Am.  Jour.  Pharm  \ 
September,  1894.  / 
The  Opium  Assay  Method. 
All 
2-23  per  cent.;  the  correction  by  the  use  of  lime-water  is  stated  to 
be  less  convenient  and  less  accurate  than  by  the  use  of  alcohol,  and 
not  to  be  compared  with  the  ash  method,  but  no  figures  substantiate 
this  statement.  Other  publications  could  be  quoted  showing  the 
impurity  of  the  morphine  by  Squibb's  process,  but  more  appears 
useless  since  the  author  of  the  method  insists  upon  a  necessary 
correction. 
One  other  point  may  be  mentioned  here  concerning  the  influence 
of  an  excess  of  the  morphine  precipitant,  ammonia  :  E  Dieterich, 
in  his  dilute  solutions,  finds  that  the  ammonia  may  be  present  in 
pretty  fair  excess  without  affecting  the  results,  while  Dr.  Squibb  has 
found  that  an  excess  of  ammonia  will  prevent  the  precipitation  of 
the  maximum  quantity  of  morphine,  and  advises  that  the  quantity 
of  ammonia  be  reduced  for  inferior  samples  of  opium. 
This  review  of  the  important  points  in  opium  assaying  is  not 
occasioned  by  the  desire  to  offer  a  new  process,  but  to  assist  in  the 
explanation  of  some  observations  recently  made  while  assaying  two 
samples  of  opium  ;  these  observations,  it  is  hoped,  will  be  confirmed 
by  others  working  in  this  line  of  assay  work ;  the  suggestions 
made  must  not  be  considered  as  reserving  to  the  writer  this  field  of 
work,  but  as  an  invitation  for  the  co-operation  of  all  desiring  to 
have  this  opium  assay  method  perfected. 
The  process  adopted  by  the  pharmacopoeia  of  1890  is  that  of  Dr. 
Squibb  with  the  improvement,  originally  proposed  by  E.  T.  Tesche- 
macher,  of  washing  the  crude  morphine  with  morphiated  alcohol 
(Teschemacher's  morphiated  spirit  contained  some  ammonia, 
whereas  the  pharmacopoeia  uses  simply  alcohol  saturated  with  mor- 
phine) and  with  the  serious  oversight  of  not  giving  a  test  for  the 
purity  of  the  weighed  morphine ;  this  need  not  be  amplified  upon, 
as  the  previous  and  subsequent  parts  of  the  paper  prove  the  neces- 
sity. 
A  sample  of  powdered  opium  was  used  for  the  first  set  of  assays; 
the  pharmacopoeia  process  was  followed  until  the  washing  with 
alcohol  and  ether  was  directed,  so  that  by  simply  washing  with 
water  we  have  the  original  process  of  Dr.  Squibb.  To  determine  if 
it  was  necessary  to  postpone  evaporation  of  the  opium  filtrate  until 
the  second  filtrate  was  ready,  in  Nos.  2  and  3,  the  first  filtrate  was 
used  as  soon  as  obtained,  and  the  second  filtrate  added  to  the  con- 
centrated first  filtrate;  the  results  would  indicate  that  no  loss  of 
