Electrification of water by splashing and spraying

Abstract

The experiments of Lenard and Sir J. J. Thomson on the electrification produced by the splashing of pure water and other liquids are well known. It was found that distilled water when splashed at a metal obstacle took up a positive charge, giving a negative charge to the air. Very dilute solutions of different substances gave very remarkable results, the sign and magnitude of the charge on the liquid depending on the dissolved substance and the degree of concentration of the solution. In all cases the electrification ultimately approached zero as the strength of the solution increased, so that for solutions of quite moderate strength the effect was inappreciable. Simpson has shown that if drops of distilled water are allowed to fall into a vertical jet of air of sufficient velocity, the drops are broken up and acquire a positive charge. Investigations of the electrification produced in the air when splashing takes place have been made by Kähler, Aselmann and Simpson. Similar investigations have been made in connection with bubbling and spraying of liquids by Townsend, Sir J. J. Thomson, Kosters, Eve and M. Bloch. A complete account of the subject will be found in a memoir by J. J. Rey. The work described in this paper was undertaken with a view to obtaining some precise data from which it might be possible to establish a connection between the charge produced on the liquid and the extent to which it had been broken up.