4m.  Jour.  Pharm.  ) 
July  1,  1872.  J 
The  Calabar  Bean. 
305 
THK  CALABAR  BEAN* 
By  Dr.  L.  Yincent. 
'  In  a  sojourn  of  nearly  two  years  at  the  Gaboon,  during  which  time 
he  had  opportunities  of  studying  the  numerous  substances  possessing 
medical  properties  produced  in  that  part  of  equatorial  Africa,  Dr. 
Vincent's  attention  was  particularly  directed  to  the  Calabar  bean.  It 
is  used  in  that  country,  together  with  several  other  toxic  agents,  such 
as  the  Icaza  mboundu,  the  Inee,  the  Alehiuse,  etc.,  by  the  tribes  still 
plunged  in  barbarism  and  fetichism,  for  the  compounding  of  their  or- 
deal drinks.  From  a  memoir  giving  the  result  of  his  inquiries  we  are 
enabled  to  glean  the  following  particulars : 
The  first  specimens  of  this  drug  were  sent  to  Europe  by  English 
missionaries  from  Old  Calabar,  where  the  natives  called  it  "here." 
About  ten  years  afterwards  its  botanical  position  was  assigned  by  Pro- 
fessor Balfour,  and  at  nearly  the  same  time  Dr.  Fraser,  of  Edinburgh, 
while  studying  its  physiological  properties,  discovered  the  remarkable 
property  it  possesses  of  contracting  the  pupil  of  the  eye.  In  1866 
it  was  found  in  the  French  possessions  in  the  Gaboon,  not  far  from 
the  banks  of  the  rivers  Como  and  Rhamboe.  It  is  also  found  in 
abundance  on  the  banks  of  the  Ogo-wai ;  and  as  the  physostigma  pre- 
fers marshy  and  humid  soils,  it  is  probable  that  it  occurs  on  the  bor- 
ders of  all  the  rivers  flowing  into  the  Atlantic,  from  Old  Calabar  on 
the  north  to  Cape  Lopez  on  the  south. 
The  Calabar  bean  is  the  seed  of  the  Physostigma  venenosum,  Balf., 
which  has  been  placed  by  Balfour  in  the  Leguminosce,  sub-tribe  Eu~ 
phaseolce,  the  only  tribe  of  the  Leguminosce  that  contains  poisonous 
plants. 
It  is  a  perennial  woody  climber,  attaining  sometimes  a  height  of 
from  forty  to  fifty  feet.  It  twines  from  right  to  left  round  the  neigh- 
boring trees,  and  in  spite  of  any  obstacles  that  may  temporarily  pre- 
vent its  progress  in  this  direction,  it  will  after  a  time  resume  its  course. 
The  leaves  are  alternate,  trifoliate,  the  middle  leaflet  ovate,  very 
acute  at  the  tip,  regular  at  the  base,  stipulate,  the  lateral  leaflets  un- 
symmetrical.  There  are  also  two  short  stipules  at  the  base  of  the 
general  petiole.  The  flowers  are  disposed  in  clusters,  and  rose-col- 
ored, with  magnificent  purple  veins.  The  calyx  is  unequally  five- 
toothed ;  the  corolla  papilionaceous  with  vexillary  aestivation  ;  stamens, 
*  Journ.  Pharm.  ct  de  Chimie  [4],  vol.  xv,  p.  109, 
20 
