566  Water  of  Crystallization  in  Morphine,  {^"'nov.^isss^''""' 
THE  AMOUNT  OF  WATER  OF  CRYSTALLIZATION  IN 
MORPHINE.! 
By  0.  Hesse. 
Until  recently  it  was  generally  considered  that  morphine  dried  at 
100°  C.  had  the  composition  represented  by  the  formula  Ci^HjgNOg 
+  H2O,  notwithstanding  that  several  years  since  I  pointed  out  that 
at  this  temperature  the  alkaloid  would  lose  its  water  of  crystalliza- 
tion. Subsequently,  however,  Dott  showed  ^  that  morphine  is  already 
anhydrous  at  90°  C.  Dieterich  has  also  recently  found  ^  that  the 
above  formula  does  not  hold  good  for  the  alkaloid  dried  at  100°  C, 
and  is  equally  inapplicable  to  the  air-dried  substance,  since,  instead  of 
the  calculated  amount  of  water  (5*94  per  cent.),  6*39  per  cent,  was 
obtained.  Dieterich,  however,  only  carried  out  one  experiment,  so 
that  control  was  wanting.  Meanwhile  it  must  be  remembered  that 
Dott  also  found  more  water,  and  upon  the  basis  of  his  experiments 
represented  the  air-dried  alkaloid  by  the  formula  8(Ci7Hi9N03)  + 
9H2O,  which  requires  6*62  per  cent,  of  water,  whilst  the  average  of 
that  found  was  6*56  per  cent. 
Against  this  average  value,  however,  some  objection  can  be  raised. 
In  the  first  place  it  may  be  observed  that  morphine  frequently  encloses 
small  quantities  of  the  solvent  from  which  it  has  been  separated,  and 
which  under  ordinary  conditions  escapes  with  difficulty  or  not  at  all. 
In  order  therefore  to  render  this  accident  harmless  in  the  determina- 
tion of  the  water  it  is  necessary  to  rub  the  crystals  to  a  fine  powder, 
which  Dott  does  not  appear  to  have  done,  so  far  as  can  be  inferred 
from  his  communication. 
The  last  two  quantities  given — 6*22  and  6  "35  percent. — correspond 
very  well  with  the  formula  hitherto  accepted,  but  differ  considerably 
from  the  quantity  calculated  for  the  more  complex  formula  and  also 
that  found  by  Dieterich.  As  Dieterich  found  practically  more 
water  than  Dott,  it  seemed  to  me  that  an  occasion  presented  itself  to 
me  to  repeat  my  determinations  on  the  point.  A  freshly  precipitated 
preparation,  operated  upon  in  accordance  with  the  previously  men- 
tioned facts,  gave,  after  forty-eight  hours,  water  of  crystallization 
^  From  the  Pharmaceutische  Zeitung,  August  11. — Reprinted  from  Pharm.  Jour- 
nal and  Transactions,  August  25,  p.  148 . 
^  Pharm.  Journal,  [3],  xviii.,  701. 
3  Pharm.  Centralhalle,  1888,  p.  317. 
