Pleasant Ways in Science. 463 



from that in which we now find it, as its present form and 

 aspect differ from the nebulous cloud, or the seething fiery ball, 

 and it will still be what man in his day denominated the earth 

 — but yet how changed ! 



Mental identity is evidenced by continued and recurring 

 consciousness. Could we conceive a being that only thought 

 and felt once in a thousand years, he might be as certain of his 

 existence and of his identity as another being capable of 

 evolving thought and becoming conscious' of feeling any 

 number of thousand times in a second. We have clocks with 

 short pendulums, and clocks with long ones; and could we 

 construct a chronometer with a pendulum so long, that it would 

 require ages for the completion of its gigantic sweep, its far- 

 separated beats would bear the same relation to each other, 

 and testify to the identity of the instrument, as completely as 

 does the quick and busy ticking of the little watch. 



We cannot limit the time distance between the co-ordinated 

 successions that may be comprehended under one identity, nor 

 can we limit the space distance of portions of one great whole. 

 In the fabric of a little ball which we can hold between our 

 fingers incessant motions are going on, but yet the ball remains 

 the same for its appointed time. All its particles, with all 

 their movements, are, so to speak, under the dominion of, and 

 are the expressions of, the same idea. The globe, with its 

 mightier changes, has a similar identity ; the solar system is 

 one again in its harmonious relations — ever changing, but yet 

 the same. May we not go further, and see a still more 

 gigantic oneness in the entire universe, imaging the greatest 

 oneness which man is able to conceive ? 



It is common, though scarcely philosophical, to speak as if 

 each globe and system constituted an isolated existence. 

 Modern philosophers have indeed imagined — without sufficient 

 reason — that the sun continually receives additions to his mass 

 in the shape of bombarding meteors, whose crash against his 

 sides they suppose the physical cause of the renewal of hfs 

 heat ; and comets, in their eccentric orbits, have been thought 

 likely to roam within the attraction of bodies powerful enough 

 to stop their wanderings and appropriate their materials. But 

 there is a wider supposition that seems to have the reasoning 

 of analogy to commend it, and according to which all the 

 matter throughout the universe is in eternal flux. Here 

 nebulas condense into planets, or suns ; there suns and planets 

 dissipate into nebulas. Astronomers and physicists fill space 

 with an ether, whose vibrations are light and heat ; but if such 

 an atmosphere of space exists, why should it be subject to 

 vibrations only ? Why should not, as- some have supposed, 

 this all- enwrapping ether-sea have its currents and its waves ? 



