Vegetation

Abstract

By using platinum needles, partly connected to the bark and the wood of a living tree, Becquerel observed different electric current flows, revealing that the earth obtains continuous positive charges and that the parenchyma transmits negative charges to the air by means of water vapour. Becquerel went so far that he declared, in a memorandum of 1850, that the earth’s vegetation is one of the principle origins of atmospheric electricity. This Becquerel was himself the grandfather of the Becquerel who received the Nobel prize and whose name is related to the disintegration rate of radioactive material. It is strange that, although still cited by Dary in 1900, this remarkable conclusion has since been neglected. Recent studies on the currents through a tree during a thunderstorm or during a point discharge event make no mention Becquerel’s remarks. It is a pleasure on one hand, and a pity on the other, that the current situation of the earth’s lower atmosphere indicates that Becquerel was probably right and that he will not so easily be forgotten this time.