246  Opium  .-I.v-sy^//.  { ^"'Mry"'iS''>^''"" 
alcohol  (s.  g.  '820)  with  one  measure  of  water  is  to  be  used  instead  of 
water  alone^  for  the  exhaustion,  and  as  this  mixture  is  not  as  good  a 
solvent  for  the  morphia  salts  in  tlie  opium  as  water,  more  of  it  is 
required,  and  the  washing  and  percolating  should  be  carried  to  250  cc. 
=  8*33  fluidounces  of  solution  from  the  10  grams  =  154'32  grains 
of  opium.  The  process  after  exhaustion  is  the  same  as  where  water  is 
used  as  the  solvent. 
Filter  off  the  solution  into  a  tared  or  marked  vessel  and  percolate  the- 
residue  on  the  filter  with  water  dropped  onto  the  edges  of  the  filter  and 
the  residue  until  the  filtrate  measures  about  120  cc  = -4  fluidounces^ 
and  set  this  strong  solution  aside.  Then  return  the  residue  to  the  bottle 
by  means  of  a  very  small  spatula,  without  breaking  or  disturbing  the 
filter  in  the  funnel,  add  30  cc.  =  1  fluidounce  of  water,  shake  well  and 
return  the  magma  to  the  filter.  When  drained  rinse  the  bottle  twice,, 
each  time  with  10  cc.  =  '33  fluidounce  water,  and  pour  the  rinsings 
upon  the  residue.  When  this  has  passed  through,  wash  the  filter  and 
residue  with  20cc.  =  '66  fluidounce  of  water,  applied  drop  by  drop 
around  the  edges  of  the  filter,  and  upon  the  contents.  W^hen  the 
filter  has  drained,  there  should  be  about  70  cc.  =  2'33  fluidounces  of 
the  weaker  solution.  This  (120  +  70  =  )  190  cc.  =  6-33  fluidounces 
of  total  solution  will  practically  exhaust  almost  any  sample  of  10 
grams  =  154*32  grains  of  opium.  But  occasionally  a  particularly 
rich  opium,  or  one  in  coarse  powder,  or  an  originally  moist  opium 
which  has  by  slow  drying  become  hard  and  flinty,  will  require  further 
exhaustion.  In  all  such  cases,^  or  cases  of  doubt,  the  residue  should  be 
again  removed  from  the  filter  and  shaken  with  30  cc.  =  1  fluidounce  of 
water,  and  returned,  and  be  again  washed  as  before.  The  filter  and 
residue  are  now  to  be  dried  until  they  cease  to  lose  weight  at  100°C. 
=  212°F.  If  any  residue  remains  in  the  bottle,  the  bottle  is  also  to 
be  dried  in  an  inverted  position  and  weighed.  Evaporate  the  weaker 
solution  in  a  tared  capsule  of  about  200  cc.  =  6*66  fluidounces  capacity^ 
without  a  stirrer,  on  a  water-bath  until  reduced  to  about  20  grams 
=  309  grains.  Now  add  the  120  cc.  of  stronger  solution,  thereby 
subjecting  this  portion  to  the  shortest  practicable  heating  with  least 
injury  to  the  alkaloid — and  evaporate  the  whole  again  to  about  20 
grams  =  309  grains.  Cool  the  capsule  and  contents,  and  when 
cool  add  5  cc.  ==  '17  fluidounce  of  alcohol  (s.  g.  '820)  and  stir  until  a 
uniform  solution  is  obtained,  and  no  extract  adhering  undissolved  on 
the  capsule.  If  this  solution  should  contain  an  appreciable  precipitate,, 
as  from  rare  specimens  of  opium  it  will,  it  must  be  filtered,  and  the; 
