The Grounchvork of the Universe, &c. 71 



between the bodies, a star is formed which contains most of the 

 ordinary elements at a temperature somewhere between that of 

 the electric arc and the electric spark. A further continuance of 

 the evolutionary process yields stars of a temperature at least as 

 high as that of the electric spark ; and in the hotter stars of this 

 group cai'bon apparently ceases to be capable of existence, since it 

 vanishes from the spectra. A further step upward in temperature 

 results in the disappearance of many metals, so that the spectra 

 become simpler. Finall}^, when the stars are so heated that they 

 become "gaseous stars," even the metals cease to be stable at 

 these tremendous temperatures and only the very simplest 

 elements of low atomic weight such as hydrogen and helium 

 (together, probably, with forms of matter even simpler than 

 helium) exist at all. Then, as the evolutionary process proceeds 

 and the flaming mass of gas cools down by radiating its heat into 

 the depths of space, the cycle is reversed. Gradually a few 

 metals appear in the stars ; then more are generated as the bodies 

 cool down ; finally carbon comes into existence once more and 

 the stai-s disappear from our view into the dark state which 

 reveals nothing to our spectroscopes. 



Let us now turn back to the laboratory and see if in recent 

 research anything can be traced which is comparable to this 

 process of evolution postulated by Lockyer among the stars. 

 Evidently we must search for two x>henomena : the simplification 

 of elements into atoms of smaller mass such as hydrogen ; and 

 the building up of hydrogen into more complex materials. 



In the problem of simplification the pioneer was Sir William 

 Ramsay. Recognizing the tremendous store of concentrated 

 energy which exists in the radio-elements, he endeavoured to 

 utilize it in order to break up " complex " materials into simpler 

 components. By allowing niton to act upon copper, he found 

 that lithium made its appearance. At the tirne, this result was 

 not received with any enthusiasm by some physicists, as they 

 contended that there were no grounds in theory for supposing 



