238 PRUSSIC ACID IN THE LEGUMINOS^ 



In spite of all these researches and the conclusions to 

 be drawn from them, the fact still remains that these peas 

 form a very useful nutriment and are in very general use. 

 There is consequently ground for believing that these traces 

 of prussic acid are not formed during cooking, and that 

 prolonged boiling causes them to disappear. Not a single 

 case of poisoning has been recorded, although for many 

 years past numerous varieties of beans have been in use, 

 both for human and animal food. 



It is therefore easy to believe that only a few rare species 

 are harmful, and it is wrong, merely on account of a rumour, 

 to deprive mankind of the resources offered by nature, 

 especially in new countries. 



Some authors seem to attribute the varying proportion 

 of prussic acid in similar varieties to the colour. Judging 

 from our experiments, we are not of this opinion, but it is 

 practically certain that peas improve under cultivation and 

 that the glucoside tends to disappear. 



The seeds of PluiscoJus lunatus (Burma pea), either red 

 or white, now on the market, do not appear to have caused 

 any accidents. 



In both these kinds the content of the cyanogenetic 

 element apparently does not exceed an amount equivalent to 

 o'020 per cent, of prussic acid. 



As regards the other varieties, beans from the Cape, 

 Madagascar, Lima, and Sieva, in general use as human food, 

 cultivation has caused a very large portion of the poisonous 

 principle to disappear, the amount usually not exceeding 

 o'oio per cent, (calculated in prussic acid). 



All these peas give excellent results and deserve attention, 

 forming as they do a first-rate nitrogenous food. 



DANGEROUS PLANTS. 



Prussic acid is not the only danger offered by the 

 Leguminosse, a danger which, although it has sometimes 



