﻿98 
  Messrs. 
  A. 
  Holt 
  and 
  E. 
  Hopkinson 
  on 
  Decomposition 
  

  

  formed 
  with 
  the 
  same 
  spark-tube, 
  but 
  a 
  stream 
  of 
  carbon 
  

   dioxide 
  was 
  substituted 
  for 
  the 
  water-vapour. 
  

  

  The 
  arrangement 
  of 
  the 
  apparatus 
  is 
  shown 
  in 
  fig. 
  3. 
  

  

  Fig. 
  -°>. 
  

  

  A 
  

  

  A 
  

  

  M 
  

  

  o 
  

  

  Hi 
  

  

  The 
  carbon 
  dioxide 
  was 
  generated 
  by 
  heating 
  in 
  an 
  air- 
  

   bath, 
  pure 
  sodium 
  bicarbonate, 
  contained 
  in 
  the 
  tube 
  A. 
  

  

  The 
  water 
  produced 
  by 
  the 
  decomposition 
  of 
  the 
  bicarbonate 
  

   was 
  partly 
  condensed 
  in 
  B, 
  which 
  was 
  immersed 
  in 
  cold 
  

   water, 
  after 
  which 
  the 
  gas 
  was 
  passed 
  through 
  a 
  mixture 
  of 
  

   fused 
  calcium 
  chloride 
  and 
  anhydrous 
  sodium 
  carbonate 
  con- 
  

   tained 
  in 
  C 
  so 
  as 
  to 
  completely 
  dry 
  it. 
  The 
  dry 
  gas 
  next 
  

   passed 
  through 
  a 
  very 
  fine 
  capillary 
  tube, 
  0. 
  clipping 
  into 
  

   concentrated 
  sulphuric 
  acid 
  contained 
  in 
  the 
  vessel 
  D. 
  The 
  

   capillary 
  tube 
  was 
  of 
  such 
  a 
  bore 
  that 
  when 
  there 
  was 
  prac- 
  

   tically 
  a 
  vacuum 
  on 
  one 
  side 
  of 
  it 
  and 
  carbon 
  dioxide 
  at 
  

   atmospheric 
  pressure 
  on 
  the 
  other, 
  the 
  gas 
  would 
  pass 
  through 
  

   ai 
  the 
  rate 
  of 
  about 
  five 
  litres 
  (at 
  N.T.P.) 
  per 
  hour. 
  This 
  

   was 
  about 
  the 
  mean 
  rate 
  of 
  the 
  water-vapour 
  current 
  in 
  the 
  

   previous 
  experiments. 
  

  

  After 
  bubbling 
  through 
  the 
  concentrated 
  sulphuric 
  acid, 
  

   any 
  spray 
  being 
  removed 
  by 
  the 
  glass-wool 
  E, 
  the 
  gas 
  entered 
  

  

  