Am7u°ner;i903?rm'}     Quantitative  Estimation  of  Strychnine.  255 
three  or  four  times  during  this  time.  The  red  liquid  is  now  trans- 
ferred to  a  separator  containing  25  c.c.  of  a  10  per  cent,  solution  of 
sodium  hydrate,  and  the  vessel  in  which  digestion  of  the  alkaloids 
has  taken  place  is  washed  three  or  four  times  with  very  small 
amounts  of  water. 
Care  must  be  taken  that  sufficient  alkali  is  present  to  neutralize 
all  the  HNO3  and  leave  the  liquid  alkaline.  This  is  then  shaken 
out  with  chloroform,  using  20  c.c.  for  the  first  shaking,  and  10  c.c. 
each  for  two  subsequent  shakings. 
The  chloroformic  solution  is  now  filtered  through  a  small  plain 
double  filter,  arranged  so  that  there  are  four  folds  of  paper  on  each 
side,  into  a  tared  flask,  taking  care  to  wash  the  filter  and  stem  of 
the  funnel  with  small  amounts  of  chloroform,  and  to  the  colorless 
solution  of  strychnine  thus  obtained  are  added  2  or  3  c.c.  pure  amyl 
alcohol,  which  distills  between  1280  and  1320  C.  and  leaves  no  resi- 
due on  evaporation. 
^(This  prevents  decrepitation  of  strychnine,  on  removal  of  last  traces 
of  chloroform  by  heat.) 
The  chloroform  is  now  distilled  off  completely,  and  the  small 
amount  of  amyl  alcohol  left  behind  is  removed  by  keeping  the 
vessel  on  the  water-bath  and  blowing  air  over  the  opening. 
The  vessel  is  now  dried  for  about  two  hours  at  a  temperature  of 
1 350  to  1400  C,  and  when  cold,  weighed. 
Gordin's  figures  show  this  method  to  give  very  accurate  results, 
and  its  great  advantage  is,  that  it  is  very  easily  carried  out  and 
occupies  but  a  short  time. 
I  have  not  attempted  to  test  the  accuracy  of  the  process  by  work- 
ing on  the  pure  alkaloids  ;  but  during  the  last  six  months  have 
used  it  exclusively  in  assays  of  the  drug  and  also  of  liquid  and  solid 
extracts.  In  every  case  the  percentage  of  strychnine  found  has 
been  within  the  limits  of  40  to  45  per  cent,  of  the  total  alkaloid. 
Lyons  states  in  his  "Assay  of  Drugs  "  that  the  average  is  about 
42  per  cent. 
A  powdered  extract  of  nux  vomica  yielded  20  per  cent,  impure 
alkaloids  by  weight. 
n 
This  was  dissolved  in  20  c.c.  -  H2S04  (which  is  about  equivalent 
to  the  prescribed  15  c.c.  of  3  per  cent.  H2S04),  half  of  which  was 
titrated  with — NaOH,  using  the  factor  0-181^  (from  the  mean  of 
100  &  J  v 
