446 
The  Opium  Assay  Method. 
(Am.  Jour.  Pharai. 
t  September.  1894. 
(4)  .  Information  as  to  the  nature  of  the  second  precipitation 
(which  Dr.  Squibb  states  is  probably  meconate  of  calcium),  and  its 
effects,  if  any,  upon  the  yield  of  morphine,  if  the  assay  be  allowed 
to  stand  until  no  further  precipitation  takes  place. 
(5)  Information  as  to  the  error  involved  by  the  solubility  of  the 
morphine  impurities  in  the  lime  water  test  for  the  purity  of 
morphine. 
The  following  remarks  may  be  of  assistance  in  following  up  this 
matter : 
(2),  (3)  and  (4)  will  be  helped  along  by  collecting  the  ethereal 
solutions,  the  mother-liquors,  and  the  several  washings  in  separate 
containers.  To  solve  (3)  the  mother-liquor  and  the  aqueous 
washings  must  be  taken  together,  freed  from  precipitate  (which  is  to 
be  examined  separately  for  morphine),  and  then  shaken  out  with  two 
portions  of  chloroform  of  30  cubic  centimetres  each,  as  first  carried  out 
by  Dieterich  (in  Dieterich's  process  alcohol  was  added  to  the  mother- 
liquor  to  make  about  a  20  per  cent,  alcohol  solution  before  shaking 
with  chloroform),  the  chloroform  solution  is  evaporated  to  dryness, 
the  residue  dissolved  in  2  cubic  centimetres  n.  sulphuric  acid,  adding 
3  cubic  centimetres  water,  and  2  cubic  centimetres  n.  ammonia, 
filtering,  washing  the  filter  and  precipitate  with  a  little  water,  mixing 
the  filtrate  and  washings  with  2  grams  ether  and  0  5  cubic  centi- 
metres n.  ammonia,  and  setting  aside  for  twenty-four  hours  to  allow 
the  crystallization  of  the  morphine ;  by  this  method  he  claims  to 
ascertain  the  entire  quantity  of  morphine  left  in  the  mother-liquor 
varying  from  0.2-0-65  per  cent. 
(5)  can  very  likely  be  solved  by  collecting  the  precipitates 
occurring  in  the  mother-liquor  and  aqueous  washing,  drying,  taking 
a  definite  weight  (0  5  gram)  and  putting  it  through  the  lime-water 
test  ;  the  difference  in  weight  before  and  after  will  indicate  the 
quantity  going  into  solution;  as  a  control  experiment  this  purified 
precipitate  can  be  tested  a  second  time  by  solution  in  lime-water. 
