Electrification of air, of vapour of water, and of other gases

1. In this paper the authors describe a long series of experiments on the electrification of air and other gases with which they have been occupied from May, 1894, up to the present time (June, 1897). Some results of earlier experiments, and of preliminary efforts to find convenient methods of investigation, have from time to time been communicated to the Royal Society, the British Association. and the Glasgow Philosophical Society. 2. The method for testing the electrification of air which was used in their earliest experiments was an application of the water-dropper, long well known in the ordinary observation of atmospheric electricity.