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VI. Electrification of Air, of Vapour Oj Water, and of Other Gases. 



By Lord KELVIN, G.C.V.O., F.R.S., MAGNUS MACLEAN, D.Sc., F.R.S.E., and 



ALEXANDER GALT, B.Sc., F.R.S.E. 



Received and Read, June 17, 1897. 



1. IN this paper we describe a long series or experiments on the electrification of 

 air and other gases, with which we have been occupied from May, 1894, up to the 

 present time (June, 1897). Some results of our earlier experiments, and of prelimi- 

 nary 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 we used in our earliest 

 experiments, was an application of the water-dropper t (long well-known in the 

 ordinary observation of atmospheric electricity). Its use by MACLEAN and GOTO,J in 

 1890, led to an interesting discovery that air in an enclosed vessel, previously non- 

 electrified, becomes electrified by a jet of water falling through it. An investigation 

 of properties of matter concerned in this effect, related as it is to the " development 

 of electricity in the breaking up of a liquid into drops," which had been discovered 

 by HOLMGREN as early as 1873, and to the later investigations and discoveries 



* " On the Electrification of Air," ' Proc. Roy. Soc.,' May 31, 1894, and ' Phil. Mug.,' August, 1894. 

 " Preliminary Experiments to find if Subtraction of Water from Air Electrifies It," ' Brit. Assoc. 

 Report,' 1894, p. 554. " Electrification of Air and other Gases by Bubbling through Water and other 

 Liquids," ' Proc. Roy. Soc.,' February, 1895. " On the Diselectrification of Air," ' Proc. Roy. Soc.,' 

 March, 1895. " On the Electrification of Air," ' Proc. Glasgow Phil. Soc.,' March, 1895. " On the 

 Electrification and Diselectrification of Air and other Gases," ' Brit. Assoc. Report,' 1895, p. 630. 



f KELVIN and MACLEAN, ' Proc. Roy. Soc.,' 1894, and KELVIN, MACLEAN, and GALT, ' Proc. Roy. Soc.,' 

 February, 1895. " Electrostatics and Magnetism," 262 (from ' Proc. Lit. and Phil. Soc. of Manchester,' 

 October 18, 1859). 



J "Electrification of Air by Water- jet." By MAGNUS MACLEAN and MAKITA GOTO, 'Phil. Mag.,' 

 August, 1890. 



" Sur le developpement de 1'electricite a 1'occasion de la dissolution en gouttes des liquides." 

 ' Kongl. Svensk. Vet. Ak, Handl.,' 1 c., vol. 11, No. 8, pp. 14-43 (pour 1'an 1873), - 



2 B 2 25.6.98 



