136        A  Method  for  Assaying  Vinegar  of  Opium.  {AmMirch,f894.rm' 
A  METHOD  FOR  ASSAYING  VINEGAR  OF  OPIUM. 
By  Lyman  F.  Kebler,  Ph.C. 
Having  prepared  a  sample  of  vinegar  of  opium  according  to  the 
directions  of  the  United  States  Pharmacopoeia  of  1890,  I  was  desir- 
ous of  estimating  the  per  cent,  of  morphine  it  contained.  Turning 
to  this  authority  for  instructions,  I  found  the  following  :  "  To  assay 
this  preparation,  transfer  100  cc.  of  it  to  a  small  capsule,  add  4  gm. 
of  precipitated  calcium  carbonate,  or  such  a  quantity  as  will  neu- 
tralize the  free  acid,  and  then  proceed  further  as  directed  under 
Tinctura  Opii!1 
It  is  unnecessary  here  to  go  into  details  concerning  the  method  ; 
suffice  it  to  say  that  the  final  evaporation  is  continued  until  the 
extract  weighs  14  grams. 
According  to  the  process  of  manufacture  and  final  preparation 
for  assay  each  100  cubic  centimeters  contains  20  grams  of  sugar, 
about  8  grams  of  calcium  acetate  and,  making  a  conservative  esti- 
mate that  the  menstruum  will  extract  50  per  cent,  of  the  opium,  or  5 
grams,  giving  us  a  total  of  at  least  33  grams  of  solids.  In  fact, 
when  100  cubic  centimeters  are  evaporated  to  50  grams  the  residue 
becomes  nearly  solid.  Is  the  method  practical  or  even  possible  of 
execution  as  it  stands  ? 
I  have  devised  a  method  which  has  given  me  very  encouraging 
results,  although  it  has  not  been  applied  very  extensively.  In 
triple  assays  of  the  same  sample  the  following  results  were  secured  : 
1220  per  cent.,  1-237  per  cent.,  1-213  per  cent. 
The  method  is  as  follows  :  100  cubic  centimeters  of  the  vinegar 
of  opium  are  rendered  alkaline  with  strong  ammonia  water  (8-10 
cubic  centimeters)  intimately  mixed,  2  cubic  centimeters  of  ether 
added,  to  prevent  frothing,  vigorously  shaken  for  10  minutes  and 
set  aside  for  6  hours  or  overnight.  After  the  alkaloids  are  com- 
pletely precipitated,  pass  through  a  filter  previously  wetted  with 
water  and  wash  the  precipitate  sparingly.  While  the  precipitate  is 
yet  decidedly  moist  transfer  it  into  a  small  capsule  by  means  of  a 
wash  bottle,  using  as  little  water  as  possible.  To  the  contents  of 
the  capsule  add  10  cubic  centimeters  of  5  per  cent,  sulphuric  acid  or 
enough  to  render  acid,  warm  on  the  water-bath,  cool,  allow  to  stand 
one  hour  or  more,  filter  and  wash  the  filter  and  residue  well  with 
distilled  water.    The  exact  process  of  the  Pharmacopoeia  can  be 
