SOME FAMILIAR VEGETABLES 167 



when he wrote : " We may suppose that in the ordinary 

 life of land plants especially during the continually altering 

 differences of electrical tension between the atmosphere 

 and the soil, equalisations take place through the bodies 

 of the plants themselves. The land plant rooted in the 

 soil offers a large surface to the air, by means of its branches, 

 and the roots are still more closely in contact with the 

 moist earth, while the whole plant is filled with fluids which 

 conduct electricity and are decomposed by currents. Such 

 being the case it can hardly be otherwise than that the elec- 

 trical tensions between the atmosphere and the earth become 

 equalised through the plant itself. Whether this acts 

 favourably on the processes of vegetation, however, has not 

 been scientifically investigated, since what has been done 

 here and there in the way of experiments in this sense 

 can scarcely lay claim to serious notice." 



