116 
Australian  Alstonia  Bark. 
( Am.  .Tour.  Pliarm 
I      Mar.,  1881. 
don  the  further   examination  of  this  base,  for  which  the  name 
porphyrosina  is  proposed. 
The  ethereal  solution  is  now  likewise  treated  with  dilute  acetic  acid 
and  this  solution  precipitated  by  ammonia.    The  dried  mass  is  boiled 
with  a  little  genuine  ligroin;  a  portion  dissolves  therein,  but  from  the 
solution,  upon  cooling,  a  certain  amount  is  again  separated.    The  por- 
phyrina  remains  thereby  for  the  most  part  dissolved,  and  can  be 
obtained  by  the  evaporation  of  this  solution,  but  for  its  complete  puri- 
fication it  is  necessary  that  the  alkaloid  in  acetic  acid  solution  be 
treated  with  animal  charcoal.    The  porphyrina  precipitated  from  the 
decolorized  solution  by  ammonia  forms  white,  amorphous  flakes,  and 
upon  drying  a  white,  adherent  mass,  furnishing  a  white  powder.  It 
dissolves  readily  in  ether,  alcohol  and  chloroform,  and  is  again 
obtained  by  the  evaporation  of  these  solutions  in  an  amorphous  condi- 
tion.   The  alkaloid,  dried  in  the  exsicator,  was  found  to  melt  at  97^ 
C.  (uncorr.)    If  the  alcoholic  solution  of  prophyrina  be  diluted  with 
much  water,  a  feeble  blue  fluorescence  is  observed.    Pure  concentrated 
sulphuric  acid  and  that  containing  molybdic  acid  dissolve  the  alkaloid 
with  a  purple  color;  sulphuric  acid  containing  chromic  acid  with  a 
greenish-blue,   the   solution   becoming    gradually   yellowish -green. 
Concentrated  nitric  acid  dissolves  the  base,  as  previously  stated,  with 
a  purple  color,  which,  however,  fades  quite  quickly  and  passes  into 
yellowish  or  brownish-green.    In  acid  solution  porphyrina  shows  a 
blue  fluorescence.    The  amount  of  porphyrina  contained  in  the  Aus  - 
tralian alstonia  bark  is  very  small,  from  nearly  two  kilograms  of  bark 
only  about  0*6  grm.  having  been  obtained,  but  which  was  deemed 
sufficient  for  determining  the  elementary  composition.    From  the 
results  of  the  analysis  the  formula  C21H25N3O2  is  deducted  for  the 
alkaloid,  and  for  the  platinum  salt,  dried  at  120°C.,  the  formula 
(C2iH25N302)2*PtClgH2,  thc  air  dried  platinum  salt  containing  in  addition 
4  molecules  II2O. 
Alstoniclina  was  prepared  from  that  portion  of  the  alkaloids  diffi- 
cultly soluble  or  insoluble  in  ligroin  by  dissolving  it  in  the  requisite 
quantity  of  boiling  ligroin,  whereupon,  on  cooling,  at  first  isolated 
needles  and  afterwards  concentrically  grouped  needles  separated.  All 
attempts  to  isolate  these  apparently  different  substances  by  crystalliza- 
tion from  ligroin  were  unsuccessful.  In  the  further  course  of  the 
examination,  however,  the  author  succeeded,  by  means  of  sulphuric 
acid,  in  separating  from  the  crystalline  mixture  an  alkaloid.    To  this. 
