Am.  Jour.  Pharm. 
July,  1921. 
Glycyrrkizin  in  Licorice  Root. 
477 
stand  several  hours.  The  mixture  is  then  transferred  to  a  percolator, 
and  50  cc.  of  water  added,  which  for  every  100  cc.  contains  three  to 
four  drops  of  alkali,  to  combine  with  the  glycyrrhizic  acid,  and  con- 
vert it  to  a  soluble  form.  The  mixture  stands  overnight.  The 
liquid  is  then  allowed  to  drop  at  12-15  drops  to  the  minute,  adding 
fresh  alkaline  water  all  the  time.  The  extraction  is  continued  until 
the  percolate  is  tasteless.  The  extraction  takes  place  at  150. 
At  a  higher  temperature  Erikson  adds  a  few  drops  of  chloroform  to 
prevent  fermentation,  and  the  formation  of  mold.  The  extraction 
liquid  is  received  in  a  sterile  flask  and  made  up  to  200  cc." 
Houseman  has  objected  to  this  method,  that  the  long  standing  - 
will  cause  losses  by  enzyme  action,  and  this  objection  is  not  without 
justice,  because  the  extraction  to  exhaustion  takes  over  two  days.  I 
have  often  observed,  that  aqueous  extracts  of  licorice  root  decompose 
extraordinarily  easily.  I  notice  this  in  extracting  large  quantities  of 
licorice  root  to  make  chemically  pure  glycyrrhizic  acid.  It  would,  how- 
ever, be  difficult  to  find  a  way  of  avoiding  these  losses. 
"For  the  analysis,  pipette  off  40  cc.  of  the  extract,  add  44  cc.  90 
per  cent,  alcohol  and  heat  in  a  beaker  on  the  water  bath.  The  gummy 
substances  are  precipitated  by  the  alcohol.  This  operation  and  the  sub- 
sequent removal  of  the  alcohol  must  be  conducted  as  rapidly  as  pos- 
sible, in  order  that  the  sugars  may  not  be  decomposed.  After  the 
alcohol  has  been  completely  removed,  filter  through  a  small  filter, 
and  wash  thoroughly  with  water,  uniting  the  washings  with  the  fil- 
trate." 
Attention  must  here  be  called  to  a  remarkable  difference  between 
the  directions  for  root  and  for  extract.  Erikson  says  for  root,  that 
the  heating  and  evaporation  must  take  place  as  rapidly  as  possible, 
in  order  to  avoid  losses  of  sugar.  On  the  contrary,  she  lets  the  cor- 
responding licorice  extract  solution  stand  for  half  an  hour  on  the 
water  bath  with  alcohol. 
2.  Determination  of  Glucose. 
[Translator's  Note. — Linz  points  out  that  Erikson  only  makes 
a  single  experiment,  on  one  variety  of  root,  to  establish  that  the  max- 
imum amount  of  cuprous  oxide  is  precipitated  in  15  hours  in  the 
cold.  It  is  remarkable  that,  having  considered  this  time  for  maxi- 
mum preciptation  established,  she  does  not  use  it  anyway.  Linz 
further  shows  that  although  Erikson  admits  that  this  Fehling  reduc- 
