352 
ON  A  FALSE  CINCHONA  BARK  OF  INDIA. 
texture,  but  abundant  in  large,  woody  cells,  which  are  thickened 
and  hardened  by  ligneous  deposit,  so  that  they  produce  an 
almost  gritty  sensation  when  placed  between  the  teeth.  The 
bark  possesses  the  remarkable  property  of  being  very  bitter 
when  quite  fresh,  but  this  bitterness  diminishes  on  keeping,  so 
that  after  a  few  days  it  has  so  decreased  that  the  bark  becomes 
nearly  tasteless. 
The  foregoing  circumstances  induced  me  to  submit  the  bark 
to  a  careful  chemical  examination,  in  the  hope  that  I  might  be 
fortunate  enough  to  discover  a  proximate  principle,  whose  con- 
stitution might,  perhaps,  throw  some  light  on  that  of  the  true 
cinchona  alkaloids. 
By  the  kindness  of  Major  Morgan,  Deputy-Conservator  of 
Forests,  I  obtained  a  supply  of  the  fresh  bark  from  the  neigh- 
borhood of  Mudumullay.  From  it  I  was  finally  successful  in 
obtaining  the  bitter  principle  in  a  pure  crystalline  state.  After 
many  trials,  I  found  the  following  simple  process  enabled  me  to 
obtain  it  in  considerable  quantities : — The  sliced  fresh  bark  is 
boiled  with  water  till  it  becomes  somewhat  soft,  when  it  is 
drained  and  squeezed  through  a  cloth.  The  bitter  decoction  thus 
obtained  is  carefully  evaporated  to  a  small  bulk  over  an  open 
fire,  when  it  is  mixed  with  a  sufficient  quantity  of  calcined  mag- 
nesia to  render  it  of  a  creamy  consistency,  after  which  it  is 
evaporated  to  dryness  by  a  steam  heat.  The  residue  is  then 
powdered,  placed  in  a  flask,  and  repeatedly  exhausted  with 
strong  alcohol,  and  filtered.  The  alcoholic  extract  thus  produ- 
ced is  magnificently  fluorescent,  surpassing  in  this  respect  a  so- 
lution of  sulphate  of  quinine.  The  alcohol  is  then  nearly  re- 
moved by  distillation,  and  the  liquid  residue  is  set  aside  in  a 
cool  place  for  twelve  hours,  when  the  whole  solidifies  into  a  mass 
of  fine  white  prismatic  crystals,  which  can  be  obtained  quite 
pure  by  two  further  crystllizations  from  water. 
The  crystals  are  somewhat  sparingly  soluble  in  cold  water  and 
alcohol,  but  readily  dissolves  in  those  liquids  when  boiling.  The 
solutions  are  beautifully  fluorescent,  but  they  loose  this  property 
by  the  addition  of  a  drop  of  hydrochloric  acid.  When  boiled 
with  the  latter  reagent,  and  the  solution  subsequently  poured 
into  a  hot  alkaline  solution  of  cupric  salt,  a  precipitate  of  red 
