ON THE ORIGIN OF THE PLANETARY SYSTEM. 191 



mit us to conclude that our sun also is a body which 

 slowly gives out its store of heat, and thus will some 

 time become extinct. 



The term of 17,000,000 years which I have given 

 may perhaps become considerably prolonged by the 

 gradual abatement of radiation, by the new accretion of 

 falling meteors, and by still greater condensation than 

 that which I have assumed in that calculation. But 

 we know of no natural process which could spare our 

 sun the fate which has manifestly fallen upon other 

 suns. This is a thought which we only reluctantly 

 admit; it seems to us an insult to the beneficent 

 Creative Power which we otherwise find at work in 

 organisms and especially in living ones. But we must 

 reconcile ourselves to the thought that, however we 

 may consider ourselves to be the centre and final 

 object of Creation, we ate but as dust on the earth ; 

 which again is but a speck of dust in the immensity 

 of space ; and the previous duration of our race, even 

 if we follow it far beyond our written history, into the 

 era of the lake dwellings or of the mammoth, is but 

 an instant compared with the primeval times of our 

 planet; when living beings existed upon it, whose 

 strange and unearthly remains still gaze at us from 

 their ancient tombs ; and far more does the duration 

 of our race sink into insignificance compared with the 

 enormous periods during which worlds have been in 



