Am.  Jour.  Ptaarm. 
July,  1897. 
Notes  on  Opium  Assaying. 
347 
filters  (7  centimetres),  rinsing  the  precipitate  in  the  flask  upon  the 
filter  by  the  use  of  small  portions  of  the  filtrate  ;  wash  the  flask  and 
filter  with  5  c.c.  lime-water,  added  in  portions  of  I  c.c.  After  the 
last  c.c.  drains  off,  set  aside  the  filtrate  and  washings  and  wash  the 
filter  with  5  c.c.  distilled  water  applied  in  portions  of  I  c.c.  ;  after 
draining  press  the  filter  between  bibulous  paper  and  dry  at  50-5  5  0  C. 
to  constant  weight ;  this  weight  is  then  calculated  to  entire  weight 
of  crude  morphine,  and,  subtracted  from  the  weight  of  the  crude 
morphine  as  weighed  on  a  watch-glass,  gives  the  weight  of  the  pure 
morphine,  which  is  then  calculated  to  100  parts  of  opium. 
The  lime-water  solution  of  the  crude  morphine  is  thoroughly 
agitated  after  adding  6  c.c.  ether  (just  enough  to  saturate  the  solu- 
tion, and  for  the  purpose  of  rendering  the  precipitation  of  morphine 
as  complete  as  possible ;  morphine,  particularly  in  presence  of 
foreign  organic  matter,  is  less  soluble  in  water  saturated  with  ether 
than  in  pure  water);  0-150  gramme  ammonium  chloride  is  next 
added  and  agitation  continued  for  ten  minutes  before  setting  aside 
for  10  to  12  hours,  or  over  night  (the  55  c.c.  lime-water  require 
0-140  gramme  ammonium  chloride  for  neutralization,  so  that  there 
is  but  a  slight  excess  added);  filter  through  counterbalanced  filters 
(7  centimetres) ;  rinse  the  flask  several  times  with  a  little  of  the 
filtrate  to  remove  the  remaining  morphine  crystals,  and  then  wash 
the  morphine  and  filter  with  15  c.c.  distilled  water,  applied  in  por- 
tions of  1  c.c;  dry  the  filter  as  above  described,  at  50-550  C,  and 
weigh.  The  combined  weights  of  the  recovered  morphine  and  of 
the  correction  subtracted  from  0-500  gives  the  loss  sustained  in  the 
purification,  and  represents  chiefly  the  morphine  remaining  dis- 
solved in  the  55  c.c.  of  mother-liquor. 
In  looking  over  these  results  it  will  be  seen  that  the  impurity  in 
the  crude  morphine  does  not  depend  so  much  upon  the  length  of 
time  in  which  the  assay  is  allowed  to  stand  as  upon  variations  in 
the  samples  of  opium  (the  assays  standing  15  hours,  for  instance, 
illustrate  this  point);  it  has  previously  been  proven  that  in  any  given 
sample  of  opium  the  impurity  increases  with  the  time  allowed  for 
precipitation. 
Believing  that  the  great  difference  in  the  quantity  of  the  impurity 
was  due  to  variation  in  the  ash-yielding  constituents,  a  number  of 
the  samples  of  opium,  kept  in  the  partly  dried  condition,  were  ex- 
amined. Two  grammes  of  the  sample  were  dried  at  ioo°  C,  then  in- 
