34 M. C. Blondeau on the Irritability of Plants. 



current produced hj means of a very small Euhmkorff's coil. 

 The results were then quite different. Scarcely had the cur- 

 rent begun to pass, when the leaflets were seen to apply them- 

 selves to one another, then the petioles were depressed along 

 the stem, and the movement was rapidly propagated from one 

 end of the plant to the other. According to this result, the 

 plant is sensitive to electrical disturbances, and behaves in 

 this respect exactly like animals. 



We wished to ascertain whether the subjection of the plant 

 to electricity for a longer or shorter time would produce in it 

 phenomena worthy of notice ; and with this view we caused 

 the induction-current to act upon three of our Sensitive Plants 

 during different periods of time. The first plant submitted to 

 experiment received for five minutes the disturbances produced 

 by the Euhmkorff's coil, and at the end of this time it was left 

 to itself. For more than a quarter of an hour the plant re- 

 mained in the state of prostration to which it had been reduced 

 by the electrical action ; but by degrees the leaflets opened, 

 and the stalks raised themselves again, and in about an hour 

 the plant had regained its original position, and did not appear 

 to have suffered in the least by the shocks to which it had been 

 subjected. 



A second Sensitive Plant was subjected to the same treat- 

 ment, but continued for ten minutes. At the end of this time 

 the induction-current which traversed the stem was suspended 

 and the plant left to itself. The Sensitive Plant remained in 

 the state of prostration to which it had been brought by the 

 action of the current for more than an hour, and it was only 

 after this lapse of time that the leaflets began to open and the 

 petioles to elevate themselves. This movement moreover took 

 place more slowly and laboriously than in the preceding case. 

 Evidently the plant had been fatigued ; for it did not return to 

 its original position until two hours and a half after the current 

 had ceased to traverse it. 



Our third Sensitive Plant was subjected to the action of the 

 induced current for five-and-twenty minutes, and then the 

 plant was left to itself. In this case we waited in vain for it 

 to resume its original position : the prolonged electrical action 

 had been sufficient to destroy all irritability, and even to cause 

 the plant to perish ; for on the following day we found our 

 Sensitive Plant withered, and even blackened as if it had been 

 struck by lightning. 



Our fourth Sensitive Plant was reserved for an experiment 

 which has proved to us that electrical disturbance acts upon 

 plants in the same way as upon animals. 



We know that man, as well as the other animals, when sub- 



