Am.  Jour.  Pharm. 
June,  1921. 
Glycyrrhizin  in  Licorice  Root. 
411 
The  method  discussed  above  which  was  published  in  1889  has 
become  the  basis  for  va  large  number  of  methods  published  later. 
Although  certain  changes  have  been  introduced  in  these  later  meth- 
ods, the  principle  has  remained  the  same.  After  intelligent  comple- 
tion of  missing  or  faulty  directions,  the  method  gives  practical  re- 
sults. 
7.  Py  {1897). 
"Two  g.  licorice  are  dissolved  in  about  30  cc.  water  on  the  water 
bath.  After  cooling,  alcohol  is  added  until  a  strength  of  75  per  cent, 
alcohol  is  attained.  After  standing  12  hours,  the  mixture  is  poured 
through  a  fluted  filter,  and  the  filter  and  residue  washed  with  75  per 
cent,  alcohol.  The  alcohol  is  evaporated,  the  residue  dried  at  a 
ioo°,  and  weighed.  It  is  then  dissolved  again  in  lukewarm  water, 
and  treated  with  dilute  sulphuric  acid  (1:9).  The  precipitate  is  col- 
lected on  the  filter,  and  washed,  first  with  water  acidified  with  sul- 
phuric acid,  and  then  with  distilled  water,  and  finally  dissolved  from 
the  filter  with  saturated  ammonia-water.  The  filter  is  washed  with 
ammonia  until  colorless.  The  ammoniacal  solution  is  evaporated, 
dried  at  ioo°,  and  weighed." 
This  method  does  not  give  detailed  instructions,  and  further 
makes  rather  many  inexact  statements.  Otherwise  it  does  not  differ 
from  the  others. 
[Translator's  Note. — The  author  (Linz)  also  objects  to 
evaporating  the  alcoholic  solution  to  dryness,  also  to  the  fact  that  Py 
does  not  state  quantities  for  dissolving  the  dry  alcoholic  extract  in 
water,  for  sulphuric  acid  used  in  precipitation,  and  for  acidified 
water  used  in  washing.  In  control  experiments,  Linz  obtained  7.6- 
8.15  per  cent,  ammoniated  glycyrrhizin  with  losses  estimated  at  2.22- 
2.75  per  cent.  The  insoluble  matter  he  determined  as  47  per  cent. 
(P.A.H.)] 
This  glycyrrhizin  determination  gives,  therefore,  the  usual  values 
if  one  intelligently  completes  the  many  inexact  instructions.  If  one 
does  not  do  this,  one  cannot  obtain  comparative  results.  The  method 
in  its  original  form  cannot,  therefore,  be  used. 
8.  Parry  (19 10). 
"2.5  g.  licorice  are  covered  with  15  cc.  hot  water,  and  warmed 
on  the  water  bath  until  dissolved.   After  cooling,  25  cc.  80  per  cent, 
alcohol  are  added  slowly  with  stirring  and  then  50  cc.  95  per  cent. 
