THE VEGETABLE KINGDOM. 417 



burned in the theatres on the torches of the Furies. This 

 can be seen in the Fraxinella cultivated in our gardens. 

 Should the atmosphere be less tranquil, the experiment is 

 easily made by surrounding the plant with a glass case, as 

 in our engraving. So soon as an ignited body is plunged 

 into it, a general combustion ensues. 



Other plants, during darkness, project inexplicable gleams 

 of light. This extraordinary phenomenon, which is at- 

 tributed to electricity, was first pointed out by Mademoi- 

 selle Linnaeus, and afterwards recognized by some natural- 

 ists. 1 



When speaking of vegetable secretions, we cannot, in the 

 present day, omit a beautiful tree of the family of Sapo- 

 tacese, formerly considered useless, but which furnishes us 

 with one of the most precious substances, gutta-percha. 

 Spread over the coasts of Sumatra and Java, its produce 

 has only been advantageously worked during the last twenty 



1 Mademoiselle Linnaeus remarked that during twilight, or towards the begin- 

 ning of dawn, the flowers of the monkshood produced passing gleams from mo- 

 ment to moment. She communicated these observations to her father, and to 

 several authorities on physics. These species of lightnings were generally at- 

 tributed to a disengagement of electricity, and this was the opinion of M. Vilcke 

 in particular. 



M. Ijjaggren has made similar observations on different flowers. In order to 

 be certain that this phenomenon was not due to any aberration of vision, he as- 

 sociated to himself another observer, who was to indicate by a signal the moment 

 at which he perceived the luminous sparks. The learned Swede became con- 

 vinced that there could be no illusion, for his companion saw the lights at pre- 

 cisely the same instant that he did. These passing gleams are sometimes seen 

 in quick succession, but they often only appear at intervals of several minutes. 

 They are best seen on flowers of an orange-yellow; the pale varieties of the same 

 species do not produce them. They may be observed in the marigold, the monks- 

 hood, the tagetes (Tagetes erecta, Linn.), and the heliotrope. 



