Vol. Xril. No. 30G. 



THE AGRICULTCTRAL NEWS. 



21 



AGRICULTURE AND ELEGTRiCITY. 



EXPERIMENTS WITH THE SOIL. PLANTS 

 AND ANIMALS. 



A short time ago an account was published in this journal 

 of the results of Professor Priestley's experiments with electri- 

 city on the stimulation of plant growth in the held In continu- 

 ation of the subject, quite recently, a very interesting paper on 

 electro-agriculture has been read by Mr. T Thome IJaker. 

 A.M lE.E , F.C.S., and [mblished in the .founial of the 

 Jioi/al Surieti/ qt Arts (December \2, 1913). The first part 

 . of this paper deals more particularly with the various means 

 of producing different types of electric current — a technical 

 matter with which the agriculturist is only indirectly 

 concerned. In dealing with the subject, therefore, in the 

 present article, consideration will be given only to the actual 

 results obtained as regards the effect of currents upon the 

 objects dealt with. 



It will be interesting to record first, the fact that a 

 plant when alive is a feeble generator of electricity, and if its 

 upper extremities be connected by a conductor through a 

 sensitive electrometer to the roots, an electric current, 

 generated by the live processes going on within the plant 

 will be indicated by the instrument. In this connexion it 

 Kay be pointed out parenthetically, that thes^; currents are 

 exceedingly minute, and that one of the lllo^t essential things 

 in successful electro-agriculture is tn employ minute currents 

 or minute amounts of electro-energy comparable with those 

 at work in nature. • 



The way in which atmospheric electricity passes 

 into the plant appears to be mainly by means of the hairs, 

 each hair acting a.s a miniature lightening conductor. 

 The effect of electrification may be due to several things. 

 It may cause a contraction in the capillary tubes of the 

 plant stems, which would increase capillary attraction and 

 cause a quicker and more ready rise upwards of the 

 natural juices. The electrical stimulus may possibly assist 

 also some of the enzymic actions taking place during 

 plant nutrition. In considering these matters it is necess- 

 ary to bear in mind the kind cif currert that one is 

 working with. A number of experiments made with 

 bacteria, ferments, moulds and other microorganisms have 

 led investigators to the conclusion that almost every 

 individual plant or organism requires its own particular type 

 of electricity if the best results are to be obtained. 



In the discussion following the reading of the paper 

 under consideration, Mr. Newman, Sir Oliver Lodge's 

 collaborator in electro-agricultural research, also dwelt upon 

 the importance of this matter. It would seem that the 

 effect of high frequency currents on plants themselves 

 differs very much from that of high tension continuous 

 currents, though it is probable that both may have a useful 

 effect. 



Turning to a consideration of some of the uses to which 

 what is called an 'eflluve' discharge has been put, reference 

 may be made to the electro treatment of fungus diseases. 

 As an example of such treatment, the red variety of the 

 American gooseberry blight was treated with an efHuve dis- 

 charge, but was not killed by it; on first spraying the blight, 

 however, with a weak solution of a soluble sulphide, and 

 then playing on it with a high freqiiency effluve, ionization 

 cf the sulphide was effected, and the nascent sulphur killed 

 the blight organism. Another interesting application of the 

 eflluve discharge has been to cheese mites. These little 

 organisms infect the rind of certain cheeses and eventually 



the inside of the cheese; but the destruction can be stopped 

 owing to the fact that the little animals can be readily 

 electrocuted. By attaching a brush of fine silver hairs in 

 an ebonite handle to the high frequency apparatus, and 

 brushing over the surface of the cheese with it, the surface- 

 organisms are destroyed It is noteworthy that in this 

 instance, again, the kind of current makes a difference, for it 

 was found that one type of efttuve discharge not only did 

 not kill the mites but actually invigorated them. Similar 

 experience has been met with in the electro-treatment of 

 fungus diseases of fishes. 



The closely related problem of the application of radio- 

 activity to plant growth possesses features of perhaps 

 greater promise than electrical discharges, particularly in 

 relation to the .soil. As regards the source of the 

 radioactive material, it may be mentioned that in the 

 preparation of radium there is a large amount of residual 

 waste, which may contain anything up to 1 or 2 milligrammes^ 

 of radium per ton; and this practically inactive material mixed 

 with many times its own weight of ordinary Roil has been 

 found to produce very marked results. The author of the- 

 paper under consideration found that cress plants grown on 

 radio active soil were each 7 to 10 per cent, heavier than thfr 

 plants grown on ordinary soil. With radishes the result 

 was nothing less than extraordinary, the growth being about 

 three times more rapid. Itadium also has a stimulating effect 

 upon germination. Experiments with wheat gave equally 

 favourable results, though it must be remembered that the 

 experiments lately conducted in England with the assistance 

 of the Board of Agriculture gave an increase of 2" per cent. 

 in one year and only 3 per cent, in the next. This renders- 

 it necessary to reflect upon whether radio-active substances 

 will be quite so beneficial as Mr. Baker hopes. One thing 

 is certain, that there are now comparatively large source* 

 of radio-active material, chiefly carnatite, to afl'ord an ample 

 supply for purposes of agriculture in the future. 



To come now to some practical experiments in the 

 application of an electric stimulus to animal life, it will be 

 seen that in one direction certainly there is great promise of 

 economic success. ^ oung chickens hatched in incubators 

 can be grown under electric stimulus at about double 

 the rate, thus doubling the out-put of a chicken farm 

 and halving the food bill per chicken. But what is 

 of far more importance from an economic standpoint 

 is the decrease of the death roll during the first few 

 days after hatching. In the summer months, under nor- 

 mal conditions, the mortality is often as much as .50 per cent. 

 This disastrous dying off is practically non existent where 

 suitable electrification is used. In the experiments, the 

 chickens were kept in a chicken house which was electrified 

 by a large helix of heavily insulated wire wound round it in 

 turns about (! inches apart. The current was applied for 

 ten minutes every hour during the day. There was only 

 a mortality of 15 per cent, and as much as 35 per cent, 

 increase in weight of the electrified chickens after three 

 months. The vitality of the treated birds is reported to be 

 remarkable. In the words of the author; 'instead of running 

 away when one puts one's finger to the netting, they will rush 

 up and peck vigorously. During the treatment they are so 

 highly charged with electricity that quite a distinct shock is 

 felt in the fingers on touching them, although the birds 

 themselves are unconscious of anything. The sparks 

 which ttv from their beaks on their pecking one's finger do 

 not appear to be felt in the least by them.' It must be 

 borne in mind, however, that too strong or too frequent 

 application is liable to have a harmful rather than a stimu- 

 lating action. 



