January 27, 1892.] 



Garden and Forest. 



47 



copallina) are found to grow in the extreme south-eastern part 

 of the state, and the Little Rocky Mountain Maple (Acer 

 glabrum) in Sioux County, in the north-west. Tlie Sug'ar 

 Maple (A. Iiarbatum) and the Red Maple (A. rubrum), which 

 were credited to eastern Nebraska in the Census Report, are 

 now said not to grow naturally in any part of the state, al- 

 though it seems probable that the second of these trees may 

 yet be found near the borders of some of the streams which 

 flow through the south-eastern coimties into the Mississippi. 

 Other additions to the Nebraska silva are the Witch Hazel 

 (Hamamelis Virginiana), the Indian Cherry (Rhamnus Caro- 

 liniana), the Mountain Mahogany (Cercocarpus parvifolius), 

 a widely distributed Pacific species, the Western Choke Cherry 

 (Prunus demissa), the Sheepberry (Viburnum Lentago), and 

 the Red Ash (Fraxinus pubescens). 



These facts show the importance of Professor Bessey's in- 

 vestigation, and how much there is still to be learned about 

 even such an apparently simple matter as the distribution of 

 some of our most common and best-known trees. They show 

 in particular the necessity of a careful study of the vegetation 

 of the mid-continental region, in which are mingled plants of 

 the east and of the west, and in which many eastern species 

 finally disappear, and a few western species find the eastern 

 limit of their distribution. Professor Bessey's report suggests 

 that there is still much to be learned of the distribution of 

 trees in the two Dakotas, in Kansas, in the Indian Territory 

 and in Texas ; and it is to be hoped that botanists living in 

 those states, and with facilities for collecting facts about their 

 vegetation, will follow the example of the Professor of Botany of 

 the University of Nebraska, and make public the results of 

 their observations. 



Much remains, too, still to learn of the distribution east- 

 ward, in Idaho and Montana, of several trees of the north- 

 west coast, and of the northern and eastern distribution of the 

 trees of British Columbia, whose silva, in spite of the good 

 field-work and excellent reports of Dr. Dawson and Professor 

 Macoun, is still very imperfectly known. 



Electricity in Agriculture is the -title of bulletin No. 16, 

 lately prepared by Mr. Clarence D. Warner, Meteorologist of 

 the Massachusetts Agricultural College Experiment Station. 

 In vol. ii., p. 443, we published the results of some experi- 

 ments made at Cornell University which seemed to strengihen 

 the opinioii that electric light might be of advantage in some 

 branches of horticulture. The experiments in Massachusetts, 

 however, have nothing to do with light, but they are an at- 

 tempt to show that electric currents passing through the 

 ground and atmosphere have some influence on vegetation. 

 As this is the first of a series of bulledns, it includes a brief 

 rSsumg of what has been done by former experimenters, and 

 Mr. Warner prefaces this historical sketch by the statement 

 that the currents of sap which are carried through the rootlets, 

 stalk and leaves of the plant depositing the elements of plant- 

 food in their proper places are due to electricity, a theory 

 which can hardly be considered as established. He adds, that 

 since the plant at night is generally covered with dew it be- 

 comes a good conductor for electrical currents, which convert 

 in their passage soil elements into plant-food and stimulate 

 the sap to gather up the dissolved elements and carry them to 

 their proper places. He thinks it probable, therefore, that this 

 accounts for the fact why most plants grow more rapidly dur- 

 ing the night than during the day. 



The history given of the earlier experiments is briefly this : 

 In 1845 plates of copper and zinc were placed in the soil where 

 plants were growing and connected by a wire, but these efforts 

 were fruitless of results. In 1847 Hubeck, in Germany, sur- 

 rounded a field with a network of wires, and concluded that 

 seeds germinated more rapidly and buckwheat gave larger 

 returns. In all other cases electricity produced no result. 

 Other men of science carried on experiments with negative 

 results, and the abandonment of the project of applying elec- 

 tricity to agriculture was advised. Some years later Fichtner 

 used a battery with effect. Parallel wires were placed in the 

 soil, and between the wires Peas, Grass and Barley showed an 

 increase of from thirteen to twentj'-seven per cent, when com- 

 pared with ordinary modes of cultivation. Fischer, of Wald- 

 heim, placed metallic supports to the number of sixty around 

 each hectare (about two acres and a half), and at the summit of 

 the supports were electrical accumulators in the form of 

 crowns surmounted by teeth, which were united by metallic 

 connection. The result appeared to increase the crop of 

 cereals by one-half. Plates of zinc and copper, alternately 

 placed about a hundred feet apart and connected two and two 

 by a wire, were said to increase twofold to fourfold the pro- 

 duction of certain garden-plants. Fischer stated that it was 



proved that electricity aided in breaking up the soil constitu- 

 ents, and he stated that plants under this treatment matured 

 more rapidly, were more healthy and were not affected by 

 fungoid growth. In later experiments bySpecnew, seeds were 

 submitted to the action of an electric current, with the result 

 of hastening germination and better-developed young plants 

 than those grown from non-electrified seeds. The current 

 did not affect the yield. At Kew Gardens plates of copper and 

 zinc were placed in the soil so as to make a battery of zinc, 

 earth and copper, with the result of increasing the crops of 

 vegetables. Other experiments made in Pskov, in Russia, at 

 the School of Forestry in Nancy, France, and other places, 

 seemed to indicate that an electrical current could be profit- 

 ably employed in not only garden and field crops, but that 

 Grape-vines subjected to this treatment yielded fruit with a 

 larger percentage of water and sugar and a lower percent- 

 age of undesirable acid. 



The following experiments were made in the greenhouse at 

 Amherst : Rectangular frames were made three feet long by 

 two feet wide, across which were run copper wires in series of 

 from four to nine strands, each series separated by a space of 

 four inches, and the strands by a space of half an inch. The 

 frames were buried in the soil so that the roots of the plants 

 would come in contact with the wires, with the supposition 

 that the currents of electricity passing through the wires would 

 decompose into its constituents the plant-food near the roots 

 and prepare it for the plants. Two electric gardens were thus 

 prepared and furnished with a battery arranged to allow con- 

 tinuous currents through each series of wires. Near each 

 electric garden was a plot prepared in the same way, except 

 that it lacked the electrical apparatus. These gardens are 

 designated as A and B. The soil was carefully prepared for 

 Lettuce, and were placed where much trouble from mildew 

 had been experienced, in order to test the effect of electricity 

 upon the fungus. In garden A fifteen Lettuce-plants of the 

 same size and vigor were set over the wires, the plants well 

 cared for and the current kept continuous. The experiment 

 began the ist of January, and on the ist of April five of the 

 plants had died from mildew ; the others were well developed 

 and the heads large. The largest heads were over the greatest 

 number of wires and nearest the electrodes. It appeared that 

 the healthiest plants as soon as the currents became feeble or 

 ceased would be affected by mildew. On examining the roots 

 of the plants it was found that they had grown about the wires, 

 as if they found there the greatest amount of nourishment. 

 The roots appeared in no way injured by the current, but 

 rather benefited by the electrical influences. Beside this gar- 

 den was one of the same dimensions, used as a check, having 

 the same kind of soil, and treated in the same manner as the 

 first, except that the electrical apparatus was wanting. At the 

 close of the experiments only three plants had partially devel- 

 oped ; two of these were nearly destroyed by mildew, and only 

 one of these was free from disease. In the second garden, B, 

 twenty plants of the same variety of Lettuce and equal size 

 were taken and treated the same as in A. At the close of the 

 test only five plants were free from mildew, seven died before 

 they were half-grown, the rest were well-developed, but in the 

 last part of the experiment they began to be affected. Several 

 heads were large, the largest fjeing over the greatest number 

 of vi^ires and nearest the electrodes. Near this plot were twenty 

 other plants subjected to like conditions, but without elec- 

 tricity ; all but one died from mildew before they were half- 

 grown. The solitary survivor only developed partly at the 

 close of the experiment, and was badly affected with the dis- 

 ease. The general result was that the plants subjected to the 

 greatest electrical influences were hardier, healthier, larger, 

 had better color, and were less affected by mildew than the 

 others. Experiments were made with various Grasses, but no 

 marked results were obtained. 



Mr. Warner concludes: "It would seem that electricity is 

 one of the agents employed by nature to aid in supplying the 

 plant with nourishment and to stimulate its growth. To what 

 extent plants maybe subjected to electrical influences, or what 

 strength of current is best suited, and what currents may 

 prove detrimental to their development have not been deter- 

 mined, but it is desirable to continue this research unfil some 

 definite information shall be gained on these points. Experi- 

 ment alone can determine whether different varieties of plants 

 differ in their capacity for enduring the action of electrical cur- 

 rents without injury." Mr. Warner also suggests that there 

 may be a limit reached where electricity would conipletely 

 overcome the attack of mildew and stimulate plants to a healthy 

 and vigorous condition throughout their entire growth. We 

 mayaddthatif electricity is so potent in giving vigor to Lettuce it 

 might under certain conditions give equal vigor to the mildew 



