460 
The  Chemistry  of  Cacur. 
Am.  Jour.  Pharm. 
Sept.,  1887. 
ployed  is  one  pepo,  which  when  dried  and  the  seeds  removed  would 
weigh  about  three  or  four  grains ;  two  pepoes  are  employed  when 
emesis  is  desired.  In  either  case  the  Kaffirs  heat  the  fruit  before  using 
it,  probably  to  render  the  pulp  more  watery,  as  they  squirt  the  con- 
tents of  the  pepoes  into  their  mouths  and  swallow  the  expelled  ma- 
terial. A  considerable  quantity  of  colloid  material  is  in  the  pulp,  and 
doubtless  assists  the  action  of  the  drug  by  retarding  absorption  of  the 
active  principle,  for  this  when  isolated,  as  described  below,  acted  less 
constantly  than  the  fresh  pulp.  No  tannic  acid  is  found  in  the  fruit, 
but  a  considerable  quantity  of  chlorophyll  is  present.  The  active 
principle,  as  mentioned  above,  is  injured  by  a  high  temperature,  as  by 
that  of  boiling  water  ;  this,  together  with  the  fact  that  few  reagents 
precipitate  it,  render  its  isolation  somewhat  difficult  by  any  of  the  or- 
dinary processes,  which  were  all  tried  with  varying  and  inconstant 
results.  The  method  which  gave  a  satisfactory  yield,  quantitatively 
and  qualitatively,  was  very  simple.  The  seeds  were  removed  from 
the  pepoes,  which  were  cut  up  as  finely  as  possible  and  then  dried  at 
a  low  temperature  in  an  air-bath.  The  product  was  powdered  and  ex- 
hausted with  rectified  spirit.  The  spirituous  solution  was  evaporated 
almost  to  dryness,  as  small  an  amount  of  heat  as  possible  being  em- 
ployed, and  the  residue  dissolved  in  a  little  water  to  which  freshly 
precipitated  oxide  of  lead  was  added  to  decolorize  the  solution.  This 
required  about  twenty-four  hours  with  frequent  agitation.  The  mix- 
ture was  then  filtered,  and  the  almost  colorless  filtrate  exhausted  with 
ether  without  further  evaporation.  The  ether  extracted  the  active 
principle,  and  when  decanted  was  quite  colorless,  but  possessd  a  very 
bitter  taste.  After  slow  evaporation  of  the  ether  a  very  pale  yellow 
body  was  left,  which  became  resinoid  in  appearance  and  brittle,  being 
easily  reduced  to  a  pale  yellow  powder,  intensely  bitter,  and  producing 
the  pharmacological  actions  of  the  fruit,  but  not,  as  previously  stated, 
being  so  constant  in  action.  The  yield  was  very  small ;  it  was  quite 
amorphous,  no  method  of  treatment  yielding  any  trace  of  crystalliza- 
tion. The  body  so  extracted  dissolves  readily  in  water;  it  is 
soluble  in  alcohol  of  all  strengths,  but  less  readily  in  very  strong 
than  in  weaker  alcohol.  In  ether  it  dissolves,  but  not  very 
readily,  although  sufficiently  to  allow  extraction  by  its  means. 
In  chloroform  it  is  only  slightly  soluble,  and  less  so  in  petroleum 
spirit.  When  heated  on  the  platinum  foil  it  burns  readily  with 
little  charring,  and  leaves  no  residue.    Strong  sulphuric  acid  dis- 
