in vegetable Structures. 243 



and leaves the infant plant in a negatively electric state. I 

 am aware that an objection may be, and I believe has been, 

 raised against the deductions from M. Pouillet's experiments, 

 as to the origin of the electricity detected by the electrometer, 

 on the ground, that the mere evaporation of the moisture con- 

 tained in the vegetable mould employed, would be sufficient to 

 elicit free electricity. This objection, however, I regard as 

 very slight; for not only is the evolution of electricity much 

 more considerable than evaporation of moisture would ac- 

 count for, but it does not appear until the plantule has 

 extended into the atmosphere; although it is evident that 

 evaporation of moisture must have commenced from the first 

 instant of placing the mould in the capsules. 



Let us now attempt the investigation of the probable origin 

 of these electric currents developed during germination ; for I 

 am unwilling to consider their origin, or, indeed, that of any 

 other of the varied phenomena occurring in organised tissues, 

 as a purely vital effect, so long as any probable physical ex^ 

 planation can be applied. Whenever electric currents are set 

 in motion, we have good reason to suppose, in most, if not in 

 every case, the previous or simultaneous occurrence of chemi- 

 cal action ; for the elaborate researches of Dr. Faraday and 

 M. de la Rive have been more than sufficient to demonstrate 

 that electric currents and chemical action bear to each other 

 the relation of cause and effect ; and, therefore, that an acid 

 cannot combine with a base, a simple body with oxygen, a 

 new compound be formed, or one already formed decom- 

 posed ; without electrical action coming into play. It is 

 scarcely necessary to state, that most important chemical 

 changes are constantly occurring in a vegetable, from the 

 first instant of germination to the last moment of organic 

 •existence ; the least of which changes are fully competent to 

 the production of a considerable quantity of electricity of low 

 intensity. To follow out the enquiry with some minuteness, 

 let us, for an instant, glance at the physiology of a true seed. 

 This we find destined to perpetuate the vegetable species, 

 containing that vital germ which requires but heat, light, and 

 moisture for its developement. This germ, or embryo, at the 

 first instant of germination, possesses a degree of vitality far 

 too feeble to elaborate food for itself from the crude mate- 

 rials: it may, indeed, be compared to an animal during its 

 fcetal existence, but wanting that maternal connexion by 

 which nourishment may be conveyed to it. And here we ob- 

 serve a most beautiful provision of nature for the supply of fit 

 food to the infant plant. A reservoir of amylaceous matter, 

 or starch, is laid up, either in the cotyledons of the embryo, 



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