JEFFERSONIA  DIPIIYLLA. 
5 
have  at  present  a  number  of  astringent  acids  called  tannic,  which, 
like  gallic  acid,  produce  no  precipitates  with  gelatin,  nor  combine 
with  it.  Would  it  not  be  more  appropriate,  and  give  a  better  idea 
of  their  reactions,  to  style  them  gallic,  instead  of  tannic  acids  ? 
Another  portion  of  5000  grains  was  treated  like  the  former,  i.  e. 
a  tincture  made  and  evaporated  to  the  consistency  of  a  syrup,  and 
treated  as  in  the  preparation  of  polygalic  acid.  It  was  washed 
well  with  ether  to  remove  tannic  acid,  and  then  dissolved  in  water 
and  filtered  ;  to  the  filtrate,  solution  of  subacetateof  lead  was  added 
in  excess,  the  precipitate  collected  on  a  filter  and  w7ashed  with 
water.  The  precipitate  suspended  in  water  was  decomposed  by 
means  of  sulphuretted  hydrogen,  filtered  from  the  sulphuret  of 
lead,  the  solution  evaporated,  and  the  extract  exhausted  with 
spirits,  and  evaporated.  The  mass  left  after  evaporation  was  of 
a  light  yellow  color,  transparent,  and  easily  pulverizable,  soluble 
in  water,  soluble  in  alcohol,  from  which  solution  it  was  preci- 
pitated by  the  addition  of  ammonia,  and  yields  precipitates  with 
metallic  salts.  To  the  taste  it  was  acrid  and  nauseous.  I  have 
tried  the  effects  of  its  administration  upon  myself  with  decidedly 
unpleasant  results  ;  both  times  I  tried  it,  it  produced  vomiting 
and  a  sensation  of  nausea  for  some  time  after.  It  is,  I  presume, 
the  acrid  principle  of  the  root,  and  in  some  of  its  properties,  as 
far  as  my  knowledge  extends,  it  is  similar  to  polygalic  acid,  as 
described  in  the  various  works  on  materia  medica. 
Both  the  watery  infusion  and  alcoholic  tincture  of  this  root  pos- 
sess, to  a  very  great  degree,  the  property  of  frothing  upon  agita- 
tion, or  upon  being  poured  from  one  vessel  to  another.  In  this 
respect  it  resembles  senega ;  and  the  isolated  acrid  principle  in 
solution  has  this  property,  which  is  also  characteristic  of  poly- 
galic acid  and  saponin,  a  principle  obtained  from  Saponaria  offi- 
cinalis. 
The  resin  left  upon  the  filter,  in  the  examination  of  the  tannic 
acid,  was  well  washed  with  water ;  in  the  finely-divided  nascent 
state  it  was  of  a  light  yellow  color,  and  bland  to  the  taste.  In  dry- 
ing, the  mass  contracted  very  much,  and  assumed  a  dark  brown 
color,  and  a  resinous  fracture.  It  was  perfectly  soluble  in 
alcohol. 
From  the  above  experiments  upon  the  root  of  this  plant,  its 
organic  constituents  found  are,  albumen,  gum,  tannic  acid,  of  the 
