﻿BAROMETER 
  GAGE 
  EUDIOMETER. 
  

  

  393 
  

  

  Meanwhile, 
  by 
  due 
  attention 
  to 
  the 
  gage, 
  the 
  quantity 
  which 
  has 
  

   been 
  absorbed 
  may 
  be 
  ascertained 
  ; 
  and 
  consequently, 
  the 
  propor- 
  

   tion 
  of 
  carbonic 
  acid 
  resulting 
  from 
  the 
  oxidizement 
  of 
  all 
  the 
  carbon 
  

   in 
  the 
  gas 
  subjected 
  to 
  analysis. 
  

  

  Instead 
  of 
  employing 
  the 
  forcing 
  air 
  pump, 
  by 
  substituting 
  a 
  large 
  

   valve 
  cock 
  for 
  the 
  screw 
  by 
  means 
  of 
  which 
  an 
  aperture 
  in 
  the 
  bottle 
  

   at 
  A 
  is 
  closed, 
  mercury 
  may 
  be 
  introduced 
  through 
  a 
  funnel, 
  and, 
  by 
  

   its 
  pressure, 
  the 
  residual 
  gas 
  may 
  be 
  easily 
  conveyed, 
  by 
  a 
  flexible 
  

   leaden 
  tube, 
  to 
  a 
  receiver 
  over 
  the 
  mercurial 
  reservoir, 
  and 
  analyzed 
  in 
  

   the 
  usual 
  way. 
  For 
  this 
  purpose 
  it 
  is 
  necessary 
  that 
  the 
  valve 
  cocks 
  

   with 
  which 
  the 
  mercury 
  comes 
  into 
  contact, 
  should 
  be 
  of 
  iron 
  or 
  steel 
  ; 
  

   and, 
  accordingly, 
  I 
  employ 
  such 
  where 
  mercury 
  is 
  to 
  be 
  used. 
  

  

  The 
  gases 
  may 
  be 
  supplied, 
  without 
  previous 
  measurement 
  and 
  ad- 
  

   mixture, 
  by 
  receiving 
  them 
  into 
  the 
  bottle 
  from 
  their 
  respective 
  reser- 
  

   voirs, 
  and 
  measuring 
  them 
  as 
  they 
  enter, 
  by 
  means 
  of 
  the 
  gage.* 
  

  

  * 
  I 
  subjoin 
  engravings 
  of 
  the 
  self-regulating 
  reservoirs 
  which 
  I 
  employ 
  in 
  such 
  eudiome- 
  

   trical 
  experiments 
  as 
  are 
  described 
  in 
  the 
  preceding 
  article 
  ; 
  also 
  of 
  the 
  calorimotor, 
  by 
  means 
  

  

  Fig. 
  i. 
  

  

  Fig. 
  2, 
  

  

  VOL. 
  V. 
  5 
  A 
  

  

  