434 
The  Opium  Assay  Method. 
( A.m.  Jour.  Pharm. 
I  September,  1894. 
(intended)  complete  extraction,  although  this  is  not  even  attained 
by  the  process  of  Squibb,  as  he  himself  calls  attention  to  the 
color  and  the  bitter  taste  imparted  to  water  after  extracting  the 
opium  with  thirty-two  parts  of  water. 
A  second  objection  to  these  methods  is  that  the  morphine  is  pre- 
cipitated from  a  too  dilute  solution,  the  morphine  remaining  in 
solution  depending  upon  the  quantity  of  the  mother-liquor,  and 
claims  as  a  special  value  of  his  method  the  precipitation  from  a  con- 
centrated solution.  Dieterich,  by  a  method  to  be  given  later,  claims 
to  have  determined  the  morphine  left  in  the  mother-liquor  of  his 
process,  and  states  it  to  vary  from  0-2  to  0  65  per  cent.,  depending 
upon  the  kind  of  opium  and  the  solvent  used  to  remove  narcotine, 
etc.  (using  ether  as  this  liquid  0-44-0-66  per  cent.,  using  acetic  ether 
0-18-0-57  per  cent.);  upon  the  strength  of  these  determinations 
Dieterich  announces  that  the  aqueous  solution  (1:8)  from  which  he 
precipitates  the  morphine  is  a  poorer  solvent  for  morphine  than  an 
aqueous  solution  containing  the  same  quantity  of  ammonia  ;  this 
favorable  result  he  believes  to  be  due  to  the  presence  of  the  extract- 
ive matter  of  the  opium  which  facilitates  the  precipitation  of  the 
morphine. 
In  Squibb's  process  the  aqueous  extract,  concentrated  to  twice 
the  weight  of  the  opium,  is  mixed  with  half  its  weight  of  alcohol, 
making  about  a  30  per  cent,  alcohol  solution,  although  the  subse- 
quent addition  of  ether  removes  part  of  the  alcohol,  and  leaves  a 
more  dilute  alcoholic  liquid  saturated  with  ether;  the  alcohol  is 
absolutely  necessary  in  this  process  to  keep  the  large  amount  of 
coloring  matter  from  precipitating  with  the  morphine.  Dr.  Squibb 
quotes  that  an  investigator,  probably  P.  Carles,  determined  that  a 
33  per  cent,  alcohol  had  a  low  solvent  power  for  morphine,  and 
repeatedly  calls  attention  to  the  fact  that  his  process  indicates  all  of 
the  morphine  except  that  remaining  in  the  mother-liquor,  which,  of 
course,  constitutes  a  saturated  solution;  no  attempt  has  been  made 
to  ascertain  what  amount  is  retained  in  the  mother-liquor,  but  it  is 
stated  that  the  mother-liquor  has  a  somewhat  variable  solvent  power 
for  morphine,  greater  for  morphine  in  the  nascent  state  than  for 
morphine  added  to  it;  the  solvent  power  is  greater  than  that  of  a 
clean  solution  of  alcohol  and  water  made  to  represent  the  mother- 
liquor;  the  precipitation  of  coloring  and  other  matter  which  may 
finally  be  weighed  with  the  morphine  will  not  more  than  counter- 
