548 
COLORING  MATTERS  OF  FLOWERS. 
Effects  of  the  Mixture  of  the  White  and  Colored  Juices  of 
Flowers-  —When  flowers  of  iris,  of  violets,  of  pasonies,  of  Cercis 
siliquastrum,  &c,  are  infused  in  alcohol,  one  is  struck  with  the 
weakness  of  tint  of  the  alcoholic  solution,  even  when  the  petals 
are  completely  deprived  of  color.  It  appears  natural,  at  first  sight, 
to  attribute  this  decoloration  to  the  influence  of  the  alcohol,  which 
may  act  as  a  reducing  agent ;  but  a  close  examination  of  the  facts 
does  not  permit  us  to  rest  satisfied  with  this  explanation  ;  and 
without  denying  that  alcohol  may  exercise  the  influence  attributed 
to  it  by  MM.  Fremy  and  Cloez,  I  think  that  the  following  theory, 
either  alone  or  combined  with  that  just  referred  to,  may  readily 
account  for  the  circumstances  in  question.  In  fact,  if,  instead  of 
treating  the  above-mentioned  flowers  with  alcohol,  they  are  infused 
in  boiling  water,  the  watery  -  solution  is  not  more  deeply  colored 
than  the  alcoholic  tincture.  It  would  be  necessary,  therefore,  to 
admit  that  water  itself  is  a  reducing  agent,  which  is  by  no  means 
probable. 
If  into  these  solutions,  whether  watery  or  alcoholic,  the  smallest 
quantity  of  a  soluble  acid  be  poured,  they  instantly  acquire  a  bright 
red  color,  far  deeper  in  tint  than  the  original  liquid.  The  kind  of 
acid  is  quite  immaterial,  for  even  sulphurous  acid  immediately 
brightens  the  shade,  and  reproduces  the  color  which  was  only  con- 
cealed. The  prolonged  action  of  this  acid,  however,  soon  destroys 
the  color.  Can  it  be  imagined  that  the  coloring  matter  would  re- 
appear immediately  upon  the  addition  of  any  acid,  if  it  had  been 
reduced  %  And  especially  on  this  hypothesis,  can  we  account  for 
the  action  of  sulphurous  acid  ?    I  think  not. 
In  my  opinion,  the  decoloration  is  due  to  the  mixture  of  the  juice 
contained  in  the  colorless  cells  with  that  of  the  colored  cells.  When 
alcohol  or  boiling  water  acts  upon  a  flower,  its  organization  is 
destroyed,  the  juices  contained  in  its  cells  becomes  mixed,  and  the 
coloring  matter  disappears.  The  following  experiment  lends  sup- 
port to  this  explanation. 
If  two  equal  volumes  of  a  slightly  acidulated  infusion,  either 
watery  or  alcoholic,  of  paeony  flowers,  be  diluted,  the  one  with 
four  times  its  volume  of  water,  the  other  with  four  times  its  volume 
of  an  infusion  of  white  flowers,  it  will  be  seen  that  the  latter  will 
retain  much  less  color  than  the  former. 
The  white  juices  consequently  destroy,  or  rather  dissemble  the 
