AmNJo°Ci8P76arm*}       Assay  of  Opium  for  Morphia.  505 
be  present  the  action  is  more  marked,  whilst  with  alkalies  the  action  is 
stronger  still,  and  a  flocculent-brown  precipitate  is  soon  formed.  The 
following  experiments  may  prove  useful  as  showing  that,  provided  allow- 
ance be  made  for  the  solubility  of  morphia  in  water,  the  precipitate  is 
complete  : 
I  took  '583  gr.  of  pure  morphia,  dissolved  in  acid  and  treated  with 
slight  excess  of  ammonia.  After  twenty-four  hours  the  precipitate  was 
collected,  dried  and  weighed  ;  it  gave  '552  gr.  of  morphia;  the  wash 
water  was  30  cc,  equivalent  to  "030  of  morphia,  thus  making  the  total 
•582  gr. 
•113  gr.  of  pure  morphia,  treated  as  above,  gave  *ioo  gr.  of  precipi- 
tate and  13  cc.  of  liquid,  which  would  correspond  to  '013  gr.  of  mor- 
phia, thus  making  the  total  '113. 
Ammonia  added  to  tincture  of  opium,  or  to  an  alcoholic  solution  of 
the  precipitate  produced  by  ammonia,  produces  a  precipitate  of  part 
of  the  morphia  and  part  of  the  narcotina  present,  the  amount  remaining 
in  solution  depending  on  the  strength  and  quantity  of  the  alcoholic 
liquid  ;  if  the  liquid  be  tincture  of  opium,  then  the  precipitate  contains 
meconate  of  calcium. 
Part  II. — In  commencing  my  criticisms  on  the  processes  in  use  I 
will  begin  with  the  most  simple,  and  then  proceed  to  describe  others 
more  complicated. 
Arnoldi's  process  ("  Jour.  Chem.  Soc,"  1874).  Opium  is  ex- 
hausted with  water,  the  solution  treated  with  animal  charcoal,  concen- 
trated and  precipitated  by  ammonia.  The  precipitate  is  collected,  dried 
and  weighed  as  impure  morphia.  The  author  states  that  good  opium 
should  yield  above  14  per  cent. 
The  objections  are  : 
1.  That  the  morphia  is  not  entirely  precipitated  by  ammonia. 
2.  That  the  precipitate,  though  called  impure  morphia,  does  not 
contain  much  more  than  half  its  weight  of  ammonia. 
3.  The  use  of  animal  charcoal  ensures  loss  of  alkaloid,  as  the  under- 
mentioned experiment  will  prove  : 
2*435  grams  of  pure  morphia  were  dissolved  in  acid  and  boiled  with 
animal  charcoal.  The  morphia  was  precipitated,  and  the  amount 
obtained,  allowing  for  loss  by  solubility,  was  2*405  gr.,  thus  indicating 
a  loss  of  over  1  per  cent. 
A  second  experiment  showed  even  a  higher  loss. 
