Am. jounPharm. i        Glycyrrhizin  in  Licorice  Root.  403 
licorice,  say  a  very  good  one,  a  medium  quality,  and  a  very  bad  one, 
the  work  necessary  to  carry  through  this  idea  would  spread  beyond 
the  limits  of  this  task.  Above  all,  time  would  not  permit  of  exact  and 
exhaustive  treatment.  With  this  thought  in  mind,  after  trying  vari- 
ous kinds,  I  decided  to  use  the  Baracco  brand  for  my  control  experi- 
ments. I  obtained  this  from  the  firm  of  Caesar  &  Loretz.  The 
method  of  our  Pharmacopoeia  gave  the  following  results : 
Residue  insoluble  in  water  was  31  per  cent. 
11.4356  g.  of  licorice  lost  1.8777  g.  when  dried  at  a  ioo°  to  con- 
stant weight,  equivalent  to  16.42  per  cent,  moisture. 
The  ash  was  9.78  per  cent.  (4.324  g.  licorice  gave  a  residue  of 
0.4229  g.). 
Characteristic  of  this  licorice  was  its  extraordinary  content  of 
copper.  Every  solution  in  water,  even  of  quite  small  quantities, 
showed  in  the  insoluble  sediment  a  more  or  less  large  quantity  of 
pure  copper,  sometimes  as  a  powder  and  sometimes  in  large,  long, 
flaked  pieces.  I  have  found  pieces  as  long  as  5  millimeters,  and 
weighing  as  much  as  0.062  grams. 
In  the  present  research,  this  was  the  only  kind  of  licorice  used. 
The  controls  covered  over  100  individual  glycyrrhizin  estimations, 
and  consumed  more  than  half  a  year.    In  order  not  to  be  affected  by 
changes  in  humidity,  which  would  naturally  cause  changes  in  the 
moisture  content  of  the  licorice,  I  used  a  finely  powdered  extract, 
which  had  been  dried  for  several  days  in  a  vacuum  desiccator  over 
sulphuric  acid,  and  of  whose  moisture  content  I  could  be  assured. 
An  experiment  showed  that  5.0358  g.  of  dried  licorice  after  drying 
to  constant  weight  at  a  1000,  lost  0.2652  g.   The  dried  licorice  which 
I  used  for  all  this  work  therefore  still  contained  5.27  per  cent,  mois- 
ture.   In  order  to  obtain  comparative  results  I  naturally  followed 
exactly  the  methods  described.    If,  for  any  reason,  this  could  not  be 
done,  I  made  particular  note  of  it.    If  an  author's  directions  were 
ambiguous,  or  if  they  seemed  to  me  to  be  missing  at  some  important 
point,  I  substituted,  particularly  when  it  was  a  question  of  volumes 
of  liquids,  amounts  which  seemed  to  me  suitable  for  the  case  in 
point.    On  repeating  particular  experiments,  I  was  naturally  guided 
by  the  amounts  added  previously,  in  order  to  be  able  to  compare  the 
values  obtained.   I  always  conducted  two  determinations  side  by  side 
by  the  same  method.    The  experiments  were  repeated  until  I  ob- 
tained average  values  which  did  not  differ  from  one  another  by 
