22 SCIENCE AND IMMORTALITY 



atoms become chipped and broken and worn, the 

 objects they formed would alter, " nor could the 

 generations so often reproduce, each after its 

 kind, the nature, habits, ways of life, and motions 

 of the parents." 



It is interesting to find that, many centuries later, 

 Newton employed almost exactly the same reason- 

 ing. " While the same particles continue entire, 

 they may compose bodies of one and the same 

 texture in all ages ; but should they wear away or 

 break in pieces, the nature of things depending on 

 them would be changed. Water and earth com- 

 posed of old worn-out particles would not be of 

 the same nature and texture now with water and 

 earth composed of entire particles in the beginning. 

 And, therefore, that Nature may be lasting, the 

 changes of corporeal things are to be placed only 

 in various separations, and new associations, and 

 motions of these permanent particles." 



Lucretius supposes, further, that atoms vary in 

 size, shape, and weight, but that the varieties are 

 finite in number. If not finite, he points out, 

 some would be infinitely large ; and further, there 

 would be an infinite variety of things, and fresh 

 things would be always forming. Though he had 

 probably no conception of the ultra-microscopic 

 dimensions of the atom of modern chemists, he yet 

 pictured the average atoms as invisibly small ; and 



