 
  water, 
  before 
  entering 
  

   the 
  inductor. 
  

  

  25. 
  The 
  charge 
  carried 
  by 
  the 
  hydrogen 
  evolved 
  from 
  

   a 
  hydrochloric-acid 
  electrolyte 
  varies 
  in 
  a 
  very 
  peculiar 
  

   manner. 
  When 
  new 
  carbon 
  electrodes 
  are 
  used 
  and 
  the 
  

   current 
  turned 
  on, 
  the 
  electrometer 
  shows 
  that 
  the 
  gas, 
  at 
  

   first, 
  has 
  a 
  positive 
  charge, 
  but 
  although 
  the 
  current 
  is 
  

   kept 
  constant, 
  this 
  charge 
  diminishes 
  gradually, 
  and 
  after 
  

   some 
  minutes 
  becomes 
  negative 
  ; 
  it 
  soon 
  reaches 
  its 
  maximum 
  

   negative 
  value, 
  and 
  the 
  charge 
  then 
  remains 
  constant, 
  except 
  

   for 
  a 
  small 
  variation 
  due 
  to 
  temperature. 
  When 
  the 
  electro- 
  

   lyte 
  is 
  cooled, 
  and 
  the 
  same 
  current 
  again 
  sent 
  through 
  

   the 
  acid, 
  the 
  hydrogen 
  begins 
  to 
  come 
  off 
  with 
  a 
  negative 
  

   charge. 
  

  

  26. 
  The 
  chlorine 
  which 
  has 
  been 
  evolved 
  from 
  the 
  positive 
  

  

  