1 8  Emetine  Octoiodide  and  Alkaloids.  {^ji^yfS11' 
In  the  assay  of  ipecac,  given  at  the  end  of  this  paper,  the  method 
used  was  that  of  Dr.  Lyons.  The  other  drugs  have  been  extracted 
by  our  method  as  described  above,  and  the  results  compared 
with  those  obtained  by  Lyons'  method. 
The  periodide  assay  method  applied  to  nux  vomica,  along  with  a 
modification  of  Dunstan  and  Short's  method  of  separation  of  strych- 
nine from  brucine12  affords  a  convenient  way  of  separate  estimation 
of  each  of  these  alkaloids  in  the  drug,  as  follows: 
The  acidulated  alkaloidal  solution  obtained  from  nux  vomica  in 
any  suitable  way,  and  representing  4  grams  of  the  drug,  is  made 
up  to  a  definite  volume,  say  100  c.c  Of  this  solution  25  c.c,  which 
represent  I  gram  of  nux  vomica,  is  run  from  a  burette  into  a 
IOO  c.c.  flask  in  which  has  been  placed  20  c.c.  of  decinormal  iodine 
solution  and  2  c.c.  dilute  hydrochloric  acid,  and  the  amount  of 
iodine  consumed  by  the  total  alkaloids  contained  in  that  1  gram  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  845  which  is  equal  to  one 
hundred  times  the  mean  factor  of  strychnine  and  brucine,  and  the 
percentage  of  total  alkaloids  is  at  once  obtained. 
THE  SEPARATE  ESTIMATION  OF  STRYCHNINE  AND  BRUCINE. 
For  the  separate  estimation  of  each  of  these  alkaloids,  another 
portion  of  the  alkaloidal  solution,  representing  2  grams  of  the 
nux  vomica,  that  is  50  c.c,  is  run  out  from  the  burette  into  an  Erlen- 
meyer  flask  of  the  capacity  of  about  300  c.c,  and  to  the  contents  of 
the  flask  10  c.c.  of  a  2  per  cent,  solution  of  sulphuric  acid  is  added, 
and  then  water  enough  to  make  in  all  about  200  c.c.  Then  pour  in 
25  c.c.  of  a  5  per  cent,  solution  of  potassium  ferrocyanide,  stopper 
the  flask  and  shake  continuously  for  about  half  an  hour.  Now  filter, 
wash  the  precipitate  on  the  filter  repeatedly  with  water  containing 
I  per  cent,  of  sulphuric  acid,  till  a  few  drops  of  the  filtrate  diluted 
with  a  little  water  have  no  bitter  taste.  The  filter  is  then  pierced 
and  the  precipitate  rinsed  with  the  wash  bottle  into  a  100  c.c 
flask.  To  the  contents  of  the  flask  is  then  added  20  c.c  of  a  5  per 
cent,  solution  of  zinc  sulphate,  and  the  flask  kept  on  a  boiling  water 
bath  for  about  fifteen  minutes.  The  zinc  sulphate  decomposes  the 
strychnine  ferrocyanide,  zinc  ferrocyanide  is  precipitated  and  strych- 
12  Pharm.  J.  Trans.  (3)  14,  290  ;  Am.  J.  Phar.  1883,  579. 
