AmNJo0^r-x8P76arm-}       Assay  of  Opium  for  Morphia.  507 
necessitates  long  applications  of  heat  for  evaporating,  which  tends  to 
destroy  the  morphia.  The  meconic  acid  present  is  also  split  up  and 
forms  other  colored  matters,  which  help  to  make  the  morphia  impure. 
2.  The  animal  charcoal  used  retains  alkaloid. 
3.  If  the  alcoholic  solution  be  evaporated,  the  results  are  high,  as  it 
contains  coloring  matter  and  resin. 
4.  If  washed  with  alcohol  (dilute)  and  water,  morphia  is  dissolved 
away. 
5.  No  mention  is  made  of  the  morphia  lost  in  precipitating. 
It  is,  however,  the  best  of  those  processes  in  which  water  is  used 
alone  as  a  solvent,  and  by  slightly  modifying,  as  follows,  can  be  made 
to  produce  very  good  results. 
The  solution  from  which  the  morphia  has  been  precipitated  by  am- 
monia should  either  be  measured  and  allowance  made  for  the  morphia 
dissolved,  or  it  should  be  treated  with  amylic  alcohol  as  before 
described. 
1.  The  opium  should  be  first  treated  with  benzin,  as  by  that  means 
less  water  is  required  for  exhaustion,  and  the  marc  should  be  perco- 
lated, not  macerated. 
2.  The  use  of  animal  charcoal  should  be  precluded,  the  morphia 
being  purified  by  being  dissolved  in  acid,  made  neutral,  filtered,  and 
then  adding  ammonia. 
The  process  devised  by  Merck,  consists  in  exhausting  with  water, 
and  precipitating  by  means  of  carbonate  of  soda  and  heat.  The  pre- 
cipitate is  dissolved  in  acetic  acid  and  made  neutral,  filtered,  and  excess 
of  ammonia  added. 
This  process  has  the  following  objections  : 
1.  The  alkali  and  heat  cause  destruction  of  the  morphia. 
2.  No  account  is  taken  of  the  loss  by  precipitation.  It  has  the 
advantage  that  the  method  of  purification  proposed  avoids  loss  of 
morphia. 
Guillermond's  process  consists  in  treating  opium  with  alcohol,  and 
adding  ammonia  to  the  alcoholic  solution.  The  morphia  so  produced 
is  very  pure,  but  as  a  large  quantity  remains  dissolved  in  the  alcohol, 
it  is  only  a  comparative  method.  The  precipiate  also  contains  meco- 
nate  of  calcium. 
The  process  of  Staples,  which  consists  in  adding  alcohol  to  concen- 
trated infusion  of  opium,  then  after  filtration  mixing  more  alcohol  and 
ammonia,  is  also  open  to  the  same  objections  as  the  last. 
