258  Volatile  Oil  of  Aristo  lochia  Reticulata.  {AmjJu0nUe"iF9iarm- 
channels  of  the  drug  market.  The  amount  of  the  material  used  was 
about  forty-five  kilograms. 
The  same  Centigrade  thermometer  was  used  in  all  instances 
except  where  more  than  one  was  required,  when  its  fellows  were 
compared  with  it.  The  boiling  points  in  air  were  taken  on  a  sand 
bath  ;  a  thin  test  tube,  containing  sufficient  substance  to  completely 
submerge  the  thermometer  bulb,  being  used.  The  several  temper- 
atures stated  in  giving  the  boiling  points  of  the  oils  were  points  at 
which,  in  the  first  given,  the  oil  showed  ebullition,  and,  in  the  others, 
increased  vigor,  until  the  highest  and  apparently  constant  boiling 
temperature  was  reached.  Between  these  several  points  the  tem- 
perature rose  slowly. 
The  specific  gravities  were  taken  by  means  of  the  bottle. 
The  rotary  powers  were  taken  with  a  Wilde's  polaristrobometer 
with  the  use  of  the  sodium  flame.  The  one  hundred  millimeter 
tube  was  used,  as  the  color  of  the  oil  would  not  allow  the  use  of  a 
longer  column. 
The  barometic  pressures  were  reduced  to  0°  from  the  observed 
height  of  the  mercury  column,  as  a  correction  for  atmospheric 
temperature,  and  are  here  stated  in  millimeters.  All  the  rectifications 
and  distillations  were  conducted  under  reduced  pressure.  Upon 
boiling  the  oils  and  the  fractions  in  air  all  became  darker  in  color, 
but  the  other  physical  properties  remained  unchanged. 
By  appropriate  tests  the  oil  was  found  to  be  composed  entirely  of 
carbon,  hydrogen  and  oxygen.  The  combustions  were  made  in  an 
open  tube  with  cupric  oxide  and  a  stream  ot  oxygen ;  the  vapor 
densities  with  the  Victor  Meyer  apparatus,  and  the  results  calculated 
by  the  rule  which  eliminates  all  differences  in  barometric  and  ther- 
mometric  influences  and  gives  the  density  of  the  vapor  of  the 
substance  at  0-760°  mm.  pressure,  compared  with  air  under  similar 
conditions.  The  compounds  were  vaporized  in  a  flask  heated  to 
from  40-500  above  their  boiling*  points. 
Distillation. — The  contused  drug  in  quantities  of  about  two  kilo- 
grams, was  macerated  over  night  with  about  six  litres  of  water,  and 
then  distilled,  the  volume  of  water  being  maintained  by  additions 
from  time  to  time  through  the  tubulure  of  the  still.  It  was  found 
when  four  litres  of  distillate  had  been  collected  that  the  drug  was 
exhausted  of  oil.  The  distillate  was  collected  in  quantities  of  one  litre, 
and  the  oil  which  separated  from  each  portion  was  specifically  lighter 
than  that  respective  part  of  the  distillate. 
