Am.  Jocr.  Phakm.  ) 
March  1,  1872.  / 
The  Odors  of  Plants. 
121 
cose  is  dissolved ;  the  ehrysophanine  is  best  obtained  by  treating  the 
cathartine  first  with  ether,  next  dissolving  it  in  water,  and  precipitating 
that  solution  with  acetate  of  lead,  the  ehrysophanine  combining  with 
lead,  and  being  set  free  by  treating  this  lead  compound  with  sulphur- 
etted hydrogen.  Y\rhen,  however,  it  is  desired  to  obtain  a  large  quan- 
tity of  ehrysophanine,  it  is  best  to  work  with  a  strong  senna  infusion, 
from  which  the  mucilage  is  thrown  down  by  means  of  alcohol,  the 
clear  solution  next  treated  with  neutral  acetate  of  lead  solution,  fur- 
ther treatment  with  sulphuretted  hydrogen,  filtration,  evaporation  of 
the  clear  liquid  to  syrupy  consistence,  and  precipitation  with  alcohol 
at  90  per  cent.  ;  the  precipitate  (crude  ehrysophanine)  is  purified  by 
means  of  alcohol,  until  that  liquid  runs  off  colorless.  The  properties 
of  ehrysophanine  will  be  described  by  the  author  in  another  paper. — 
Ohem.  News,  Jan.  19,  1872,  from  Compt.  rend.,  Bee.  18,  1871. 
THE  ODORS  OF  PLANTS  * 
By  James  Britten. 
The  subject  of  the  phenomena  of  odor  and  color  in  plants,  and  of 
the  causes  which  induce  or  govern  them,  is  one  of  considerable  inter- 
est ;  and  the  relations  which  exist  between  the  two  are  sufficiently 
striking.  Thus,  it  has  been  statistically  ascertained,  and  a  very  little 
reflection  will  confirm  the  conclusion,  that  white  flowers  stand  highest 
in  number  among  fragrant  species,  next  yellow,  then  red,  and  lastly, 
blue.  And  it  is  among  white  flowers  that  disagreeable  odors  are  most 
seldom  found,  while  orange  and  brown  are  frequently  unpleasant  in 
scent.  In  such  calculations,  however,  it  must  be  remembered  that 
the  appreciation  of  odors  is  by  no  means  the  same  to  different  people  : 
scents  which  are  agreeable  to  one,  are  often  the  reverse  to  another. 
The  strong  odor  of  Tagetes  patida  and  T.  erecta  is  not  objectionable 
to  some  ;  while  others,  besides  the  well-known  fox  hunter,  are  of 
opinion  that  the  Sweet  Violet  is  a  "  stinking  flower."  There  are  even 
some  unhappy  beings — we  trust  they  are  but  few — who  cannot  endure 
the  scent  of  a  rose.  The  sense  of  smell,  too,  is  much  more  acute  in 
some  persons  than  in  others ;  and  we  have  frequently  remarked  an 
analogy  to  color-blindness  in  the  want  of  perception  of  odors  mani- 
fested by  some  among  our  friends. 
A  good  summary  and  comparison  of  scents  will  be  found  in  M. 
*  Reprinted  from  the  Gardener's  Chronicle. 
