AmJu0nUe?lf9hlf^m•}  Volatile  Oil  of  Aristolochia  Reticulata.  259 
The  oil  which  separated  with  some  difficulty  in  very  small  quan- 
tity from  the  first  litre  was  colorless.  The  second  litre  yielded  a 
transparent  lemon  yellow  oily  layer  constituting  about  one-half  of 
the  whole  yield.  From  the  third  litre  a  greenish  layer  of  oil  was 
obtained  in  about  one-fourth  of  the  entire  amount.  Green  oil  in 
about  the  same  amount  was  separated  from  the  fourth  litre.  In  the 
subsequent  distillations  the  process  of  cohobation  was  employed. 
The  watery  distillates  were  neutral  to  litmus.  The  oil  was  dried 
by  means  of  neutral  calcium  chloride. 
The  yield  of  oil  from  three  commercial  lots  of  the  rhizome  (lot 
III  amounting  to  about  25  kilograms)  was  as  follows  :  (I)  -94  per  cent., 
(II)  -73  per  cent,  and  (III)  -6i  per  cent.;  the  average  being  -76  per 
cent.    The  oil  from  lot  III  was  used  for  most  of  this  work. 
Properties  of  the  Volatile  Oil. — In  bulk  the  oil  was  of  an  amber  or 
golden  yellow  color,  in  thin  layers  greenish  yellow;  odor  camphor- 
aceous  and  mildly  valerianic ;  taste,  camphor-like,  with  but  little 
sensation  of  cold  when  air  was  drawn  into  the  mouth ;  reaction, 
neutral  or  indistinctly  acid.  On  exposure,  in  thin  layers,  the  oil 
dried  slowly  to  a  varnish  film. 
All  the  different  lots  of  oil  agreed  closely  with  this  description, 
and  all  failed  to  separate  solids  at  a  prolonged  exposure  to — 170  to 
—  1 5°  in  a  freezing  mixture  of  salt  and  ice,  or  in  a  snow-bank  over 
night;  the  only  change  noticed  was  the  usual  one  of  increased 
viscosity. 
The  specific  gravity  of  the  oil  from  lot  I  was  -9785  at  15-5°,  and 
•9758  at  200  C;  and  from  lot  III  -9745  and  -9719,  respectively. 
The  rise  in  the  boiling  point  was  noted  as  follows  : 
No.  Oil.         pommenced.       Increased.      Brisk.       Full  and  Constant.       Barora.  Press. 
I,  1630  1720  2040  207-2100  7577  mm. 
Ill,  1650  1790  2050  213-2140  767-3121111. 
The  rotary  power  was  ascertained  to  be  — 4-0  in  a  100  mm.  tube ; 
temperature  of  the  oil  20-5°. 
The  oil  is  readily  soluble  in,  or  miscible  with,  an  equal  volume  of 
ether,  chloroform,  benzol,  benzin  (boiling  point  45-800),  methyl 
alcohol, carbon  disulphide,  turpentine,  glacial  acetic  acid,  bromethane, 
ethylene  dibromide,  nitro-benzol,  ethyl  benzoate,  aniline,  toluol,  and 
olive  oil ;  not  so  freely  soluble  in  ethyl  acetate  ;  sparingly  in  water; 
almost  insoluble  in  acetic  aldehyde  and  in  glycerin  (sp.  gr.  1-25); 
apparently  miscible  in  all  proportions  with  alcohol  (sp.  gr.  -820). 
