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QUININE  IN  CINCHONA  BARE. 
PROCESS  FOR  ASCERTAINING  THE  PROPORTION  OF  QUININE 
IN  CINCHONA  BARK. 
This  process,  published  by  M.  Guillermond  in  the  <  Gazette 
Medicale'  of  Lyons,  is  a  modification  of  one  already  published 
by  the  same  writer  in  1847.  The  following  is  the  process  : 
Take  twenty  grammes  of  yellow  bark,  powder  it  without  leaving 
any  residue,  and  pour  upon  the  powder  alcohol  at  76°,  in  suffi- 
cient quantity  to  form  a  soft  paste,  which  is  to  be  heated  for  a 
few  minutes  until  the  fibre  is  thoroughly  penetrated  by  the 
liquid ;  then  introduce  into  the  paste  ten  grammes  of  hydrated 
lime  in  fine  powder :  mix  thoroughly,  so  as  to  form  a  homoge- 
neous mass,  which  is  to  be  heated  on  a  plate  until  all  humidity 
is  completely  eliminated.  This  powder  is  afterwards  to  be 
treated  with  100  grammes  of  rectified  sulphuric  ether,  which 
will  dissolve  and  remove  all  the  quinine.  This  ether  is  then  to 
be  rapidly  evaporated  at  the  heat  of  boiling  water,  and  the  resi- 
due will  contain  only  the  quinine  and  a  small  proportion  of  a 
yellow  coloring  matter,  which  may  be  neglected.  In  order  to 
determine  the  quantity  of  quinine  obtained,  either  of  the  three 
following  methods  may  be  adopted  : 
1.  Dry  completely  the  ethereal  residue.  Its  weight  will  give 
that  of  the  quinine,  plus  the  portion  of  coloring  matter,  the 
quantity  of  which  is  insignificant.  2.  Dissolve  the  residue  in 
a  little  alcohol  and  acidulate  it  with  very  dilute  sulphuric  acid, 
the  saturating  power  of  which  for  quinine  is  ascertained.  For 
this  purpose  a  graduated  tube  may  be  employed,  so  that  a  given 
quantity  of  the  dilute  acid  corresponds  to  one  gramme  of  quinine. 
3.  Weigh  the  sulphate  of  quinine  which  is  obtained.  It  may 
be  dried  in  a  few  moments  by  exposing  it  to  the  sun  or  to  the 
heat  of  a  stove. 
This  process,  according  to  M.  Guillermond,  is  recommended 
by  its  simplicity,  and  the  celerity  with  which  the  result  is  ob- 
tained, for  only  about  three  hours  are  required  in  the  operation  : 
and  the  plan  possesses  the  additional  advantage  of  separating 
completely  the  whole  of  the  alkaloid. — Brit,  and  For.  Med. 
Rev.  from  Bull.  Gen.  de  Ther.  Oct.  SOth,  1858. 
