Am.  Jour.  Pharm.  ) 
October,  1909.  J 
New  Essential  Oils. 
495 
rated  from  the  tartaric  acid  solution  by  means  of  carbonate  of  soda, 
possessed  an  extraordinarily  penetrating  narcotic  odor.  It  had  a 
rather  inconstant  b.  p.  between  1300  and  1400  (5  mm.  press.). 
(The  quantity  of  the  material  employed  was  barely  1  Gm.)  From 
the  hydrochloric  acid  solution,  on  treatment  with  platinum  chloride, 
no  crystals  separated  off. 
The  citronella-like  odor  of  the  oil  freed  from  the  base  made  us 
suspect  the  presence  of  citronellal.  As  a  matter  of  fact  the  oil 
reacted  with  bisulphite  liquor  partly  neutralized  by  sodium  car- 
bonate, a  crystalline  mass  being  separated.  From  the  latter,  after 
filtering  with  the  suction  pump  and  purifying  with  alcohol  and  ether, 
an  aldehyde  was  liberated  by  warming  with  carbonate  of  soda  solu- 
tion. Its  constants  showed  it  to  be  citronellal;  b.  p.  73 0  to  75 0  (7  to 
8  mm.  press.),  b.  p.  2050  to  2080  (atmosph.  press.),  d.]0  0.8560, 
aD+  I3°6/,  nD2o0  1.44710.  Its  semicarbazone  melted  at  81 0  to  820. 
From  500  Gm.  of  oil  we  isolated  about  220  Gm.  of  aldehyde.  The 
smaller  part  of  the  oil  freed  from  citronellal  passed  over  between 
450  and  103 0  (5  mm.  press.),  the  larger  portion  remained  behind  in 
the  flask  in  the  form  of  a  brown,  viscous  oil.  The  fractions  with 
the  lowest  b.  p.  contained  small  quantities  of  methylheptenone,  which 
was  separated  in  the  form  of  a  semicarbazone.  Only  after  recrys- 
tallizing  it  three  or  four  times  from  dilute  alcohol  the  m.  p.  of  this 
derivative  was  found  to  be  1340  to  135  °.  This  circumstance,  as  well 
as  the  fact  that  when  the  odor  observed  was  not  that  characteristic  of 
methylheptenone,  but  rather  reminded  of  a  saturated  fatty  ketone, 
indicated  the  presence  of  another,  additional,  ketone.  The  semicar- 
bazone referred  to  above,  when  mixed  with  that  from  the  pure 
methylheptenone,  showed  no  depression  of  the  melting  point. 
In  a  fraction  having  the  b.  p.  75 0  to  82 0  (5  mm.  press.)  and  the 
opt.  rot.  4-  6°  54',  small  quantities  of  d-menthone  could  be  detected, 
but  only  through  the  semicarbazone.  Only  when  the  oil  mixed  with 
it  had  been  removed  from  the  semicarbazone  solution  by  steam  dis- 
tillation, the  derivative  could  be  obtained  in  the  solid  form.  After 
repeated  recrystallization  from  alcohol  it  melted  at  1780  to  181  °, 
and  when  warmed  with  diluted  acid  it  developed  the  unmistakable 
odor  of  menthone.  Efforts  were  also  made,  unfortunately  without 
success,  to  separate  by  means  of  the  oxime  larger  quantities  of 
menthone  from  the  fractions  which  preceded  and  succeeded  the  one 
referred  to  above,  and  to  reconstitute  the  ketone  from  them.  It  is 
therefore  probable  that  the  somewhat  pronounced  odor  of  mint 
