376 
Pelargonium  Oil. 
5  Am.  Jour.  Pharm. 
\      June,  1921. 
ORIGINAL  PAPERS 
PELARGONIUM  OIL. 
Professor  Richard  Knuth, 
charlottenburg,  germany. 
(Continued  From  the  May  Number,  Page  315.) 
CHEMICAL  CONSTITUTION  OF  THE  PELARGONIUM  OIL. 
It  is  probable  that  the  oil  was  produced  first  by  Recluz,  at  Lyons, 
in  1819,  by  means  of  steam  distillation  (Pharm.  Jour.,  London,  I,  11, 
1852,  p.  325).  The  knowledge  of  its  constitution  is,  however,  the 
result  of  the  last  thirty  years.  The  reason  for  this  is  the  compli- 
cated construction  of  most  of  its  elements  which,  like  many  cam- 
phors, stand  on  the  frontier  between  the  acyclic  and  cyclic  hydro- 
carburets.  Up  to  now  there  are  known  to  be  contained  in  the 
pelargonium  oil :  the  alcohols :  geraniol,  citronellol,  linalol,  isoamyl- 
alcohol ;  a  parafnne ;  the  terpenes  phellandrene  and  pinene ;  a  cyclic 
ketone ;  the  menthone ;  the  terpineol ;  a  blue-colored  high-boiling 
potion,  and  different  parafnne  acids. 
The  geraniol,  C10Hi8O  represents  the  well-redolent  part  not 
only  of  the  pelargonium  oil,  but  also  of  the  palmarosa-oil,  the  true 
rose-oil,  and  of  many  other  etherial  oils.  Some  of  the  secondary  in- 
gredients confer  upon  the  oil  the  by-odor  which  distinguishes  the 
pelargonium-oil  from  the  true  rose-oil.  The  geraniol  itself  was 
produced  artificially  for  the  first  time  by  the  firm  Schimmel  &  Co., 
from  the  citronella  oil.  This  method  was  protected  by  the  German 
Imperial  Patent  Xo.  76,435.  According  to  the  accounts  (Schimmel, 
Ber.,  1894,  I,  p.  63  ;  1894,  II,  p.  77;  1895,  I,  p.  76),  the  pure  geraniol 
is  a  colorless  liquid  of  roseal  odor,  optically  inactive,  and  with  a 
specific  gravity,  varying  from  0.882  to  0.885,  at  a  temperature  of 
1 5°  C.  It  boils  at  2300  C.  In  alcohol  it  is  very  easily  soluble:  in 
from  12  to  15  parts  of  a  50  vol. -per  cent,  alcohol.    A  disadvantage 
