Am.  Jour.  Pharra.  \ 
December,  1897.  / 
Chemistry  of  Clove  Oil. 
639 
The  low  specific  gravity  of  the  oil  distilled  from  clove  stalks,  as 
compared  with  the  large  amount  of  eugenol  it  contains,  is  explained 
by  the  absence  of  aceteugenol,  the  relation  between  the  specific 
gravity  and  the  amount  of  eugenol  in  the  case  of  clove  oil  being 
due  to  the  presence  of  some  aceteugenol,  the  specific  gravity  of 
which  is  much  greater  than  that  of  eugenol. 
On  saponifying  clove  oil  with  a  known  quantity  of  alcoholic 
potash,  and  determining  the  residual  free  alkali,  a  result  was  obtained 
indicating  the  presence  of  a  much  larger  quantity  of  aceteugenol 
than  was  actually  present,  and  this  was  ascertained  to  be  due  to  the 
presence  of  a  compound  yielding  salicylic  acid,  the  occurrence  of 
which  in  clove  oil  was  pointed  out  by  Schenck,3  but  disputed  by 
Wassermann.4 
By  merely  shaking  clove  oil  with  solution  of  caustic  alkali,  no 
indication  of  salicylic  acid  is  obtained  ;  but  after  the  saponification 
effected  by  boiling  with  soda  solution,  salicylic  acid  can  be  detected 
in  the  aqueous  liquor.  It  is  suggested  that  the  compound  present 
in  clove  oil,  and  yielding  salicylic  acid  by  saponification,  may  be 
eugenol  ester  of  acetyl  salicylic  acid. 
The  yellow  coloration  produced  on  treating  clove  oil  with  caustic 
alkali  was  suggestive  of  the  presence  of  an  aldehyde,  and  a  product 
was  obtained  which  proved  to  be  furfurol,  a  substance  which  Messrs. 
Schimmel  have  also  found  in  clove  oil,  together  with  normal  amyl- 
methyl  ketone,  to  which  they  attribute  some  influence  as  to  the 
cause  of  the  ether-like  odor  of  clove  oil,  which  a  mixture  of  eugenol, 
caryophyllene  and  furfurol  does  not  possess. 
Erdmann  also  suggests  that  eugenol  is  probably  not  the  only 
phenolic  constituent  of  clove  oil,  because  the  boiling-point  of  the 
crude  product  has  a  wider  range  than  is  consistent  with  its  chemical 
individuality,  and  also  because  in  redistilling  eugenol  he  has  obtained 
a  residue  of  phenolic  character,  though  its  resinoid  character  did 
not  invite  further  investigation. 
3  Ann.  Lhem. ,125,  14. 
*  Ann.  Chem.,  179,  369. 
