ELECTROCULTUEE 21 



The treatment continued 24 hours a day for S6 days for barley and 

 139 days for potatoes, beginning in April. Both barley and potal 

 showed excellent growth, but no differences between the treated and 

 control plats were discernible at any time. Other experiments 

 were conducted with plants grown in boxes provided with copper 

 and zinc plates connected overhead by wires. Trials with rye. 

 wheat, and lupine gave no difference between treated and untreated 

 crops. 



Homberger (2Jf) reported that the passage of high-frequency 

 currents through the soil was beneficial to plant growth. His 

 experiments were conducted on a small scale, using flowerpots with 

 only a few plants, the treatment consisting of three applications 

 daily until the temperature of the soil reached 35° C. when th< 

 current was cut off. The leaves and stems of the treated plants 

 showed more chlorophyll than the controls. A photograph shows 

 one pot each of treated and control plants, the treated plants being 

 about five times as high as the others. In order to determine 

 whether the heating was the main cause of increased growth another 

 pot was subjected to test currents for five minutes daily. These 

 plants were about four times the height of the controls when photo- 

 graphed. From these comparisons Homberger concluded that the 

 oscillating field and not the temperature was the main cause of the 

 stimulation, and he believed his results to be due to chemical changes 

 taking place under the influence of the oscillating electromagnetic 

 field, analogous to the catalytic action of fight. 



In 1907 (17) and 1909 Cl8) Gassner reported upon experiments 

 with charged soil which indicated a general unfavorable action upon 

 plant growth. 



Kovessi (28 obtained unfavorable results in researches involving 

 some 1.100 experiments. 



Considerable publicity has been criven to an apparatus called a 

 •'geomagnetifier."" a sort of lightning rod designed to gather in 

 atmospheric electrical energy and supply it to the crops. Among 

 those who have reported favorable results through the use of sucE 

 apparatus are Maccagno (35), Basty (2), and Paulin 39 



At the present time methods of electroculture employing soil- 

 conducted currents have few proponents. 



EXPERIMENTS WITH MODIFIED POTENTIAL GRADIENTS 



Grandeau {21), in 1S7S. reported studies on the effect of the 

 electrical condition of the atmosphere upon the growth of vegetation 

 He crew plants in a Faraday cage consisting of four iron rods 1. 

 centimeter in diameter by 1.5 meters high, holding fine iron wires 

 forming 15 by 10 centimeter meshes. The cage was grounded in 

 order to destroy the normal electrical field. Experiments were 

 made with tobacco, corn, and wheat. The plants under the cage 

 were reported weak and slender. Six stalks of wheat grown in 

 free air weighed 6.57 grams, as compared with 4.95 grams for six 

 stalks grown under the cage. 



Grandeau was led by these experiments to the belief that high 

 trees act as a grounded network, in that they shield the vegetation 

 beneath their foliage from the action of the normal electrical field. 

 thereby causing a decreased rate of growth. With a sensitive 

 Thompson electrometer, he compared the strength of the field in the 



