In subsequent experiments it will be found
almost impossible to produce further condensation of vapour.
But these forces may also be of electrical origin. Von Helmholtz long
since showed that electricity exercises an influence on the
condensation of the vapour of water, and Mr C.T.R. Wilson, with this
view, has made truly quantitative experiments. It was rapidly
discovered after the apparition of the X rays that gases that have
become conductors, that is, ionised gases, also facilitate the
condensation of supersaturated water vapour.
We are thus led by a new road to the belief that electrified centres
exist in gases, and that each centre draws to itself the neighbouring
molecules of water, as an electrified rod of resin does the light
bodies around it. There is produced in this manner round each ion an
assemblage of molecules of water which constitute a germ capable of
causing the formation of a drop of water out of the condensation of
excess vapour in the ambient air. As might be expected, the drops are
electrified, and take to themselves the charge of the centres round
which they are formed; moreover, as many drops are created as there
are ions.
Pages:
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319