Physostigma venenosum Balt. 
The best known ordeal poison of the western part of 
Africa, was the famous Ordeal Bean of Calabar, Physo- 
stigma venenosum Balf. of the Leguminosae. This tall, 
woody vine grew to an approximate length of 15 meters 
and a width of 5 centimeters at the base. Its habitat was 
the swampy areas from Sierra Leone to the Cameroons, 
and especially the Calabar Coast near the Gulf of Guinea 
at the mouth of the Niger River. The vernacular names 
of this plant were isho, esere, and djirou. In Gabon it 
was known as 2’chogo or m’boundou, and in the Pahouin 
tribe as ztounda, although it was rare in these areas. 
Its active principles, the properties of which are anti- 
dotal to strychnine and atropine (and are used by the 
present-day natives in this capacity), are the alkaloids 
physostigmine (or eserine), calabarine, and eseridine (or 
geneserine). he most important principle, physostig- 
mine (Ci3;HeiN3Q02), acted as a powerful sedative of the 
spinal cord, resulting in a progressive and ascending 
paralysis of the lower limbs, a loss of voluntary muscular 
control, the paralysis of the smooth muscles of respira- 
‘tion, and death by asphyxiation. It acted on the invol- 
untary muscles in a way resembling pilocarpine, 1.e., 
there was an ascending and progressive tetanic contrac- 
tion of the smooth muscles of the alimentary tract. 
Its action was contradictory in that it paralyzed the 
motor nerve centers but stimulated the nerve endings. 
However, in highly poisonous doses, the central effect 
overcame the peripheral. Further action was illustrated 
by an acute increase in the volume of the blood and in the 
number of red corpuscles. This was probably due to the 
stimulation of the smooth muscles which expressed blood 
from stagnant areas. 
The two less important principles, calabarine (compo- 
[ 807 ] 
