236 PRUSSIC ACID IN THE LEGUMINOS^ 



The proportion of prussic acid in the seeds varies accord- 

 ing to the district from which they come ; for instance, the 

 prussic acid content in the seeds of P. lunatus from the 

 Dutch Indies dififered from that in seeds from British India. 

 Beans from the Cape, Madagascar, Lima, and Sieva are very 

 largely used for human consumption and have never been 

 responsible for any accident, notwithstanding the fact that 

 according to some analyses they contain as much as o'oio gr. 

 per cent, of poisonous principles. This proportion is only 

 exceeded where the plant shows a tendency to revert to the 

 wild state. 



Numerous varieties of the Java bean exist which are 

 edible. Several are grown in Reunion and are highly 

 esteemed ; the seeds are of various colours and the white 

 pea, known as the pois dragee, is generally held to be the 

 best . 



Some people have attempted to generalize from the 

 poisonous action that some Leguminosae, such as Phaseolus 

 lunatus, may possess, and have cast suspicion on such excel- 

 lent peas as Canavalia cnsiformis (jack bean), and some 

 others as well. 



The experiments we have carried out on these peas at 

 the Agronomic Station have always given negative results. 

 It is admitted that there are some which should not be eaten, 

 such as Phaseolus lunatus, Mucuiia atropurpurea, Dolichos 

 bulbosus, &c., but the jack bean, square pea (Psophocarpus 

 tetragonolobus), and all the peas cultivated in our gardens 

 offer no danger whatever ; on the contrary, thev make 

 extremely palatable dishes. 



However that may be, according to the figures we give 

 below not one of these peas contains anv prussic acid. 



Canavalia ensi] or mis ... ... ... ... ... none 



Vigiia Catjang ... 

 Psofi/tocarpw: letragonolohii c 

 Dolichos bulbosus 

 Mucuna ntilis 

 Phaseolus helvohis 

 ,, vulgaris 



