130  THE  ODOROU  PRINCIPLE  OF  VANILLA. 
ON  VANILLIN  THE  ODOROUS  PRINCIPLE  OF  VANILLA: 
By  M.  Gobley. 
The  odorous  properties  of  vanilla,  and  the  useful  medicinal 
action  which  it  exercises  on  the  organism  as  an  excitant  tonic, 
gives  to  the  chemical  bodies  to  which  it  owes  these  advantages  a 
peculiar  interest. 
Vanilla  is  the  fruit  of  a  climbing  and  branching  plant  which 
grows  in  the  maritime  countries  of  Mexico,  Colombia  and  Guai- 
ana.  The  plant  belongs  to  the  family  Orchidese  and  was  named 
by  Linnaeus  Epidendrum  Vanilla,  and  by  Swartz  under  that 
of  Vanilla  aromatica. 
The  chemical  researches  which  have  been  made  in  vanilla  are 
already  old,  by  Bucholz  and  Vogel.  The  former  found  in  va- 
nilla a  fatty  oil  with  disagreeable  odor ;  a  soft  resin,  which 
when  heated  smelled  weakly  of  vanilla  ;  a  slightly  bitter  extrac- 
tive, resembling  tannin  ;  sugar ;  starchy  matter  and  benzoic 
acid. 
In  these  researches  the  odorous  principle  has  been  entirely 
neglected.  What  is  its  nature  ?  to  what  class  of  chemical  bodies 
does  it  belong  ?  Is  it  constituted  of  an  essential  oil,  or  by  a 
substance  of  a  different  nature  ?  And  in  either  case,  what  are 
the  composition  and  properties  of  the  substance  ?  These  are 
questions  the  author  proposed  to  resolve. 
Vanilla,  properly  divided,  was  exhausted  with  alcohol  of  85°, 
evaporated  to  an  extract,  this  softened  with  water  and  agitated 
in  a  flask  with  ether,  as  long  as  it  cedes  any  color  to  the  ether. 
The  ethereal  liquid  is  evaporated  and  treated  with  boiling  water, 
which  dissolves  the  aromatic  principle  and  gives  it  in  the  form 
of  crystals  by  evaporation  in  an  impure  state,  which  requires 
treatment  with  animal  charcoal  and  recrystallization  to  get  it 
pure. 
Thus  obtained  in  a  state  of  purity,  this  substance  is  color- 
leas,  in  the  form  of  long  four-sided  needles,  terminated  with  two 
faces.  It  presents  a  strong  aromatic  odor  of  vanilla,  and  a  hot, 
biting  taste.  Its  crystals  are  hard  and  crack  under  the  teeth, 
and  are  neutral  to  litmus.  When  heated,  it  fuses  at  195°  F., 
and  volatilizes  at  302°  F.  in  little  needle-shaped  crystals  of  a 
shining  whiteness,  and  possessing  a  sweet  odor  of  vanilla. 
