1 62 PIONEERS OF EVOLUTION PART 



first to put into shape what is known as the nebular 

 theory. In his General Natural History and Theory 

 if tJte Celestial Bodies ; or an Attempt to Account for 

 the Constitution and the Mechanical Origin of the 

 Universe upon Newtonian Principles, published in 1 7 5 5, 

 he 'pictures to himself the universe 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 develop- 

 ment 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 prodigi- 

 ous eddy in the slow progress of millions of ages, 

 gradually reclaiming 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 con- 

 stituents together, which then, by the heat evolved, are 

 converted 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, Cos- 

 mos 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 body from which they were cast off; sun, 

 planets, and moons (those of Uranus excepted) 

 moving in a common direction, and almost in the 

 same plane. The probability that these harmonious 

 movements are the effects of like causes he calculated 

 as 200,000 billions to one. 



