110 



BIOLOGY OF PLANTS. 



ment in theendosmometer, but the liquid passes out, in much 

 less quantities than it passes in. This movement is called 

 exosmose, and may illustrate the process of transpiration, or 

 perhaps favor the theory that plants excrete nourishment into 

 the soil, unfitted for their own species, but capable of nourish- 

 ing those of a different family. 



The influence of electricity upon germination, according 

 to Davy, is to increase the vital energies. He found that 

 corn sprouted more rapidly in water positively electrified by 

 the voltaic battery, than in water negatively electrified. We 

 should suppose, from analogy, that electricity would exert a 

 powerful influence upon the vital power of vegetables, from 

 its known influence upon this power in minerals. In medi- 

 cine, it has long since been employed as a remedy, especially 

 to restore sensation to parts which have become deprived of 

 feeling. Some experiments seem to prove, that continued 

 voltaic action upon animals of microscopic dimensions, so 

 excites and quickens the vital power, as to increase their 

 growth a thousand fold ; thus, converting animalculae, which 

 are too small to be seen, into visible and tangible insects. 

 This fact has led some men even to adopt the hypothesis, 

 that they were created by this power, that the vital and 

 electrical powers were identically the same, and that the pro- 

 cess of life is carried forward by a galvanic battery, consist- 

 ing principally of the brain and nervous system. 



As vegetables, however, are not sensitive beings, it is 

 more difficult to trace in them, the influence of this agent ; 

 but enough is known to infer its utility, and perhaps neces- 

 sity to the existence of the vegetable kingdom. 



Sect. 4. Agency of Man. 



There is but one remaining agent required for the most 

 vigorous action of the vital principle, and that is the farmer 

 himself. The vital power may exist in the seed, but it will 



