558  Concerning  Two  Sweet-tasting  Drugs.  {A™ecemberPi9iT" 
divided  into  an  ether-soluble  and  an  ether-insoluble  resin,  the  latter 
having  a  bitter,  disagreeable  taste.  Both  resins  are  soluble  in  96  per 
cent,  alcohol. 
The  following  tabulation  gives  the  per  cent,  of  resins  in  unpeeled 
glycyrrhiza  coming  from  various  sources : 
Per  cent,  of      Per  cent,  of         Per  cent,  of 
Source  of  Drug  ether-soluble  ether-insoluble      total  resins 
resin  resin 
1.  Russia   4.12  8.16  12.28 
2.  Syria    3.03  9.16  12.19 
3.  Anatolia   2.35  10.04  12.39 
4.  Arabia    1.75  10  56  12.31 
5.  Italy    2.82              9.76  12.58 
6.  Alicante  (Spanish)   3.37              9.18  12.45 
7.  Cordova  (Spanish)    2.96              8.97  11.93 
8.  Zaragossa  (Spanish)   ....  2.07              8.78  10.85 
9.  Sevilla  (Spanish)    2.00  10  75  12.75 
10.  Toledo  (Spanish)    2.26  10. 11  12.37 
These  resins  are  insoluble  in  water,  but  on  boiling  the  drug,  the 
method  resorted  to  in  the  making  of  extract  of  licorice,  they  are 
dissolved  by  virtue  of  the  glycyrrhizin.  Hot  water  rendered  alkaline 
also  dissolves  them.  If  a  solution  of  these  resins  be  acidified,  a 
black  precipitate  is  thrown  down,  which  on  being  tested  biologically 
proves  hsemolytically  active. 
The  ether-soluble  resin,  after  proper  purification  with  acetic 
ether,  proved  chemically,  as  well  as  biologically,  identical  with 
glycyrrhetinic  acid — the  substance  resulting  from  the  hydrolysis  of 
glycyrrhizinic  acid.  The  ether-insoluble  resin  may  be  considered  an 
alcohol-soluble  substance,  closely  allied  to  glycyrrhizin.  It,  like 
glycyrrhizin,  is  biologically  inactive,  but  on  hydrolysis  yields  a 
hsemolytically  active  sapogenin. 
Summary. 
1.  A  really  hsemolytically  active  saponin  does  not  exist  in  gly- 
cyrrhiza. The  only  biologically  active  substance  is  a  preformed 
prosapogenin,  which  resides  in  the  bark  of  the  drug. 
2.  Glycyrrhiza  pharmacologically  belongs  to  the  group  of 
saponin-containing  plants.  It  is,  however,  the  mildest  in  the  group 
and  consequently  the  least  harmful  expectorant  of  all  of  them.  Its 
agreeable,  pure  sweet  taste  makes  it  a  valuable  corrective  for  dis- 
agreeable-tasting   medicinal    substances.     Properly-purified  gly- 
