56 ELECTRICITY IN AGRICULTURE 
increase of Ig per cent., or from 14'2 per cent. to 16°1 per 
cent., which makes 13'4 per cent. increase on the percen- 
tage of sugar in the sugar beets from the control field. 
The increase percentages are small for potatoes as well 
as for sugar beets, and it comes near the fact to suspect the 
cause to be a greater fertility of the control fields, in 
analogy with the second experimental and control fields in 
the case of the meslin. It is known with certainty that, on 
the mixing of the soil, the subsoil of the fields showed very 
different constituents. In favour of this view also there 
is the negative result with the fodder beets, which always 
previously have given a fairly high increase per cent. If 
the fertility of the two fields had been the same, and if 
the electric air-current had had no effect, the harvest ought 
to have been the same from both fields, but the negative 
result shows a smaller fertility of the soil of the experi- 
mental field. Carrots, which have always been a delicate 
crop, cannot here serve as a proof. 
At all events, the summer was so wet in the latter half of 
August and the earlier part of September that the condition 
of the subsoil had a marked influence on the fertility of the 
soil. That the electric current had exercised an influence 
on the roots during a long period, and ought thus to have 
produced a higher increase per cent., if both fields had been 
of an equal fertility, is shown by the great increase of the 
percentage of sugar in the sugar beets, for such a condition 
is not produced suddenly. 
The chief cause, however, of the low ncrease per cent. 
lies in the circumstance that the influence machine from ist 
August to 15th September had not been at work for more 
than 22 days, hence there were 23 days of inactivity. From 
15th September to 8th October, or 23 days further, the 
machine was out of use owing to a misunderstanding of 
the skilled manager in Atvidaberg, Mr. Tillberg, who, with 
never-failing interest, exercised the supervision and direction 
of these experiments. He reported on the 15th September 
