1910.] Overhead Electrical Discharges. 



ig 



This acceleration effect seems to be only one indication 

 of many, pointing to a raised vitality in the plant, as evinced 

 by a more active pursuance of its normal physiological 

 functions. 



Thus several experiments point to the fact that the elec- 

 trified plants give off water more rapidly, and as a conse- 

 quence may suffer, as compared with their unelectrified 

 fellows, if too strongly electrified during a dry season. This 

 seems to me the most probable cause of the smaller strawberry 

 crop, accompanied by a much sweeter if, on the average, 

 smaller fruit, from the Evesham fields, in 1908. (See 

 page 28.) 



It is well known nowadays that the disease-resisting 

 power of a plant seems largely a function of its vitality, 

 and when grown under unsuitable conditions the less 

 virile plants seem more easily to succumb to the parasitic 

 attack. It is hence, perhaps, worthy of note that on one or 

 two occasions in the cucumber houses at Bitton, electrified 

 houses seem to have shown indication of greater resistance 

 both to the ordinary Cercospora spot disease and to other 

 occasional outbreaks of disease. From the nature of the 

 trials, however, I fear no very definite statement is possible, 

 and the question is not easily decided by experiments in the 

 laboratory. 



Various workers have reported increased chemical activity 

 in the plant under electrification, particularly Pollacci, who 

 reports that the manufacture of carbohydrates from atmo- 

 spheric carbon dioxide is possible in leaves, with an electric 

 current traversing them, at light intensities too feeble to 

 admit of such synthesis without the current. 



Such a conclusion points to the application of the current 

 at times near the hours of sunset and sunrise ; in many of 

 the practical trials in this country some such hours have 

 been employed, without, however, the effect being markedly 

 more beneficial than in trials when the current has been 

 applied at other hours. 



The numerous experiments of Berthelot reported in the 

 first volume of his " Chemie Vegetale et Agricole " also seem 

 to suggest that the electrified plant may be capable of 

 increased chemical activity, and perhaps along unusual lines, 



c 2 



