THE 
AMERICAN  JOURNAL  OF  PHARMACY. 
SEPTEMBER,  1870. 
ON  THE  MOST  DELICATE  COLOR  TEST  FOR  THE  DETECTION 
OF  STRYCHNIA. 
By  William  T.  Wenzell,  of  San  Francisco,  Cal. 
Toxicologists  seem  greatly  at  variance  as  to  the  precise  limit 
of  sensibility  of  the  color  tests  usually  applied  for  the  detection 
of  strychnia.  Among  writers  and  authorities  may  be  cited  those 
who  have  designated  limits  beyond  which  the  identification  of 
the  alkaloid  is  regarded  as  doubtful ;  Wm.  Copney  places  the 
test  limit  at  l-500,000th,  G.  .T.  Wormley  l-100,000th,  Dr.  De 
Vry  l-60,000th,  Jordan  l-50,000th,  all  of  whom  recom- 
mend and  use  the  test  of  bichromate  of  potassa  and  sulphuric 
acid.  Wm.  A.  Guy  uses  a  test  liquid  of  a  solution  of  10  grs. 
of  permanganate  of  potassa  in  one  ounce  of  water,  and  is 
used  in  conjunction  with  sulphuric  acid.  He  gives  a  stated  limit 
of  1-12,000.  Rodgers  and  Girtwood  use  a  test  which  consists 
of  500  grains  of  sulphuric  acid  holding  1  grain  of  chromic  acidll 
in  solution,  which  the}^  esteem  particularly  useful  for  the  dete®- 
tion  of  minute  quantities  of  strychnia  ;  but  its  limit  of  sensibility 
has  not  been  stated. 
The  best  form  of  using  and  manner  of  applying  the  color  tests 
has  also  been  a  matter  of  opinion,  but  it  is  now  generally  be- 
lieved that  the  application  of  the  color  test  in  the  solid  form  is 
that  which  is  to  be  preferred.  The  deserved  superiority  of  using; 
it  in  this  form,  although  it  is  the  best  for  the  detection  of  cjuan- 
tities  not  exceeding  the  l-100,000th  of  a  grain  of  strychnia,  im 
greater  attenuations  it  seems  incapable  of  inducing  that  charac- 
teristic development  of  colors  which  forms  the  means  of  positive 
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