76 ACTION OF CHLOROFORM ON THE SENSITIVE PLANT. 
above the chloroformed leaf are not at all effected. DeCan- 
dolle, in making an analogous experiment on a sensitive 
plant with a drop of nitric or sulphuric acid, remarked on the 
contrary, that it was the leaves above the leaf touched which 
closed, without those situated beneath participating in this 
motion. The observation of our learned countryman is quite 
naturally explained by attributing to the ascending sap the 
transport of the corrosive poison, a transport which, in this 
case, would take place in the direction from below upwards- 
But how to account for the apparent transmission of the 
effects of the chloroform in the contrary direction, from 
above downwards ? Might the descending sap more pecu- 
liarly have the property of transmitting the narcotic effects 
of this singular compound from one part of the sensitive 
plant to the other ; or might there exist in this plant some 
special organ susceptible of being affected by certain vege- 
table poisons in a manner analogous to the nervous system 
of animals? Notwithstanding the interesting investigations 
of Dutrochet and other physiologists, there still prevails too 
much obscurity on this subject to hazard an opinion. But 
in any case the fact is singular, and appears to me to merit 
the attention of persons accustomed to engage in questions 
of this nature. 
Experiments of the same kind, made on the contractility 
of the sensitive plant with rectified ether, have furnished 
me results nearly similar to the preceding; with this differ- 
ence, however, that whilst one drop of chloroform placed 
on the common petiole of a leaf situated at the extremity 
of a branch of a sensitive plant suffices to cause most of the 
other leaves situated beneath on the same branch to close, 
ether in general produces an effect only on the leaf itself 
with which it is put in contact. The next leaves have 
generally appeared to me not effected, I must however 
add, that my experiments with ether having been made 
after others, and at a lime of year when the sensitiveness of 
