^""^rissi!'"  }  Color  of  Floivers.  255 
Last  year  M.  Gallais  made  the  experiment  of  drying  the  root  in  the 
sun,  but  the  result  was  not  satisfactory.  The  thick  pieces  dried  slowly 
iind  became  completely  decolorized,  instead  of  retaining  their  dirty 
yellow  tint,  whilst  the  cellular  tissue  underwent  a  considerable  altera- 
tion, due  to  a  slight  fermentation.  M.  Gallais  considers  that  these 
alterations  would  be  prevented  by  a  rapid  drying,  and  the  juice  being 
concentrated  in  the  interior  of  the  piece  its  aroma  would  be  preserved, 
whilst  the  pieces  would  consequently  acquire  a  commercial  value  in 
proportion  to  their  thickness. 
M,  Gallais'  operations  have  as  yet  been  carried  on  upon  a  limited 
scale,  but  he  makes  an  estimate  in  which  he  values  the  product  at  six 
francs  per  kilogram,  from  which  it  would  appear  that  the  cultivation 
could  be  carried  on  profitably. — Phar.  Jour,  and  Trans.,  March  12. 
THE  COLOR  OF  FLOWERS. 
At  a  recent  meeting  of  the  Vaudois  Society  of  Natural  Science, 
Professor  Schnetzler  read  an  interesting  paper  on  the  color  of  flowers. 
Hitherto  it  has  generally  been  supposed  that  the  various  colors  observed 
in  plants  were  due  to  so  many  different  matters — each  color  being  a 
different  chemical  combination  without  relation  to  the  others.  Now, 
however.  Professor  Schnetzler  shows  by  experiment  that  w^hen  the 
color  of  a  flower  has  been  isolated  by  putting  it  in  alcohol,  one  may, 
by  adding  an  acid  or  an  alkali,  obtain  all  the  colors  which  plants 
exhibit.  Plants  of  Pseony,  for  example,  yield,  when  macerated  in 
alcohol,  a  violet-red  liquid.  If  some  acid  oxalate  of  potassa  be  added, 
the  liquid  becomes  pure  red ;  while  soda  changes  it,  according  to  the 
proportion  used,  into  violet,  blue  or  green.  In  the  latter  case,  the 
green  liquid  appears  red  by  transmitted  light  just  as  a  solution  of 
chlorophyll  does.  The  sepals  of  Pseony,  which  are  green  bordered 
with  red,  become  wholly  red  when  placed  in  a  solution  of  acid  oxalate 
(binoxalate)  of  potassa.  These  changes  of  color,  which  may  be  / 
obtained  at  will,  may  quite  well  be  produced  in  the  plant  by  the  same 
causes;  since,  in  all  plants,  there  always  exist  acid  or  alkaline  matters. 
Further,  it  is  stated  that  the  transformation  from  green  into  red, 
observed  in  the  leaves  of  many  plants  in  autumn,  is  due  to  the  action 
of  the  tannin  which  they  contain,  on  the  chlorophyll.  Thus,  without 
desiring  to  affirm  it  absolutely.  Professor  Schnetzler  supposes,  d  jwiori, 
that  there  is  in  plants  only  one  coloring  matter — chlorophyll,  which, 
