SPURGEWORTS. 97 



medicine ;* yet the fatal character of others is such 

 that no medical man would dare to prescribe them. 

 One foreign tree in particular, called the Manchi- 

 neel, which bears a handsome, apple-shaped fruit, 

 is so poisonous that persons are said to have died 

 by merely sleeping beneath its shade, while a 

 single drop of juice on the skin produces an ulcer 

 difficult to heal." 



"Do you think it can be true, papa, about 

 people dying who sleep near it?" saidKobert. 



" I am not qualified to judge of its truth," said 

 his father ; " but those who are so inform me, that 

 with so volatile a poison, it is not at all unlikely 

 that delicate persons might die from sleeping under 

 it, and breathing its dangerous atmosphere." 



"What does ' volatile ' mean ?" asked Mary. 



" A substance is said to be volatile," said her 

 father, " when it easily becomes vapour and escapes 

 into the surrounding air. Camphor is volatile ; 

 and hence its powerful odour is immediately per- 

 ceived, while its very substance becomes converted 

 into vapour." 



" Oh yes," said Mary ; " the piece of camphor I 

 put with my dried plants has entirely wasted away." 



* Euphorbia, Mercurialis, Croton, &c. 



II 



