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  XIII. 
  — 
  On 
  certain 
  Salts 
  and 
  Products 
  of 
  Decomposition 
  of 
  Comenic 
  Acid. 
  By 
  

   Mr 
  Henry 
  How. 
  Communicated 
  by 
  Dr 
  T. 
  Anderson. 
  

  

  (Read 
  7th 
  April 
  1851.) 
  

  

  The 
  study 
  of 
  the 
  organic 
  acids 
  appears 
  scarcely 
  to 
  have 
  advanced 
  of 
  late 
  years 
  

   pari 
  passu 
  with 
  the 
  other 
  branches 
  of 
  organic 
  chemistry. 
  It 
  seems, 
  indeed, 
  as 
  if 
  

   the 
  development 
  of 
  each 
  of 
  the 
  different 
  departments 
  of 
  the 
  science 
  had 
  been, 
  to 
  

   a 
  certain 
  extent, 
  periodical 
  ; 
  each 
  engrossing 
  the 
  labours 
  of 
  investigators 
  to 
  the 
  

   temporary 
  exclusion 
  of 
  the 
  others, 
  themselves 
  to 
  be 
  renewed 
  when 
  some 
  new 
  

   experiments 
  should 
  reawaken 
  an 
  interest 
  in 
  them. 
  

  

  However 
  this 
  may 
  be, 
  the 
  subject 
  of 
  the 
  natural 
  and 
  artificial 
  bases 
  has 
  proved 
  

   so 
  productive 
  of 
  interesting 
  results 
  as 
  to 
  have 
  recently 
  become 
  the 
  chosen 
  and 
  

   almost 
  exclusive 
  field 
  of 
  inquiry, 
  notwithstanding 
  several 
  investigations 
  which 
  

   have 
  thrown 
  much 
  light 
  on 
  one 
  class 
  of 
  organic 
  acids, 
  namely, 
  that 
  represented 
  

   by 
  the 
  general 
  formula 
  C 
  n 
  H 
  n 
  4 
  . 
  With 
  the 
  exception 
  of 
  this 
  section, 
  the 
  his- 
  

   tory 
  of 
  the 
  organic 
  acids 
  remains 
  very 
  imperfect, 
  and 
  in 
  many 
  cases 
  we 
  have 
  but 
  

   a 
  meagre 
  account 
  of 
  a 
  few 
  of 
  their 
  salts. 
  

  

  These 
  remarks 
  apply 
  with 
  peculiar 
  force 
  to 
  the 
  polybasic 
  acids 
  ; 
  and 
  it 
  was 
  

   with 
  a 
  view 
  to 
  add 
  something 
  to 
  the 
  existing 
  information 
  respecting 
  this 
  import- 
  

   ant 
  class 
  of 
  bodies 
  that 
  I 
  undertook 
  an 
  examination 
  of 
  the 
  acid 
  which 
  forms 
  the 
  

   subject 
  of 
  the 
  present 
  paper. 
  Although 
  this 
  is 
  not 
  among 
  those 
  which 
  have 
  been 
  

   least 
  investigated, 
  many 
  gaps 
  existed 
  in 
  its 
  history 
  which 
  seemed 
  to 
  me 
  worthy 
  of 
  

   being 
  filled 
  up. 
  I 
  first 
  gave 
  my 
  attention 
  to 
  those 
  of 
  its 
  salts, 
  which 
  had 
  hitherto 
  

   remained 
  undescribed 
  or 
  been 
  but 
  imperfectly 
  examined, 
  not 
  from 
  their 
  possessing 
  

   any 
  very 
  marked 
  interest 
  in 
  themselves, 
  but 
  with 
  the 
  idea 
  of 
  obtaining 
  points 
  of 
  

   comparison 
  between 
  acids 
  likely 
  to 
  occur 
  in 
  the 
  course 
  of 
  the 
  proposed 
  investigation. 
  

  

  My 
  experiments 
  were 
  performed 
  in 
  the 
  laboratory 
  of 
  Dr 
  T. 
  Anderson. 
  

  

  Comenic 
  acid 
  was 
  discovered 
  by 
  Robiquet,* 
  who 
  observed 
  that 
  meconic 
  acid 
  

   undergoes 
  a 
  change 
  of 
  properties 
  when 
  boiled 
  with 
  water, 
  carbonic 
  acid 
  being 
  

   evolved, 
  and 
  a 
  product 
  obtained 
  to 
  which 
  he 
  gave 
  the 
  name 
  Parameconic 
  Acid, 
  

   indicative 
  of 
  isomerism 
  with 
  the 
  original 
  substance. 
  Liebig,| 
  however, 
  pointed 
  

   out 
  that 
  there 
  was 
  also 
  difference 
  in 
  composition, 
  and 
  proposed 
  the 
  provisional 
  

   name 
  Metameconic 
  Acid 
  for 
  the 
  new 
  substance, 
  whose 
  composition 
  he 
  represented 
  

   by 
  the 
  formula 
  C 
  l2 
  H 
  4 
  O 
  10 
  , 
  derived 
  from 
  the 
  analysis 
  of 
  the 
  acid 
  itself 
  and 
  of 
  a 
  

   silver 
  salt. 
  In 
  a 
  subsequent 
  paper 
  $ 
  he 
  shewed 
  its 
  bibasic 
  nature, 
  and 
  entered 
  

  

  * 
  Annales 
  de 
  Chimie 
  et 
  de 
  Phys., 
  Tome 
  51, 
  p. 
  244. 
  f 
  Ibid,, 
  54, 
  p. 
  26. 
  

  

  | 
  Annalen 
  der 
  Chemie 
  und 
  Pharmacie, 
  Band 
  26. 
  

  

  VOL. 
  XX. 
  PART 
  II. 
  3 
  P 
  

  

  