316  Acetic  Acid  in  Extracting  Drugs.  {Am-/^iF£rrm- 
with  the  first  portion,  and  the  whole  of  the  chloroform  boiled  off 
in  the  bath.  If  the  alcohol  be  omitted  from  the  residue  before  this 
second  washing,  an  emulsion  is  almost  certain.  The  apparent 
excess  of  chloroform  is  necessary  not  so  much  for  the  washing  out 
of  the  alkaloids  as  to  avoid  emulsion.  The  residue  is  run  off  from 
the  separator  into  a  beaker,  is  well  stirred,  five  or  six  drops  is  trans- 
ferred by  the  stirrer  to  the  end  of  a  strip  of  bibulous  paper  and 
dried  on  the  bath.  This,  when  taken  into  the  mouth  and  well 
chewed,  should  be  bitter-free. 
The  chloroform  solution,  when  the  chloroform,  ammonia  and 
alcohol  are  boiled  off,  leaves  a  very  dark  residue  in  the  flask  usually 
weighing  about  I  gramme.  This  is  dissolved  in  20  c.c.  of  chloro- 
form by  shaking,  and  10  c.c.  of  water  added  and  shaken.  Then 
20  c.c.  of  decinormal  sulphuric  acid  is  run  into  the  flask  from  a 
burette,  shaken  for  five  minutes  and  poured  into  a  separator.  When 
the  liquids  separate  the  lower,  chloroform  part,  is  drawn  off  into 
the  flask  again  and  the  upper  watery  portion  into  a  beaker.  Then 
10  c.c.  more  of  decinormal  acid  and  5  c.c.  of  water  are  added  to  the 
contents  of  the  flask,  the  whole  well  shaken  for  five  minutes,  returned 
to  the  separator,  the  flask  rinsed  in  with  5  c.c.  of  water,  and  the 
whole  well  shaken  in  the  separator.  When  the  liquids  separate,  the 
lower  chloroform  residue  is  drawn  off  into  a  small  beaker,  and  the 
watery  portion  into  the  beaker  with  the  first  watery  portion.  The 
chloroform  residue  is  now  tested  by  drying  upon  bibulous  paper,  as 
before  described,  and  if  found  bitter-free  it  is  thrown  away,  but  if 
still  bitter  to  the  taste  it  is  again  washed. 
To  the  acid-watery  solution  in  the  larger  beaker  30  c.c.  of  deci- 
normal potassium  hydrate  is  added  with  stirring,  the  whole  trans- 
ferred to  the  separator,  25  c.c.  of  ether  (96  per  cent.)  added  and  the 
mixture  well  shaken.  When  the  liquids  separate,  5  c.c.  of  decinor- 
mal alkali  is  poured  into  the  separator,  producing  a  large  precipitate 
that  is  redissolved  when  shaken.  This  addition  of  decinormal  al- 
kali is  repeated  until  one  addition  fails  to  produce  cloudiness.  Then 
the  mixture  is  shaken  for  five  minutes,  allowed  to  separate  and  the 
lower  watery  liquid  is  drawn  off  into  the  larger  beaker.  The  ether 
solution  cannot  be  drawn  off  clean  through  the  stopcock,  but  can 
be  poured  off  through  the  mouth  of  the  separator,  to  the  last  drop, 
into  a  tared  beaker,  leaving  a  little  emulsion  and  water  drops  be- 
hind.   To  these  residues  in  the  separator  20  c.c.  of  ether  is  added 
