CHLORODYNE. 
265 
pepperminty  odor  and  taste,  and  is  in  fact  oil  of  peppermint  dis- 
solved in  ether.  The  ether  may  be  recognized  by  the  ready  in- 
flammability of  its  vapor. 
The  middle  layer,  separated  by  a  pipette  and  gently  heated 
with  a  few  drops  of  hydrochloric  acid  and  potassium  chromate, 
gradually  assumes  a  green  coloration,  owing  to  the  reduction  of 
the  chromate,  and  indicating  the  presence  of  alcohol — a  tincture 
probably.  The  odor  of  hydrocyanic  acid  is  given  off  during  the 
heating.  This  layer  also  gives  a  precipitate  with  silver  nitrate, 
insoluble  in  nitric  acid  and  sparingly  soluble  in  ammonia,  reveal- 
ing hydrocyanic  acid.* 
The  lowest  layer,  heated  gently  with  caustic  potash,  yields 
with  silver  nitrate  a  precipitate  insoluble  in  nitric  acid,  and 
which  blackens  by  the  further  application  of  heat,  owing  to  the 
reduction  of  the  silver  formiate,  indicating  the  presence  of  chlo- 
roform. 
The  residue  in  the  retort,  consisting  of  a  dark,  semifluid  paste, 
dissolves  in  water,  and  has  a  very  pungent,  peppery  taste  of 
capsicum.  This  aqueous  solution  gives  a  precipitate  with  alco- 
hol, basic  plumbic  acetate,  and  ammonium  oxalate,  revealing  the 
presence  of  gum,  and  also  gives  the  usual  glucose  reaction  with 
the  potassio-cupric  tartrate.  The  non-volatile  alkaloids  would 
of  course  be  found  in  the  residue  in  the  retort  after  distillation, 
but  the  coloring  matter  adheres  to  its  solution  in  water,  etc., 
with  such  pertinacity  as  to  render  the  usual  tests  very  unreliable, 
and  therefore  a  fresh  sample  of  the  original  compound  is  re- 
quired, to  satisfactorily  determine  their  presence. 
The  following  is  the  plan  I  adopted  to  isolate  the  alkaloids : — 
Digest  the  chlorodyne  with  twice  its  volume  in  alcohol,  con- 
taining a  few  drops  of  acetic  acid  at  a  warm  temperature,  say 
50°  to  60°  C.  for  four  or  five  hours,  occasionally  shaking  the  mix- 
ture.   The  whole  of  the  gum  and  much  of  the  coloring  matter 
*  In  the  preliminary  examination  of  complex  organic  mixture  for  hy- 
drocyanic acid,  Schbnbein's  guaiaco  cupric  test  promises  to  be  useful. 
Thus,  the  presence  of  hydrocyanic  acid  in  chlorodyne  may  be  determined 
in  a  few  seconds  by  this  test.  It  must  be  borne  in  mind  that/ree  nitric 
acid  and  chlorine  give  the  same  reaction,  but  not  their  compounds,  neither 
do  acetic,  hydrochloric,  sulphuric,  or  phosphoric  acids. 
