THE EFFECT OF ELECTRICITY UPON PLANTS. 
195 
Apart from the increase in rapidity of germination, Dr. Cook was 
unable to satisfy himself that the passage of the low tension current 
through the soil made any difference to the plant. 
Using the overhead discharge from the Wimshurst (E.M.F. from 
25,000 to 40,000 volts) or from an induction coil (E.M.F. approxi- 
mately 45,000 volts) he obtained a continued increase in the rate of 
growth of the plant. 
Asa S. Kinney,^ in 1898, and Ahlfvengren,^ a year later, both found 
that the germinating power of seeds is apparently increased by an 
electric current passing through them. Kinney concluded that the 
optimum voltage for this current was about 3 volts. Ahlfvengren 
suggested that this optimum varied for different plants, and, also, with 
changing conditions, varied for the same plant. 
Results such as these would explain the different action of the 
current upon two different species, for one of them the voltage supplied 
may be optimum, whilst for the other it may approach the maximum, 
when it might exert a deleterious influence on the plant. 
Lowenherz^ seems to have come to similar conclusions ; he also finds 
that the effect of the current on the plant is greatest during the period 
of germination. He is of opinion that the direction in which the 
current traverses the seed is of importance. 
Other work upon the subject will be referred to when discussing the 
theoretical considerations involved in the practical application of 
electricity. 
PRACTICAL APPLICATION OF ELECTRICITY. 
Experimental. 
Mr. J. E. Newman was able during the winter of 1904 to 
Bitton. instal a small trial apparatus with the overhead discharge 
system at the Golden Yalley Nurseries at Bitton, near 
Bristol. The installation was completed by the Spring, and, apart from 
occasional breakdowns, was running until the Autumn. 
The breakdown were accounted for by the fact that the machine used 
to generate the necessary electric power was simply a small influence 
machine of the Wimshurst type, hardly suited to continuous running, 
and that the oil engine first employed to drive it was scarcely powerful 
enough. 
The machine was working beneath a dust free case in a small shed 
upon the grounds, and its two terminals were connected, — one to the 
earth the other to a system of wires running out over the grounds and 
through seven out of the fifteen glasshouses. In the open the total 
area of experimental and control plots was about a thousand square 
yards. The wires ran at a height of some sixteen inches above the tops 
^ Hatch Experimental Station. Massachusett’s Agricultural College, 1897. 
^Ahlfvengren. Ofver.sigt af Koiigl Vetenskaps-Akademien Forhandlingar, 
Stockholm, 1898, No. 8 (Kef. Bot. Centralblatt. Bd. 79, p. 53. 1899). 
^ Lowenherz. Versuche uber Electrocultur. Botanisclies Centralblatt, p. 523. 
