AmAp°rnr;imrm"}    Recent  Literature  Relating  to  Pharmacy.  179 
Thus,  he  urges  the  necessity  of  manufacture  by  percolation  with 
appropriate  menstrua,  instead  of  maceration  with  alcohol ;  praising 
the  Swiss  and  British  (1898)  Pharmacopoeias  for  the  innovation 
(method  of  U.S.P.  1 880  !).  Again,  he  praises  the  two  pharmacopoeias 
above  mentioned  as  pioneers  of  assay  of  extracts  of  nux  vomica ? 
opium  and  belladonna.  His  other  conclusions  are  that  dry 
extracts  are  preferable  to  those  of  pilular  consistency,  and  the  best 
method  of  assay  is  that  of  Keller  (see  this  Journal,  1893,  P-  78  ; 
1894,  p.  42;  1897,  p.  450),  the  titration  being  performed  with  iodine 
eosin  as  indicator.  H.  V.  A. 
ESTIMATION  OF  GLYCYRRHIZIN. 
The  following  assay  of  extract  of  glycyrrhiza  is  suggested  by 
B.  Hafner  (Ztschr.  Oest  Af>.  Ver.,  through  Ap.  Zt.,  1899,  558).  To 
IO  grammes  dry  extract  placed  in  Erlenmeyer  flask  is  added  200 
c.c.  95  per  cent,  alcohol  and  then  20  c.c.  normal  sulphuric  acid ;  the 
mixture  being  digested  with  agitation  for  several  hours.  The 
insoluble  residue  is  separated  by  filtration  and  is  washed  on  filter 
with  alcohol  till  filtrate  is  colorless.  To  this  alcoholic  filtrate  is 
added  IOO  c.c.  water  and  enough  ammonia  to  make  it  alkaline. 
Whereupon  the  alcohol  is  evaporated  on  water-bath  and  enough  water 
is  added  to  bring  residue  to  IOO  c.c.  From  this  liquid,  the  glycyr- 
rhizin  is  precipitated  by  diluted  sulphuric  acid  and  the  precipitate 
collected  on  filter  and  washed  with  2  per  cent,  sulphuric  acid  until 
filtrate  is  colorless.  The  filter  containing  precipitate  is  transferred 
to  a  beaker  and  extracted  with  acetone  two  or  three  times,  the 
solution  being  treated  with  excess  of  moist  barium  carbonate  and 
the  acetone  evaporated.  200  c.c.  hot  distilled  water  is  gradually 
added  to  the  residue  with  stirring  and  the  mixture  is  located  on 
water-bath  till  excess  of  barium  carbonate  is  fully  settled.  The 
solution  of  the  barium  compound  of  glycyrrhizin  is  then  filtered 
off  and  the  filter  washed  until  500  c.c.  filtrate  is  obtained. 
The  glycyrrhizin  in  100  c.c.  of  this  filtrate  is  estimated  either  by 
weighing  the  dry  barium  compound  (factor  0-8153)  or  by  convert- 
ing the  barium  to  sulphate  and  weighing  as  such.         H.  V.  A. 
DERIVATIVES  OF  DIGITALIS. 
The  classical  researches  of  Kiliani  on  digitalis  (this  Journal,  1899, 
P-  379)  are  being  continued  by  the  professor  and  his  students. 
He  reports  (Arch.  Pharm.,  1899,  446,  et  sea.)  that  the  formula  of 
