1912.] PUBLIC DOCUMENT — No. 31. 143 



iug to the nature of the stimulus characteristic of that pole. 

 When weak currents are employed the positive current or anode 

 gives the greatest stimulation to those cells on the anode side of 

 the root, and induces bendings in the root towards the negative 

 pole or cathode. On the other hand, when strong currents are 

 employed the positive current induces bendings towards the 

 anode due to a retardation or injury to the cells on the side of 

 the root towards the anode. 



From our various experiments in electrical stimulation we are 

 of the opinion that increasing the electrical tension or potential 

 of the atmosphere, either by the use of static charges or from 

 high tension wires, gives rise to a greater degree of stimulation 

 than passing the current through the soil. Alternating currents 

 appear to be superior to direct currents in stimulating plants. 

 There is, however, the question of increasing the number of 

 micro-organisms in the soil by electrical stimulation as well as 

 the importance of nitrification and nitrogen fixation resulting 

 from electrical stimulation, a line of research on which we are 

 now engaged and on which we hope to report later. 



