THE  COLORING  PRINCIPLES  OF  BUCKTHORN  BERRIES.  331 
porated  to  dryness,  and  the  residue  treated  with  alcohol,  to  re- 
move the  quinia  present.  The  alcoholic  liquid  is  evaporated, 
dried  at  100  C,  weighed,  and  then  calcined  to  deduct  the  inor- 
ganic matter  taken  up  by  the  spirit. 
When  a  sulphuric  solution  of  quinia  is  precipitated  by  ammo- 
nia or  soda,  the  precipitate  must  be  washed  until  the  washings 
cease  to  affect  chloride  of  barium,  because  some  subsulphate  of 
quinia  is  always  thrown  down  with  the  precipitate.  To  recover 
the  quinia  dissolved  by  washing,  the  liquors  are  evaporated  to 
dryness  and  the  residue  treated  with  alcohol.  M.  Sestini  gives 
the  following  formulae  for  the  arseniates  of  quinia  analysed  by 
him : 
2  (C20  H24     0,)  As  0,  Ha  +  8H2  0. 
2  (C20  H,,     0,)  As  0,  H3  +  6H3  0. 
C20  H24  N2     As  O4  H3  +  2H2  0. 
— Pharm.  Journ.,  London^  May,  1869. 
ON  THE  COLORING  PRINCIPLES  OF  BUCKTHORN 
BERRIES. 
By  W.  Stein. 
The  author  used  for  his  experiments  olive  green  berries.  After 
having  removed  the  fat,  by  boiling  with  petroleum  ether,*  a 
portion  was  exhausted  with  water  and  alcohol,  and  the  liquids 
precipitated  by  acetate  of  lead,  &c.  Another  portion  was  ex- 
hausted by  80  per  cent,  alcohol,  water  and  ether.  Thus  the 
author  succeeded  to  obtain  a  pure  coloring  principle  soluble  in 
•  water  (rhamnin),  one  insoluble  in  water  (rhamnetin),  a  principle 
precipitated  by  gelatin  (rhamnotannin),  a  nitrogenous  compound 
(rhamnin  ferment),  and  a  gum  (rhamnin  gum). 
Rhamnin  is  contained  in  the  aqueous  infusion  besides  gum 
and  tannin ;  the  gum  is  first  precipitated  by  alcohol,  after  which 
ether  separates  the  coloring  ;^matter  in  yellow  floccules,  which, 
washed  with  ether  and  dried  in  vacuo,  constitute  a  yellow  mass 
in  a  spongy  condition  like  tannin.  The  floccules  liquify  very 
readily  before  they  are  dry,  and  leave  then,  on  evaporation,  a 
gum-like  mass.    If  an  alcoholic  solution  of  rhamnin  is  evapo- 
*  The  so-called  benzine  of  American  commerce. 
