Electricity—Radium-, N-, and X-rays 
on cross bars above the growing plants. These wires 
were charged with electricity by means of a dynamo. 
Others again have passed (electrostatic) currents through 
the earth in which the plants were growing. Lemstrém, 
who was successful with this method, supposed that the 
soil bacteria were invigorated and wakened up by the 
current, and that their activity helped the plants, 
On the other hand, a recent observer has declared 
that continuous electric currents are distinctly injurious.! 
For most of these details, we have to thank the late 
Mr. Thwaite, whose interesting paper (Journal of the Royal 
Hforticultural Society, Jane 1908) contains full details of 
his own apparatus for electrifying plants. 
The following table (also from results cited by him) 
would seem to show that there is really some practical 
benefit to be gained. 
Author. ea | Gadi: 1 o8e 
Wheat . z Newman 29 to 39 =| Improved 
Oats. . - Lemstrém 40.7 Pr 
Rye . ‘ . 3 19.5 
Strawberries. eer 37 to 50 as sii 
ar . Newman 36 Improved | 14.5 
Potatoes . . Lemstrom 13.8-31 sie tes 
Carrots . Lemstrém 12.3 
i . » | Gloucester Expmts, 50 ‘i's ‘ae 
Beet . . PP 33 Improved LI 
Cucumber. Newman 17 as aa 
Most of these experiments seem to have been carried 
out with overhead wires. 
Priestley tried the Speschnew system of copper and 
zinc plates with beans, and found that the average volume 
of the bean increased from 1.5 ccm. to 2 ccm. (.0915 to 
.122 cubic inch), whilst the average weight increased 
from 1.71 gr. to 2.26 gr. (27 grains to 34.7 grains). 
214 
