Perceptive Power of Vegetables. 145 



But at the prefent feafon of the year, I find this 

 vegetable in a very languid ftate; fo that my 

 trials have not afforded me much fatisfaclion. 

 I could not, however, perceive any difference, 

 whether the leaves were touched with a piece of 

 polifhed iron, or a ftick of fealing wax. And 

 the following well authenticated fafts, feem to 

 refute the Abbe'S hypothefis, concerning the 

 cledtrical ceconomy of this plant. 



I. The branches of the fenfitive plant have 

 two motions, the one natural, the other artificial. 

 By the fi.rft it progreffively increafes, in the 

 morning, the angle which it forms with the 

 ftem i and retreats in the fame gradual manner, 

 in the afternoon. By the fecond it contrafls its 

 leaves, when forcibly touched or fhaken. 



II. The fenfibility of the plant feems, chiefly, 

 to refide in the articulation of the branches of 

 the common foot ftalk, or of the particular foot 

 (lalk of each wing. -. 



III. No motion enfues from cautioufly piercing 

 the branch with a needle, or other fharp inftru- 

 ment. 



IV. A ftroke, or an irritation, produces a 

 more forcible effedt, than an incifion or evea 

 an entire feflion. 



V. A flight irritation only afts upon the 

 neighbouring parts, and extends its influence 

 according to its force. 



Vol. II. L VI. Plun- 



'"V 



