206     ON  THE  ACTIVE  PRINCIPLE  OF  CATALPA  BIGNONOIDES. 
with  ether,  to  remove  all  soluble  in  that  menstruum,  repeating 
the  washings  with  fresh  portions  until  it  ceased  to  be  colored. 
The  ethereal  solution  was  evaporated  to  an  extract,  the  color 
of  which  was  a  uniform  rather  dark  brown,  the  taste  excessively 
disagreeable  and  nauseating.  It  was  acid  to  litmus  and  evident- 
ly insoluble  in  water,  with  which  it  formed  a  turbid  mixture. 
The  ethereal  extract  was  redissolved  in  a  mixture  of  equal 
parts  of  alcohol  and  water,  and  boiled  with  freshly  precipitated 
hydrated  oxide  of  lead.  Having  separated  the  liquid  it  was 
found  to  be  of  a  straw  color,  very  bitter  taste,  neutral  to  test 
paper  and  unaffected  either  by  alkalies  or  iodohydrargyrate  of 
potassium. 
Upon  evaporating  the  liquid  by  means  of  a  water-bath  to 
dryness,  the  resulting  extract  was  of  a  yellow  color,  bitter,  in- 
soluble in  water,  but  did  not  possess  the  peculiar  nauseous  taste  of 
the  bark. 
The  PbO  was  first  washed  with  a  small  quantity  of  dilute  al- 
cohol and  then  boiled  with  stronger  alcohol.  After  filtration, 
and  during  spontaneous  evaporation,  there  took  place  a  separa- 
tion of  white  quadrangular  micaceous  scales.  These  crystals, 
upon  further  examination,  were  found  to  be  insoluble  in  water  or 
dilute  alcohol ;  sparingly  soluble  in  cold  alcohol,  but  very  soluble 
in  ether  and  chloroform.  They  were  insoluble  also  in  dilute 
alkaline  solutions  and  dilute  acids,  and  were  neutral  to  test 
paper,  thus  seeming  to  indicate  their  being  a  neutral  principle.  A 
few  of  the  crystals  heated  upon  platinum  foil  melted  and  inflamed, 
the  remaining  mass  of  carbon  finally  also  incinerating,  thus 
proving  them  to  be  essentially  an  organic  product.  The  crystals 
possessed  an  intensely  nauseous  and  bitter  taste,  resembling  that 
of  the  bark.  Upon  further  evaporation  of  the  mother-liquor  no 
more  crystals  could  be  obtained,  but  a  dark  resin  separated, 
which  was  readily  inflammable,  like  the  crystals,  and  possessed 
their  taste. 
That  portion  of  the  original  alcoholic  extract  which  remained 
after  having  been  washed  with  ether,  was  found  to  be  compara- 
tively tasteless,  with  Trommer's  test  gave  evidence  of  the  exist- 
ence of  glucose,  and  with  sesqui-salts  of  iron  showed  the  presence 
of  tannin.  A  tasteless  resin  was  also  separated  which  was  in- 
soluble both  in  water  and  ether. 
