494 
Studies  on  Licorice  Root. 
5  Am.  Jour.  Pharm. 
I      July,  1921. 
kognosie"  gives  6.42-7.13  per  cent.,  although  in  an  earlier  publication 
he  speaks  of  3  per  cent. 
The  method,  which  I  have  given  above,  yields  a  glycyrrhizin 
more  nearly  approaching  purity  than  that  of  any  method  heretofore 
published.  The  glycyrrhizin  obtained  by  my  method  (ether  extrac- 
tion, followed  by  75  per  cent,  alcohol)  is  light  in  color,  intensely  sweet, 
and  practically  free  from  resins  and  bitter  principles.  Yet  I  find  fig- 
ures from  about  10-14  Per  cent.,  the  former  figure  being  for  Spanish 
and  Greek  roots,  and  the  latter  for  Anatolian,  with  Russian  and 
Chinese  intermediate. 
Licorice  extracts  should  contain  about  twice  as  high  a  percentage 
of  glycyrrhizin  as  the  corresponding  roots,  but  there  is  no  doubt  that, 
in  factory  practice,  a  considerable  loss  of  glycyrrhizin  through  hy- 
drolytic  decomposition  occurs. 
With  regard  to  determining  other  analytical  items  in  licorice  ex- 
tract and  root,  there  is  little  new  to  add  to  the  information  contained 
in  my  earlier  papers. 
In  root  one  would  usually  determine  moisture,  total  ash,  ash  in- 
soluble in  hydrochloric  acid  (sand,  dirt),  resins  (ether  extract), 
glycyrrhizin,  sugars,  crude  fibre,  and  screen  analysis  (on  powdered 
roots).  The  sugar  determination  is  made  with  Fehling  solution  be- 
fore and  after  inversion,  employing  either  the  filtrate  and  washings 
from  the  glycyrrhizin  determination,  or  an  original  portion  of  root, 
using  normal  lead  acetate  and  following  suitable  methods  given  by 
the  Association  of  Official  Agricultural  Chemists,  of  Washington, 
D.  C. 
Crude  fibre  is  also  done  according  to  the  A,  O.  A.  C. 
In  licorice  extract  one  may  determine  moisture,  ash,  matters  in- 
soluble in  cold  water  and  in  hot  water,  starch  and  gums,  glycyrrhizin 
and  sugars. 
Matters  Insoluble  in  Cold  Water. 
Two  grams  of  the  licorice  mass  are  weighed  into  a  small  copper- 
gauze  basket,  which  is  suspended  in  a  100  cc.  centrifuge  tube.  The 
tube  is  nearly  filled  with  cold  water,  and  when  the  paste  is  com- 
pletely disintegrated  (after  about  18  hours),  the  basket  is  agitated, 
washed  and  removed.  The  contents  of  the  tube  are  whirled  in  an 
electrical  centrifuge  for  to  minutes  at  about  1500  R.  P.  M.  The  clear 
liquor  is  poured  off,  and  the  sediment  stirred  up  with  fresh  water 
