^  Fe"b  Tm^**' 1        MorpJiiometrical  Process,  etc,  65 
ON  A  MORPHIOiVIETRIC  PROCESS  FOR  THE  PHARMACOPCEIA. 
By  William  Procter,  Jr. 
The  question,  "  What  is  the  best  process  for  assaying  opium  to 
.determine  its  morphia  strength,  suited  for  adoption  into  the  United 
States  Pharmacopoeia?"  was  accepted  by  the  writer  at  the  Chicago 
meeting. 
Reflection  on  the  query  suggests  that  it  is  not  so  much  what  is  the 
best  analytical  process,  as  to  decide  what  process  is  best  suited  for 
practical  use  by  druggists  and  pharmaceutists  in  determining  the 
morphia  value  of  opium  for  the  purposes  of  the  Pharmacopoeia.  Those 
who  take  the  view  that  the  process  should  embody  the  nicest  and  most 
refined  manipulations  of  the  analytical  laboratory,  may  not  accept 
this  view,  but  when  it  is  understood  that  a  large  majority  of  the  per- 
sons needing  its  use  are  not  analytical  chemists,  it  is  believed  that 
simplicity,  united  to  a  fair  degree  of  accuracy,  is  more  available  than 
extreme  accuracy,  beyond  the  reach  of  most  apothecaries,  applied  in 
a  complex  process. 
So  many  able  chemists  have  published  processes,  some  of  which  are 
well  known  in  connection  with  their  names,  as  Staples'  process, 
Mohr's,  Guillermond's,  &c.,  that  the  ground  would  appear  to  be  well 
examined.  The  process  of  Staples  is  that  of  the  United  States  Phar- 
macopoeia. Its  point  is  in  the  employment  of  alcohol  to  retain  the 
coloring  matter  in  solution  during  the  precipitation  of  the  morphia, 
and  in  mixing  the  ammoniacal  precipitant  also  with  alcohol.  The 
process  of  Mohr  avails  itself  of  the  selective  power  of  boiling  lime- 
water  to  reject  narcotina,  and  retain  morphia  in  solution.  Both  of 
these  processes  extract  the  opium  with  cold  water.  Guillermond's 
process  employs  alcohol  of  71  per  cent,  to  extract  the  opium,  which 
is  then  precipitated  by  ammonia.  The  precipitate,  as  in  Staples' 
process,  contains  narcotina. 
Ohe  difficulty  in  extracting  the  portion  of  opium  soluble  in  water 
is  the  caoutchoucoid  matter  which  tends  to  resist  its  solvent  action. 
The  idea  of  employing  benzine  or  light  coal  oil  to  remove  this,  as 
well  as  the  free  narcotina,  has  been  suggested  by  Albert  E.  Ebert 
for  another  purpose,  and  has  been  used  by  Dr.  Fluckiger  in  his  ex- 
amination of  opium.  It  is  believed  that  the  preliminary  use  of  this 
solvent  in  opium  assays  may  be  usefully  adopted. 
Believing  that  the  best  way  to  arrive  at  a  solution  of  the  query  was 
5 
