124 Prof. Buff 071 the Electricity of Plants. 



equilibrium was soon established again, either of itseK, or by 

 the moderate moving of the liquid metal by a glass rod. 



To examine the electric condition of a plant, it was placed 

 between the two beakers in the place of the bibulous paper. At 

 the termination of the experiment the circuit was again closed 

 with the paper, in order to be assured that at the commencement 

 of a new experiment every foreign influence was effectually re- 

 moved. 



In the first place, plants of the most varied kinds, having 

 their roots washed in flowing water, were examined. The roots, 

 including the attached fibres, dipped into one of the beakers ; a 

 portion of the uninjured leaves into the other. Having observed 

 the direction of the consequent defiection, the experiment was 

 interi'upted, and, when the equilibrium had once more esta- 

 bhshcd itself, the position of the plant was reversed and the 

 experiment repeated ; that is to say, the roots were now caused 

 to dip into the beaker, which in the formci- experiment con- 

 tained the leaves ; the ciu'rent, so far as it was dependent on an 

 electric excitation due to the plant, must therefore in the latter 

 case be reversed in dii'ection. 



The observed deflection sometimes amounted to a few degrees 

 mei'el)'^, sometimes it was a large arc. The direction of the de- 

 flection was however in all cases the same, and announced the 

 existence of a current which passed thi'ough the plant from the 

 root to the leaves. 



As the numerous plants experimented Nvith were not all equally 

 sappy, nor did they possess equal lengths and thicknesses, they 

 did not present the same surface of contact to the water ; great 

 differences as to the resistance offered to the passage of the cur- 

 rent were thus unavoidable. The inequality of the currents was 

 certainly in a great measure due to this circumstance ; in several 

 cases the magnitude of the deflection might be increased at 

 pleasure, when several plants of the same kind were placed, in 

 the same direction, one above another. 



The same mode of experiment enables us to examine, not only 

 the whole plants, but also any portions of them. The place of 

 severance from the plant (sometimes after the removal of the 

 exterior bark) dipped into one glass vessel, the leaves, and fre- 

 quently only a single leaf, dipped into the other. The current 

 was in no case absent, and its direction was always from the in- 

 jured portion, for example, from the place of severance, to the 

 external sm'face of the leaves. Severed branches, which had 

 remained several days in water, or even the fallen and half- 

 withered leaves, still acted, though with diminished energy, in 

 the same manner as the freshest. 



When the interior of the plant was exposed at any place, 



