HO SCIENCE AND IMMORTALITY 



probably very much more — some have estimated 

 it at a thousand million. 



And now the Earth has attained to a placid, 

 rotund respectability, it has driven the Moon 

 264,000 miles away ; its waters are cool, its 

 crust is solid, it takes twenty-four hours to turn 

 round, and only occasional little earthquakes and 

 volcanoes serve to remind it that it has had a 

 past. Yet still its heart is hot, and the crust 

 between us and cauldrons of molten metal is only 

 about fifty miles thick — not thicker, in proportion, 

 than the skin of an apple. 



It is usually assumed that the sea was at one 

 time in the form of an atmosphere around the 

 world, and that when it condensed the present 

 atmosphere was left behind ; but to the writer 

 both assumptions seem rather rash. The nitrogen 

 of the atmosphere may quite well be considered a 

 by-product left over from the chemical combina- 

 tions of molten mass of the world ; but how about 

 oxygen, carbonic acid, and water ? How did they 

 escape occlusion in the cooling slag of the Earth's 

 crust, or how did they fail to enter into chemical 

 combination with the rocks of the Earth ? How 

 did these gases escape from the heavy, dense 

 vapours and rains of iron ? How was water 

 formed in such quantities ? Do we find water or 

 vapour in the other young atmospheres, e.g. of 



