Amjunue?i903arm'}     Quantitative  Estimation  of  Strychnine.  253 
oxide  that  the  liquid  which  had  passed  through  contained ;  or  if, 
finally,  distilled  water  had  been  passed  through  the  charcoal  until 
the  portion  of  the  original  arsenical  liquid  (330  c.c.)  which  remained 
to  saturate  the  charcoal  had  been  washed  out,  and  the  total  quantity 
of  liquid,  including  the  washings,  had  been  concentrated  by  evap- 
oration and  the  arsenic  determined  therein,  it  is  reasonable  to 
believe  that  64-30  per  cent,  of  the  arsenious  oxide  in  the  original 
solution  would  have  been  retained  by  the  animal  charcoal.  Under 
this  assumption  each  gramme  of  the  previously  dried  animal  char- 
coal retained  o  0006  gramme  of  arsenious  oxide. 
EXPERIMENT  MO.  2. 
A  quantity  of  animal  charcoal  —  undried  —  weighing  763-7 
grammes  was  employed.  3*3972  grammes  arsenious  oxide  was 
dissolved  in  3,000  c.c.  of  water  and  the  solution  was  passed  through 
the  animal  charcoal.  The  time  required  for  the  passage  of  the  solu- 
tion was  two  hours.  Of  the  3,000  c.c.  of  solution,  2,630  c.c.  passed 
through,  leaving  370  c.c.  in  the  mass  of  charcoal. 
Three  determinations  of  arsenic,  using  100  c.c.  of  the  liquid  in 
each  case,  were  made. 
a  yielded  0-0843  gramme  arsenious  sulphide. 
b      "   0-0863 
c     "   0-0868 
The  mean  of  the  three  determinations  is  0-0858  gramme,  which 
corresponds  to  0-06905  gramme  arsenious  oxide.  Each  10c  c.c. 
of  the  original  solution  before  it  was  passed  through  the  charcoal 
contained  o- 1 1  324  gramme  arsenious  oxide;  therefore,  the  amount 
of  arsenious  oxide  retained  by  the  animal  charcoal  from  each  100  c.c. 
of  solution  was  0-04419  gramme  or  39-02  per  cent.  The  assump- 
tion stated  in  experiment  No.  1  would  also  apply  here.  In  this 
case  each  gramme  of  undried  animal  charcoal  retained  0-00278 
gramme  of  arsenious  oxide. 
THE  QUANTITATIVE  ESTIMATION  OF  STRYCHNINE. 
By  F.  J.  Smith. 
Several  methods  have  been  proposed  tor  the  quantitative  estima- 
tion of  strychnine  in  mixtures  of  strychnine  and  brucine,  principally 
in  the  form  of  impure  alkaloids  as  extracted  from  tinctures  and  fluid 
extracts  in  the  process  of  standardization. 
