August 6, 1908] 



NATURE 



ELECTRICITY IN AGRICULTURE. 

 CJOME thirty years ago Prof. Lemstrom, of the University 

 ■^ of Helsingfors, sought to elucidate the Aurora Borealis 

 by trying to imitate its appearance by electrical experi- 

 ments. For this purpose he produced high-tension dis- 

 charges of various kinds, and sent them through vacuum 

 tubes until he got an appearance very like those of the 

 northern lights. Some of these e.Kperiments he conducted 

 in his greenhouse — to tlie best of my belief, according to 

 his own account, given when on a visit to England — and 

 he noticed incidentally that the plants seemed to thrive 

 under the treatment, and that the electrification thus pro- 

 duced in their neighbourhood appeared to do them good. 

 He also noticed, as remarkable, the flourishing development 

 of plants in Arctic regions, where the sunlight was very 

 weak, and he attributed part of this growth to the influence 

 of electric discharges. 



He says that when the plants in the north of Norway, 

 Spitsbergen, and Finnish Lapland have resisted the fre- 

 quently destructive night frosts, they show a degree of 

 development which greatly surpasses that of plants in 

 more southern regions, where the climatic conditions are 

 more advantageous. This rich development appears prin- 

 cipally in the fresh and clear colours of the flowers, in 

 their strong perfume, in the rapid 

 development of the leaves on the trees, 

 and their scent, but particularly in the 

 rich harvest which different seeds — such 

 as rye, oats, and barley — will produce, 

 when, as before stated, they are not 

 destroyed by the frosts. From a bushel 

 of rye sown there will often result 

 forty bushels, and from barley twenty 

 bushels, and so forth. It is the same 

 with grass. These results are attained 

 notwithstanding the fact that the 

 people cultivate their soil very imper- 

 fectly, using only ploughs and harrows 

 of wood. 



He pursued the matter by careful 

 observation, taking test-plants in pairs 

 or groups ; electrifying one group — that 

 is to say, discharging some electricity 

 into the air above it — and keeping a 

 similar group away from the elec- 

 tricity, in order to be able to compare 

 them. Then he photographed the two 

 groups side by side, and found in 

 nearly all cases a marked improvement 

 as the result of the electrical treatment. 

 He concluded that the needle-like shape 

 of the leaves in fir-trees, and the beard 

 on the ears of most cereals, have the 

 discharge of electricity as their func- 

 tion ; and he found that they do act in 

 this way. 



This observation and these experiments of Prof. 

 Lemstrom were not, indeed, the beginning of the applica- 

 tion of electricity to plant growth, because pioneer attempts 

 had been made long before by the Abb^ Berthelon in 1783, 

 but it was the beginning of a thorough and scientific 

 treatment of the problem. Prof. Berthelot, at Meudon, 

 has also attacked it; so have Dr. Cook and Mr. J. H. 

 Priestley, of Bristol. During the winter of 1904 Mr. J. E. 

 Newman installed a small trial apparatus, consisting of a 

 small influence machine of the Wimshurst type and over- 

 head discharge wires, at the Golden Valley Nurseries at 

 Bitton, near Bristol. The wires ran about sixteen inches 

 above the tops of the plants, or above the rows of 

 tomatoes in the glasshouses ; and short pieces of fine wire, 

 with the free ends pointing downwards, acted as discharge 

 points. Mr. G. R. Newman has now established a large- 

 scale installation there. 



Attempts of a different kind had also been made by other 

 experimenters. Plates had been sunk in the ground, and 

 a current passed between them among the roots of plants ; 

 but whatever effect is thus caused is of a totally different 

 kind from that excited by high-tension electricity sup- 

 plied to the air above them. Both in a manner are 

 natural processes. There are natural earth currents, and 



NO. 2023, VOL. 78] 



these must flow among the roots of plants, though 

 whether they produce an appreciable effect may be doubted. 

 There is a natural atmospheric electrification, and this 

 must be playing an important part in many phenomena. 

 .Atmospheric electrification is responsible for the coalescence 

 of cloud globules into rain. During fine weather the elec- 

 tricity in the air is usually of one sign : positive. When 

 wet weather sets in, the electricity in the air usually 

 changes sign, becoming negative. The whole subject is 

 a large one ; a great deal is known about it, and vastly 

 iiiore remains to be known ; but meanwhile it can hardly 

 be doubted that the electrification of the air has some 

 effect on growing plants. For it is found that under tiie 

 influence of ultra-violet light, electrified plants can give 

 off electricity into the air from the leaves ; and the fact 

 that the upper air is normally electrified, relatively to the 

 soil, must cause all plants to be electrified also ; so that 

 in all probability they are in a constant state of slow 

 electrical discharge, which becomes more rapid when the 

 sun is up. In what way this discharge of electricity from 

 their growing tips, and hair, and surface generally, really 

 acts, must be studied and reported on by physiological 

 botanists, but it is natural to suppose that it cannot be 

 without influence, and reasonable to think that that in- 



FiG. 1. — Inside the t 



transformer shed, showing the inductive break, special coil, and high-tenbion 

 valves. 



fluence may be beneficial — a hypothesis which direct ex- 

 periment confirms. 



Possibly in some sunny countries the effect is excessive, 

 and might, with advantage, be moderated, but in this 

 climate it turns out that artificial supply of electricity does 

 increase the rapidity and assist the amount of growth. 

 .•\t any rate, the experiments of Lemstrom, which had 

 been repeated and extended by others, clearly pointed in 

 that direction. So when, after some preliminary experi- 

 ments at Bitton, Mr. J. E. Newman, of 3 Howard Street, 

 Gloucester, acting in conjunction with Mr. R. Bomford, of 

 Bevington Hall, Evesham, at his farm near Salford Priors, 

 determined to try the phenomenon on a really large scale, 

 and came to me to see if I could help them electrically, 

 and enable them to maintain a continuous high-tension 

 discharge for hours together each day over ten or eleven 

 acres by means of power furnished by an oil engine and 

 dynamo, I very willingly assented, and set my son, Mr. 

 Lionel Lodge, upon the work. 



The method is to stretch over the field to be treated 

 a number of wires on poles, something like low telegraph 

 wires, but high enough for loaded waggons and all the 

 usual farming operations to go on underneath the wires 

 without let or hindrance. The wires are quite thin, and 



