444 THE PRINCIPLES OF SCIENCE. 



actually occurred in the history of the solar system. Olbers 

 sought for the minor planets or asteroids, on the sup- 

 position that they were fragments of an exploded or 

 fractured planet, and he was rewarded with the discovery 

 of some of them. The retrograde motion of the satellites 

 of the more distant planets, the abnormal position of the 

 poles of Uranus and the excessive distance of Neptune, are 

 other indications of some violent event, of which we have 

 no other evidence. I adduce all these facts and argu- 

 ments, not to show that there is any appreciable proba- 

 bility, so far as we can judge, of actual interruption 

 within the scope of human history, but to prove that the 

 Uniformity of Nature is theoretically consistent with the 

 most unexpected events of which we can form any con- 

 ception. 



Possible States of the Universe. 



When we give the rein to scientific imagination, it 

 becomes apparent that conflict of body with body must 

 not be regarded as the rare exception, but as the general 

 rule and the inevitable fate of each star system. So far 

 as we can trace out the results of the law of gravitation, 

 and the dissipation of energy, the universe must be re- 

 garded as undergoing gradual condensation into a single 

 cold solid body of gigantic dimensions. Those who so 

 frequently use the expression Uniformity of Nature, seem 

 to forget that the universe might exist consistently with 

 the laws of nature in the most diverse conditions. It 

 might consist, on the one hand, of a glowing nebulous mass 

 of gaseous substances. The heat might be so intense 

 that all elements, even carbon and silicon, would resemble 

 permanent gases, and all atoms, of whatever nature, would 

 be flying about in chemical independence, diffusing them- 

 selves almost uniformly in the neighbouring parts of 

 space. There would then be no life, unless we can 



