170 
Bark  of  Pinus  Echinata. 
Ana.  Jour.  Pharro. 
April,  1899. 
bark,  the  hide  powder  method  was  followed.  This  process  showed 
10-24  per  cent,  of  tanning  material. 
The  small  amount  of  soluble  tannin  met  with  in  the  course  of 
the  above  analysis  indicates  the  readiness  with  which  the  tannin 
of  this  bark  changes  into  phlobaphenes. 
An  attempt  was  made  to  extract  and  purify  the  tannin,  but  this 
proneness  to  decomposition  again  asserted  itself. 
125  grammes  of  the  bark  were  exhausted  with  acetone,  and  the 
solvent  recovered  by  distillation  on  the  water-bath ;  the  extracted 
matter  was  then  treated  with  water,  and  the  mixture  filtered  to  re- 
move insoluble  substances.  The  clear  filtrate  was  agitated  with 
acetic  ether,  and  subsequently  saturated  with  sodium  chloride. 
Upon  separation  of  the  acetic  -ether  layer  and  recovery  of  solvent, 
very  little  residue  was  obtained.  Upon  treatment  with  water  this 
was  changed  almost  entirely  into  phlobaphenes. 
A  small  sample  of  the  extracted  tannin  of  Pinus  echinata  was 
obtained  from  the  collection  of  tannins  owned  by  the  late  Professor 
Trimble. 
It  was  of  a  reddish-brown  color,  had  a  bitter  astringent  taste  and 
was  sparingly  soluble  in  water.  Its  aqueous  solution  gave  the  fol- 
lowing reactions : 
Lead  acetate  Flesh  colored  precipitate. 
Bromine  water  Yellow  precipitate. 
Lime  water    .  .  .  .  Brown  precipitate. 
Ferric  chloride   Green  color  and  precipitate. 
The  material  was  treated  with  several  successive  portions  ot 
ether  to  remove  any  soluble  matter  and  afterwards  thoroughly  dried 
at  1100. 
The  dried  material  was  submitted  to  ultimate  analysis  with  the 
following  percentage  results: 
I.  II, 
Carbon  58*36  5874 
Hydrogen                                                              4*93  4  78 
Oxygen  3671  3648 
The  results  of  the  combustion  as  well  as  the  qualitative  tests,  show 
this  tannin  to  belong  to  the  oak  bark  tannin  group  and  not  to  the 
gall  tannin  group.* 
*  See  Trimble's  "The  Tannins,"  Vol.  II,  p.  132. 
