47o 
Alkaloidal  Assays. 
/Am.  Jour.  Hliarm. 
1     October,  1899. 
up  to  ioo  c.c,  and  the  flask  well  shaken  till  the  supernatant  liquid 
becomes  perfectly  transparent,  but  has  a  dark-red  iodine  color.1 
Fifty  c.c.  are  now  filtered  off  and  the  excess  of  iodine  determined 
by  the  standard  sodium  thiosulphate,  using  starch  as  indicator. 
The  amount  of  iodine  consumed  by  the  y2  gramme  of  opium, 
multiplied  by  149-8  (==  0749  X  100  X  2),2  gives  the  percentage  of 
morphine  in  the  opium. 
If  only  an  iodometric  assay  be  desired,  but  1  gramme  opium  need 
be  taken  for  the  assay,  and  the  latter  conducted  exactly  as  described 
above  up  to  the  point  where  the  chloroform-alcohol  has  been  re- 
moved by  evaporation.  At  this  point  the  residue  is  taken  up  with 
good  lime  water  by  rubbing  the  evaporating  dish  thoroughly  with 
it,  pouring  the  mixture  in  a  100  c.c.  flask,  filling  the  latter  up  with 
lime  water  to  make  100  c.c,  shaking  the  flask  about  an  hour, 
filtering  off  50  c.c,  into  another  100  c.c.  flask,  acidulating  and  then 
finishing  up  as  above. 
THE  ASSAY  OF  NUX  VOMICA.3 
The  acidulated  water  solution  of  the  total  alkaloids  of  the  drug, 
as  obtained  by  the  directions  on  page  given  above,  or  other  method 
of  extraction,  is  made  up  to  a  definite  volume,  say  100  c.c.  If  4 
grammes  of  the  drug  have  been  taken,  then  25  c.c.  will  represent  I 
gramme  of  the  drug,  and  will  be  sufficient  for  one  estimation.  This 
volume,  then,  is  run  from  a  burette  into  a  100  c.c.  flask  in  which  has 
been  placed  20  c.c.  of  the  decinormal  iodine  solution  and  2  c.c.  di- 
lute hydrochloric  acid,  when  the  amount  of  iodine  consumed  by  the 
total  alkaloids  in  that  I  gramme  of  nux  vomica  is  reached  in  the 
way  described  above.  Let  that  amount  be  a.  If  only  the  amount 
of  total  alkaloids  in  the  nux  vomica  is  desired,  it  is  sufficient  to 
multiply  a  by  47-8,  which  is  equal  to  100  times  the  mean  factor  of 
strychnine  and  brucine,  and  the  percentage  of  total  alkaloids  is  at 
once  obtained. 
For  the  separate  estimation  of  strychnine  and  brucine,  a  modifica- 
1  vSee  our  article  in  J.  Am.  Chem.  Soc,  1898,  p.  722  ;  "Proc.  Am.  Phar.  As- 
soc.," 1898,  p.  368. 
2  075  is  here  taken  instead  of  074914,  which  is  the  factor  for  morphine  (Loc. 
tit.,  p.  724). 
'■'  From  an  article  by  the  authors  in  Pharm.  Review,  Vol.  17,  1899. 
