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XII. Some Obfervations on the Irritability of Vegetables . 
By James Edward Smith, M. D. F. R. S. 
Read February 14, 1788. 
H AVING often heard that the ffarnina of the Barberry, 
Berberis communis , were endued with a confiderable de- 
gree of irritability, I made the experiment in Chelfea Garden, 
* 
May 25, 17S6, on a bufh then in full flower. It was about 
one o’clock P. M. the day bright and warm, with little wind. 
The Ramin a of fuch of the flowers as were open were bent 
backwards to each petal, and fheltered themfelves under their 
concave tips. No Ihaking of the branch appeared to have any 
effect upon them. With a very fmall bit of flick I gently 
touched the infide of one of the filaments, which inftantly 
fprung from the petal with confiderable force, flriking its an- 
thera againfl the fligma. I repeated the experiment a great 
number of times ; in each flower touching one filament after 
another, till the tips of all fix were brought together in the 
center over the fligma. 
I took home with me three branches laden with flowers, 
and placed them in a jar of water, and in the evening tried the 
experiment on fome of thefe flowers, then {landing in my 
room, with the fame fuccefs. 
In order to difcover in what particular part of the filaments 
this irritability refided, I cut off one of the petals with a very 
fine 
