612 SCIENCE PROGRESS 



day the experimental vessel was again electrified for five hours, 

 and electrification was continued up to the eighth day. At 

 that time all the seeds in the electrified vessel had germinated 

 and were fifteen to sixteen lines high, while in the control vessel 

 only two or three seedlings had appeared, and these were no 

 more than three to four lines high. 



Similar observations on the stimulation by means of elec- 

 tricity of the plant in various stages of its life — germination, 

 the growing period, opening of dormant buds — -were made by 

 numerous observers at this period, for instance Jallabert, 

 Menon, and Niirnberg. 



About this time atmospheric electricity had become a 

 favourite subject of investigation, and we find suggestions to 

 the effect that atmospheric electricity is an important environ- 

 mental factor in the life of the plant. Thus Father Beccaria 

 of the University of Turin, writing in 1 775, says : " With regard 

 to atmospheric electricity it appears manifest that nature 

 makes an extensive use of it for promoting vegetation " ; and 

 again : " Besides, the mild electricity by excess, (positive electric 

 action of low tension,) which, as I have observed for these many 

 years past, constantly prevails when the weather is serene, 

 certainly contributes to promote vegetation, in the same 

 manner as experiments have shewn us that this is likewise 

 the effect of artificial electricity without sparks. And is it not 

 likely that the former kind of electricity promotes vegetation 

 still better than the latter can do, since nature increases it and 

 lessens it in such circumstances and at such times as particu- 

 larly require it ? " Similar views were put forward at the same 

 time, and with perhaps even greater force, by the Abbe 

 Bertholon, who designed an apparatus, the electro-vegetometer, 

 for collecting atmospheric electricity and distributing it over 

 growing crops. 



There were, however, a few observers who concluded from 

 their experiments that electricity was either harmful to vege- 

 tation, or at least did not stimulate it. The earliest of these 

 appears to be Koestlin, who in 1775 reported that negative 

 electricity is harmful to vegetation ; but probably it was the 

 testimony of the famous Dutch physicist Ingen-Housz which 

 carried most weight, and who on account of his repute as a 

 plant physiologist has been often quoted in favour of the 

 theory that stimulation of vegetation by electrical means is 



