﻿Properties 
  of 
  Newly 
  Prepared 
  Gases. 
  143 
  

  

  been 
  caused 
  nearly 
  entirely 
  by 
  the 
  force 
  of 
  gravity 
  acting 
  on 
  

   the 
  drops 
  forming 
  the 
  cloud. 
  The 
  experiment 
  shows 
  that 
  the 
  

   charge 
  resides 
  on 
  the 
  drops 
  forming 
  the 
  cloud. 
  

  

  A 
  similar 
  result 
  was 
  obtained 
  in 
  the 
  case 
  of 
  charged 
  oxygen 
  

   carrying 
  a 
  cloud 
  ; 
  the 
  corresponding 
  numbers 
  of 
  divisions 
  of 
  

   the 
  scale 
  being 
  4 
  and 
  20, 
  showed 
  that 
  five 
  times 
  the 
  charge 
  

   is 
  removed 
  by 
  the 
  tube 
  when 
  it 
  is 
  turned 
  from 
  the 
  vertical 
  to 
  

   the 
  horizontal 
  position. 
  

  

  Rough 
  values 
  for 
  the 
  size 
  of 
  the 
  drop 
  might 
  be 
  deduced 
  

   from 
  these 
  numbers 
  ; 
  but 
  the 
  variations 
  in 
  density 
  per 
  c. 
  c. 
  

   (due 
  to 
  the 
  cloud) 
  are 
  so 
  great, 
  that 
  it 
  would 
  be 
  impossible 
  to 
  

   arrive 
  at 
  satisfactory 
  values, 
  especially 
  in 
  the 
  case 
  of 
  hydrogen, 
  

   where 
  the 
  weight 
  of 
  the 
  cloud 
  can 
  be 
  as 
  great 
  as 
  ^th 
  of 
  the 
  

   weight 
  of 
  the 
  gas 
  in 
  the 
  same 
  volume. 
  

  

  20. 
  Even 
  when 
  the 
  gas 
  has 
  been 
  bubbled 
  through 
  sul- 
  

   phuric 
  acid 
  before 
  entering 
  C, 
  a 
  slight 
  effect 
  of 
  this 
  kind 
  is 
  

   still 
  to 
  be 
  found. 
  Thus, 
  when 
  the 
  tube 
  is 
  turned 
  from 
  a 
  

   vertical 
  to 
  a 
  horizontal 
  position, 
  the 
  charge 
  acquired 
  by, 
  

   it 
  per 
  minute 
  increases 
  from 
  16 
  to 
  19 
  divisions 
  of 
  the 
  elec- 
  

   trometer-scale 
  per 
  minute. 
  If 
  the 
  coefficient 
  of 
  viscosity 
  

   can, 
  even 
  roughly, 
  be 
  applied 
  as 
  in 
  Section 
  13 
  to 
  determine 
  

   the 
  size 
  of 
  the 
  carrier, 
  the 
  effect 
  of 
  gravity 
  could 
  not 
  exert 
  

   on 
  a 
  carrier 
  a 
  force 
  that 
  would 
  cause 
  it 
  to 
  move 
  through 
  the 
  

   gas 
  surrounding 
  it 
  with 
  a 
  velocity 
  of 
  the 
  same 
  order 
  as 
  3^ 
  

   centimetre 
  per 
  second. 
  In 
  fact, 
  if 
  we 
  take 
  the 
  density 
  of 
  

   the 
  carrier 
  to 
  be 
  unity, 
  its 
  radius 
  should 
  be 
  as 
  big 
  as 
  3 
  . 
  10~ 
  5 
  

   in 
  order 
  that 
  the 
  force 
  of 
  gravity 
  should 
  make 
  it 
  move 
  with 
  

   a 
  velocity 
  3- 
  J-^ 
  centimetre 
  per 
  second, 
  in 
  hydrogen 
  ; 
  whereas 
  

   we 
  have 
  found 
  that 
  its 
  radius 
  is 
  of 
  the 
  order 
  5 
  . 
  10 
  -7 
  (Sec- 
  

   tion 
  13). 
  

  

  But 
  if, 
  instead 
  of 
  considering 
  a 
  single 
  carrier, 
  we 
  take 
  

   the 
  case 
  of 
  a 
  finite 
  quantity 
  of 
  gas 
  (occupying 
  unit 
  volume 
  

   say) 
  as 
  differing 
  from 
  the 
  surrounding 
  gas 
  by 
  *05 
  per 
  cent, 
  

   in 
  density, 
  which 
  could 
  arise 
  from 
  various 
  causes, 
  a 
  vertical 
  

   motion 
  far 
  greater 
  than 
  the 
  above 
  would 
  ensue, 
  which 
  would 
  

   affect 
  the 
  discharging-power 
  of 
  a 
  horizontal 
  tube. 
  

  

  The 
  gases 
  can 
  be 
  sent 
  through 
  a 
  tube 
  containing 
  phos- 
  

   phorus 
  pentoxide, 
  after 
  bubbling 
  through 
  sulphuric 
  acid, 
  so 
  

   as 
  to 
  remove 
  all 
  traces 
  of 
  moisture, 
  and 
  if 
  the 
  powder 
  is 
  

   placed 
  loosely 
  in 
  a 
  horizontal 
  tube 
  about 
  8 
  centimetres 
  long, 
  

   with 
  glass 
  wool 
  at 
  the 
  ends 
  to 
  prevent 
  dust 
  being 
  carried 
  

   along, 
  not 
  more 
  than 
  half 
  the 
  charge 
  on 
  the. 
  gas 
  will 
  be 
  lost. 
  

   The 
  hydrogen 
  when 
  dried 
  in 
  this 
  manner 
  loses 
  more 
  of 
  its' 
  

   charge, 
  in 
  passing 
  along 
  the 
  vertical 
  tube 
  C, 
  than 
  if 
  it 
  had 
  

   been 
  dried 
  by 
  sulphuric 
  acid 
  alone 
  ; 
  but 
  the 
  loss 
  of 
  charge 
  

   was 
  not 
  found 
  to 
  be 
  increased 
  by 
  turning 
  the 
  tube 
  from 
  the 
  

   vertical 
  to 
  the 
  horizontal 
  position. 
  

  

  M2 
  

  

  