INVESTIGATION  01?  POISONOUS  ALKALOIDS. 
355 
2.  Pure  or  alkaline  water  does  not  remove  the  bases  thus 
dissolved ;  but, 
3.  It  separates  them  completely  when  it  has  been  previously 
acidulated  with  hydrochloric  acid,  the  organic  chlorides  which 
are  formed  being  almost  insoluble  in  amylic  alcohol. 
The  following  is  the  method  of  operation  : — Reduce  the  sus- 
pected matter  into  a  pulp  with  water,  slightly  acidulated  with 
hydrochloric  acid.  Then  leave  it  to  digest  for  two  hours  at  a 
temperature  of  from  60°  to  80°  C.  ;  pass  a  wet  cloth  over  it, 
and  exhaust  the  residue  with  acidulated  warm  water,  and  after 
mixing  the  liquids  add  a  slight  excess  of  ammonia  ;  concentrate 
over  an  open  fire,  and  dry  in  a  water-bath.  After  exhausting 
the  residue  with  warm  amylic  alcohol,  filter  it  through  a  paper 
previously  moistened  with  amylic  alcohol. 
The  filtered  product  is  generally  mixed  with  fatty  or  coloring 
matters,  which  must  be  eliminated  by  quickly  shaking  up  the 
liquid  with  almost  boiling  water,  acidulated  with  a  little  hydro- 
chloric acid.  The  amylic  alcohol  then  yields  the  alkaloid,  while 
it  retains  the  greater  part  of  the  fatty  or  coloring  matters. 
Draw  it  off  by  a  small  india-rubber  pipe,*  then  shake  the  warm 
aqueous  liquid  with  a  fresh  supply  of  amylic  alcohol,  and  the 
foreign  matters  will  be  got  rid  of  without  much  trouble,  so 
that  the  acid  solution  containing  the  alkaloid  in  the  state  of 
hydrochlorate  is  completely  decolorised.  Slightly  concentrate 
this  solution,  add  a  slight  excess  of  ammonia,  and  then  amylic 
alcohol,  which  after  repeated  shakings  takes  up  the  alkaloid. 
After  duly  separating  the  two  layers  of  liquid,  withdraw  the 
upper  one,  containing  alcohol  and  alkaloid,  and  attack  the 
lower  layer  by  adding  a  fresh  portion  of  warm  amylic  alcohol  ; 
then  mix  the  alcoholic  liquids  and  evaporate  them  by  a  water- 
bath,  and  the  residue  is  generally  pure  alkaloid.  If  it  has 
preserved  its  color,  the  operator  need  not  continue  the  opera- 
tions just  described ;  that  is  to  say,  dissolve  in  hydrochloric 
acid,  shake  with  amylic  alcohol,  and  draw  off  by  a  small  pipe ; 
supersaturate  with  ammonia,  shake  with  amylic  alcohol,  and 
eliminate  it  by  evaporation  in  a  water-bath. 
*  This  precaution  is  essential  to  prevent  the  inhalation  of  the  vapors  of 
amylic  alcohol. 
