But, it may be urged, he who speaks of foundations speaks of a beginning of a structure; he who speaks of evolution must have a starting-point. Was there a time when the ether was a smooth, continuous fluid, without electrons or atoms, and did they gradually appear in it, like crystals in the mother-lye? In science we know nothing of a beginning. The question of the eternity or non-eternity of matter (or ether) is as futile as the question about its infinity or finiteness. We shall see in the next chapter that science can trace the processes of nature back for hundreds, if not thousands, of millions of years, and has ground to think that the universe then presented much the same aspect as it does now, and will in thousands of millions of years to come. But if these periods were quadrillions, instead of millions, of years, they would still have no relation to the idea of eternity. All that we can say is that we find nothing in nature that points to a beginning or an end. [*] * A theory has been advanced by some physicists that there is evidence of a beginning. WITHIN OUR EXPERIENCE energy is being converted into heat more abundantly than heat is being converted into other energy. This would hold out a prospect of a paralysed universe, and that stage would have been reached long ago if the system had not had a definite beginning. But what knowledge have we of conversions of energy in remote regions of space, in the depths of stars or nebulae, or in the sub-material world of which we have just caught a glimpse? Roundly, none. The speculation is worthless. One point only need be mentioned in conclusion. Do we anywhere perceive the evolution of the material elements out of electrons, just as we perceive the devolution, or disintegration, of atoms into electrons? There is good ground for thinking that we do. The subject will be discussed more fully in the next chapter. In brief, the spectroscope, which examines the light of distant stars and discovers what chemical elements emitted it, finds matter, in the hottest stars, in an unusual condition, and seems to show the elements successively emerging from their fierce alchemy. Sir J. Norman Lockyer has for many years conducted a special investigation of the subject at the Solar Physics Observatory, and he declares that we can trace the evolution of the elements out of the fiery chaos of the young star. The lightest gases emerge first, the metals later, and in a special form. But here we pass once more from Lilliputia to Brobdingnagia, and must first explain the making of the star itself. CHAPTER III. THE BIRTH AND DEATH OF WORLDS