Amju?yri92iarm '\        Glycyrrhizin  in  Licorice  Root.  469 
purification,  as  well  as  a  more  convenient  manipulation,  since  the 
acetone  causes  violent  bumping,  when  evaporated  from  the  tall 
beaker.  Zetsche  in  criticising  HafTner,  proposjes  to  avoid  this  bump- 
ing by  using  barium  hydrate  and  a  large  porcelain  dish. 
Linz  points  out  that  the  clumsy  and  inconvenient  method  of 
Haffner  will  not  justify  itself  unless  his  statement  had  been  correct, 
i.  e.,  "The  higher  the  barium  content,  the  purer  the  glycyrrhizic  acid," 
and  Linz  clearly  shows  experimentally,  that  the  statement  does  not 
hold,  and  that  other  constituents  of  licorice,  those  of  acid  nature, 
will  form  barium  salts,  and  so  increase  the  result.  Zetsche  objects 
to  Haffner's  method  of  obtaining  barium  sulphate,  and  also  believes  * 
that  500  cc.  water  are  not  enough  to  dissolve  the  barium  glycyrrhizin- 
ate,  but  Linz  does  not  support  either  of  these  objections  of  Zetsche. 
(P.A.H.)] 
Linz  summarizes  his  views  of  Haffner's  method  as  follows : 
"1.  The  method  is  more  troublesome  than  others. 
"2.  The  values  are  lower  than  one  would  expect,  from  the  re- 
sults of  other  methods. 
"3.  Values  obtained  agree  well  with  one  another. 
"4.  I  cannot  prove  direct  sources  of  error  in  Haffner's  method, 
but  the  low  yield  can  only  be  explained  by  the  occurrence  of  losses 
during  the  course  of  the  analysis. 
"5.  The  opinion  which  Haffner  has  emphasized  that  the  barium 
content  of  the  barium  glycyrrhizinate  weighed  is  a  key  to  the  purity 
of  the  acid  is  probably  not  true.  At  any  rate  it  can  be  experimentally 
proved  that  it  is  not  always  true." 
26.  Cederberg  (ipo/). 
"Ten  g.  roughly  powdered  licorice  extract  are  covered  with  200 
cc.  95  per  cent,  alcohol  in  an  Erlenmeyer  flask,  then  25  cc.  normal 
sulphuric  added,  and  digested  for  several  hours  with  frequent  shak- 
ing. Filter,  and  wash  with  100  cc.  of  hot  alcohol.  To  the  filtrate,  add 
half  its  volume  of  water  and  render  ammoniacal.  Remove  the  alco- 
hol by  evaporation  to  less  than  100  cc.  Make  up  to  100  cc.  and  add 
an  equal  volume  of  20  per  cent,  sulphuric  acid.  Collect  the  precipi- 
tated glycyrrhizin  on  a  filter,  wash  with  50  cc.  10  per  cent,  sulphuric 
acid,  and  dissolve  on  the  water  bath  in  95  per  cent,  alcohol.  After 
washing  with  50  cc.  warm  alcohol,  the  filtrate  is  treated  with  half  its 
