SENSITIVE PLANTS. 
31 
mission of the effect from one end of the shoot to the other, and 
its ultimate death, are due, it would be premature to assert, as 
it is difficult in such a case to eliminate the irritant effect of 
the ether (clearly it did not here act as an anaesthetic) from the 
effect of the cold and ice produced by its rapid evaporation. It 
may here be stated, that two or three drops placed on the leaf 
ift the ordinary way had no effect at all. A few days after, simi- 
lar trials were made in the Botanic Grarden, Chelsea, on some 
plants of the same species, grown in a colder house, and which 
were shorter jointed ” and altogether firmer in texture. In 
these instances no other effect was produced than the death of the 
leaf. The other case to which allusion may be made was a 
Maranta, also growing in a stove, and in which the application 
of ether-spray to the tip of a leaf caused it to roll up on to the 
under side like a roll of paper. In the young state the leaves 
of this plant are rolled lengthwise (convolute), but the effect of 
the ether was to cause the leaf to roll up along the under surface 
from the tip towards the stalk. Similar experiments were tried 
on other Marantas, but without effect. 
Now, though of course little stress can be laid on these ex- 
periments, they appear to be worth recording, as suggesting 
other trials at a more favourable season — trials from which pos- 
sibly something may be learnt as to the movements of plants, 
the propagation of impressions, the action of irritants, or of 
frost. 
So suggestive a matter has not been lost sight of by the stu- 
dents of electricity ; the results, however, of electrical experi- 
ments are somewhat conflicting. Some months since. Dr. 
Sigerson, who was corroborated in his statements by Dr. Divers, 
stated that the leaves of the sensitive plant when touched 
with glass (a non-conductor) failed to exhibit their customary 
sensibility, but if touched with steel or other good conductor 
the usual results were at once manifested. Dr. Sigerson even 
stated that he felt a painful sensation in the ulnar nerve at the 
right elbow (the funny-bone) after having touched with the 
little finger of the same side the leaf of the Dioncea. On 
repeating these experiments ourselves on several occasions we 
have not seen any difference in the effect of glass or other sub- 
stance used to touch the leaflets. Mr. Hamilton, writing from 
Grrey Town, Nicaragua,* where the Mimosa grows wild, also 
repeated these experiments without the results seen by Dr. 
Sigerson, but he confirms the opinion expressed by that gentle- 
man that children affect the plant’s movements more than 
adults do. Dr. Sigerson even hints that the movements are more 
active when excited by a person in a tonic ” condition than 
when he is weary or exhausted. M. Blondeau, one of the most 
* Gard. Chron. 1867, p. 31. (Extract from the Athenaeum.) 
