The Respiration of Plants under Various Electrical 
Conditions, 
BY 
R. C. KNIGHT 
AND 
J. H. PRIESTLEY, 
Botanical Department , University of Leeds. 
With six Figures in the Text. 
Introduction. 
I N a large number of field experiments carried out during recent years, 
plants, otherwise under normal conditions, have been subjected to an 
electric discharge from an overhead system of wires during a considerable 
portion of their growing period, and, as a result, acceleration of growth and 
increase in yield have been constantly reported. 
It has been pointed out in a rfcume of these experiments, published by 
one of us , 1 that this treatment must considerably alter many factors in the 
plant habitat and in the plant’s reaction to this habitat, and consequently it 
is difficult to ascribe the effect, apparently due to the electric discharge, to 
any particular physiological cause. 
This paper records some of the first results of an attempt to analyse 
the effect of the discharge upon the plant by an investigation, under 
laboratory conditions, of the effect produced by such discharge upon one 
physiological function of the plant. 
The particular function first selected for investigation was respiration 
in so far as this is measured by the output of carbon dioxide, in part 
because this can be estimated fairly accurately, but more especially because 
it was considered that the amount of carbon dioxide evolved by the plant 
would give a good indication of the progress of katabolic processes within 
the plant. Attention was directed to these katabolic processes because it 
was thought that an increase of available energy within the plant might 
explain the general acceleration of growth upon electrification, which has 
been so characteristic a feature of the reports of the field trials. 
1 Journal of the Board of Agriculture, vol. xvii, p. 14. 
[Annals of Botany, Vol. XXVIII. No. CIX. January, 1914.] 
