liKU.] PUBLK^ DOCUMENT— No. 83. 27 



action on plants as we do about the eifects of light in produc- 

 ing hcliotropic bendings, or of gravit}^ in producing gcotro[)ic 

 bendings. Some of the various theories pertaining to elec- 

 trical action, however, possess interest and are worthy of 

 citation. Frecke held the idea that electricity was the great 

 moving force of animate creation, and identical with nervous 

 influence. ]\hirat was ol' the opinion that electricity exerted 

 a marked influence on the fertility of the soil, and similar 

 ideas have been advanced by others in more recent times. 

 Fichtner and Sohne claimed to have found that electricity 

 rendered soluble the constituents of the soil ; and the same 

 opinion was advanced by Tsehinkel, who believed that accel- 

 eration and growth were brought about by the action of elec- 

 tricity upon the salts and other constituents of the soil. 

 Jodro attached a double function to the action of the soil 

 current : first, it acts chemically on soil, in dissolving those 

 constituents necessary for plant nourishment; and second 

 it acts mechanically, in setting the particles of the soil into 

 a state of molecular vibration, thus loosening the earth. 

 These views relating to the decomposition of the certain 

 salts in the earth by passing a current of electricity through 

 it have not been confirmed by Wollny. He made a series 

 of careful analyses of soil, electrically treated and untreated, 

 and found absolutely no difference, which could be attributed 

 to the effects of electricity, in the percentages of potassium, 

 ammonia, phosphoric acid, potassium nitrate and carbonic 

 acid gas. The action of electricity upon oxygen, as is well 

 known, gives rise to ozone ; and some botanists have be- 

 lieved that the production of ozone in the seed b}^ electric 

 currents is the prime factor in accelerating germination and 

 growth. 



Most of these theories are very fanciful, and all inade- 

 quately explain the stimulating effect of electricity upon 

 plants, nor is there any reason to believe that this phenom- 

 enon can be explained by simple mechanical theories. There 

 may exist a fundamental basis for the theory that electricity 

 is capable of decomposing certain constituents of the soil and 

 rendering them more available, but in all probability the 

 strength of current which is capable of advantageously stim- 



