AMAugUi;Pi874M'  }      Acids  with  Oil  of  Peppermint  367 
which  the  most  important  doubtless  is  the  fluorescence,  the  red  fluor- 
escence being  characteristic  and  confined  to  these  two  substances. 
Supposing  it  probable  that  in  both  cases  the  appearance  is  due  to 
chlorophyll,  the  author  endeavors  to  explain  its  formation  in  the  oil 
of  peppermint.  He  considers  that  as  his  experiments  were  made  with 
colorless  oil  of  peppermint  it  is  necessary  to  assume  that  the  constit- 
uent elements  of  chlorophyll  exist  in  that  essence  ;  but  probably  they 
exist  there  in  a  state  of  reduction,  and  that  it  is  only  under  the  influ- 
ence of  acids  that  a  kind  of  synthesis  of  the  chromule  takes  place. 
The  blue  principle  (Fremy's  phyllocyanin)  and  the  yellow  principle 
(phylloxanthin)  are,  so  to  speak,  in  a  latent  and  colorless  state,  either 
in  consequence  of  reduction  or  their  combination  with  the  other  color- 
ing principles  present  in  the  oil.  Under  the  influence  of  acids  the 
phyllocyanin  is  regenerated,  and  at  the  same  time  the  phylloxan- 
thin, separated  from  the  red  and  violet  principles,  unites  with  the 
blue  especially  to  form  the  green  color.  With  picric  acid  and  nitric- 
acid  the  green  coloration  is  more  intense  than  with  the  other  acids? 
because  an  oxidizing  action  is  combined  with  a  separative  action. 
According  to  this  hypothesis,  which  the  author  proposes  to  test  by 
further  experiment,  chlorophyll,  or  at  least  its  constituents,  are  vola~ 
tilizable  in  the  state  in  which  it  actually  exists  in  oil  of  peppermint, 
The  greenish  color  which  is  seen  in  the  oil  when  imperfectly  rectified 
wouldt  hen  be  due  probably  to  chlorophyll,  of  which  the  elements  have 
not  been  completely  altered  in  a  first  distillation. 
Action  of  adored  upon  Oil  af  Peppermint. — The  rose  coloratioB 
which  takes  place  when  hydrate  of  chloral  is  shaken  with  oil  of  pep- 
permint, which  was  pointed  out  by  M.  Carl  Jehn,*  has  also  been  the 
subject  of  experiment  by  the  author.  He  has  come  to  the  conclusion 
that  the  color  is  produced  in  the  oil  of  peppermint  and  not  in  the 
chloral  hydrate,  and  that  it  only  occurs  when  the  chloral  hydrate  used 
is  acid,  it  being  more  intense  in  proportion  as  the  chloral  hydrate  i» 
more  acid.  But  he  has  not  yet  been  able  to  experiment  with  per- 
fectly neutral  specimens.  In  this  case  the  reaction  would  be  due  to 
the  formic  acid  contained  in  the  chloral  hydrate,  or  possibly  to  hydro- 
chloric acid  resulting  from  partial  decomposition. — Pliarm.  Journ, 
and  Trans.,  June  6,  1874. 
*  See  Pharmaceutical  Journal,  before,  p.  556;  Amer.  Jour,  of  Phar.,  1873,  p, 
447  ;  compare  also  Amer.  Jour.  Phar.,  1874,  p.  273. 
