﻿Properties 
  of 
  Newly 
  Prepared 
  Gases. 
  133 
  

  

  into 
  the 
  weight 
  of 
  the 
  corresponding 
  cloud, 
  we 
  obtain 
  the 
  

   number 
  of 
  drops 
  per 
  cubic 
  centimetre. 
  

  

  When 
  the 
  number 
  of 
  drops 
  is 
  divided 
  into 
  the 
  charge 
  per 
  

   cubic 
  centimetre 
  the 
  charge 
  on 
  each 
  is 
  obtained. 
  

  

  The 
  charge 
  on 
  the 
  positive 
  carrier 
  was 
  thus 
  found 
  to 
  be 
  

   2*4 
  x 
  10 
  -10 
  , 
  and 
  that 
  on 
  the 
  negative 
  carrier 
  to 
  be 
  2*9 
  x 
  10~ 
  10 
  . 
  

   When 
  we 
  take 
  into 
  account 
  all 
  the 
  experimental 
  errors, 
  these 
  

   two 
  charges 
  may 
  be 
  considered 
  equal 
  and 
  approximately 
  ' 
  

   3x1 
  -10 
  . 
  The 
  charge 
  on 
  the 
  hydrogen 
  was 
  found 
  to 
  be 
  

   between 
  one-third 
  and 
  two-thirds 
  of 
  this 
  value, 
  but 
  could 
  not 
  

   be 
  arrived 
  at 
  very 
  accurately 
  owing 
  to 
  the 
  difficulty 
  of 
  finding 
  

   the 
  size 
  of 
  the 
  drop. 
  For 
  present 
  purposes 
  this 
  charge 
  will 
  

   be 
  taken 
  as 
  | 
  x 
  10~ 
  10 
  . 
  

  

  Velocity 
  of 
  the 
  Carrier 
  when 
  acted 
  on 
  by 
  an 
  Electric 
  Force. 
  

  

  8. 
  It 
  has 
  been 
  shown 
  that 
  the 
  radius 
  of 
  the 
  drop 
  forming 
  

   the 
  cloud 
  is 
  in 
  the 
  case 
  of 
  negatively 
  charged 
  oxygen 
  

   8 
  x 
  10 
  -5 
  , 
  so 
  that 
  its 
  weight 
  is 
  2 
  x 
  10~ 
  12 
  grammes, 
  and 
  when 
  

   acted 
  on 
  by 
  gravity 
  it 
  moves 
  at 
  the 
  rate 
  of 
  eighteen 
  milli- 
  

   metres 
  in 
  four 
  minutes. 
  The 
  force 
  acting 
  on 
  the 
  drop 
  is 
  

   practically 
  2 
  x 
  10 
  -9 
  , 
  so 
  that 
  it 
  would 
  require 
  an 
  electric 
  

  

  2 
  X 
  10 
  -9 
  

   force 
  of 
  o 
  — 
  m-io 
  absolute 
  units 
  to 
  produce 
  an 
  equal 
  velo- 
  

  

  city, 
  or 
  2000 
  volts 
  per 
  centimetre. 
  As 
  we 
  are 
  only 
  dealing 
  

   with 
  small 
  electromotive 
  forces 
  it 
  is 
  evident 
  that 
  we 
  may 
  

   disregard 
  the 
  effect 
  of 
  mutual 
  repulsion 
  of 
  the 
  carriers 
  when 
  

   the 
  gas 
  is 
  carrying 
  a 
  cloud. 
  When 
  the 
  gas 
  is 
  bubbled 
  

   through 
  sulphuric 
  acid 
  the 
  radius 
  of 
  the 
  carrier 
  is 
  so 
  much 
  

   reduced 
  that 
  the 
  effect 
  of 
  the 
  mutual 
  repulsion 
  of 
  the 
  par- 
  

   ticles 
  carrying 
  the 
  charge 
  is 
  easily 
  detected. 
  

  

  9. 
  The 
  following 
  is 
  a 
  general 
  method 
  of 
  investigating 
  the 
  

   motion 
  of 
  a 
  gas 
  in 
  a 
  vessel 
  of 
  any 
  shape, 
  the 
  initial 
  distri- 
  

   bution 
  being 
  uniform. 
  Let 
  p 
  be 
  the 
  density 
  of 
  electrification 
  

   in 
  any 
  part 
  of 
  the 
  gas, 
  w, 
  v, 
  and 
  w 
  the 
  velocities 
  of 
  the 
  carriers 
  

   along 
  the 
  axes 
  of 
  ,r, 
  y, 
  and 
  z. 
  

  

  mi 
  ,. 
  n 
  ..... 
  1 
  ^p 
  clu 
  dv 
  dw 
  -. 
  

  

  lne 
  equation 
  oi 
  continuity 
  is 
  _ 
  ^ 
  + 
  t 
  _ 
  +t- 
  + 
  ^— 
  =0, 
  

  

  the 
  notation 
  being 
  the 
  same 
  as 
  that 
  used 
  in 
  Lamb, 
  ' 
  Motion 
  of 
  

  

  Fluids/ 
  Let 
  <fi 
  be 
  the 
  electric 
  potential; 
  — 
  j- 
  , 
  — 
  -~ 
  9 
  

   7 
  i 
  ax 
  ay 
  

  

  and 
  — 
  -j-- 
  are 
  the 
  forces 
  which 
  act 
  on 
  the 
  charged 
  carriers, 
  

   and 
  their 
  velocities 
  u, 
  v, 
  and 
  w 
  are 
  given 
  by 
  the 
  equations 
  

  

  