INORGANIC EVOLUTION 21 



of this volume will not permit going into the details, as 

 Arrhenius has done. The immense space occupied by the 

 nebula of planets is incomprehensible. The largest 

 among them is situated near star B in the Great Bear. It 

 is perhaps many hundred times as large as the orbit of 

 Neptune. In the very densest portion it is not more than 

 a billionth of the density of our air. Their luminosity is 

 feeble compared with that of the stars. Their temperature 

 is equally low. The immense time it will take for the 

 condensation of this nebula into a system of globes like 

 our solar system, whether by the method laid down by 

 La Place, or by the Lockyer and Chamberlain hypothesis, 

 is inconceivable by us. But nature is duration, not time, 

 as we conceive it. So that, the theories of world forma- 

 tion are true, upon the basis of the known laws of gases 

 and of matter. The nebular theory of Kant, La Place, 

 and William Herschel, in accounting for inorganic evolu- 

 tion, presupposes the homogeneity and gaseous condition 

 of all matter: and from that nebular condition, the 

 present heterogenous stellar universe has been evolved. 

 The greatest advance in astronomy, made in late years 

 have been the disclosures, by photography, of nebulosity, 

 existing throughout space. More than 120,000 nebulae 

 are known ; they are being frequently discovered, and by 

 observing these, astronomers are studying the phases, 

 through which, our earth, and solar system, seem to have 

 passed. 



The theory presupposes that the nebula, from which 

 the sun and the planets, for example, have integrated, 

 filled the space within the orbit of Neptune with 

 homogeneous matter in a very attenuated gaseous state. 

 Or it is likely the nebula extended a sufficient distance 

 beyond that orbit to leave Neptune in the relative 

 position it now occupies, in the solar system, after the 



