214 
Rhus  Aromaticd. 
(  Am.  Jour.  Phaim. 
X      May,  1881. 
milk  of  lime,  nitrate  of  silver  and  ferric  salts,  identical  Avith  those 
produced  by  gallic  acid ;  this,  therefore,  seems  to  be  a  gallotannin. 
a^.  Filtrate  from  precipitate  by  subacetate  of  lead. — The  lead  was 
precipitated  by  hydrosulphuric  acid,  the  filtrate  boiled  to  free  from 
;  concentrated  and  divided  into  several  portions : 
1.  Acid  reaction  (from  the  acetic  acid  of  the  lead),  mercurio-potassic 
iodide  gave  no  precipitate ;  absence  of  alkaloids. 
2.  Solution  of  iodine  in  potassium  iodide ;  no  precipitate ;  absence 
of  alkaloids. 
3.  Reduces  Fehling's  solution  Avithout  heating ;  glncose. 
4.  Evaporated  to  dryness,  the  residue  had  a  sweet  taste  and  a 
somewhat  aromatic  odor ;  was  soluble  in  water  and  alcohol  and  con- 
sisted of  two  portions,  one  soluble  in  a  mixture  of  alcohol  and  ether 
(3  to  1),  the  other  insoluble  in  this  menstruum.  Both  reduced  Fehling's 
solution  without  the  aid  of  heat  and  were  consideeed  to  be  "  extrac- 
tive'^ matter  and  glucose. 
b.  Insoluble  in  nmter. 
b^.  Soluble  in  dilute  sidpliuric  acid. — Coloring  matter  only ;  soluble 
when  heated,  deposited  upon  cooling.  Negative  reactions  for  glucosides 
and  alkaloides. 
Ir.  Insoluble  in  dilute  sulphuric  acid. — Entirely  soluble  in  dilute 
amnionic  hydrate,  reprecipitated  upon  the  addition  of  an  acid.  This 
was  considered  to  be  an  acid  resin ;  it  was  thoroughly  washed  and  its 
characteristics  noted  as  follows  :  Blackish-brown  color,  brittle,  lustrous, 
opaque  in  mass,  translucent  in  scales.  Odor  and  taste  similar  to  that 
of  parched  coffee  ;  concentrated  alcoholic  solution  has  an  acid  reaction.. 
Insoluble  in  cold  water,  ether,  benzol  and  dilute  acids ;  soluble  in 
boiling  Avater  (reprecipitated  upon  cooling),  alcohol  and  alkalies.  Con- 
centrated sulphuric  acid  dissoh^es  it  sloAvly  ;  the  solution  is  dark-brown 
at  first,  assuming  a  pinkish  hue  around  the  edges  upon  standing. 
Ferric  salts  give  a  black  precipitate  not  unlike  that  produced  by  tan- 
nin. Its  solution  in  alcohol  is  Avholly  precipitated  by  an  alcoholic 
solution  of  acetate  of  lead,  the  precipitate  being  of  a  yelloAvish  color 
at  first,  but  changes  to  a  dark-broAvn.  The  resin  is  dissipated  at  a  red 
heat,  and  Avhen  boiled  AA^th  dilute  sulphuric  acid,  the  solution  treated 
with  barium  carbonate  to  get  rid  of  the  acid,  the  resulting  solution  does 
not  reduce  Fehling's  solution— proving  that  the  substance  is  not  a. 
glucoside. 
