EFFECT OF ELECTRICITY ON PLANTS 



31 



kept them constantly electrified for some days, after 

 which they were sown. He found germination accel- 

 erated. Vassalli, in 1788, obtained beneficial results 

 from treatment, and so did de Rozieres, who experi- 

 mented with wheat, beans, rye, peas, radish, and 

 others. De Rozieres maintained that not only was 

 germination accelerated, but in all cases the 

 electrified plants were larger, with longer roots and 

 greener leaves. Hum- 

 boldt believed that 

 electricity exerted 

 considerable influence 

 on plant growth. On 

 the other hand, Sene- 

 bier was doubtful, 

 while de CandoUe was 

 led to think by his 

 experiments that elec- 

 tricity had very little 

 effect on plants. 



The various experi- 

 ments which were 

 made with electricity 

 up to this time were 

 made with static elec- 

 tricity. With the dis- 

 covery of voltaric electricity, other methods of 

 experimenting were employed. 



From the year 1800, the suject of electricity and 

 plant growth received little attention until 1844, 

 when there was considerable interest manifested in 

 the subject from the results of Forster's experi- 

 ments. He endeavored to utilize the atmospheric 

 electricity by stretching wires over a crop of 

 barley, and found that growth was increased in 

 a most extraordinary manner. In 1844, Ross 

 made some experiments with galvanic currents 

 which were described in the proceedings of the 

 New York Farmers' Club. He planted a field of 

 potatoes, at one end of which he buried a copper 

 plate five feet in length and fourteen inches deep, 

 connected with a wire to a zinc plate of the same 

 size 200 feet away, at the opposite end of the row. 

 According to Ross, potatoes grown on the treated 

 row were two and one-half inches in diameter, 

 while those grown on the untreated row in July 

 were only one-half inch in diameter. Similar gal- 

 vanic culture experiments have been made by 

 Sheppard, Helmert, Fitchner and Sohne, Tschinkel, 

 Holdefleiss, Maercker, Wollny and others. Sheppard 

 employed copper and zinc plates two feet long and 

 nine inches wide. These were connected with wires 

 and buried in the soil nine feet apart, and a num- 

 ber of seeds of different kinds were sown in be- 

 tween them. He found that many of the seeds 

 germinated poorly, and some of the plants eventu- 

 ally died, although the electrically stimulated 

 turnip plants showed a greater development than 

 the check plants. Helmert found in some instances 

 that growth was accelerated ; on the whole, how- 

 ever, he obtained negative results. Fitchner and 

 Sohne secured positive results with buckwheat, sum- 

 mer wheat, peas, and certain other crops. The gain 

 was 16 to 127 per cent. Tschinkel obtained a con- 

 siderable acceleration in germination and growth. 



The electrified plants, he asserted, were much more 

 robust. He attributed the beneficial effects of elec- 

 tricity to the decomposition of certain salts in the 

 soil. Holdefieiss found both growth and germination 

 to be accelerated. Maercker experimented with 

 sugar-beets, and his experiments showed no differ- 

 ences between the treated and the untreated plants 

 either in the weight or percentage of sugar. Some 



Fie. 48. An early plan for applying electrified water to plants (Bertholon, 1783). The man was 

 to stand on an insulated mounted platform drawn by the two attachments at the right. The 

 electric current was to be carried by a wire attached to the pot, and uncoiling at the opera- 

 tor's feet. (After Wollny.) 



experiments were made by Wollny on a more exten- 

 sive scale and in a very careful manner, with rye, 

 beans, peas, potatoes, rape, beets and others, and in 

 almost every instance he obtained negative results. 

 Chemical analysis of the treated and untreated soil 

 showed no difference in the amount of potash, 

 ammonia, phosphoric acid and potassium nitrate, 

 even when comparatively strong currents had been 

 passed through it. Blondeau found that when seeds 

 of peas, beans and wheat were treated one minute 

 with a constant induction current, germination was 

 hastened, and the electrified seed gave rise to 

 stockier and greener plants. He also found that the 

 fruit of the apple, pear and others ripened much 

 earlier when subjected to electrical treatment. 



Chodat employed static electricity, and found that 

 the germination of the pea was accelerated, and 

 that the electrically treated seedlings were longer 

 and thinner, and their leaves somewhat smaller 

 than normally grown plants. Paulin, who likewise 

 used static electricity, obtained positive results. 

 He placed his seeds inside a Leyden jar in which 

 was suspended a copper wire connected with the 

 conductor of a frictional machine. In order to get 

 the best results, he found that the jar containing 

 the seeds must be charged hourly, the length of 

 time which this must be kept up depending entirely 

 on the kind of seed employed. He maintained that 

 electricity not only accelerates germination but 

 that it is capable of awakening the dormant life in 

 seeds. 



Speschnew found germination greatly accele- 

 rated by the use of galvanic electricity. According 

 to Speschnew, treated seeds germinated four or 

 five days earlier than untreated seeds and possessed 

 longer and stockier stems. Weakes applied electri- 

 fied water to seed, which resulted in an accele- 

 rated germination and growth of seedlings. McLoud 

 found, by the use of direct currents, that many seeds 



