INOKGANIC EVOLUTION. 31 



indicated by Laplace's Nebular Hypothesis. Possil>ly such 

 a collision of two dark bodies might account for the origin of 

 a nebula, even if we suppose with Lockyer that a nebula is 

 essentially a great swarm of meteorites ; especially as the 

 discovery of radio-activity and the immense stores of energy 

 shut up in the atom render it unnecessary to postulate such 

 a high rate of speed in the colliding masses. 



Lockyer claims to have discovered that the stars having thin 

 hydrogen lines and thick metallic lines in their spectra are 

 increasing in temperature, while those with thick hydrogen lines 

 and thin metallic lines are getting cooler. In accordance with 

 this he has arranged a series illustrating the different stages in 

 what he calls the life history of a star. First we have a nebula, 

 then a nebulous star, next a reddish star like Antai'es, then 

 through stages represented by the Pole Star, Alpha Cygni, 

 Rigel, and the Orion stars, to some stars in the constellation 

 Argo, which he considers the very hottest of all. Then as the 

 temperature falls we get stages represented by Algol, Markab, 

 Sirius, our Sun, Arcturvis, a deep red star in the constellation 

 Pisces, and finally a dark star. Thus he claims that as the 

 Greologist, examining the various strata in the earth's crust from 

 the oldest to the most recent formations, finds an ever-increasing 

 complexity in the organic remains which they contain, so the 

 Astronomer, analyzing the light of the stars from hottest to 

 coldest, finds an increasing complexity in the so-called elements 

 he can detect in them. And finally on the Earth, the only cold 

 body we can examine, we find the thousands of elements and 

 compounds familiar to Chemists. 



Lockyer' s theory is very fascinating, and much might be said 

 in its favou^r, but it has not yet, I believe, been generally accepted 

 by astronomers. Assvuning it to be true, what becomes of the 

 dark stars ? Are they somehow or other, perhaps, as Croll 

 suggested, by coming into collision with each other, eventually 

 reconverted into a swarm of meteorites, and does the cycle 

 recommence ? Or is the Universe like a clock running down, and 

 will a time come, infinite aeons hence, when the last nebula shall 

 have been converted into stars, when the last star shall have 

 become dark and cold, and the whole universal Scheme of things 

 a Chaos of darkness and death ? We can hardly believe this. 

 Though we can comprehend neither Infinity nor Eternity, still 

 less can we picture to ourselves a Universe finite in space or time. 

 And in any case we know that He who made the Universe can 

 restore it, and we are told that a new Heaven and a new Earth 

 will be the final abode of t^lorified Man. 



