582 
Esthnation  of  Alkaloids  in  Belladonna  Leaves. 
f  Am.  Jour.  Pharm. 
t       Nov.,  1885. 
ESTIMATION  OF  THE  ALKALOIDS  IN  THE  LEAVES 
OF  ATEOPA  BELLADONNA.! 
By  Pkofessor  Wyndham  Dunstan  and  Francis  Hansom. 
In  a  previous  communication  to  the  Pharmaceutical  Society,  which 
formed  the  first  part  of  this  inquiry,  we  described  a  simple  process  for 
the  estimation  of  the  alkaloids  in  the  root  of  the  Atropa  Belladonna^ 
which  consisted  in  extracting  the  root  with  a  mixture  of  chloroform 
and  alcohol,  and  removing  the  alkaloidal  salts  from  this  mixture  by 
agitating  it  with  water.  From^lthe  aqueous  solution  the  alkaloids  are 
liberated  by  ammonia  and  removed  by  chloroform.  That  the  alkaloidal 
residue  obtained  in  this  way  consisted  of  pure  alkaloid  was  proved  by 
the  precipitation  of  a  certain  quantity  in  the  form  of  the  periodides  and 
by  the  recovery  of  the  original  quantity  of  the  free  bases  from  these 
salts.  It  was  experimentally  shown  (1)  that  the  root  was  entirely 
exhausted  of  alkaloid  by  the  solvent;  (2)  that  no  loss  of  alkaloid 
occurred  during  the  subsequent  purification  of  the  liquid ;  (3)  that  the 
final  residue  was  wholly  alkaloidal.  In  every  similar  inquiry  it  is 
necessary  that  these  three  points  be  individually  established  by  experi- 
ment. The  foregoing  process  has  since  been  employed  by  other  work- 
ers  for  the  purpose  of  estimating  the  alkaloidal  value  of  belladonna 
root.  In  continuing  the  investigation  with  the  aid  of  a  further  grant 
from  the  Conference,  we  have  sought,  in  the  first  2>lace,  to  devise  a 
reliable  and  convenient  process  whereby  the  alkaloids  could  be  isolated 
without  loss  in  a  pure  state  from  the  leaves  of  the  Atropa  Belladonna^ 
For  this  purpose  the  method  which  had  proved  so  successful  with  the 
root  of  the  plant  had  to  be  considerably  modified.  Great  difficulties 
were  experienced  in  the  extraction  of  the  whole  of  the  alkaloid  from 
the  leaves,  and'  in  the  subsequent  separation  of  the  alkaloid  from  the 
mixture  of  fat  and  chlorophyll.  Without  describing  in  detail  the 
results  of  the  numerous  experiments  which  were  instituted,  the  fol- 
lowing conclusions  may  be  summarized.  In  extracting  the  leaves 
absolute  alcohol  alone  is  to  be  preferred  to  a  mixture  of  alcohol  and 
chloroform.  By  continuous  percolation  with  boiling  absolute  alcohol 
the  leaves  can  be  freed  from  every  trace  of  alkaloid.  This  was  proved 
by  showing  that  the  leaves  after  this  treatment  yielded  no  alkaloid 
either  when  boiled  with  dilute  hydrochloric  acid,  or  when  mixed  with 
^  Read  before  the  British  Pharmaceutical  ConfereKce.. 
