•Am  jour  Pharm.)      Estimation  of  Alkaloids  in  Belladonna  Leaves.  583 
Nov.,  iSso.       i  ^ 
lime  and  extracted  with  chloroform.  From  the  extract  which  is 
obtained  by  evaporating  the  alcoholic  liquid  it  is  practically  impossible 
to  wholly  extract  the  alkaloid  by  means  of  water  or  even  dilute  hydro- 
chloric acid.  After  many  successive  treatments  with  dilute  hydro- 
chloric acid  considerable  quantities  of  alkaloid  still  remain  associated 
with  the  chlorophyll  and  fat,  and  even  after  several  days'  digestion,  a 
solution  of  iodine  in  potassium  iodide  indicated  the  presence  of  more 
than  traces  of  alkaloid.  We  have  found  that  by  far  the  best  method 
of  separating  the  whole  of  the  atropine  and  hyoscyamine  from  the 
alcoholic  liquid  is  to  dilute  it  considerably  with  water  acidulated  with 
hydrochloric  acid,  and  then  to  remove  the  chlorophyll  and  fat  by 
repeatedly  agitating  it  with  chloroform.  In  this  way  an  acid  solution 
of  the  alkaloids  is  prepared,  from  which  the  free  bases  may  be  readily 
obtained  pure  by  adding  excess  of  ammonia  and  extracting  the  alka- 
line liquid  with  chloroform.  It  may  here  be  observed  that  chloroform 
is  by  far  the  best  solvent  for  extracting  atropine  and  hyoscyamine 
from  an  alkaline  liquid.  Ether,  quite  apart  from  manipulative  diffi- 
culty, is  required  in  much  larger  quantity  to  effect  the  same  result. 
It  now  remained  to  prove  that  the  alkaloidal  residue  which  was 
obtained  by  evaporating  the  chloroform  was  pure.  This  was  done  by 
the  method  that  we  have  described  in  a  previous  paper.  The  residue 
is  dissolved  in  dilute  hydrochloric  acid  and  then  precipitated  with  a 
solution  of  iodine  in  potassium  iodide.  The  periodides  of  the  alka- 
loids obtained  in  this  way  are  decomposed  by  sodium  thiosulphate, 
and  after  ammonia  has  been  added  the  alkaloids  recovered  from  the 
liquid  by  means  of  chloroform.  If  the  residue  was  pure  the  weight 
of  the  alkaloids  obtained  in  this  way  should  coincide,  within  the  limits 
of  experimental  error,  with  the  original  weight  of  the  residue.  As 
examples,  the  following  out  of  many  results  may  be  cited  : 
Residue  taken.  Pure  alkaloid  found. 
On  the  foregoing  experiments  is  based  the  following  process  for  the 
estimation  of  the  atropine  and  hyoscyamine  in  the  leaves  of  Airopa 
Belladonna,  a  process  which  fulfils  the  three  fundamental  conditions 
that  have  been  previously  pointed  out.  Twenty  grams  of  the  dried 
and  finely  powdered  leaves  are  welFpacked  iu  an  extraction  apparatus 
and  exhausted  with  about  100  cc.  of  absolute  alcohol.    The  alcoholic 
0-011  sram. 
0-0105  " 
0-0115  " 
0-010  gram. 
0-010  " 
0-011  " 
