158 
ON  EXTRACT  OE  LIQUORICE. 
as  some  of  the  commercial  varieties.  It  contains  18-6  of  matter 
insoluble  in  cold  water ;  and  an  excess  of  alcohol  precipitated 
27-2  per  cent,  of  matter  from  the  watery  solution ;  in  all  45*7  per 
cent,  of  the  weight  of  the  extract. 
The  committee  being  at  a  loss  to  reconcile  these  results  with 
the  alleged  purity  of  M.  Delondre's  extract,  wrote  to  him  an  ac- 
count of  their  labors,  when  he  maintained  his  previous  assertion, 
could  not  give  the  rationale,  but  proposed  to  join  the  committee 
in  clearing  up  the  difficulty,  which  he  did  by  frankly  explaining 
the  modus  operandi  of  his  process.    It  is  as  follows  : — 
M.  Delondre  puts  in  a  suitable  vessel,  260  kilogrammes  (573 
lbs.)  of  liquorice  root  in  coarse  powder,  and  admits  a  current  of 
steam  during  twelve  hours.  In  this  way  the  fibres  of  the  wood 
are  thoroughly  penetrated  and  acted  on,  and  the  resulting  con- 
densed liquid  drawn  off.  This  treatment  is  renewed  for  five 
successive  days,  the  several  liquids  are  decanted,  clarified  with 
two  kilogrammes  (4-41fos.)  of  gelatine,  and  rapidly  evaporated  in 
jacketted  boilers.  The  extract  is  removed,  made  into  rolls,  and 
put  into  a  drying  room  kept  at  77°  Fahr.  for  ten  days. 
This  explanation  from  the  author  of  the  process  at  once  showed 
the  cause  of  the  difference,  viz. :  that  the  continued  action  of 
steam  was  capable  of  extracting  principles  insoluble  in  warm 
water. 
To  fully  satisfy  themselves,  the  committee  requested  M.  De"- 
londre  to  make  four  experiments  : — 
1st.  To  prepare  an  extract  with  cold  water  by  displacement. 
2d.  To  treat  the  residue  with  hot  water. 
3d.  To  treat  the  second  residue  by  steaming. 
4th.  And  to  make  an  extract  by  his  own  process,  direct  from 
the  root. 
These  several  products  were  then  examined  by  the  committee. 
1.  The  first  extract  amounted  to  15  per  cent,  of  the  root 
treated ;  was  soluble  in  its  own  weight  of  water,  except  4*22  per 
cent.,  and  when  dissolved  in  1000  times  its  weight  of  water,  the 
solution  had  a  decided  liquorice  taste.  100  parts  dissolved  in 
water  yielded  a  precipitate  of  36  parts  by  adding  an  excess  of 
alcohol. 
2.  The  second  treatment  yielded  7*5  per  cent,  of  extract.  The 
extract  was  hygroscopic  ;  had  a  taste  nearly  as  strong  as  the  pre- 
