INFLUENCE OF ELECTRICITY ON VEGETATION. 95 



endeavoured to prove that the experiments of those who electri- 

 fied seeds or plants in deep jars were not to be depended upon, 

 because in such arrangements evaporation would be checked : the 

 results of his experiments were in favour of the beneficial influ- 

 ence of electricity. In a later paper* he still maintains the same 

 opinion, and states, as his belief, that electricity assists in giving 

 to growing plants their green colour. 



The last writer of any note who published observations on this 

 subject was M. de Rozieres, by whom there are two long and 

 carefully detailed papers in Ilozier!s ' Observations sur la Phy- 

 sique.'t After this the all-absorbing questions of European poli- 

 tics seem to have diverted the attention of naturalists from the 

 discussion, and, when the retui'n of peace allowed the followers 

 of science to pursue their studies again, new trains of investiga- 

 tion arose, new and brilliant fields of inquiry were everywhere 

 opening to view, and the older and less interesting subjects of 

 inquiry were neglected and almost forgotten. The discovery 

 of voltaic electricity, and the brilliant discoveries which it led 

 to, completely eclipsed the hitherto favourite study of frictional 

 electricity. M. de Rozieres entitles his papers ' Essai sur cette 

 Question — Quelle est ITnfluence de I'Electricite sur la Germina- 

 tion et la Vegetation des Plantes ?' They contain numerous 

 experiments on chervil, wheat, beans, rye, peas, mustard, 

 radish, lettuce, trefoil, &c., the result of which was, that nearly 

 in all cases the electrified plants came up first, grew larger, and 

 had longer roots than the others ; " the leaves were more nume- 

 rous, larger, and of a decidedly more beautiful green." The results 

 of these experiments, which occupied M. de Rozieres from 1786 to 

 1790, confirmed the truth of the original experiments of Nollet 

 and Jallabert, and proved that the view taken by Ingenhousz was 

 incorrect, and that the effects in question were not results of 

 imperfect experiments and due to the unequal influence of light, 

 but were really caused by electricity, as those philosophers had 

 stated. In this view he was also borne out by the experiments 

 of Mr. Bilsborrow in 1797, who found germination decidedly 

 accelerated by positive electricity, and still more by negative. 



A. von Humboldt, in his masterly ' Aphorismen aus der Che- 

 mischen Physiologic der Pfianzen,' 1794, observes that there 

 is hardly any problem on which the learned are more divided 

 than respecting the influence of electricity on vegetation. He 

 evidently himself believes that it has considerable effect on vege- 



* Giornale Scientifico, t. iii. f Rozier, 1791, pp. 351-65 and 427-46. 



