﻿46 
  

  

  Prof. 
  Chattock 
  and 
  Mr. 
  Tyndall 
  on 
  Changes 
  

  

  reading 
  of 
  the 
  pressure-gauge 
  at 
  the 
  middle 
  of 
  the 
  two 
  

   minutes' 
  discharge 
  and 
  the 
  mean, 
  of 
  the 
  readings 
  before 
  and 
  

   after 
  the 
  discharge 
  (see 
  Curve 
  I. 
  c). 
  

  

  Table 
  7. 
  

  

  Percentage 
  of 
  

   Oxygen 
  in 
  

  

  A/watts. 
  

  

  

  

  Hydrogen. 
  

  

  + 
  Discharge. 
  

  

  — 
  Discbarge. 
  

  

  o-o 
  

  

  5 
  

  

  12 
  

  

  •00016 
  

  

  6 
  

  

  13 
  

  

  •00075 
  

  

  a 
  

  

  12 
  

  

  •0040 
  

  

  6 
  

  

  15 
  

  

  •012 
  

  

  6 
  

  

  14 
  

  

  •025 
  

  

  6 
  

  

  9 
  

  

  •036 
  

  

  6 
  

  

  7 
  

  

  •10 
  

  

  5 
  

  

  8 
  

  

  •11 
  

  

  6 
  

  

  9 
  

  

  •15 
  

  

  6 
  

  

  8 
  

  

  •22 
  

  

  7 
  

  

  9 
  

  

  •72 
  

  

  6 
  

  

  6 
  

  

  2-2 
  

  

  7 
  

  

  9 
  

  

  2-3 
  

  

  6 
  

  

  7 
  

  

  4-6 
  

  

  6 
  

  

  6 
  

  

  62 
  

  

  7 
  

  

  8 
  

  

  91 
  

  

  7 
  

  

  8 
  

  

  14-1 
  

  

  7 
  

  

  8 
  

  

  It 
  will 
  be 
  seen 
  that 
  above 
  0*012 
  per 
  cent. 
  — 
  that 
  is 
  just 
  

   where 
  the 
  negative 
  peak 
  is 
  falling 
  — 
  the 
  values 
  for 
  negative 
  

   discharge 
  are 
  also 
  falling 
  rapidly 
  towards 
  a 
  constant 
  value. 
  

   For 
  positive 
  discharge 
  the 
  values 
  are 
  practically 
  constant 
  

   throughout. 
  

  

  If 
  we 
  may 
  take 
  this 
  as 
  indicating 
  that 
  the 
  fall 
  of 
  the 
  peak 
  

   is 
  accompanied 
  by 
  an 
  increase 
  in 
  the 
  size 
  of 
  the 
  negative 
  

   ions, 
  the 
  conclusion 
  receives 
  support 
  from 
  an 
  observation 
  of 
  

   "Warburg's* 
  that 
  minute 
  traces 
  of 
  oxygen 
  added 
  to 
  hydrogen 
  

   or 
  nitrogen 
  largely 
  diminish 
  the 
  current 
  from 
  a 
  negative 
  

   point 
  at 
  a 
  fixed 
  potential, 
  and 
  only 
  slightly 
  diminish 
  that 
  

   from 
  a 
  positive 
  point. 
  

  

  Warburg 
  unfortunately 
  did 
  not 
  work 
  with 
  known 
  amounts 
  

   of 
  oxygen, 
  so 
  that 
  we 
  cannot 
  be 
  sure 
  that 
  our 
  peak 
  region 
  

   corresponds 
  with 
  the 
  region 
  in 
  which 
  he 
  observed 
  the 
  fall 
  of 
  

   conductivity. 
  But 
  the 
  potential 
  measurements 
  seem 
  to 
  show 
  

   that 
  the 
  two 
  regions 
  are 
  the 
  same 
  ; 
  and 
  if 
  so 
  our 
  values 
  of 
  /* 
  

  

  * 
  Drude's 
  Anncden, 
  ii. 
  p. 
  295. 
  

  

  