Irritability of Plants,. 147 



their petioles, we caused the current to traverse them ; but the 

 leaves did not fold up, the petioles did not fall, and the plants 

 seemed insensible to the electric action. We then varied the 

 experiment, and instead of employing the direct current of the 

 battery, we used an induced current obtained by the aid of a 

 very small Ruhmkorff's coil. The results were then quite 

 different. Scarcely had the current commenced when the 

 leaflets began to fold together, and the leaf-stalks drooped 

 down along the stems. These movements were quickly pro- 

 pagated from one end to the other of the plants. According to 

 this experiment the plants are sensible to electric disturbances, 

 and behave under such conditions like animals. 



We then wished to see whether the application of the elec- 

 tricity for a longer or shorter time would give rise to any 

 special phenomena, and we exposed three of the plants to electric 

 action for varying periods. The first plant received the current 

 from the RuhmkorfF coil for five minutes, and was then left to 

 itself. For more than a quarter of an hour it remained in a 

 state of prostration, but gradually its leaflets reopened, the 

 leaf-stems lifted themselves up, and in about an hour it re- 

 assumed its natural appearance, and seemed none the worse for 

 the shocks it had received. 



A second plant was similarly treated for ten minutes, and 

 then left alone. The state of prostration in this case lasted 

 for an hour, and it was not till the expiration of that time that 

 the leaflets began to open, and the leaf-stalks to rise, and these 

 movements seemed to be accomplished with greater difficulty 

 than in the preceding case. The plant was evidently fatigued, 

 and did not fully recover for two hours and a half. The third 

 plant was electrified for twenty-five minutes and then left to 

 itself. In this case we waited in vain for its restoration — the 

 prolonged electric action had destroyed its irritability, and 

 even its life, for the next day we found it withered, and 

 blackened, as if struck by lightning. 



The fourth plant was reserved for an experiment which 

 proves that electric disturbance acts upon plants, as it does 

 upon animals. It is known that man, and other animals, ex- 

 posed to the anaesthetic action of ether, become insensible to 

 induction currents, even when strong. We desired to ascer- 

 tain if it was the same with the sensitive plant. With this 

 object in view we placed a plant under a bell-glass with two 

 openings, through which two copper wires could convey the 

 electric current to it. A few drops of ether were sprinkled 

 in the glass, and in a short time the plant experienced the 

 anaesthetic action of that substance, for when shaken it did not 

 close its leaves, or manifest any sensibility. In this state we 

 passed the induction current through it, but it gave no sign of 



