Am.  Jour.  Pharm."! 
September,  1894.  / 
The  Opium  Assay  Method. 
443 
cases  the  very  last  portions  gave  the  test  for  meconie  acid.  The 
washing  with  alcohol  is  an  improvement,  since  in  every  instance 
color  was  removed  from  the  morphine ;  about  fifteen  cubic  centi- 
metres of  the  morphiated  alcohol  were  used  to  obtain  a  practically 
colorless  filtrate,  in  No.  4  about  thirty  cubic  centimetres  were  used 
and  then  the  alcohol  was  still  colored  (hence,  in  this  process,  wash- 
ing the  morphine  with  alcohol  cannot  replace  the  alcohol  in  the 
mother-liquor);  the  filters  in  the  assays,  excepting  Nos.  3  and  4, 
were  hardly  stained  after  taking  off  the  pale  yellow  morphine,  which 
speaks  well  for  this  improvement  of  Squibb's  process.  The  alcohol 
is  here  shown  to  be  absolutely  necessary  ;  the  appearance  of  the 
ethereal  layer  collected  with  the  mother-liquor  was,  in  ail  cases 
where  alcohol  was  used,  of  a  dark  brown  color ;  in  the  one  case 
where  alcohol  was  not  used,  it  was  only  light  yellow,  so  that  the 
alcohol  not  only  keeps  the  coloring  matter  dissolved  in  aqueous 
solution,  but  causes  considerable  of  it  to  pass  into  the  ethereal 
solution. 
The  use  of  the  morphiated  alcohol  is  sometimes  stated  to  be  only 
for  the  mechanical  displacement  of  the  water  held  by  the  morphine 
crystals,  but  this  is  not  believed  to  be  going  far  enough  since  we 
have  here  a  means  of  getting  rid  of  one  of  the  impurities  of  the 
morphine  without  causing  any  appreciable  error  ;  the  best  method  of 
applying  this  alcoholic  morphine  solution  is  to  distribute  two  to 
three  cubic  centimetres  at  a  time  over  the  filter  and  precipitate  and 
then  covering  with  a  watch- glass  until  dropping  ceases,  when  an- 
other portion  is  added  ;  the  use  of  fifteen  cubic  centimetres  cannot 
occasion  a  loss  amounting  to  one  cubic  centimetre  if  carried  out  as 
directed.  Considering  the  error  possible  by  the  evaporation  of  the 
alcohol  with  separation  of  morphine  on  the  inner  filter,  which  will 
then  be  weighed  as  though  belonging  to  the  assay,  the  following 
figures  will  give  information  :  The  pharmacopoeia  gives  the  solu- 
bility of  morphine  in  alcohol  as  1:300;  E.  Dieterich,  1:166.  Dr. 
Squibb  (in  speaking  of  the  purification  of  crude  morphine  by  Still- 
well's  procedure,  says  0-5  morphine  will  require  about  seventy-five 
cubic  centimetres  alcohol  to  dissolve  it  and  hold  it  in  solution  when 
cold)  makes  the  solubility  in  alcohol  even  greater  ;  taking  the  last 
as  1:150,  the  fifteen  cubic  centimetres  (approximately  twelve  grams) 
will  hold  in  solution  about  0  080  morphine,  so  that  the  largest  pos- 
sible error  that  could  be  incurred  by  the  evaporation  of  all  the  alco- 
