^  ApS'.im™1*'}    Estimation  of  Alkaloids  in  Extracts.  181 
EXTRACT  OF  HYOSCYAMUS. 
7.  0*572  per  cent,  alkaloid.  0-058  per  cent,  alkaloid. 
8.  0710       "         "  0-116      "  " 
It  is  evident  that  by  titration  a  smaller  quantity  is  obtained  than  by 
weighing,  but  the  difference  is  so  great  that  it  cannot  be  attributed  to 
impurity  of  the  alkaloid.  0*04  gram  of  pure  atropine  required  13*6  cc. 
of  100th  normal  acid,  which  is  equal  to  0*0393  atropine. 
A  strong  penetrating  odor  and  white  fumes  were  noticed  coming 
from  the  chloroform  solution  whilst  evaporating  on  a  water-bath,  and 
recalling  the  fact  that  chloroform  vapor  at  a  red  heat  is  decomposed 
yielding  carbon,  chlorine  and  hydrogen  chloride,  decomposition  was 
supposed  to  be  due  to  the  flame  under  the  water-bath.  Part  of  the 
chlorine  compound  was  found  in  the  alkaloidal  residue  by  the  follow- 
ing experiments  : .  A  piece  of  moistened  blue  litmus-paper  was  placed 
over  the  flame  whilst  the  chloroform  was  being  evaporated,  and  red- 
dening of  the  paper  was  soon  observed.  A  small  quantity  of  chloro- 
form was  placed  alongside  of  some  ammonia  in  a  covered  flat  glass 
vessel,  and  immediately  on  placing  a  lighted  spirit-lamp  under  the 
chloroform  white  fumes  of  ammonium  chloride  were  noticed,  and  in  a 
very  short  time  the  ammonia  solution  after  acidulating  with  nitric 
acid,  gave  a  strong  chlorine  reaction  with  silver  nitrate.  Undoubt- 
edly a  portion  of  the  alkaloid  combines  with  the  acid  thus  liberated 
and  is  lost  for  titration.  It  is  unnecessary  to  remark  that  the  chlo- 
roform was  examined  before  trying  these  experiments  and  found  to 
be  pure. 
It  being  desirable  to  control  the  gravimetric  analysis  by  titration y 
another  solvent — ether — was  used  with  satisfactory  results.  Slight 
differences  were  noticed  in  the  yield  of  alkaloid,  but  by  repeatedly 
shaking  with  ether  a  larger  yield  was  obtained  ;  it  is  however  doubt- 
ful if  all  the  alkaloid  can  thus  be  extracted,  and  as  a  result  of  his  ex- 
periments Dieterich  comes  to  the  conclusion  that  it  is  impossible  to 
completely  exhaust  such  organic  substances  by  shaking  or  precipitation. 
Very  satisfactory  results  were  obtained  by  displacement.  To  accom- 
plish this  the  extract  was  treated  with  an  alkali,  the  mixture  made 
porous  and  then  exhausted  with  ether.  To  liberate  the  alkaloids  lime, 
baryta  and  ammonia  were  used,  and  for  porous  substances  lime  and 
washed  powdered  pumice  stone.  After  making  sure  that  the  lime  (in 
the  form  of  burnt  marble)  did  not  decompose  atropine,  hyoscyamine, 
strychnine,  brucine,  etc.,  the  quantity  of  water  most  suitable  for  the 
