PHYSIOLOGY. BOs 
our organs of sense allow us to go. Whether we 
would be able with more perfect organs to observe 
more, is an useless investigation. 
The only thing which could give us some faint 
proofs of sensation in plants, would be the experi- 
ments with the Galvanic pile. Mr Humboldt did 
not succeed in rendering even very sensible plants> 
especially the Mimosa pudica, susceptible of it. Rain 
tried metallic stimuli wishout eifect in Parietaria, Ber- 
beris, Parnassia. In the Mimosa sensitiva, however, 
he succeeded whenever he put goldfoil upon the 
leaves without shaking them. [ut how easy is it in 
such experiments to be misled or deceived ! 
Vital power is peculiar to plants, as to organized 
bodies in general. Vhe simple experiment of let- 
ting a plant dry completely in a pot, without water- 
ing it, when, after it is completely dry, even by a 
careful supply of water, it never grows again, shows 
clearly, that its life is lost, and that fluids ascend 
through it by other means than capillary tubes, 
viele was Hales’s favourite opmion. Van Marum 
too has proved by experiment that plants can be de- 
prived of life by electric shocks. I have myself 
made‘a similar observation. Uaving isolated a very 
fast growing plant, the Drosera rotundifolia, 1 ex- 
posed. it to an electrical bath, on purpose to ob- 
serve whether the irritability of the an would be 
augmented, but I found no difference ; AIG aiGen) | 
drew sparks from some of the leaves, the plant very 
rapidly decayed. The vital power, therefore, may 
in plants, as well as in animals, be extinguished by 
excessive applicatign of electricity. Moderate use 
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