AN  ESSAY  ON  GILLENIA  TRIFOLIATA. 
201 
absolute  alcohol.  The  tincture  thus  obtained  was  of  a  red  color, 
possessing  the  odor  and  taste  of  the  root  ;  the  result  of  the  addi- 
tion of  a  few  drops  of  the  tincture  of  chloride  of  iron,  was  a 
blue-black  precipitate  (which  was  not  dissipated  bj  heat.) 
Gelatin  threw  down  a  white  precipitate,  proving  the  presence  of 
tannic  acid. 
Experiment  2d.  The  alcoholic  tincture  thus  obtained  was 
evaporated  to  the  consistence  of  an  extract ;  this  was  then  treated 
with  cold  water,  and  the  solution  filtered  and  evaporated  to  a 
syrupy  consistence,  spread  on  glass  and  dried.  The  water  took 
up  most  of  the  coloring  matter  and  tannic  acid,  with  a  small  por- 
tion of  the  active  principle,  which  made  the  product  assume  a 
reddish-brown  color,  with  an  astringent  and  bitter  taste,  very 
deliquescent  and  soluble  ;  this  is  impure  gillenin. 
Experiment  3d.  Another  process  was  then  resorted  to  in 
order  to  obtain  gillenin  in  a  pure  form  :  thus,  a  portion  of  the 
impure  article  was  dissolved  in  water,  acidulated  with  sulphuric 
acid,  and  magnesia  added  to  saturation.  The  solution  was  then 
evaporated,  and  the  residuum  dried,  powdered,  digested  in  strong 
alcohol  and  filtered.  The  solution  was  then  concentrated  and  dried 
with  a  gentle  heat.  But  the  result  was  unsatisfactory,  for  though 
deprived  of  tannic  acid,  it  still  contained  a  large  quantity  of 
coloring  matter,  which  occasioned  deliquescence. 
Experiment  4ih.  The  substance  which  remained  after  the 
alcoholic  extract  was  treated  with  water,  had  a  resinous  appear- 
ance, a  very  bitter  taste,  and  a  marked  odor  of  the  root ;  this 
was  macerated  in  water,  acidulated  with  sulphuric  acid  for  ten 
days  and  filtered,  then  saturated  with  magnesia,  evaporated  and 
dried.  To  this,  alcohol  was  added  for  the  purpose  of  taking  up  the 
active  principle,  this  was  filtered  and  the  solution  set  aside  and 
allowed  to  evaporate  spontaneously.  The  residue  was  collected 
from  oif  the  sides  and  bottom  of  the  capsule  and  reduced  to 
powder. 
PHYSICAL  AND    CHEMICAL    PROPERTIES  OF  GILLENIN. 
It  is  whitish,  unalterable  in  the  air,  having  a  slight  odor  and 
very  bitter  taste,  soluble  in  water  and  alcohol  either  cold  or  hot, 
ether,  and  dilute  acids ;  neutral  to  test  paper ;  concentrated 
nitric  acid  produces  a  blood  red  color,  chromic  acid  a  fine 
green  color.   No  change  is  observable  on  the  addition  of  tannic 
