440  Solvents  for  Alkaloids  and  Alkaloidal  Salts.  |  %c^;  S'm- 
alcohol  is  decreased  by  water.  Pure  commercial  methylalcohol  of 
98-99  per  cent,  dissolves  crystallized  alkaloid  morphine  easily  in  the 
proportion  of  1  grm.  to  15  c.c,  while  of  methylalcohol  of  80 
per  cent.  200  c.c.  are  required  for  solution  at  25 0  C. 
Chloroform,  benzol  and  other  liquids  are  separated  out  by  water 
from  the  methylalcoholic  mixture.  The  solubility  of  morphine  salts 
in  methylalcohol  is  increased  by  water. 
For  the  determination  of  morphine  in  dry  preparations,  salts, 
pills,  tablets,  etc.,  the  testing  material  corresponding  to  about  0.3 
grm.  of  morphine,  is  to  be  finely  triturated  in  a  small  mortar  with 
a  sufficient  quantity  of  purified  sharp  sand  under  the  addition  of  an 
excess  of  bicarbonate  of  soda,  carbonate  of  lime  or  magnesia,  etc., 
and  the  mixture  moistened  with  as  little  water  as  possible.  The 
mass  is  allowed  to  dry  out  slowly  in  the  mortar,  exposing  it  to  a 
temperature  of  30-40 0  C,  occasionally  triturating  until  dry.  The 
mixture  is  transferred  to  an  Erlenmeyer  flask,  the  mortar  cleaned 
with  sand  and,  if  necessary,  washed  with  a  few  cubic  centimetres  of 
the  solvent  to  remove  all  traces  of  the  alkaloid  to  the  flask.  About 
30-40  c.c.  of  a  freshly  made  mixture  of  1  vol.  methylalcohol  and 
4  vol.  of  chloroform  is  added  and  the  flask  allowed  to  stand  for 
1  hour,  moderately  but  frequently  shaking  the  same.  A  mixture  of 
1  vol.  methylalcohol  and  4  vol.  of  benzol  can  also  be  used.  The 
liquid  is  filtered  off  through  a  small  filter  and  the  residue  thoroughly 
washed  3-4  times  with  about  10  c.c.  each  time  of  the  solvent.  The 
solution  is  distilled  off,  the  residue  taken  up  with  N/20  sulphuric 
acid  and  the  excess  of  the  acid  titrated  in  the  usual  way,  using 
cochineal  or  methyl  red  as  indicator. 
I  found  mixtures  of  methylalcohol  with  chloroform  or  benzol 
in  the  proportion  1  :  4  to  give  the  most  satisfactory  results,  while, 
however,  the  solvent  power  of  the  liquid  can  be  increased  if  circum- 
stances require  it,  using  as  solvents  pure  commercial  methylacohol 
or  a  mixture  containing  a  higher  percentage  of  it.  At  25 0  C.  methyl- 
alcohol dissolves  U.S. P.  alkaloid  morphine  1  grm.  in  15  c.c,  a  mix- 
ture of  1  vol.  methylalcohol  and  4  vol.  of  chloroform  dissolves  the 
alkaloid  1  :  22  c.c,  1  :  4  vol.  benzol  mixture  dissolves  it  in  the  pro- 
portion 1  :  40  c.c.  whilst  it  is  soluble  in  15  c.c.  of  a  mixture  of  1 :  2 
vol,  chloroform  and  in  25  c.c  of  1  :  2  vol.  benzol.  Mixtures  with 
methylalcohol  cannot  be  used  to  determine  morphine  from  aqueous 
solutions  of  morphine  salts  by  the  shaking  out  process.  For  this  pur- 
pose I  have  used  for  years  as  a  very  convenient  solvent  a  mixture  of 
