We have just seen that very different causes acting in a continuous manner, such as light, can dissociate matter and finally transform it into elements which no longer possess any material properties, and cannot again become matter.
This dissociation, which has gone on since the beginning of the ages, must have played a great part in natural phenomena. It is probably the origin of atmospheric electricity, and no doubt that of the clouds, and consequently of the rainfall which exercises so great an influence on climate. One of the characteristic properties of radioactive emissions is that of condensing the vapor of water, a property which also belongs to all kinds of dust, and is demonstrated by an experiment of long standing (1). A globe full of water in ebullition is placed in communication with two other globes, one filled with ordinary air from a room, the other filled with the same air cleared of dust by simple filtration through cotton wool. It can then be seen that the stream coming into the globe containing the unfiltered air immediately condenses into a thick fog, while that in the globe containing pure air does not condense.
[(1) See Mr John Aitken: Trans. Roy. Soc. Edinburgh, vol. xxx (1883), p. 337; cf. C. Wilson, Philos. Trans. cxii, p. 403]
We see how the importance of the phenomenon of the dissociation of matter increases with the study of it. Its universality spreads daily, and the hour is not far distant, I believe, when it will be considered as the source of a great number of phenomena observed on the surface of our planet.
But these are not the most important of the phenomena due to the dissociation of matter. We have already shown it to be the source of solar heat, and we shall see presently that it is the origin of electricity.
~~Gustave Le Bon