64 The Bible of Nature 



curate arithmetic can make up for. The fact is 

 that the age of the earth is an unsolved problem, 

 but it must amount to many millions of years. 

 We have dwelt upon this because in our concep- 

 tion of nature must be included the datum that 

 the time required to bring about a result may be 

 practically unimaginable in its amount. The 

 span of the longest human life is but a tick of the 

 geological clock. If genius be an infinite patience, 

 we see it in the making of the earth. Nature is 

 never in a hurry. She works "ohne Hast, ohne 

 Rast." 



" One lesson, Nature, let me learn of thee — 

 One lesson which in every wind is blown, 

 Of toil unsevered from tranquillity." 



Inorganic Evolution. — But what of the material 

 of the earth throughout its history? There are 

 perhaps a quarter of a million of quite distinct 

 kinds of compounds on the earth; these are all 

 due to diverse combinations of some eighty ele- 

 ments; and there is no reason to doubt that they 

 have been gradually made in the course of the 

 earth's cooling. But have the elements also a 

 history? It is too soon to say much about in- 

 organic evolution, but we may recall the known 

 fact that radium gives rise to helium, and the 

 probability that uranium gives rise to radium. 

 There is here a hint of the transmutation or trans- 



