366  Acids  with  Oil  of  Peppermint.  {^^Si": 
color  and  a  strong  red  fluorescence.  The  rose  coloration  first  pro- 
duced by  the  acids  had  a  violet  reflection.  Moreover,  when  chloro- 
form was  employed  in  the  place  of  ether,  sometimes  a  violet  or  a  grey 
color  was  obtained,  the  latter  being  the  result  of  a  mixture  of  yellow 
and  violet,  or  perhaps  red  and  green,  or  even  blue  and  orange. 
From  the  foregoing,  the  author  concludes  that  the  coloration  pro- 
duced by  picric  acid  when  reacting  upon  the  oil  of  peppermint  is  not 
a  property  peculiar  to  itself,  but  common  to  the  strong  acids;  that 
the  picrate  of  the  hydrocarbide  wThich  he  sought  was  not  produced  ; 
that  it  was  not  a  case  of  oxidation  pur  et  simple  as  might  have  been 
supposed  with  picric  acid.  He  looks  upon  the  coloration  as  a  phe- 
nomenon dependent  upon  the  separation  and  combination  of  the  col- 
oring matters  contained  in  the  oil  of  peppermint.  He  thinks  that  the 
acids  split  up  the  oil  into  five  coloring  principles,  red,  blue,  green, 
yellow  and  violet;  and  that,  according  to  the  quantity  and  nature  of 
the  acid  employed,  one  or  other  of  these  principles  is  obtained,  or 
perhaps  a  grey  resulting  from  a  mixture  of  two  complimentary  colors. 
Relation  of  the  Crreen  Coloring  Matter  to  Chlorophyll. — The  author 
remarks  upon  the  striking  analogy  which  appears  to  exist  between 
the  green  substance  obtained  by  the  action  of  acids  upon  oil  of  pep- 
permint and  chlorophyll,  which  is  set  forth  in  the  following  table : — 
Green  Matter  obtained  by  the  Ac- 
Chlorophyll.  tion  of  Acids  on  Oil  of  Pepper- 
mint. 
Strong  red  fluorescence.  Strong  red  fluorescence. 
Becomes  reddish-yellow   in   the  air     Exposed  to  air,  it  is  changed  into  a 
(dead  leaves).  reddish-yellow  substance. 
Treated  with  alkalies  it  becomes  yel-     Treated  by  alkalies,  it  becomes  yellow. 
low. 
Reduced  and  decolorized  by  nascent  Reduced  and  transformed  into  a  brown 
hydrogen.  matter  by  nascent  hydrogen. 
Yellow  leaves  become  green  by  the  After  being  made  yellow  by  alkalies, 
action  of  acids.  again  becomes  green  when  treated 
with  acids. 
The  green  aud  blue  colors  obtained  The  green  and  blue  colors  obtained 
by  the  action  of  acids  on  chlorophyll  by  the  action  of  acids  upon  oil  of 
are  decomposed  by  light.  peppermint  are  decomposed  by  light. 
This  comparative  table  presents  points  of  great  resemblance,  of 
