AmjJu°iyj?o3arm-}  Alkaloidal  Color  Tests. 
337 
in  1846,  proposed  the  use  of  manganese  dioxide,  and  about  the 
same  year  Otto  brought  forward  the  use  of  potassium  bichromate. 
Since  then,  potassium  ferricyanide,  ammonium  vanavate,  and  cero- 
soceric  oxi^de  have  all  been  ardently  advocated.  Potassium  bichro- 
mate is  the  favorite  of  many  workers  ;  but  on  account  of  the  rapid 
change  of  colors  it  produces,  and  the  resulting  green,  chromium 
coloration,  others  prefer  lead  or  manganese  dioxide,  both  of  which 
produce  a  remarkably  well-developed  play  of  colors. 
As  can  readily  be  imagined,  one  or  more  of  the  successive  colora- 
tions produced  in  the  series  of  color  reactions  for  strychnine  can 
easily  be  imitated,  with  a  number  of  organic  bodies,  under  the  same 
conditions,  such  bodies  are  acetanilid,  anilin,  antipyrin,  curarine,  cod- 
liver  oil,  gelsemine,  pyroxanthine,  papaverine,  narceine,  solanine  and 
veratrine.  In  regard  to  these  it  may  be  said  in  general  that  there 
is  more  fiction  than  truth  about  these  substances  interfering  with 
the  identity  tests  for  strychnine.  These  reactions  are  usually  classed 
as  fallacy  tests. 
It  is  the  common  belief  that  most  of  the  above  substances,  that 
may  interfere  with  the  tests  for  strychnine,  will  be  removed  from  the 
strychnine  by  the  conventional  methods  of  isolation;  but  it  must 
not  be  forgotten  that  the  line  of  separation  is  very  seldom  so  com- 
plete as  to  entirely  eliminate  all  associated  impurities,  except  when 
sublimation  can  be  resorted  to  according  to  Helwig's  1  scheme,  sub- 
sequently improved  by  Drs.  Guy2  and  Wormley3  and  frequently  used 
at  the  present  time. 
Within  a  few  years  there  has  come  to  our  attention  a  mixture  of 
morphine  and  hydrastine,  which  is  supposed  to  give  color  reactions 
simulating  those  of  strychnine.  Curious  enough,  it  has  come  to  us 
in  the  form  of  fiction,  ««  Stringtown  on  the  Pike,"  by  J.  U.  Lloyd, 
and,  as  can  readily  be  imagined,  has  created  some  little  stir  in  cer- 
tain circles.  The  writer  has  carefully  gone  over  these  tests,  and 
finds  that,  while  there  is  a  similarity  of  color  reaction,  when  the 
above  mixture  is  treated  with  the  usual  reagents  employed  for  iden- 
tifying strychnine,  yet  when  the  first  of  the  above  propositions  laid 
down  is  applied  to  this  mixture,  it  will  be  found  that  it  will  not  dis- 
solve without  coloration  in  sulphunc  acid,  which  immediately  elimi- 
1  Das  Mikroscop  in  der  Toxicologic 
2 1867,  Pharm.  fourn.  Trans.  (2),  8,  719,  and  9,  10  and  58. 
3  Micro-chemistry  of  Poisons. 
