Amjufy,ri^i.arm* }        Glycyrrhizin  in  Licorice  Root.  467 
1:9)  and  again  whirled  for  fifteen  minutes.  The  liquid  is  poured 
off  again,  and  the  residue  washed  by  centrifuging  for  ten  minutes 
with  10  cc.  water.  If  the  lfquid  poured  off  is  still  colored,  the  washing 
is  repeated.  The  aqueous  and  ammoniacal  extracts  are  united  with  the 
washings,  and  evaporated.  The  thick  extract  is  transferred  to  a 
centrifuge  tube,  and  water  added  to  a  10  cc.  mark;  25  cc.  of  alcohol 
are  then  added.  Gums  and  albumens  are  precipitated.  After  centri- 
fuging fifteen  minutes,  the  alcoholic  liquid  is  poured  off  and  evapor- 
ated. The  thick  extract  is  dissolved  to  50  cc.  with  warm  water,  and 
after  cooling,  1  cc.  hydrochloric  acid  is  added  with  shaking.  After 
standing  twenty-four  hours,  the  liquid  is  poured  off,  and  the  residue 
washed  with  small  portions,  totaling  25  cc,  of  water  saturated  with 
ether.  The  filtration  is  made  carefully,  so  as  to  bring  as  little  as 
possible  of  the  precipitate  on  to  the  filter.  The  residue  in  the  tube 
is  dissolved  in  1  cc.  of  ammonia,  and  poured  through  the  same  filter. 
The  tube  and  filter  are  washed  until  colorless,  with  ammonia  water 
(1  :  9),  and  the  filtrate  evaporated  to  constant  weight." 
[Translator's  Note. — A  summary  of  the  criticisms  of  Linz 
for  this  method  is  as  follows :  The  abstracts  in  the  German  journals 
contain  errors  so  that  the  original  had  to  be  consulted  for  checking 
up  the  method.  Linz  finds  a  second  washing  of  the  ammoniacal 
residue  necessary.  He  calls  attention  to  the  fact  that  50  cc.  is  too 
large  a  volume  from  which  to  precipitate  the  glycyrrhizin.  He  ap- 
proves the  use  of  water  saturated  with  ether,  but  thinks  25  cc.  too 
much.  He  also  approves  of  the  time  saved  by  the  centrifuge.  Linz 
obtained  by  this  method  8.97-9.27  per  cent,  ammonium  glycyrrhizin- 
ate,  with  losses  determined  at  1.6- 1.82  per  cent.  Linz  finds  this 
method  for  glycyrrhizin  unnecessarily  inconvenient,  and  does  not 
see  how  to  improve  it  in  this  respect.  (P.  A.  H.)  ] 
24..  Durier  (1913). 
[Translator's  Note. — This  method  uses  ammoniacal  alcohol 
on  the  original  licorice  extract.  It  uses  the  centrifuge,  and  precipi- 
tates from  50  cc,  with  hydrochloric  acid,  washing  the  precipitate  with 
5  portions  of  5  cc.  water.  A  correction  of  0.023  g.  for  losses  in  wash- 
ing, is  made  when  2  g.  of  original  licorice  is  used. 
Linz  objects  to  the  use  of  ammoniacal  alcohol,  to  the  large  vol- 
ume of  50  cc  for  precipitating  glycyrrhizin,  to  adding  1  cc.  of  ammo- 
nia before  .such  precipitation,  and  to  the  use  of  the  prescribed  quan- 
