468 
Glycyrrhizin  in  Licorice  Root. 
5  Am.  Jour.  Pharm. 
(      July,  1921. 
tity  of  water  for  washing.  He  shows  that  the  Durier  solubility-cor- 
rection is  incorrect,  and  he  finds  the  loss  to  be  3.3  per  cent.  Linz 
says  the  method  cannot  be  recommended,  the  results  being  decidedly 
too  low  as  the  losses  are  very  high.    (P.  A.  H.)] 
25.  Haffner  (1899). 
"Ten  g.  licorice  extract  are  treated  with  about  200  cc.  95  per 
cent,  alcohol;  25  cc.  normal  sulphuric  acid  are  then  added,  and  al- 
lowed to  stand  several  hours  with  shaking.  Filter,  and  wash  with 
strong  alcohol,  as  long  as  the  filtrate  is  colored.  Treat  the  filtrate 
with  a  100  cc.  of  water,  and  with  ammonia,  until  weakly  alkaline. 
Remove  alcohol  on  water  bath,  bring  the  residue  to  a  100  cc.  and 
acidify  with  dilute  sulphuric  acid.  Settle  for  an  hour,  filter,  wash 
the  residue  with  2-3  per  cent,  sulphuric  acid,  until  the  washings  are 
colorless.  Dry  the  filter  in  a  sulphuric  acid  vacuum  desiccator,  ex- 
tract with  acetone  two  or  three  times  on  the  water  bath  until  the  last 
extract  is  colorless.  To  the  acetone  extract  add  a  suspension  of 
barium  carbonate  in  water  and  remove  the  acetone  on  the  water 
bath,  using  a  tall  beaker.  The  residue  is  extracted  with  portions  of 
hot  water,  totalling  200  cc.  The  solution  of  barium  glycyrrhizinate, 
after  cooling,  is  filtered  into  a  500  cc.  volumetric  flask  which  is  filled 
to  the  mark. 
"The  total  solids  in  100  cc.  of  the  above  solution  are  determined. 
The  glycyrrhizic  acid  is  calculated  from  the  barium  glycyrrhizinate. 
The  latter  is  evaporated  with  sulphuric  acid,  and  ignited  to  constant 
weight.  From  the  barium  sulphate  weighed,  the  barium  glycyrrhizin- 
ate in  the  total  solids  residue  is  calculated.  The  higher  the  barium 
content,  the  purer  the  weighed  product." 
HafTner's  method  brings  forward  a  number  of  new  ideas.  Above 
all,  the  alcoholic-sulphuric  extraction  is  new  and  good.  I  have  spoken 
of  it  in  detail  in  the  introduction.  The  purification  of  the  precipi- 
tated acid  with  acetone,  is  also  new,  as  is  especially  the  determination 
of  glycyrrhizin  as  a  barium  salt. 
[Translator's  Note.— Linz  goes  on  to  point  out  that  the  large 
amount  of  alcohol  necessary  to  wash  the  original  insoluble  matter, 
and  the  difficulty  of  washing  the  precipitated  acid  until  colorless 
with  2-3  per  cent,  sulphuric  acid,  involves  some  loss.  Linz  is  unable 
to  get  a  sharp  acetone  separation.  Linz  makes  an  experiment  to 
show  that,  by  using  alcohol,  instead  of  acetone,  he  obtains  a  greater 
