300 
SENSITIVE PLANT. 
on being touched, or from any of the causes which 
excited their action before. If the end of the branch 
is kept in water, the leaves will continue to act for 
a considerable time. It is of no consequence with 
what substance we touch the plant ; but this is not 
exactly the case with respect to the part, since there 
is, in the articulations of the leaves, a little place, 
known by its wdiite colour, which appears to be par- 
ticularly irritable. 
If the sensitive plant be plunged into water, the 
leaves from the influence of the cold will close; but 
afterwards they will recover themselves, and if 
touched in this state, will again shut themselves up 
as if they had been in the open air; but by no 
means so quickly. This experiment does not ma- 
terially injure the plant ; for in the course of a day 
or two it completely recovers, and appears as vigorous 
as if it had never been removed from its natural ele- 
ment. 
Any violent application to this very curious plant 
immediately produces the most sensible effect : if 
the extremity of a leaf exposed to the rays of the 
sun, is burnt either with a lens or with a lighted 
taper, or is squeezed between a pair of hot pincers, 
it closes in an instant; and in the same moment, not 
only the leaflet which is opposite to it does the 
same, but all that are upon the same stalk ; and this 
will take place more or less, according to the strength 
of the impression, so that when the injury has been 
very great, the plant will be violently agitated for 
some distance round the spot. 
