344 
Notes  on  Opium  Assaying. 
( A_m.  Jour.  Pharm. 
I       July,  1897. 
tities  of  moist  and  perfectly  dry  opium  are,  however,  to  be  calculated 
from  the  loss  sustained  in  drying.  This  procedure  enables  a  uni- 
form sample  from  which  concordant  results  can  be  obtained  when 
assayed  at  some  subsequent  time,  and  calculated  to  opium  contain- 
ing the  original  quantity  of  moisture. 
In  powdering  the  partly  dried  opium  in  glass  or  iron  mortars, 
electricity  is  developed  and  there  is  difficulty  in  avoiding  loss  from 
particles  being  thrown  about;  this  phenomenon  was  not  noticed 
when  using  wedgewood  mortars. 
The  crude  morphine  obtained  by  the  U.S. P.  process  was  first 
weighed  on  counterbalanced  filters  and  again  after  transferring  to  a 
watch-glass ;  it  will  be  noticed  that  there  is,  in  the  majority  of  cases, 
a  difference  due  to  but  a  few  milligrammes.  In  transferring,  a  camel's 
hair  pencil  has  to  be  used  with  some  force  to  remove  all  of  the 
morphine  from  the  filter,  and  this  generally  results  in  loosening  some 
of  the  fibres  of  the  paper,  which  then  contaminate  the  morphine. 
The  purity  of  the  morphine  is  an  important  matter  ;  for  its  deter- 
mination, several  methods  are  in  use,  as  the  solubility  in  lime-water, 
the  solubility  in  alcohol  and  the  ash  method.  If  we  look  into  the 
question  of  the  impurities  which  can  be  present  in  crude  morphine, 
there  may  be  other  opium  alkaloids,  particularly  narcotine,  sulphates 
of  calcium  and  strontium,  phosphates  of  calcium  and  magnesium, 
meconates  of  potassium,  calcium  and  magnesium,  and  generally  a 
little  coloring  matter;  this  does  not  exhaust  the  list  of  substances 
that  are  possible,  or  even  of  those  that  have  been  found,  but  it  is 
sufficiently  comprehensive  to  allow  some  reflections  upon  the  prob- 
able accuracy  of  these  several  methods  of  correction.  The  alcohol 
method  will  give  as  morphine  everything  soluble  in  alcohol,  hence, 
narcotine  and  coloring  matter  will  be  returned  as  morphine ;  it 
reveals  the  ash-yielding  constituents,  particularly  if  absolute  alcohol 
be  used;  and  if,  after  weighing  the  insoluble  matter,  this  be  ignited 
and  weighed,  the  factor  for  calculating  ash  into  impurity  can  be 
obtained  and  compared  with  the  present  factor,  which  is  simply 
theoretical.  The  objection  to  the  alcohol  method  has  been  the 
expense  and  the  difficulty  of  filtering  out  the  very  fine  precipitate. 
The  lime-water  method  was  the  one  first  proposed  for  ascertaining 
the  purity  of  the  morphine  and  was  particularly  recommended  as  a 
means  of  detecting  narcotine.  After  Stillwell  proposed  the  alcohol 
method  Squibb,  in  a  series  of  experiments,  obtained  almost  identical 
