260  Volatile  Oil  of  Aristo lochia  Reticulata.  { Am  ju°ne%biarm 
When  heated  with  finely  powdered  copper  nitroprusside,  no 
change  in  color  was  noticed.  Fronde's  reagent  in  equal  quantity 
gave  rapidly  a  black  color  which  was  produced  slowly  by  sulphuric 
acid  alone.  An  equal  amount  of  five  per  cent,  alcoholic  solution  of 
ferric  chloride,  at  first,  gave  a  greenish  color  (due  to  reduction  of  the 
ferric  compound),  the  mixture  gradually  became  dark  red  brown, 
almost  black,  and  resinous  in  about  an  hour.  The  odor  and  taste 
seemed  to  be  unchanged. 
Neither  alcoholic  solution  of  ammonium  sulphide  nor  saturated 
aqueous  solution  of  sodium  acid  sulphite  gave  indications  of  alde- 
hydes or  of  ketones.  With  the  last  reagent  a  cherry  red  color  was 
slowly  developed,  but  after  separating  and  washing  the  oil,  the  taste 
and  odor  were  found  unchanged. 
Rectification. — This  was  effected  by  a  simple  distillation  of  the  oil, 
under  reduced  pressure  on  an  oil  bath,  the  process  being  continued 
as  long  as  the  oil  distilled  without  decomposition.  The  same  colors 
were  noticed  in  the  distillate  thus  obtained  as  in  the  distillation  from 
the  rhizome. 
The  residue  in  the  flask  at  the  end  of  the  operation  was  red  brown,  \ 
resinous,  acid  in  reaction,  and  solidified  upon  cooling.    Further  dis- 
tillation of  this  residue  gave  only  decomposition  products,  as  the 
distillates  so  obtained  boiled  in  air  at  much  lower  temperatures  than 
those  required  for  their  production  under  the  diminished  pressure. 
The  rectified  oil,  consisting  of  the  mixed  distillates  obtained 
previous  to  threatened  decomposition,  was  of  a  greenish  yellow 
color ;  camphoraceous  in  odor  and  taste,  and  neutral  in  reaction. 
The  specific  gravity  at  15-5°  was  (I)  -95 5 ,  (III)  -9675,  and  at 
20°  C.  -953  and  -9648,  respectively. 
The  rectified  oil  commenced  to  boil  at  165 °;  boiling  increased 
at  1770;  was  brisk  at  195-2000,  and  constant  between  207  and 
208-5  ;  barom.  pressure  756-7  mm. 
The  rotary  power  of  the  rectified  oil  (temperature  250,  100  mm. 
tube)  was  — 16-5. 
Rectification  did  not  change  the  behavior  toward  the  solvents 
mentioned  before,  but  the  rotary  power  indicated  that  the  decom- 
position in  the  highest  boiling  portions  took  place  at  the  expense  of 
dextro-rotary  substances. 
Fractional  Distillation. — This  operation  was  conducted  on  an  oil 
bath,  and  by  its  means  the  rectified  oil  was  separated  into  the  frac- 
