230 
ON  THE  COLOR-TESTS  OF  STRYCHNIA,  ETC. 
cess  of  a  solution  of  potassa  was  added,  and  then  an  equal 
measure  of  chloroform,  which  dissolved  out  the  strychnia,  and 
subsequently  yielded  it  as  a  filmy  deposit  in  a  capsule,  by  spon- 
taneous evaporation. 
With  sulphuric  acid  and  bichromate  of  potassa,  the  proper 
test-color  was  manifested  by  the  deposit  in  each  case. 
In  my  opinion,  these  experiments  determine  conclusively  that 
strychnia  can  be  detected  by  color-tests,  even  when  masked  by 
morphia — either  as  the  alkaloid  or  one  of  the  salts — to  the  ex- 
tent of  twenty  times  its  own  weight. 
But  the  question  raised  is  not  so  much,  whether  strychnia 
will  be  masked  by  pure  morphia  or  its  salts,  uncontaminated 
with  anything  else,  as  whether  morphia  in  the  presence  of  or- 
ganic mixtures  has  the  power  of  preventing  the  recognition  of 
strychnia  by  the  usual  color-tests.  To  determine  this  latter 
point,  my  attention  was  directed  in  the  next  instance,  to  the 
devisal  of  a  simple  and  practical  method,  by  which  its  recogni- 
tion could  be  secured.  Upon  reflection,  I  concluded  that  the 
most  feasible  plan  of  overcoming  the  difficulty,  would  be  to 
separate  the  poison  entirely  from  the  organic  mass,  by  chemical 
agents  and  solvents. 
After  careful  investigation  and  repeated  trials,  I  selected  as 
the  agents  the  three  fluids  used  in  experiment  2.  These  fluids 
can  always  be  obtained  at  trifling  cost,  of  easily  ascertained 
strength,  and  of  known  purity.  They  are,  1.  Acetic  acid,,  of 
the  specific  grav.  1-041.  2.  A  solution  of  one  drachm  of  caustic 
potassa  in  a  fluidounce  of  water.    And,  3.  Chloroform. 
Acetic  acid  was  chosen,  because,  when  in  excess,  it  has  the 
property  of  dissolving  all  of  the  ordinary  salts,  both  of  morphia 
and  strychnia,  as  well  as  their  tannates,  which  are  generally 
described  as  being  insoluble;  and,  therefore,  by  treating  an 
organic  mass  containing  these  alkaloids  with  this  acid,  we  would 
obtain  a  solution  of  the  acetates  of  morphia  and  strychnia. 
The  solution  of  caustic  potassa  was  selected  for  several  reasons. 
For  instance,  in  neutralizing  the  acetic  acid  it  forms  a  soluble 
salt  of  potassa — thereby  getting  rid  of  the  acid  when  we  are 
done  with  it.  It  saponifies  the  fats  of  the  organic  materials  • 
it  decomposes  their  sugars  ;  and  it  dissolves  morphia,  but  does 
not  dissolve  strychnia,  thus  enabling  us  to  separate  the  one 
alkaloid  from  the  other  by  its  agency. 
