ON  THE  COLOR-TESTS  OF  STRYCHNIA,  ETC. 
229 
bichromate  was  employed,  the  sequence  of  colors  was  blue  or 
violet,  instantly  changing  to  purple,  then  gradually  becoming 
red,  and  finally  greenish-yellow.  When  the  ferricyanuret  was 
used  the  color  was  a  rich  bluish-purple,  changing  rapidly  to  a 
light  rose-red.  It  is  important  to  proportion  the  sulphuric  acid 
to  the  amount  of  alkaloid,  avoiding  an  excess  beyond  what  is 
necessary  to  its  perfect  solution ;  and  therefore  it  is  better  to 
take  the  acid  out  of  the  bottle  by  a  pointed  glass  rod,  rather 
than  to  drop  it  from  the  lip. 
The  first  series  of  experiments  was  instituted  for  the  purpose 
of  determining  how  far  pure  morphia  or  one  of  its  salts,  when 
combined  with  strychnia,  would  prevent  the  manifestation  of 
the  color-tests. 
JExpt,  1.  Accordingly,  equal  weights  of  the  pure  alkaloids 
were  rubbed  together  in  a  mortar  and  tested ;  next,  one  part 
of  strychnia  to  three  parts  of  the  sulphate  of  morphia;  then 
one  of  strychnia  to  four  of  the  acetate  of  morphia ;  then  one 
of  strychnia  to  eight,  and  finally,  one  to  twenty  parts  of  the 
sulphate  of  morphia.  In  each  case  the  result  was  entirely  satis- 
factory ;  the  color-test  flashing  out,  with  more  or  less  distinct- 
ness in  proportion  to  the  relative  quantity  of  morphia,  as  soon 
as  the  margins  of  the  two  solutions  on  the  plate  came  in  contact. 
As  intimated  above,  one  solution  was  made  by  rubbing  the 
powdered  bichromate  with  a  drop  of  water,  the  other  by  tritura- 
ting a  portion  of  the  morphia  and  strychnia  with  a  drop  of 
sulphuric  acid,  being  careful  to  use  just  sufficient  acid  to  insure 
a  perfect  solution.  I  did  not  consider  it  necessary  to  carry  this 
experiment  any  further,  because,  in  a  case  of  poisoning  in  which 
the  morphia  should  be  twenty  times  greater  than  the  strychnia, 
the  fatal  result  and  the  attendant  symptoms  would  probably  be 
more  characteristic  of  the  action  of  the  former  than  of  the  latter, 
and  our  experiments  would  be  devoted  to  its  detection. 
Expt.  2  was  an  exact  duplicate  of  the  first  in  all  of  the  varied 
strengths  of  the  two  articles,  with  the  simple  difference  of 
having  them  in  solution  in  water  acidulated  with  acetic  acid, 
instead  of  being  in  the  solid  form. 
To  obviate  the  necessity  of  a  subsequent  concentration  of  the 
solutions  by  heat,  the  salts  or  alkaloids  were  macerated  in  small 
measures  only,  of  acidulated  water,  and  to  each  solution  an  ex- 
