196 
THE EFFECT OF ELECTRICITY UPON PLANTS. 
of the plants, or above the rows of tomatoes in the glasshouses, and 
upon these wires at intervals were twisted short pieces of fine wire with 
the free ends pointing downwards, and thus acting as discharge points. 
The wires were supported on ordinary telegraph wire insulators, 
which proved satisfactory except in wet weather, when there was such 
a rapid leakage of the charge that there was practically no discharge 
on to the plants. 
From March 7th up to July 26th the machine was running during 
108 days for a period of 9 '3 hours daily. Until May 20th the machine 
was running chiefly in the day time, and after that date it was running 
principally at night. 
In all cases control plots were provided, which, apart from the 
electric treatment were, as far as practicable, under identical conditions. 
The crops from the electrified and control plots were gathered and 
estimated separately, usually by weighing. 
The results of electrification in the case of the various crops grown is 
given in the following table : — 
Cucumbers, 17 per cent, increase. 
Strawberries (5 year plants), 36 per cent, increase. 
,, (1 year plants), 80 percent, increase, and more 
runners produced. 
Broadbeans, 15 per cent, decrease, but ready for picking 5 
days earlier. 
Cabbages (Spring), Ready for picking 10 days earlier. 
1 Celery, 2 per cent, increase. 
Tomatoes, No difference. 
One point requires special mention in the case of the cucumbers 
grown in the houses. On May 8th a spot disease, of bacterial nature, 
appeared in all the '‘cucumber houses, and unquestionably made far 
more headway in the unelectrified houses. 
It seems probable that the ravages of the disease were largely 
inhibited by the electric discharge, for during one week when the 
influence machine broke down the disease progressed far more rapidly 
under the wires, and was again checked upon restarting the machine.^ 
The action of the electric discharge may be due to one of two causes, 
either the resisting properties of the host have been increased, or the 
attacking power of the parasite diminished. 
Recent work by Massee,^ by Ray,^ and by Miyoshi^ supports the 
’^ow that the greater immunity of the treated cucumbers might be due 
^ The small increase in the case of the Celery may be connected with the fact 
that in this case the wires used as discharge points were not so fine. As a 
consequence the amount of current flowing from the air to the ground was 
probably considerably less. In all the other cases fine wire was used for the 
discharge points. 
See also “Fruitgrower, Fruiterer and Florist,” p. 106. August 17th, 1905. 
•* Massee. On the Origin of Parasitism in Fungi. Philosophical Trans- 
actions of the Royal Society. 197 B. 
Ray. Etude Biologique sur le Parasitisme. Comptes Rendus. Vol. 136, 
p.566. 1903. 
^ Miyoshi. Ueber Chemotropisrnus der Pilzie. Botanisches Zeitung, p. 1. 
1894. 
