462 
Glycyrrhizin  in  Licorice  Root. 
( Am.  Jour.  Pharm. 
\      July,  1921. 
300  cc.  of  the  filtrate,  corresponding  to  1  g.  of  the  licorice  extract,  is 
evaporated  to  a  syrup  on  the  water  bath.  In  a  control  experiment, 
it  is  determined  whether  in  the  solution  of  this  extract  in  5  g.  of  water, 
gum  is  precipitated  by  Telle's  method.  If  this  does  not  occur,  the 
solution  in  5  cc.  of  water  is  treated,  after  cooling,  with  1  cc.  sul- 
phuric acid  (diluted  with  the  same  quantity  of  water)  and  allowed 
to  stand.  It  is  then  decanted,  washed  three  times  with  2  cc.  portions 
of  water,  the  residue  dissolved  in  ammonia,  evaporated,  and  weighed 
to  constancy." 
Guignard  by  his  method  saves  the  troublesome  time-consuming 
nitration.  Whether  accurate  results  are  obtainable  by  his  method 
seems  to  me  to  be  doubtful.  Theoretically  I  consider  this  to  be  im- 
possible. Guignard  makes  up  to  500  cc,  pipettes  out  125  cc,  then 
adds  250  cc  alcohol ;  300  cc.  are  then  to  be  measured  exactly.  This 
contains  the  alcohol-soluble  material  of  1  g.  licorice.  But  this  is  only 
the  case  when  one  works  really  exactly  and  always  uses  pipettes.  I 
call  attention  here  to  the  contraction  in  volume  of  an  alcohol- water 
mixture,  as  well  as  to  loss  of  liquid  by  evaporation  of  the  alcohol 
during  24  hours  standing.  Even  careful  covering  can  hardly  prevent 
this  evaporation. 
[Translator's  Xote. — Linz  considers  that  the  test  for  gums  ac- 
cording to  Telle  is  superfluous.  He  also  considers  the  conditions  of 
washing  by  decantation  unsatisfactory,  and  that  ammonium  sulphate 
will  be  present  in  the  product  weighed.  He  objects  to  the  fact  that 
less  than  a  decigram  of  ammonium  glycyrrhizinate  is  weighed.  This 
results  in  large  inaccuracies.  Linz  concludes  "I  cannot  therefore 
agree  with  the  author's  conclusion  'the  method  proposed  by  us,  seems 
to  give  results  nearest  to  the  truth'."  (P.  A.  H.)] 
13.  Gadais  I. 
"In  a  300  cc  beaker  graduated  at  50  cc,  5  g.  licorice  extract  are 
dissolved  in  50  cc  of  boiling  water,  and  stirred  until  disintegration 
is  complete.  After  cooling,  make  up  to  the  50  cc  mark;  100  cc.  of 
95  per  cent,  alcohol  are  then  added  with  stirring,  and  then  allowed  to 
stand  24  hours,  covered.  The  liquid  is  poured  into  an  evaporating 
dish,  and  when  the  precipitate  begins  to  go  over,  it  is  poured  on  to 
a  filter.  The  beaker,  filter  and  precipitate,  are  washed  with  three 
portions  of  15  cc  each,  of  dilute  alcohol  (two  of  alcohol  to  one  of 
water)  and  the  wash  waters  are  also  received  in  the  dish.  The  con- 
