Amjliy!'miarm'  \        Glycyrrhizin  in  Licorice  Root.  465 
17.  Muntzer  (1888).  ■ 
"Ten  g.  licorice  extract  are  extracted  for  two  hours  in  a  flask 
with  190  g.  of  water  and  10  g.  ammonia.  After  allowing  to  settle, 
pour  the  liquid  on  a  filter,  wash  the  flask,  and  filter  with  small  quan- 
tities of  the  extraction  liquid,  totaling  100  cc.  The  filtrate  is  acidified 
with  dilute  sulphuric  acid.  After  standing  one  hour,  the  precipitate 
is  filtered,  and  washed  with  water.  It  is  again  dissolved  in  5  per  cent, 
ammonia,  and  again  precipitated.  After  standing  one  hour  it  is 
filtered  through  a  dry,  tared  filter,  washed  with  pure  water,  dried  at 
ioo°,  and  weighed." 
[Translator's  Note. — Linz  points  out  the  great  loss  of  glycyr- 
rhizic  acid,  resulting  from  the  large  volume  of  wash  water  used. 
The  re-precipitation  also  causes  much  loss  of  glycyrrhizin.  Linz  de- 
termined the  losses  to  be  nearly  as  much  as  the  glycyrrhizin  actually 
weighed.  Linz  rightly  states  that  the  method  cannot  be  used  as  a 
quantitative  determination.  (P.  A.  H.)] 
18.  Morpurgo,. 
[Translator's  Note. — This  method  makes  use  of  ammonium 
oxalate,  presumably  to  decompose  calcium  glycyrrhizinate.  Linz  did 
not  check  up  this  method,  and  it  cannot  be  considered  of  any  special 
value.  (R  A.  H.)] 
19.  Dutch  Pharmacopceia  (1905). 
"Five  g.  licorice  extract  are  dissolved  in  50  cc.  water  to  which 
2  cc.  spirits  of  ammonia  have  been  added.  The  volume  is  made  up 
to  100  cc.  with  water.  Sixty  cc.  of  this  is  filtered,  and  evaporated  to 
15  cc.  After  cooling,  5  cc.  dilute  hydrochloric  acid  are  added.  After 
settling,  the  precipitate  is  brought  onto  a  filter,  washed  with  5  cc. 
water,  and  dissolved  on  the  filter  with  ammonia.  The  solution  is 
evaporated,  dried  in  a  desiccator,  and  weighed.  The  dry  residue 
should  weigh  at  least  0.24  g.,  corresponding  to  a  minimum  of  8  per 
cent,  glycyrrhizin." 
[Translator's  Note. — Linz  objects  to  the  extreme  difficulty 
of  filtering  the  original  ammoniacal  solution,  which  objection  he 
justly  raises  to  all  those  methods  which  do  not  precipitate  gums 
with  alcohol.  Linz  points  out  that  the  filtration  and  washing  of  the 
precipitated  glycyrrhizin  is  entirely  unsatisfactory.    He  considers 
