176 PIONEERS OF EVOLUTION. 



due. As remarked already, he appears to have been 

 the first to put into shape what is known as the 

 nebular theory. In his General Natural History and 

 Theory of the Celestial Bodies; or an Attempt to 

 Account for the Constitution and the Mechanical 

 Origin of the Universe upon Newtonian Principles, 

 published in 1775, he " pictures to himself the uni- 

 verse as once an infinite expansion of formless and 

 diffused matter. At one point of this he supposes 

 a single centre of attraction set up, and shows how 

 this must result in the development of a prodigious 

 central body, surrounded by systems of solar and 

 planetary worlds in all stages of development. In 

 vivid language he depicts the great world-maelstrom, 

 widening the margins of its prodigious eddy in the 

 slow progress of millions of ages, gradually reclaim- 

 ing more and more of the molecular waste, and 

 converting chaos into cosmos. But what is gained 

 at the margin is lost in the centre; the attractions 

 of the central systems bring their constituents to- 

 gether, which then, by the heat evolved, are con- 

 verted once more into molecular chaos. Thus the 

 worlds that are lie between the ruins of the worlds 

 that have been and the chaotic materials of the 

 worlds that shall be; and in spite of all waste and 

 destruction, Cosmos is extending his borders at the 

 expense of Chaos." 



Kant's speculations were confirmed by the cele- 

 brated mathematician, Laplace. He showed that the 

 " rings " rotate in the same direction as the central 



