34 ELECTRICITY IN AGRICULTURE 
The experiments in the summer of 1903, particularly 
at Atvidaberg, Sweden, showed it to be necessary to im- 
prove the method of control, as the constitution of the soil 
will have a marked influence, especially in rainy summers. 
Besides the above-described method it should have a wholly 
artificial addition of well-mixed earth put into two boxes, 
Im’. in surface and 4m. in depth, the sowing to be as equal 
as possible in number and at the same depth. One of the 
boxes should be placed under the electric air-current and 
the other 1om. apart from the field under the same current. 
The growth in these boxes will show the effect of this 
current, and also provide the means to judge if the fields 
have been of equal fertility. 
In connection with these experiments, it is to me an 
agreeable duty to express my best thanks to Baron E. 
Hisinger for the warm interest he has taken in the work 
and for the real support he has given it. 
HOW DOES ELECTRICITY EXERCISE ITS 
INFLUENCE ON THE, PLANTS? 
§10. During the summer of 1898 some experiments at 
the Physical Laboratory of the University of Helsingfors 
were performed regarding the state of liquids in capillary 
tubes under the influence of the electrical air-current. 
These experiments were continued in the spring of 1900 
by myself, assisted by a student (R. Bengelsdorff), and in the’ 
autumn and winter of 1901 with the aid of another student 
(V. J. Laine). The most important of these results may 
here be cited.* 
If a capillary tube is lowered into a glass of water united 
electrically with the earth, and a fine metal point, in con- 
ducting connection with the xegative pole of an influence 
* See the Author, ‘‘ On the State of Liquids in Capillary Tubes under 
Influence of Electrical Air-Currents,” O/versigt af Finska Wet. Soc., Férh. 
Bd. XLIII., r901. In German: Drudes Annalen. 1901, 5 Bd., p. 729. 
