AV^wiEM-}  Contributions  to  Vegetable  Chemistry.  425 
from  another  point  of  view.  A  genuine  article  may  be  readily 
obtained  at  a  moderate  price,  and  it  may  be  easily  examined ;  but^ 
so  long  as  the  authorities  require  virgin  scammony  to  be  used,  I 
would  recommend  that  the  best  that  can  possibly  be  obtained  be 
bought,  and  this  practice  alone  would  soon  stop  the  admixtures 
abroad,  which  I  cannot  but  think  arise  from  want  of  care  on  the 
part  of  the  collectors,  the  mode  in  which  it  is  collected,  and  the 
temptation  there  is  to  make  weight. 
Let  me  impress  upon  those  who  may  have  any  doubt  upon  the 
subject  that  the  substitution  of  the  cheap  scammony  for  the  scam- 
monium  of  the  B.  P.  in  the  preparations  contained  in  that  book,  or 
where  scammony  is  ordered  by  prescribers,  is  virtually  an  adulter- 
ation. The  B.  P.  states  that  from  eighty  to  ninety  per  cent,  of 
resin  may  be  extracted  by  ether,  but  it  would  be  unreasonable  to 
expect  that  every  pound  in  a  chest  taken  out  separately  would  yield 
that  percentage,  and  therefore  some  margin  should  be  allowed  in  the 
examination  of  such  a  substance  before  it  is  condemned  as  being  adul- 
terated.— Pharm.  Journ.  and  Trans.,  July  18,  1874. 
CONTRIBUTIONS  TO  VEGETABLE  CHEMISTRY. 
By  F.  A.  Hartsen. 
Thamus  Red. — In  order  to  obtain  the  coloring  matter  from  the 
fruit  of  Thamus  communis,  it  is  pressed,  and  the  juice  boiled ;  the 
coloring  matter  is  thus  precipitated  along  with  the  coagulated  albu- 
men. The  color  is  extracted  from  the  dried  precipitate  by  benzene,, 
and  a  further  quantity  may  be  obtained  from  the  dried  pods  by  the 
same  solvent.  On  allowing  the  bright  orange-colored  solution  to 
evaporate,  it  deposits  thamus  red  in  thin  prisms  or  plates,  which  may 
be  freed  from  adhering  fatty  matter  by  boiling  with  a  solution  of  pot- 
assium hydrate,  and  recrystallizing  from  benzene.  It  is  insoluble  in 
water,  readily  soluble  in  alcohol  and  ether,  and  very  soluble  in  ben- 
zene. It  dyes  linen  and  silk,  and  resists  the  action  of  strong  alkalies. 
It  is  not  attacked  by  boiling  nitric  acid,  but  dissolves  in  concentrated 
sulphuric  acid,  with  an  indigo-blue  color. 
Influence  of  the  Time  of  Year  on  Plant  Chemistry. — In  autumn  the 
author  was  unable  to  obtain  chrysophyll  either  from  Ulmus  or  from 
Mercurialis  perennis,  although  both  readily  yielded  it  in  the  spring. 
In  autumn,  too,  the  chlorophyll  obtained  from  plants,  even  before  the 
