Am.  Jonr.  Pharm  \ 
May,  1882.  J 
Opium  Assay. 
247 
filter  be  carefully  washed  through.  Then  the  filtrate  must  be  evapo- 
rated to  25  or  30  grams.  Pour  the  concentrated  solution  from  the 
capsule  into  a  tared  flask  of  about  100  cc.  =  3*33  fluidounces  capacity/ 
and  rinse  the  capsule  into  the  flask  with  about  5  cc.  of  water  used  in 
successive  portions.  Then^  if  the  solution  has  not  required  filtering, 
add  5  cc.  =  '17  fluidounce  more  of  alcohol.  If  it  has  been  filtered 
and  evaporated  add  10  cc.  =  '33  fluidounce  of  alcohol  and  shake 
well.    Then  add  30  cc.  =  1  fluidounce  of  ether,  and  again  shake  well. 
This  s.haking  together  first  of  the  watery  solution  and  alcohol  causes 
the  alcohol  to  combine  with  the  water  before  the  ether  is  added.  The 
ether  then  added,  the  second  shaking  saturates  the  watery  solution  and 
combined  alcohol  with  ether,  and  then  the  mixture  is  ready  for  the 
precipitation  of  the  alkaloid  under  the  most  favorable  condition. 
Add  now  4  cc.  =  '133  fluidounce  of  solution  of  ammonia,  of  10  per 
cent.  (s.  g.  '960)  and  shake  the  flask  vigorously  until  the  crystals 
begin  to  separate.  Then  set  the  flask  aside  in  a  cool  place  for  12  hours, 
that  the  crystallization  may  be  completed. 
This  shaking  secures  the  crystallization  in  very  small  crystals,  so  as 
to  be  easily  washed  and  not  adherent  to  the  flask.  The  crystals  will 
then  be  found  partly  at  the  bottom  of  the  flask  and  partly  in  the  ether 
at  the  surface  of  the  lower  dark,  watery  solution.  If  the  shaking  be 
frequent  and  vigorous,  two  or  three  hours'  time  will  be  sufficient  to 
complete  the  crystallization,  or  if  it  be  continuous,  half  an  hour  will 
be  sufficient,  but  as  a  general  rule  it  is  better  to  allow  the  flask  to  stand 
over  night.  When  there  is  no  haste,  a  very  good  method  is  to  mace- 
rate the  opium  over  one  night — prepare  the  solution  during  the  day, 
and  allow  the  second  night  for  completing  the  crystallization.  Then 
finish  the  assay  on  the  second  day.  If  there  be  haste,  however,  the 
assay  may  be  completed  iu  one  day  by  the  vigorous  and  frequent  shak- 
ing above  indicated.  Indeed,  maceration  without  agitation  or  percola- 
tion is  comparatively  useless  after  the  powder  to  be  exhausted  becomes 
completely  saturated ;  and  crystallization  in  a  dense  liquid  like  this  is 
very  slow  if  convection  or  liquid  diffusion  be  depended  upon ;  but 
agitation  brings  all  parts  of  the  liquid  so  thoroughly  in  intimate  con- 
tact, that  an  half-hours'  vigorous  agitation  must  be  fully  equal  to 
twelve  hour's  standing  without  agitation. 
Pour  off*  the  ethereal  stratum  from  the  flask,  as  closely  as  possible, 
onto  a  tared  filter  of  about  10  centimeters  =  4  inches  in  diameter, 
well  wetted  with  ether.  Add  20  cc.  =  '66  fluidounce  of  ether  to  the 
contents  of  the  flask,  rinse  round  without  shaking,  and  again  pour  off" 
the  ethereal  stratum  as  closely  as  possible  onto  the  filter,  keeping  the 
funnel  covered.    When  the  ethereal  solution  is  nearly  all  through, 
