Am.  Jotir.  Pharm.  ") 
Feb.  1, 1871.  J 
On  Glycyrrliizin. 
77 
ON  GLYOYRRHIZIN. 
By  Joseph  M.  Hirsh,  of  Chicago. 
What  is  the  easiest  and  most  practicable  method  of  isolating  glycyrrhizin  ;  to 
what  extent  does  it  possess  the  power  of  masking  bitterness ;  and  what  is  its 
mode  of  action  ? 
The  mode  of  preparing  glycyrrhizin,  mentioned  in  the  last  Dis- 
pensatory, of  precipitating  the  same  from  a  cold  infusion,  I  found 
highly  impractical,  on  account  of  the  slight  solubility  of  the  same  in 
cold  water.  Berzelius's  method  of  preparing  it  from  sulphate  of 
glycyrrhizin  gave  but  a  dark-colored  product,  difficult  to  purify, 
while  Vogel's  method  of  preparing  a  plumbate  of  glycyrrhizin,  and 
subsequent  decomposition  with  hydric  sulphuret,  is  rather  laborious. 
The  best  practical  process  appeared  to  be  the  preparation  from  an 
infusion  made  with  boiling  water  of  acetate  of  glycyrrhizin,  which 
upon  evaporation  to  dryness  is  dissolved  in  alcohol,  when  the  acetic 
acid  is  neutralized  with  soda,  the  new  salt  crystallizing  out,  while  the 
glycyrrhizin  remains  in  solution.  Another  method,  giving  good  re- 
sults, I  found  to  be  the  preparation  of  an  alcoholic  extract  by  perco- 
lation, which  I  heated  to  the  boiling-point,  filtered  off  from  the  deposit 
produced,  when  I  evaporated  nearly  to  dryness,  redissolved  in  alcohol^ 
from  which  solution  it  remained  behind  almost  pure  upon  evaporation. 
Experimenting  with  this  product  in  regard  to  its  relation  to  mask- 
ing bitterness,  I  found  one  part  to  cover  up  the  bitter  taste  of  four 
parts  of  Epsom  salts,  a  slight  addition  of  the  latter  being  plainly  per- 
ceptible, although  by  no  means  as  disagreeable  as  when  tasted  alone. 
Of  an  alcoholic  extract  of  coffee,  an  amount  representing  twenty 
parts  of  coffee,  lost  its  bitter  taste  upon  the  addition  of  the  glycyr- 
rhizin. A  number  of  other  experiments  of  similar  kind  were  made, 
but  your  reporter  respectfully  expresses  his  doubts  about  the  mathe- 
matical reliability  of  results,  arrived  at  by  taste  alone,  and  confines, 
therefore,  his  remarks  to  the  modus  operandi  of  the  glycyrrhizin. 
Taste  being  an  effect  upon  the  nerves  of  sensation  (of  taste),  the 
change  of  taste  can  be  produced  either  by  a  chemical  change  of  a 
substance,  or  by  a  peculiar  local  affection  of  the  nerves  of  taste.  The 
first  case,  as  might  have  been  anticipated,  with  Epsom  salts,  does  not 
occur,  the  glycyrrhizin  not  affecting  the  sulphate  of  magnesia  in  any 
way. 
The  second  supposition  then  lay  near,  namely,  that  the  nerves  were 
rendered  insensible  to  the  bitter  taste.    This  might  be  done  by  an 
