﻿AND 
  SOME 
  OF 
  ITS 
  DERIVATIVES. 
  405 
  

  

  acid. 
  Accordingly, 
  bromine 
  water 
  was 
  poured 
  upon 
  powdered 
  meconic 
  acid 
  ; 
  lively 
  

   effervescence 
  took 
  place, 
  which 
  was 
  found 
  to 
  result 
  from 
  the 
  evolution 
  of 
  carbonic 
  

   acid, 
  and 
  complete 
  solution 
  subsequently 
  ensued. 
  The 
  fluid, 
  when 
  left 
  at 
  rest 
  a 
  

   considerable 
  time, 
  deposited 
  a 
  few 
  long 
  prismatic 
  crystals 
  of 
  great 
  beauty, 
  a 
  much 
  

   more 
  copious 
  product 
  was 
  obtained 
  by 
  gentle 
  evaporation. 
  Recrystallisation 
  

   from 
  hot 
  water 
  gave 
  groups 
  of 
  brilliant 
  square 
  prismatic 
  crystals, 
  of 
  which, 
  

  

  f 
  6 
  - 
  787 
  grains, 
  dried 
  at 
  212°, 
  gave, 
  when 
  burnt 
  with 
  lime, 
  

   [5-480 
  ... 
  bromide 
  of 
  silver. 
  

  

  This 
  experiment 
  gives 
  a 
  per-centage 
  of 
  34*36 
  bromine 
  : 
  34*04 
  is 
  that 
  corre- 
  

   sponding 
  to 
  the 
  formula 
  of 
  dry 
  bromocomenic 
  acid, 
  

  

  2H0,C 
  12 
  {^}0 
  8 
  

  

  The 
  nature 
  of 
  the 
  reaction 
  is 
  seen 
  in 
  the 
  equation 
  

  

  C 
  u 
  H 
  4 
  14 
  + 
  2Br 
  = 
  C 
  12 
  { 
  **> 
  J 
  O 
  10 
  + 
  HBr 
  + 
  2 
  00, 
  

  

  Crystals 
  of 
  oxalic 
  acid 
  were 
  obtained 
  by 
  evaporating 
  the 
  original 
  mother 
  liquors 
  

   to 
  a 
  small 
  bulk. 
  

  

  Ethers 
  of 
  Meconic 
  Acid. 
  

  

  When 
  absolute 
  alcohol 
  is 
  poured 
  upon 
  meconic 
  acid, 
  and 
  the 
  mixture 
  is 
  agi- 
  

   tated, 
  partial 
  solution 
  takes 
  place, 
  accompanied 
  by 
  a 
  considerable 
  fall 
  in 
  tempe- 
  

   rature, 
  amounting 
  to 
  about 
  10° 
  or 
  12° 
  Fahr. 
  : 
  application 
  of 
  a 
  gentle 
  heat 
  causes 
  

   complete 
  solution. 
  A 
  stream 
  of 
  hydrochloric 
  acid 
  gas 
  passed 
  through 
  the 
  fluid 
  

   is 
  attended 
  by 
  the 
  usual 
  result 
  observed 
  in 
  these 
  cases, 
  the 
  formation 
  of 
  an 
  ether 
  

   compound 
  ; 
  but 
  in 
  this 
  instance 
  more 
  than 
  one 
  of 
  such 
  substances 
  are 
  pro- 
  

   duced, 
  and 
  the 
  relative 
  proportion 
  of 
  the 
  individual 
  products 
  depends 
  on 
  the 
  

   amount 
  of 
  acid 
  gas 
  and 
  the 
  strength 
  of 
  the 
  alcohol 
  employed 
  ; 
  I 
  say 
  the 
  strength 
  

   of 
  the 
  alcohol, 
  because 
  rectified 
  spirit 
  serves 
  to 
  produce 
  etherification, 
  and 
  I 
  have 
  

   employed 
  it, 
  but 
  have 
  found 
  it 
  disadvantageous, 
  because 
  whenever 
  I 
  did 
  so, 
  I 
  

   observed 
  the 
  formation 
  of 
  an 
  uncrystalline 
  compound 
  which 
  very 
  much 
  impeded 
  

   the 
  purification 
  of 
  the 
  other 
  substances. 
  The 
  large 
  amount 
  of 
  water 
  of 
  crystal- 
  

   lisation 
  of 
  meconic 
  acid, 
  amounting 
  to 
  fully 
  25 
  per 
  cent., 
  tends 
  to 
  dilute 
  the 
  alco- 
  

   hol, 
  and 
  I 
  have 
  sometimes 
  dried 
  the 
  acid 
  at 
  21 
  2 
  J 
  Fahr. 
  before 
  using 
  it, 
  and 
  found 
  

   this 
  a 
  good 
  plan 
  when 
  working 
  with 
  rectified 
  spirit. 
  

  

  The 
  results 
  I 
  have 
  observed 
  may 
  be 
  stated 
  in 
  a 
  few 
  words 
  as 
  preface 
  to 
  the 
  

   description 
  of 
  the 
  individual 
  products 
  ; 
  when 
  a 
  current 
  of 
  dry 
  hydrochloric 
  acid 
  

   gas 
  is 
  passed 
  through 
  an 
  alcoholic 
  solution 
  of 
  meconic 
  acid 
  till 
  it 
  fumes 
  strongly, 
  

   and 
  the 
  fluid 
  is 
  set 
  aside 
  to 
  cool, 
  there 
  appears, 
  after 
  a 
  shorter 
  or 
  longer 
  time, 
  

   according 
  to 
  the 
  circumstances 
  above 
  referred 
  to, 
  a 
  deposit 
  in 
  feathery 
  crystals 
  ; 
  

   the 
  fluid 
  filtered 
  from 
  this, 
  where 
  absolute 
  alcohol 
  has 
  been 
  used, 
  gives 
  no 
  further 
  

   deposit 
  ; 
  but, 
  in 
  the 
  case 
  of 
  rectified 
  spirit, 
  another 
  less 
  crystalline 
  substance 
  ap- 
  

  

  vol. 
  xx. 
  part 
  in. 
  • 
  5r 
  

  

  