CHEMICAL  TESTS  FOR  STRYCHNIA. 
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a  grain  in  each  drop,  was  placed  in  the  centre  of  a  capsule  and 
carefully  evaporated ;  a  quarter  of  a  grain  of  tartar  emetic  was 
added  and  two  drops  of  sulphuric  acid ;  these  were  intimately 
mixed  ;  on  adding  the  bichromate  of  potash  very  indistinct  evi- 
dence of  strychnia  was  given.  By  using  more  bichromate  of 
potash  and  a  little  more  acid,  the  color  was  somewhat  more  de- 
veloped, but  only  for  an  instant,  the  whole  quickly  becoming 
green.  On  repeating  this  experiment  several  times,  in  varying 
proportions,  it  was  found,  that  although  the  evidence  of  strychnia 
was  rarely  entirely  lost,  it  did  not  give  satisfactory  proof  of  its 
presence.  Thus  it  was,  it  may  be  presumed,  that  in  the  earlier 
experiments,  the  presence  of  antimony  (tartar  emetic  ?)  was  sup- 
posed to  invalidate  and  render  the  test  useless.  But,  as  before 
observed,  no  chemist  would  think  of  testing  for  a  substance  under 
circumstances  like  these.  There  is  a  long  list  of  substances 
which  would  act  in  a  similar  manner;  in  fact,  any  body  capable 
of  deoxidizing  the  chromic  acid  liberated  by  the  sulphuric,  will 
mar  the  test  more  or  less.  In  this  instance,  it  may  be  presumed, 
that  the  oxide  of  antimony  set  at  liberty  by  the  sulphuric  acid, 
is  raised  to  a  higher  oxide  (antimonic  acid)  at  the  expense  of  the 
chromic  acid.  The  strychnia,  however,  in  every  case  remains 
unchanged,  and  is  there  still — by  supersaturating  with  ammonia, 
as  recommended  by  Mr.  Rodgers,  and  agitating  with  chloroform, 
the  strychnia  is  recovered,  in  no  way  the  worse  for  its  com- 
panionship. 
Discarding  theory,  an  experiment  was  made  to  ascertain 
whether,  after  the  colors  have  been  produced  in  the  ordinary 
manner,  the  strychnia  may  even  then  be  reproduced,  which 
ended  in  a  negative  result. 
To  determine  further,  whether  the  prevention  or  masking  of 
the  test,  when  tartar  emetic  was  present,  really  depended  upon 
the  oxide  of  antimony,  an  experiment  was  made,  in  which  bitar- 
trate  of  potash  was  added,  in  lieu  of  the  tartar  .emetic — these 
elements  (potash  and  tartaric  acid)  being  in  combination  with  the 
antimony.  As  anticipated,  no  effect  whatever  was  produced, 
the  colors  coming  out  as  perfectly  as  though  this  body  had  not 
been  present. 
While  these  experiments  were  being  proceeded  with,  a  bottle 
containing  strychnia  and  some  strong  solution  of  sulphide  of  am- 
