390  Glycyrrhizin  in  Licorice  Root.        \  AmjJ^ili.arm' 
A  chronological  list  of  the  methods  of  glycyrrhizin  determina- 
tion published  to  date  is  collected  at  the  close  of  this  article  under 
Appendix  B. 
A  number  of  proposed  methods,  particularly  those  given  in  gen- 
eral works,  are  taken  in  part  from  other  sources  and  appear,  some- 
times under  other  names,  as  original  determinations.  I  found,  for 
example,  the  method  proposed  by  Diehl,  under  the  name  of  Prol- 
lius  in  Hager-Fischer-Hartwich's  "Handbuch  der  Pharmazeutischen 
Praxis,"  1896.  Hager's  Handbuch  has  the  method  of  Haffner  m 
the  supplementary  volume.  Konig's  "Nahrungs  und  Genussmittel," 
1,  p.  1065,  has  reproduced  the  method  of  Kremel. 
In  the  list  in  Appendix  B  I  have  only  included  original  methods. 
One  can  see  how  the  glycyrrhizin  content  of  licorice  varies  with 
the  large  number  of  quantitative  methods  employed.  Gliicksmann 
found  in  one  kind  of  licorice,  no  glycyrrhizic  acid  at  all,  and  others 
claimed  to  have  found  amounts  up  to  nearly  30  per  cent.  Not  only 
in  different  kinds,  but  also  in  the  same  kind  at  different  times,  have 
large  variations  in  the  glycyrrhizin  content  been  found,  a  fact  which 
finds  its  explanation  in  the  very  primitive  methods  of  manufacture 
which  are  even  yet  partly  used.  The  desire,  which  has  often  been 
expressed,  to  establish  in  the  Pharmacopoeia  a  lower  limit  for  the 
glycyrrhizin  content,  or  to  describe  the  preparation  in  the  Pharma- 
copoeia regulations,  is  justified  on  these  grounds. 
From  the  very  few  comparisons  of  different  methods  hitherto 
available,  it  is  to  be  seen  that,  by  the  many  methods  proposed,  re- 
sults differing  largely  from  each  other  are  obtained.  I  would  here 
quote  Erikson,  who  obtained  16.5  per  cent,  and  Cederberg,  14.3  per 
cent,  glycyrrhizin,  even  from  the  same  extract.  Gliicksmann  ob- 
tained 8  per  cent,  ammonium-glycyrrhizinate  from  an  ammoniacal 
extract,  and  only  2  per  cent,  from  an  aqueous  extract.  Haffner, 
using  Helfenberg's  method,  obtained  4.3  per  cent.,  Kremel's  method 
3.1  per  cent.,  and  Diehl's  method  6.4  per  cent.,  using  the  same  lico- 
rice extract  for  all.  Haffner  has  compiled  interesting  tables  in  which 
he  believes  he  demonstrates  a  connection  between  the  extraction 
liquid,  the  method  of  purification,  and  the  degree  of  purity  of  the 
glycyrrhizic  acid  obtained  and  weighed. 
These  results,  which  are  so  poorly  comparable,  justify  the  con- 
clusions that  the  question  of  the  method  of  glycyrrhizin  determina- 
tion is  not  yet  cleared  up.   This  fact,  combined  with  the  necessity  of 
