20 THE UNFATHOMED UNIVERSE 



pellate is not known in a single instance, least of all per- 

 haps in the oldest recognised case, gravitation " (Matter 

 and Energy, pp. 111-12). 



We know of over eighty elements and much about many 

 of them, but do we know "what being an element, like Mer- 

 cury or Antimony, really means, or the import of their 

 periodic classification? Great libraries are filled with our 

 descriptions of the structure and activities of plants and 

 animals, but do we know what livingness essentially is? 

 We cannot define it at present in terms of anything else, we 

 take it as ' given '. We cannot tell wherein consists the 

 essential difference between the flight of a bird and the 

 movement of a comet. How much, relatively speaking, is 

 known of ' mind ' and ' body ', how little is known in regard 

 to the relation between them, if there is a relation ! 



(7i) We hear much of the achievements of science in 

 tracing things back to their beginnings. That is the histor- 

 ical or genetic method, and it yields very interesting results. 

 The present becomes more intelligible in the light of the 

 past. But, when we get far back, how mysterious the be- 

 ginnings become. How mysterious still, to tell the truth, 

 are many of the big steps between the beginning and the 

 end ! In the inorganic sphere one collocation passes into 

 another, usually without jolts. The course runs smoothly. 

 But when we pass to organic evolution or even to individual 

 development, we are almost driven back to a belief in magic ! 

 Who can tell even in the sketchiest fashion how a Silver 

 Wyandotte was evolved from an Indian Jungle Fowl, or 

 how stage gives rise to stage as the chick develops in three 

 weeks from a minute transparent spot on the top of the yolk 

 of an egg? 



Matter has seemed to many easy-going minds a firm 



