100 POISONOUS PLANTS 



charged with dew, were employed to root up 

 plants of the hogweed in a certain park. Nearly 

 all of them experienced the same, or the next 

 day, a sensation of intense heat in the left arm 

 and about the wrist. An inflammation like 

 erysipelas developed itself accompanied by sores, 

 which prevented them from working for nearly 

 three weeks. Some beasts which ate the up- 

 rooted plants suffered internal irritation. The 

 left arm being injured is explained by the workmen 

 having torn up the plants with their right hand, 

 and then laid them across the left arm. It was 

 observed that the workmen who began their 

 work early, suffered much more seriously than 

 the later arrivals, when the sun had dissipated 

 the dew. 



Looking for the cause of Panaisie, it has been 

 suggested that it is the essential oil ; that during 

 the day this oil evaporates as it is formed ; but in 

 a misty morning, without sun, in a meadow 

 charged with dew, it is condensed instead of 

 being volatilized ; then being dissolved in the 

 dew which covers the plant, this acquires the 

 irritating property which gives rise to the complaint. 



The Ivy Family {Araliacece), 



Ivy {Hedera Helix). — This is our only represent- 

 ative, and is too well known to need description. 

 The dark-coloured berries are attractive to chil- 

 dren, as they appear in the winter ; and several 



