M. C. Blondeau on the Irritability of Plants. 33 



But the saddest part remains to be told. The six fishes 

 having been secured as above, I made no drawing or descrip- 

 tion of them, but placed them in spirits and transmitted them 

 home with other specimens. From some fault probably in the 

 spirits, these fishes were totally destroyed before arriving in 

 England, although, with the exception of some other fishes, 

 the rest of the specimens were in tolerable order. I trust, 

 however, that, as I know precisely where they are to be found, 

 I shall be able to procure new specimens from the same spot. 



V. — On the Irritability of Plants. By C. BloNDEAU*. 



We have undertaken, in the course of the present year, a great 

 number of experiments upon the irritability of plants ; and 

 these have shown us that the faculty possessed by certain 

 plants, especially the Sensitive Plant, of executing apparently 

 voluntaiy movements, may be suspended by various agents, 

 such as ether, chloroform, carbonic oxide, protoxide of nitro- 

 gen, and essence of turpentine, all of which, as is well known, 

 act upon the nervous system of animals. 



Amongst these experiments there is one which seems to us 

 to possess sufficient interest to induce us to submit it to the 

 judgment of the Academy of Sciences. This consists in sub- 

 mitting the Sensitive Plant {Mimosa pudica) to the action of 

 the galvanic current. 



In performing our experiments we selected four fully deve- 

 loped Sensitive Plants, the sensibility of which was so great 

 that the least contact, such as the friction of a fly's wing, was 

 sufficient to cause their leaflets to close, and even to depress 

 the petiole of the leaf along the stem. After placing the pots 

 in which these plants had been grown upon an insulating sup- 

 port formed by a plate of glass, we attached to the two extre- 

 mities of the stem in each of them a small copper wire for the 

 purpose of passing the current generated by a single Bunsen's 

 couple. After waiting for a few moments, the plant reopened 

 its leaflets, and the petiole was raised ; the current was then 

 passed, care being taken to avoid any movement which could 

 agitate the plant. Under these conditions we observed no 

 effect, the leaflets did not fold up, the petioles did not lower 

 themselves, and the plant seemed to be insensible to the action 

 of electricity. 



We then varied the experiment : instead of employing 

 the direct current of the pile, we made use of the induction- 



» Translated from the ' Comptes Rendus,' August 12, 1867, pp. 304-306. 

 Ann. & Mag. N. Hist. Ser. 4. Vol.'x. 3 



