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Preparation  of  Nux  Vomica.       |  A^p?nr"i92iarm" 
macist  is  then  placed  in  the  disagreeable  alternative  of  either  pre- 
paring a  dry  extract  imperfectly  deprived  of  oil,  or  deviating  from 
the  very  narrow  lines  which  are  laid  down  in  the  French  pharma- 
copoeia. It  is  this  latter  method  which  it  is  necessary  to  choose,  and 
ignore  the  paragraph  of  the  Codex,  where  it  is  stated:  "Evaporate 
with  precaution,  on  hot  water  and  away  from  all  fire,  the  ethereal 
liquids;  add  to  the  oily  residue  15  cc  of  boiling  water,  then  diluted 
acetic  acid,  drop  by  drop,  until  an  acid  reaction  persists.  Filter 
through  a  wet  filter;  wash  the  filter  with  a  little  water,  and  add  the 
filtered  liquid  to  the  product  left  in  the  flask."  After  the  preceding 
explanations,  it  can  be  understood  that  the  addition  of  acetic  acid 
to  the  water  for  the  washing  of  the  oily  residue  is  much  too  Hate ; 
it  becomes,  moreover,  perfectly  useless,  if  an  attempt  has  previously 
been  made  to  transform  the  alkaloids  into  acetates,  insoluble  in  the 
ether. 
III.  Determination  of  Total  Alkaloids. — I  shall  not  describe  in 
detail  the  official  French  procedure.  This  procedure  is  long  and 
very  delicate;  it  requires  a  great  visual  acuteness  to  grasp  the  final 
change  of  color  of  the  iodeosine  in  the  presence  of  a  hundredth 
normal  solution  of  potassium  hydroxide;  the  result  obtained  is  not 
controllable ;  it  is  more  often  above  the  real  per  cent,  of  the  alkaloids. 
Alfred  Gilkinet  has  pointed  out  in  his  Treatise  on  Pharmaceu- 
tical Chemistry  (edition  1910,  vol.  II,  page  743),  the  possibility  of 
replacing  the  Belgian  gravimetric  determination  by  a  volumetric 
determination.  He  uses  the  hundredth  normal  solution  of  potash 
(each  cc  of  hundredth  normal  solution  corresponding  to  .00364  Gms. 
of  alkaloids,  estimated  as  equal  quantities  of  strychnine  and  brucine), 
and  advises  as  indicator  the  tincture  of  cochineal,  or  better  iodeo- 
sine. 
This  method  is  as  defective  as  the  French  method,  and  for 
analogous  reasons.  It  will  be  permissible  then  to  replace  both  by 
the  following,  which  is  no  other  than  the  Belgian  method  {Belgium 
Pharmacopoeia,  pages  218  and  219),  which  I  have  endeavored  to 
render  practical  and  of  an  easy  application,  in  modifying  it  slightly 
and  in  completing  it  by  a  volumetric  determination. 
Weigh  into  a  tared  watch-glass  a  sample  of  less  than  3  grammes 
of  the  liquid  extract  perfectly  cleaned  with  ether.  Transfer  the 
sample  to  a  125  cc  flask  with  a  large  mouth,  and  ground  glass  stop- 
