114 
Australian  Alstonia  Bark. 
(  Am.  Jour.  Pharm. 
t      Mar.,  1881. 
It  was  at  first  confirmed  that  the  extraction  of  the  bark  with  ether 
furnishes  only  a  small  portion  of  the  alkaloids,  which,  however,  con- 
sist chiefly  of  porphyrina.  As  it  was  desirable  to  obtain  the  larger 
portion  of  both  alkaloids,  and  the  properties  of  chlorogenina  and  por- 
phyrina having  been  known  to  the  author,  a  method  was  adopted  which 
led  to  the  desired  end.  The  alcoholic  extract  of  the  bark  was  dis- 
solved in  water,  and  this  solution  supersaturated  with  sodium  bicar- 
bonate, whereupon  a  brown  flocculent  substance,  evidently  a  decompo- 
sition product  of  chlorogenina  or  alstonina,  was  precipitated,  and 
filtered  oif.  The  clear  filtrate  was  now  treated  so  often  with  petroleum 
ether,  and  this  with  small  amounts  of  dilute  acetic  acid,  until  nothing 
more  of  consequence  was  extracted.  In  this  way  porphyrina  and 
other  substances  soluble  in  petroleum  ether  were  removed  from  the 
carbonic  acid  solution,  while  the  alstonina  (chlorogenina)  remained 
dissolved  in  the  lower  liquid. 
Alstonina  (syn.  chlorogenina)  is  obtained  when  the  carbonic  acid 
solution,  as  above,  is  supersaturated  with  caustic  soda  and  shaken  with 
chloroform.  There  results  a  blackish-brown  chloroformic  solution  of 
the  alstonina,  which,  after  clear  filtration  and  the  addition  of  sufficient 
M^ater  and  acetic  acid,  is  freed  from  the  chloroform  by  distillation. 
The  residual  acid  solution  is  filtered  in  order  to  separate  small  amounts 
of  brown  flakes,  and  then  treated  with  animal  charcoal,  whereby,  in 
addition  to  coloring  matters,  a  considerable  amount  of  the  alkaloid  was 
precipitated  which  it  was  not  sought  to  again  obtain.  The  solution 
purified  in  this  way  was  precipitated  with  caustic  soda;  a  brownish- 
yellow  amorphous  flocculent  matter  soon  subsided,  but  could  not  be 
washed  sufficiently  upon  the  filter.  The  mother  liquor  was  therefore 
removed  as  completely  as  possible  by  thrice  repeated  decantation  with 
cold  water,  which  manipulation  was  very  successful,  although  thereby 
a  not  inconsiderable  amount  of  alkaloid  became  dissolved.  This  dis- 
solved portion  of  the  alkaloid,  however,  was  not  lost,  as  the  entire 
amount  of  wash  water  was  afterwards  shaken  with  chloroform. 
After  the  mother  liquid  is  removed  the  flocculent  alkaloid  is  brought 
upon  a  filter  and  washed  with  cold  water,  the  organic  mass  being 
separated  as  well  as  possible  from  the  sides  of  the  filter  and  divided  in 
the  water  by  means  of  a  platinum  knife.  The  alkaloid  is  finally 
brought  in  thin  layers  upon  smooth  filtering  paper,  dried  at  a  low 
temperature,  and  then  forms  a  brown  amorphous  mass,  which  may  be 
reduced  to  a  brownish-yellow  powder ;  in  the  exsiccator  it  becomes 
