which  is  soluble  in  alcohol,  acetone  and  ethyl  acetate.  Recrystallized  from
any  of  these  it  forms  fine  dark  brown  needles,  but  only  in  small  quantities,
the  majority  separating  out  again  in  an  amorphous  condition.  This  is  the
.glucoside  of  Cascara  Sagrada  which  we  have  named  purshianin,  analo-
gously to  the  glucoside  frangulin  obtained  from  rhamnus  frangula.  That
portion  of  the  residue  from  the  80  per  cent,  alcohol  extract  found  to  be
insoluble  in  absolute  alcohol  was  treated  with  hot  water  and  the  resulting
solution  treated  similarly  with  basic  lead  acetate.  The  result  was  a  dirty
yellow  precipitate  which,  after  removal  of  the  lead,  gave  a  dark  brown
resinous  substance,  different  in  color  from  that  obtained  from  the  portion
soluble  in  absolute  alcohol.  We  will  enter  into  the  details  of  the  work  on
these  glucosides  later.
v.    HOT  WATER  EXITIACT.
The  residue  from  the  absolute  alcohol  extraction,  which  had  now  as-
sumed a  dark-brown  color  and  was  practically  devoid  of  taste,  was  macer-
ated for  twelve  hours  with  water  and  then  filtered.  The  aqueous  extract
was  evaporated  to  dryness  and  found  to  represent  about  12.3  per  cent,  of
the  weight  of  the  original  air-dried  drug.  It  had  a  dark  brown  color  and
was  devoid  of  any  taste.  The  residue  from  this  aqueous  extract  was  boiled
with  dilute  sulphuric  acid  (i  :  100)  to  invert  all  starches  present,  and  the
residue  filtered  off  and  dried.  The  amount  of  the  starches,  sugar,  etc.,
so  extracted  was  not  determined,  but  will  appear  in  the  final  resume  of  the
analysis  as  difference  after  everything  else  has  been  determined.
VI.   DILUIE   ALKAU   EXTRACT.
