27 



plant. Under certain conditions these compounds liberate prussic 

 acid, one of the most deadly poisons. The fresh leaves are generally 

 considered harmless. As they begin to wither, however, the acid is 

 formed, but as this is volatile it disappears from the foliage in a short 

 time. These facts thus serve to explain how it is that only the 

 partially wilted leaves are considered poisonous. 



Symptoms of poisoning. — The prominent symptoms of black cherry 

 poisoning observed in cattle are labored respiration, diminished pulse, 

 numbness, fright, protruding eyeballs, convulsions, and death from 

 paralysis of the lungs. In some 

 cases there is considerable froth- 

 ing at the mouth ; in all there is 

 a very perceptible odor of prus- 

 sic acid in the breath. 



Remedies. — Death comes on 

 rapidly, but nevertheless it is 

 obligatory in case of a human 

 subject to use emetics and advis- 

 able to wash out the stomach 

 with a dilute solution of perox- 

 ide of hydrogen. A physician 

 should administer a solution of 

 cobalt nitrate, either internally 

 or hypodermically. Artificial 

 respiration and the use of oxy- 

 gen gas should be resorted to. 

 The extraction of blood and the 

 transfusion of blood serum or 

 salt solution should also be con- 

 sidered. 



Other native species. — Other 

 closely related species are like- 

 wise poisonous. The European 

 cherry laurel (Primus laurocera- 

 sus) has an established reputa- 

 tion. It is not common in this 

 country, but is well known in central Mexico. The laurel cherry (Prumis 

 caroliniana) of the southern coast States is also poisonous. It is largely 

 cultivated in that region for ornament and as a hedge. The choke cherry 

 (Prumis virginiana), a well-known shrub or tree distributed from the 

 Rocky Mountains to the Atlantic, has not so tempting a fruit and is 

 not extensively planted for ornament. It is therefore not so dangerous. 

 The seeds of all varieties of cherries and plums, both native and intro- 

 duced, are subject to suspicion ; the flesh of none of the species is in 

 any way poisonous. 



The freshly cut branches of the trees should in no case be thrown 

 where cattle can get at them. 



Fig. 10. 



-Black cherry (Prumis serotina), one-third 

 natural size. 



