DICOTYLEDONS AS POISONOUS PLANTS 67 



Nature of Poisons. The opium poppy contains a long list of alkaloids 

 enumerated by Fliickiger and Hanbury. The most important of the alka- 

 loids is morphin (CnH^NOs + H 2 O) which in the pure state is a colorless 

 or white shining, odorless substance with a bitter taste. Codein, also of 

 considerable importance is a nearly transparent odorless substance with 

 a faintly bitter taste and narcotin is also present. 



Wild Black Cherry (Prunus serotind). This is a medium sized forest 

 tree found in the Middle Atlantic and Ohio River states very commonly. 

 Less commonly in southern New England and Gulf states and westward 

 from Illinios, South Dakota, eastern Nebraska and Arkansas. The 

 leaves are alternate and dark green. The white flowers, which appear in 

 April and May, are produced in racemes, followed in the fall by the shining- 

 black, edible fruit, suggesting a small bunch of grapes. 



Nature of Poisoning. Poisoning is frequently caused in cattle by 

 eating the wilted leaves from branches, which have been accidently 

 broken off from the tree. A case of poisoning in horses on a stock farm 

 at Chestnut Hill, Pa., was called to the attention of the writer, where the 

 animals in passing from the paddock, where they had been feeding, to the 

 stable had browsed upon the leaves from several branches that had been 

 broken down by the passing of a wagon loaded with hay. The prominent 

 symptoms observed in cattle are labored breathing, diminished pulse, 

 numbness, protruding eyeballs, convulsions, and death from paralysis 

 of the lungs. Sometimes there is frothing at the mouth and nearly always 

 a perceptible odor of prussic, or hydrocyanic, acid on the breath. 



Active Principles. The fresh parts of the plant, including the leaves, are 

 nonpoisonous, but contain a gluccside called amygdalin (C2oH27NOn) 

 when the leaves are partially withered this glucoside is acted upon by a 

 ferment known as emulsin, and by a complex chemical change, the amyg- 

 dalin is converted into the poisonous prussic, or hydrocyanic acid (HCN) 

 with the formation of grape sugar and benzaldehyde (bitter almond oil). 

 It is the formation of the hydrocyanic acid, which causes the poisoning, 

 and if the leaves are thoroughly dried the prussic acid, being volatile, is 

 dissipated, and they become harmless. 



Other Poisonous Species of Prunus. Several other species of the 

 genus Prunus similarly become poisonous. Among them are the cherry 

 laurel (Prunus laurocerasus) of Europe, wild red cherry (Prunus pennsyl- 

 vanica), found in rocky woods from Newfoundland to the Rocky moun- 

 tains to Georgia, and Prunus demissa found on river banks from British 



