^ 
4  JEFFERSONIA  DIPIIYLLA. 
separated  by  filtration.  To  the  filtered  liquid,  hydrochloric  acid 
was  added,  which  caused  a  slight  precipitate  to  fall ;  it  was  sepa- 
rated and  washed  on  the  filter,  and  dissolved  in  boiling  alcohol,%from 
which  it  separated  on  cooling,  and  upon  the  evaporation  of  the  alco- 
hol assumed  an  amorphous  shape.  The  amount  obtained  was  so 
small  that  I  had  not  sufficient  of  ft  to  examine  it  as  I  should  have 
wished,  and  shall  take  another  opportunity  of  examining  it  ;  it 
had  a  peculiar  bitter  taste,  was  soluble  in  water  and  also  in  boiling 
alcohol,  from  which  it  was  deposited  upon  cooling. 
I  deemed  it  useless  to  make  any  further  search  for  an  alkaline 
principle,  aware  that  of  plants  of  the  order  Berberidaceae,  so  far  as 
they  have  been  examined,  none  has  been  found,  unless  berberine 
may  be  classed  as  such,  which  is  doubtful  ;  it  forms  compounds 
with  acids,  (not  true  salts,)  soluble  with  difficulty.  I  consequently 
turned  my  investigations  to  the  isolation  of  the  peculiar  acrid  prin- 
ciple of  the  plant,  upon  which  its  medicinal  properties  depend, 
and  some  further  investigation  of  its  peculiar  tannic  acid.  And 
with  this  view  5000  grains  of  the  root  were  digested  with  alco- 
hol for  twenty-four  hours,  then  placed  in  a  percolator  and  treated 
with  alcohol  until  it  passed  almost  tasteless ;  the  tincture  was  of  a 
dark  brown  color,  it  was  evaporated  to  a  syrupy  form,  and  water 
added  ;  the  fatty  and  resinous  matter  separated  by  filtration  ;  to 
the  filtered  liquid  neutral  acetate  of  lead  was  added  as  long  as  it 
produced  a  precipitate  ;  the  precipitate  was  collected  on  a  filter, 
washed,  and  decomposed  under  alcohol  by  sulphuretted  hydrogen, 
the  liquid  heated  to  expel  the  excess,  and  filtered  to  separate 
the  lead.  In  its  behaviour  with  re-agents  it  gave  the  same  results 
as  the  tannic  acid  of  Asperula  odorata,  which  has  been  examined 
by  R.  Schwartz,  (see  Chem.  Gaz.,  No.  224,)  and  strikes  with  sesqui 
salts  of  iron  a  dark  green  color  ;  alkalies  cause  the  liquid  to  as- 
sume a  brown  red  color,  which  by  exposure  and  absorption  of  oxygen 
becomes  finally  opaque  and  blackish  brown.  Albumen,  gelatin  and 
t  artar  emetic  produced  no  precipitates.  Peroxide  of  copper  caused  a 
dark  green  color,  and  both  the  neutral  and  the  basic  lead  salts  caused 
yellow  precipitates.  I  would  here  take  the  occasion  to  ask  the  ques- 
tion is  not  the  appellation  of  tannic  to  acids  of  the  behaviour  to 
reagents  mentioned'a  misnomer  1  The  most  characteristic  reaction 
of  tannic  acid  is  that  of  forming  a  precipitate  with  gelatin,  or  of 
combining  with  it  in  the  process  of  tanning,  forming  leather.  We 
