A  m.  Jour.  Pharm. 
July,  1890. 
Indian  Grass  Oils. 
355 
and  cloves.  The  sun-dried  bark  yielded:  water  (at  1 10°),  137 13 
per  cent.;  ash,  3*338  per  cent.;  soluble  in  ether,  3-841  per  cent.;  in 
alcohol,  6465  per  cent.;  in  water,  13-981  percent. ;  ligneous  matter, 
49-200  per  cent.  An  analysis  of  the  ash  is  also  given.  The  ethereal 
solution  contains  a  peculiar  essence,  fatty  compounds,  resins,  and 
waxy  matter ;  the  alcoholic  extract  contains  reddish  uncrystallizable 
resins.  Citric  acid  was  carefully  looked  for,  but  not  found.  The 
essence  was  isolated  by  distilling  the  bark  with  water,  exhausting 
the  distillate  with  petroleum,  and  distilling  off  the  solvent.  The 
crude  oil,  amounting  to  0-6428  per  cent,  of  the  weight  of  the  bark 
employed,  is  a  mixture  of  several  substances. 
Winterene,  C15H24,  is  the  essential  oil  separated  from  this  by 
fractional  distillation.  It  passes  over  between  2600  and  265 0  ;  sp. 
gr.  at  1 30  =  0-93437.  Index  of  refraction  —  1-4931  ;  sp.  rotatory 
power  at  160  [a]  •  =  -f  u-2.  It  is  readily  oxidized  on  exposure  to 
the  air,  becoming  yellow.  The  formula  <Z2f\m  was  calculated  from 
the  ultimate  analysis  and  vapor-density,  but  the  authors  consider 
that  the  ready  oxidizability  of  winterene  and  its  analogy  to  similar 
essences  points  rather  to  the  formula  C15H24,  which  would  place  it  in 
the  group  of  sesquiterpenes,  such  as  cedrene,  cubebene,  etc.,  the 
boiling  points  of  which  are  between  2500  and  2680. 
Iodine  dissolves  in  winterene  producing  a  greenish-yellow  colora- 
tion which  changes  to  green  after  a  time. 
On  adding  picric  acid  containing  a  few  drops  of  sulphuric  acid  to 
winterene,  a  yellowish-red,  crystalline  compound  is  formed. 
Pure  winterene  is  colored  green  by  a  solution  of  bromine  in  chloro- 
form, orange-red  by  a  solution  of  chloral  hydrate  in  sulphuric  acid,  . 
rose  to  yellow  by  concentrated  sulphuric  acid  or  by  sulphuric  acid 
and  chloroform,  dirty-yellow  by  Frbhde's  reagent  and  by  ferric 
chloride  and  sulphuric  acid,  rose  to  violet  by  nitric  acid. 
The  reactions  of  the  essence  after  oxidation  are  also  given. 
THE  INDIAN  GRASS  OILS  1 
By  F.  D.  Dodge. 
These  are  at  least  five  in  number,  namely,  oils  of  citronella, 
lemon-grass,  Indian  or  Turkish  geranium,  ginger-grass,  and  vetivert 
or  cus  cus.    They  are  derived  from  various  tropical  grasses  of  the 
1  Amer.  Chem.  J.,  xi,  456-469.  Reprinted  from  Jour.  Chem.  Soc,  March,  231. 
