TRANSACTIONS OF SECTION A. 809 



triclty, given to plants durinj^ days with a clear burning sun, c.iu damage them 

 very much, if enough water is not also given at the same time. 



In what way does electricity exert an influence on plants ? Either the gases 

 in the air are transformed to ozone and nitric oxides, which being heavy fall down 

 upon the plants and increase the activity of their vegetation ; or the electricity in- 

 duces the juices of the plants to ascend more rapidly in their capillary tubes (the 

 Gernez phenomenon). 



Though There is much not yet explained, the method is ready to be used for 

 practical ])iirposes, especially as the author has succeeded in constructing au 

 electric mac'.niie that will be much more applicable for the purpose than the older 

 ones, amongst which the well-known Wimshurst machine has been used with good 

 effect. 



For the present occasion the author has this summer carried out some experi- 

 ments in Finland, at the cottage Kammio nearllelsingfors, through the hindness of 

 Dr. W. E. Lybeck, on some especially interesting plants. Of these, the tobacco plant 

 did not yield, in earlier experiments, to the favourable influence of the electric 

 currents, through want of water. Photographs of the experimental and the control 

 field, which were watered to the same extent, have been prepared. The pictures 

 were taken at the same distance from both fields, and show that under the influence 

 of the current the results are at least 40 per cent, better than without it. The 

 current was applied for four hours in the morning and four hours in the afternoon, 

 with many interruptions, however, from June 17 to July 30. The total number of 

 hours was 161. 



5. The Action of Electricitij upon Plants. 

 By E. H. Cook, D.Sc. Land., Clifton Laboratory, Bristol. 



The experiments recorded in this Paper were commenced so far back as 188G. 

 They have been repeated many times as the conditions afl'ecting the results gradu- 

 ally became known. They may be considered under three heads: (1) Those 

 relating to the germination of seeds ; (2) those relating to the growing of plants 

 in soil ; (3) those dealing with the lower forms of plant life, such as Algre, 

 Fungi, &c. 



The influence of electricity on the germination of seeds showed that the general 

 effect was to give an increased development in the seeds amounting to from 10 to 

 20 per cent more than in the non-electrified ones. 



The influence on growing plants showed that in almost every case the electri- 

 cally-treated plants came to maturity first, and they were also the first to show 

 •above the soil, but I could not satisfy myself that with the currents employed, viz., 

 from 1 to oO milliamperes, and with an E.M.F. of from 5 to 25 volts, any increased 

 rate of growth was observable after the cotyledons appeared above the soil. 



In order to compare the ett'ects of the battery, the induction coil, and the 

 machine, experiments were made with the same seeds grown, (1) without any 

 electricity, (2) with a current passing between carbon electrodes, (3) under the 

 positive point from a Wimshtirst machine, (4) under the negative from the same, 

 (5) under the positive point of an induction coil, and (6; under the negative point 

 of an induction coil. In every case the positive end of the coil produced the 

 greatest efl'ect. This was with an E.M.F. of approximatel}- 45,000 volts. 



Experiments have been made with yeast, spirogyra, and other large-celled 

 fresh-water Algre. It is intended to continue these experiments. 



Applications on the Large Scale. — Experiments have been made by iM. Barratt 

 and M. Spechnew by connecting large plates of copper and zinc sunk in the soil 

 with a wire and growing plants between them, and also by connecting plates to z 

 battery. It is, however, evident that if atmospheric electricity could be employed, 

 a practically unlimited source is available. Beckeinstener was the first to try this. 

 Following him, .several experimenters in France and other countries have invented, 

 perfected, and used what has been called the ' Geomagnetifere' with remarkable 

 results. The instrument is practically a lightning-conductor set up in the middle 

 of a field, and connected below with a series of cross wires running under the soil 



