11)04.] PUBLIC DOCUMENT — No. 33. 13 



THE IXFLUEXCE OF CURRETs^T ELEC- 

 TRICITY ON PLANT GROAVTIL 



BY G. E. STONE, 



Since 1747, when Dr. Mainbray of Edinburgh electrified 

 two myrtle plants, various experiments have been made to 

 test the effects of electricity on the growth of plants. Many 

 marvelous results have been reported from time to time that 

 have arisen from electrical treatment, and, as a rule, the 

 more ignorance the experimenter displayed in his knowlqdge 

 of plant ph3'siology, the more startling and marvelous have 

 been the results. 



At the time our experiments were undertaken we were 

 unable to find instances where any attempt had actually been 

 made to study, in a methodical way, the intluence of current 

 electricity on plants ; and in practically all of the previously 

 recorded experiments the data were scant and the scope of the 

 work was extremely limited. In the various haphazard re- 

 sults that had been reported from time to time there had been 

 no attempt made to measure the current or resistance, or to 

 ascertain the electro motive force employed in any of the ex- 

 periments from which remarkable deductions had been drawn. 

 One of the criticisms which can be made in regard to all of 

 the earlier work, as well as most of the later work, is that, 

 Avith a very few excej^tions, only a few plants were employed 

 in experimenting, — frequently only one or two. As a con- 

 sequence, the errors arising from individual variation were 

 entirely ignored, since enough plants were not employed to 

 eliminate them. Indeed, in numerous cases the results ob- 

 tained were nothing more than would be obtained from indi- 

 vidual variation, or would naturally arise from a slight 

 difference in environment. The limited amount of current 

 which we have shown to act as a stinmlus to plant growth 

 would indicate that in some cases they were not in the range 



