EXAMINATION  OF  OIL  OF  PEPPERMINT. 
105 
EXAMINATION  OF  OIL  OF  PEPPERMINT. 
By  John  M.  Maiscii. 
In  the  last  volume  of  the  Amer.  Journ.  Pharm.,  page  552, 
Mr.  C.  Bullock  has  drawn  attention  to  an  oil  of  peppermint 
which  has  made  its  appearance  in  our  market,  and  which  shows 
in  many  respects  such  a  different  behaviour  from  pure  oil  of 
peppermint,  that  it  has  been  supposed  to  be  an  adulterated 
article.  A  sample  of  the  oil  has  been  subjected  by  Mr.  E. 
Parrish  to  fractional  distillation,  and  besides  the  resinous  res- 
idue in  the  retort  seven  fractions  were  obtained :  1,  below 
300°;  2,  330°;  3,  at  the  boiling  point,  338°;  as  the  boiling  point 
now  rose,  the  following  fractions  were  collected:  4,  below  314°; 
5,  below  360°;  6,  below  430°;  7,  above  430^F.;  all  were  color- 
less except  No.  7,  which  was  of  a  light  yellow. 
These  samples  were  handed  to  me  for  further  examination, 
and  Prof.  Procter  kindly  furnished  me  with  a  specimen  of  oil  of 
fireweed,  (Senecio  hieracifolius,)  which,  it  had  been  suggested, 
might  probably  be  the  adulteration.  I  likewise  obtained  a  sam- 
ple of  double  rectified  German,  of  Borton's,  and  of  an  article 
called  New  Jersey  oil  of  peppermint,  of  oil  of  cedar,  and  pure 
oil  of  spearmint,  for  comparing  the  various  reactions.  It  is  well 
to  state  here,  that  the  above  freshly  distilled  fractions  were 
nearly  inodorous ;  the  faint  smell  could  not  be  distinguished, 
and  only  that  of  the  last  portion  reminded  somewhat  of  pep- 
permint. 
My  experiments  make  it  certain  that  the  oil  has  not  been 
adulterated  by  the  oils  of  fireweed  and  of  cedar;  but  it  appears 
to  me  more  than  probable  that  oil  of  turpentine  is  the  fraudulent 
admixture. 
Oil  of  fireweed  dissolves  at  60°  in  9  parts  of  alcohol,  and  re- 
mains clear  on  the  addition  of  60  parts  more;  it  dissolves  iodine 
at  60°  and  80°,  with  little  reaction,  and  without  the  evolution  of 
vapors,'to  a  pale  brownish  red  liquid,  which  spreads  with  a  green- 
ish color  and  evaporates  entirely  ;  from  an  ethereal  solution  of 
iodine,  it  takes  up  but  little  iodine  and  evaporates,  leaving  a 
soft  resinous  mass  behind  ;  with  an  ethereal  solution  of  bromine 
it  produces  a  hissing  noise,  and  a  yellow  color,  and  evaporates 
without  thickening  previously. 
