440  Viburnum  Prunifolium,  {^"l^Ipt'xssa'"- 
dark  green  color,  and  ether  afterwards  dissolved  a  small  portion  of  bit- 
ter principle.  On  evaporating  the  residue,  it  was  found  to  be  readily 
soluble  in  water,  the  solution  giving  no  reaction  with  gelatin,  but  with 
salts  of  iron  a  dark  green  color  was  produced.  Only  a  small  portion 
of  the  bitter  principle  was  found  to  be  soluble  in  chloroform. 
The  aqueous  extract  was  treated  with  acetate  of  lead,  but  only  a 
small  portion  of  coloring  matter  was  removed,  the  resulting  liquid 
being  of  a  light  brown  color.  To  this  sulphate  of  sodium  was  added, 
evaporated  to  dryness,  and  the  bitter  ^principle  taken  up  with  stronger 
alcohol,  which  on  evaporating  left  a  syrupy  liquid  of  a  very  bitter  taste. 
Finding  it  impossible  to  obtain  the  bitter  principle  pure,  the  follow- 
ing course  was  tried  :  Two  pounds  of  bark  on  being  exhausted  with 
stronger  alcohol  gave  a  dark  brown  percolate,  to  which,  on  evaporat- 
ing, acetate  of  lead  was  added,  and  by  filtering,  a  portion  of  the  color- 
ing matter  was  removed.  To  this  filtrate  sulphate  of  sodium  was 
added,  and  evaporated  to  dryness,  and  bitter  principle  taken  up  by  alco- 
hol fortior  ;  percolation  through  animal  charcoal  failed  to  remove  any 
of  the  color.  This  alcoholic  solution  was  then  evaporated  to  dryness, 
dissolved  in  water,  and  again  treated  with  animal  charcoal,  when  a 
iportion  of  the  coloring  matter  was  removed,  but  the  percolate  was  still 
slightly  colored.  A  small  portion  was  evaporated  and  treated  with  ether 
and  chloroform,  but  nothing  was  taken  up  by  these  solvents.  The 
aqueous  percolate  was  then  treated  by  dialysis,  and  the  resulting  liquid 
was  found  to  be  still  slightly  colored,  very  bitter,  and  to  give  a  copious 
precipitate  with  Trommer's  test  for  sugar.  Various  solvents  were 
used  to  obtain  the  bitter  principle  free  from  the  sugar,  such  as  a  mix- 
ture of  equal  parts  of  alcohol  and  ether,  stronger  ether,  benzin,  chlo- 
roform, carbon  bisulphide,  or  to  precipitate  it  with  mercury  bichloride, 
but  it  was  not  affected  by  any  of  these  reagents.  It  is  probably  a  glu- 
coside,  or  allied  sugar.  The  alcoholic  solution  gave  negative  results 
with  the  general  tests  for  alkaloids. 
Examination  of  Coloring  Matter. — That  portion  which  was  precipitated 
by  acetate  of  lead  was  dissolved  in  boiling  water  ;  sulphuretted  hydro- 
gen gas  was  passed  into  this,  giving  it  a  dark  red  color  ;  this  was  con- 
tinued as  long  as  a  precipitate  was  produced,  then  filtered  and  evapo- 
rated to  dryness  and  dissolved  in  water,  when  it  gave  the  following 
results  :  With  solution  of  gelatin,  a  light  brown  precipitate  of  tannin  ; 
with  chloride  of  iron,  a  greenish-black  ;  with  subacetate  of  lead,  light 
gray  ;  with  sulphate  of  copper,  light  green  ;  and  when  evaporated  to  dry- 
