﻿146 
  

  

  Mr. 
  John 
  S. 
  Townsend 
  on 
  Electrical 
  

  

  caught 
  in 
  the 
  pores 
  of 
  the 
  porcelain, 
  or 
  whether 
  the 
  carriers 
  

   remain 
  distributed 
  throughout 
  their 
  original 
  volume 
  sur- 
  

   rounded 
  by 
  the 
  air 
  which 
  diffuses 
  in 
  to 
  take 
  the 
  place 
  of 
  the 
  

   hydrogen. 
  

  

  In 
  order 
  to 
  test 
  this 
  the 
  whole 
  apparatus 
  was 
  insulated 
  

   and 
  experiments 
  were 
  conducted 
  as 
  follows 
  : 
  — 
  

  

  The 
  outside 
  cylinder 
  Q 
  was 
  connected 
  to 
  the 
  insulated 
  

   quadrants 
  of 
  the 
  electrometer 
  and 
  the 
  hydrogen 
  from 
  the 
  

   cell, 
  after 
  bubbling 
  through 
  strong 
  sulphuric 
  acid, 
  was 
  ad- 
  

   mitted 
  into 
  P 
  by 
  means 
  of 
  the 
  tube 
  T. 
  The 
  draught 
  of 
  air 
  

   between 
  P 
  and 
  Q 
  was 
  maintained 
  in 
  order 
  to 
  make 
  the 
  

   diffusion 
  as 
  rapid 
  as 
  possible 
  ; 
  no 
  inductor 
  was 
  used, 
  so 
  that 
  

   the 
  hydrogen 
  after 
  diffusion 
  was 
  carried 
  into 
  the 
  atmosphere 
  

   of 
  the 
  room 
  through 
  F. 
  As 
  the 
  charged 
  gas 
  entered 
  P, 
  the 
  

   conducting 
  cylinder 
  Q 
  being 
  connected 
  to 
  the 
  quadrants, 
  the 
  

   deflexion 
  on 
  the 
  electrometer-scale 
  registered 
  the 
  total 
  charge 
  

   that 
  entered 
  P. 
  

  

  When 
  a 
  sufficient 
  charge 
  had 
  entered 
  P, 
  the 
  tube 
  T 
  was 
  

   closed 
  and 
  the 
  sulphuric 
  acid 
  in 
  the 
  manometer 
  U 
  rose 
  rapidly 
  

   and 
  showed 
  a 
  maximum 
  difference 
  of 
  pressure 
  between 
  the 
  

   atmosphere 
  inside 
  and 
  outside 
  P 
  of 
  about 
  three 
  centimetres 
  

   of 
  acid. 
  As 
  the 
  blowing 
  into 
  E 
  was 
  continued 
  the 
  sulphuric 
  

   acid 
  in 
  U 
  began 
  to 
  fall 
  gradually, 
  and 
  in 
  a 
  few 
  minutes 
  

   the 
  difference 
  of 
  pressure 
  was 
  reduced 
  to 
  one 
  or 
  two 
  milli- 
  

   metres, 
  which 
  showed 
  that 
  practically 
  all 
  the 
  hydrogen 
  had 
  

   diffused 
  out. 
  

  

  The 
  question 
  was 
  then 
  decided 
  by 
  observing 
  what 
  charge 
  

   could 
  be 
  blown 
  out 
  of 
  P 
  by 
  blowing 
  through 
  T, 
  and 
  it 
  was 
  

   found 
  that 
  a 
  large 
  fraction 
  of 
  the 
  original 
  charge 
  could 
  be 
  

   thus 
  removed 
  from 
  inside 
  P. 
  The 
  charge 
  which 
  is 
  thus 
  

   blown 
  out 
  does 
  not 
  represent 
  quite 
  all 
  the 
  electricity 
  left 
  in 
  

   the 
  atmosphere 
  in 
  P 
  after 
  the 
  hydrogen 
  had 
  diffused 
  out, 
  as 
  

   about 
  ten 
  per 
  cent, 
  got 
  discharged 
  in 
  bubbling 
  through 
  the 
  

   sulphuric 
  acid 
  before 
  escaping 
  through 
  U. 
  

  

  The 
  numbers 
  obtained 
  in 
  three 
  experiments 
  which 
  were 
  

   performed 
  in 
  the 
  above 
  manner 
  are 
  given 
  in 
  the 
  following 
  

   table 
  : 
  n 
  x 
  is 
  the 
  charge 
  (in 
  divisions 
  of 
  the 
  scale) 
  put 
  into 
  P 
  ; 
  

  

  n 
  v 
  

  

  t 
  v 
  

  

  K. 
  

  

  K 
  

  

  t 
  2 
  . 
  

  

  n 
  2 
  . 
  

  

  210 
  

  

  3 
  

  

  30 
  

  

  •1 
  

  

  6 
  

  

  130 
  

  

  200 
  

  

  3 
  

  

  32 
  

  

  •2 
  

  

  5 
  

  

  125 
  

  

  132 
  

  

  5 
  

  

  30 
  

  

  •2 
  

  

  4 
  

  

  98 
  

  

  