4§ 
Current  Literature. 
/Am.  Jour.  Pharm. 
^     January,  19 18. 
acid  in  the  first  2  or  3  days;  when  a  vigorous  mycelium  has  de- 
veloped the  rise  in  acidity  is  very  rapid — about  2  per  cent,  in  twenty- 
four  hours — until  the  seventh  or  eighth  day.  After  remaining  con- 
stant for  2  or  3  days  the  acidity  begins  to  decline.  In  a  proper 
fermentation  the  fungus  does  not  produce  spores  but  remains  white. 
Under  favorable  conditions  the  acidity  will  reach  10-12  per  cent, 
on  the  eighth  day;  oxalic  acid  may  amount  to  3-4  per  cent,  of  the 
total  acidity.  Fermentation  may  be  carried  out  successfully  in 
shallow  pans  and  the  liquid  pressed  out  from  the  mycelium  in  a 
filter-press.  (Through  Journal  of  the  Society  of  Chemical  In- 
dustry. ) 
Comparison  of  Methods  for  the  Estimation  of  Glycyr- 
rhizin  in  Liquorice  Root  and  in  Succus  Liquiritee. — It  is 
only  within  the  last  ten  years  that  -the  importance  has  been  empha- 
sized, rightly,  of  estimating,  in  addition  to  the  glycyrrhizin,  the 
amount  of  sugar,  in  order  that  adulteration  of  a  liquorice  with  sugar 
may  be  detected.  Since  the  amount  of  glycyrrhizic  acid  (glycyr- 
rhizin) varies  between  wide  limits,  not  only  in  different  kinds  of 
liquorice,  but  even  in  one  and  the  same  kind  at  different  times,  the 
author  used  always  the  same  liquorice  throughout  his  series  of 
comparative  experiments  on  the  trustworthiness  of  the  twenty-seven 
methods  proposed  for  the  estimation  of  glycyrrhizic  acid.  In  any 
method,  attention  must  be  given  to  the  following  points:  (1)  The 
influence  of  the  liquid  employed  as  a  solvent  of  the  liquorice; 
(2)  the  nature  of  the  acid  used  as  the  precipitant;  (3)  the  solu- 
bility of  glycyrrhizic  acid  in  water  and  in  the  precipitant,  and  the 
loss  caused  thereby;  and  (4)  the  purity  of  the  glycyrrhizic  acid 
when  brought  to  the  stage  of  weighing.  All  the  methods  are  criti- 
cized from  these  four  points  of  view,  and  the  author  draws  the 
conclusion  that  no  one  of  them  is  really  trustworthy,  mainly  on 
account  of  the  impossibility  of  isolating  the  glycyrrhizic  acid  in  a 
pure  state.  Details  are  given  of  a  method  proposed  by  the  author, 
which,  although  tedious  and  not  strictly  trustworthy,  is  less  inac- 
curate than  any  other  previously  brought  forward.  A  tabulated  list 
of  the  literature  on  the  subject  from  1808  to  19 13  is  given,  together 
with  a  classified  list  of  the  results  obtained  by  the  twenty-eight 
methods  discussed  in  the  paper.  (A.  Linz,  Arch.  Pharm.,  1916, 
254,  65-134,  204-224,  through  /.  Chem.  Soc,  1917,  112,  II,  430- 
431,  and  reprinted  from  The  Analyst.) 
