1 68  Canaigre  Tannin.  { A%JP°rU'Sar"m 
Action  of  Fused  Alkali. — One  gram  was  gradually  added  with  con- 
stant stirring  to  potassium  hydrate  in  the  fused  state.  Efferves- 
cence occurred  and  an  odor  resembling  that  produced  in  making 
soap  from  rancid  fat  was  noticed  (fusing  alkali  alone  did  not  give 
this  odor).  The  fusion  was  allowed  to  become  cold  and  solid,  when 
it  was  treated  with  water  which  produced  a  clear  and  perfect  solu- 
tion. The  alkali  was  supersaturated  with  dilute  sulphuric  acid,  the 
slight  excess  of  which  was  neutralized  with  acid  sodium  carbonate 
and  the  unfiltered  mixture  shaken  with  ether,  sp.  gr.  725,  which 
upon  evaporation  left  a  yellow  residue  which  was  destitute  of  sweet 
taste  (absence  of  phloroglucin),  almost  completely  soluble  in  hot 
water,  the  remainder  dissolved  in  alcohol.  The  pale  yellow  water 
solution  reacted  as  follows  : 
{dark  green  color,  changed  to  deep  red 
upon  adding  excess  of  sodium  car- 
bonate. 
Ferrous  sulphate,     ....      in  a  neutral  solution,  violet  color. 
Ammoniacal  silver  nitrate,  reduced. 
Basic  lead  acetate,    ...      brownish  ppt. 
Neutral  lead  acetate,  .  .  .  {  brownish  PP*-.  the  filtrate  was  further 
t     precipitated  by  basic  lead  acetate. 
Fehling's  solution,  ....      no  change  (absence  of  phloroglucin) . 
Pine  wood,  saturated  with  the  solution,  dried  and  moistened  with 
hydrochloric  acid,  turned  yellowish  (phloroglucin  produces  violet 
or  red  color).    The  above  reactions  indicate  protocatechuic  acid. 
Acetyl  Derivative. — 0-5  gram  of  the  tannin  were  boiled  with  a 
few  cubic  centimetres  of  acetic  anhydride  for  an  hour.  The 
solution  was  poured  into  a  relatively  large  bulk  of  water  when  the 
greater  part  of  the  derivative  coalesced  to  form  a  plastic  semi-solid, 
the  remainder  separating  in  an  indistinctly  granular  form.  The 
plastic  portion  was  kneaded  under  the  water  and  the  granular  por- 
tion washed  by  stirring.  After  standing  over  night,  the  coalescence 
had  become  a  yellow  solid. 
The  product  was  collected,  dried  over  sulphuric  acid,  powdered, 
washed  well  with  water  and  again  dried  over  sulphuric  acid.  The 
drying  was  completed  at  from  75 0  to  8o°  C,  above  this  tempera- 
ture decomposition  occurred  as  was  shown  by  the  acetous  odor 
exhaled.  Determinations  of  the  melting  point  were  undertaken, 
but  it  was  noticed  that  considerable  variation  existed. 
A  larger  quantity  of  the  derivative  was  heated  in  a  test  tube  on 
