﻿70 
  DR 
  ANDERSON 
  ON 
  CODEINE, 
  AND 
  

  

  added 
  ; 
  if 
  no 
  precipitate 
  appears, 
  the 
  heat 
  is 
  kept 
  up 
  for 
  a 
  short 
  time 
  longer, 
  and 
  

   another 
  quantity 
  is 
  then 
  taken 
  out 
  and 
  tested 
  ; 
  and 
  this 
  is 
  repeated 
  until 
  the 
  

   precipitate, 
  which 
  makes 
  its 
  appearance 
  when 
  the 
  acid 
  is 
  neutralised, 
  ceases 
  to 
  

   increase. 
  The 
  fluid 
  is 
  then 
  immediately 
  saturated 
  with 
  ammonia, 
  and 
  stirred 
  ra- 
  

   pidly, 
  when 
  it 
  becomes 
  filled 
  with 
  a 
  bulky 
  precipitate 
  of 
  nitrocodeine. 
  The 
  action 
  

   which 
  takes 
  place 
  is 
  extremely 
  rapid, 
  aud 
  the 
  whole 
  operation 
  is 
  complete 
  in 
  a 
  

   few 
  minutes 
  ; 
  so 
  that 
  the 
  experimenter 
  requires 
  to 
  be 
  carefully 
  on 
  the 
  watch, 
  in 
  

   order 
  to 
  hit 
  the 
  right 
  moment 
  for 
  precipitating 
  the 
  fluid. 
  No 
  red 
  fumes 
  are 
  

   evolved 
  ; 
  if 
  they 
  are 
  seen, 
  it 
  is 
  a 
  sure 
  sign 
  that 
  the 
  action 
  has 
  gone 
  too 
  far, 
  and 
  

   that 
  part 
  of 
  the 
  codeine 
  has 
  been 
  converted 
  into 
  the 
  resinous 
  acid 
  already 
  men- 
  

   tioned. 
  On 
  this 
  account 
  it 
  is 
  better 
  to 
  stop 
  the 
  action 
  before 
  the 
  whole 
  of 
  the 
  

   codeine 
  is 
  decomposed, 
  the 
  quantity 
  left 
  being 
  easily 
  recovered 
  from 
  the 
  solu- 
  

   tion 
  ; 
  but 
  even 
  with 
  the 
  greatest 
  possible 
  care, 
  the 
  formation 
  of 
  a 
  small 
  quantity 
  

   of 
  the 
  resinous 
  acid 
  cannot 
  be 
  avoided, 
  and 
  its 
  presence 
  is 
  always 
  indicated 
  by 
  

   the 
  dark 
  colour 
  which 
  the 
  fluid 
  acquires 
  when 
  saturated 
  by 
  ammonia. 
  

  

  On 
  the 
  addition 
  of 
  ammonia, 
  the 
  nitrocodeine 
  falls 
  in 
  the 
  form 
  of 
  minute 
  

   silvery 
  plates, 
  with 
  a 
  very 
  slight 
  shade 
  of 
  yellow. 
  It 
  is 
  purified 
  by 
  solution 
  in 
  

   hydrochloric 
  acid, 
  boiling 
  with 
  animal 
  charcoaFand 
  a 
  reprecipitation 
  with 
  ammo- 
  

   nia, 
  in 
  order 
  to 
  separate 
  colouring 
  matter 
  and 
  any 
  unchanged 
  codeine 
  which 
  may 
  

   have 
  been 
  precipitated 
  along 
  with 
  the 
  first 
  crystals. 
  The 
  nitrocodeine 
  is 
  then 
  

   crystallised 
  by 
  dissolving 
  in 
  dilute 
  alcohol, 
  or 
  a 
  mixture 
  of 
  alcohol 
  and 
  ether. 
  

  

  Nitrocodeine 
  crystallised 
  from 
  alcohol 
  is 
  deposited 
  in 
  the 
  form 
  of 
  slender 
  

   silky 
  needles 
  of 
  a 
  pale 
  fawn-colour, 
  which, 
  on 
  drying, 
  mat 
  together 
  into 
  a 
  silky 
  

   mass. 
  From 
  alcohol 
  and 
  ether 
  it 
  is 
  obtained 
  by 
  spontaneous 
  evaporation 
  in 
  small 
  

   yellowish 
  crystals, 
  which, 
  under 
  the 
  microscope, 
  are 
  seen 
  to 
  be 
  four-sided 
  prisms, 
  

   terminated 
  by 
  dihedral 
  summits. 
  Nitrocodeine 
  is 
  sparingly 
  soluble 
  in 
  boiling 
  

   water, 
  from 
  which 
  it 
  is 
  deposited 
  in 
  minute 
  crystals 
  on 
  cooling. 
  It 
  dissolves 
  

   abundantly 
  in 
  boiling 
  alcohol, 
  and 
  but 
  sparingly 
  in 
  ether. 
  It 
  is 
  soluble 
  in 
  acids, 
  

   with 
  the 
  formation 
  of 
  salts 
  which 
  are 
  neutral 
  to 
  test-paper, 
  and 
  from 
  which 
  pot- 
  

   ash 
  and 
  ammonia 
  precipitate 
  the 
  base 
  as 
  a 
  crystalline 
  powder. 
  When 
  heated 
  

   carefully, 
  it 
  melts 
  into 
  a 
  yellow 
  fluid, 
  which 
  concretes 
  on 
  cooling 
  into 
  a 
  highly- 
  

   crystalline 
  mass. 
  At 
  a 
  higher 
  temperature, 
  it 
  suddenly 
  decomposes 
  without 
  

   flame, 
  leaving 
  a 
  bulky 
  charcoal. 
  

  

  Its 
  analysis 
  yielded 
  the 
  following 
  results, 
  of 
  which 
  No. 
  1 
  is 
  from 
  the 
  base 
  

   crystallised 
  from 
  the 
  first 
  precipitate 
  by 
  ammonia, 
  before 
  I 
  had 
  observed 
  its 
  ten- 
  

   dency 
  to 
  carry 
  down 
  codeine 
  with 
  it, 
  and 
  which 
  has 
  therefore 
  given 
  a 
  slight 
  ex- 
  

   cess 
  ; 
  the 
  others 
  are 
  from 
  the 
  pure 
  base. 
  Crystallised 
  nitrocodeine 
  is 
  anhydrous. 
  

  

  {5 
  - 
  748 
  grains 
  of 
  nitrocodeine, 
  dried 
  at 
  212°, 
  gave 
  

   13-301 
  ... 
  of 
  carbonic 
  acid, 
  and 
  

   3-128 
  ... 
  of 
  water. 
  

  

  15-523 
  ... 
  of 
  nitrocodeine 
  gave 
  

   12-724 
  ... 
  of 
  carbonic 
  acid, 
  and 
  

   2-887 
  ... 
  water. 
  

  

  