1 88 THE METAPHYSICS OF EVOLUTION. 



ments suggest also that the supposed homogeneity 

 of the particles of a chemical substance was based 

 upon our ignorance. Atoms are not, as Sir J. 

 Herschel said, and Clerk Maxwell endorsed, 

 " manufactured articles," exactly equal and similar, 

 but, like all other real things, they possess individual 

 differences and have an individual character. The 

 individual differences appear so small only because 

 of the minuteness of the whole scale, just as from a 

 sufficiently lofty standpoint the individual differences 

 between men also might appear as evanescent as 

 those between the atoms do to us. And in chemical 

 interactions these individual differences would be 

 manifested by differences of atomic weight, not only 

 between the different " elements," but within them. 

 Some atoms of calcium might have the atomic 

 weight of 39*9, and others of 40'i, and the ''atomic 

 weight" of calcium, viz., 40, would be only the 

 average of the closely related groups. Hence if we 

 discover any method of separating the atoms of 

 the atomic weight, 39^9, from those of the atomic 

 weight, 40*1, we should get two substances differing 

 slightly from the ordinary calcium of the chemists, 

 and differing still more from each other. This, or 

 something similar, is what may be supposed to have 

 happened in the case of didymium and yttrium. It 

 is probable, then, that the splitting up of elements 

 into '' meta-elements " has been first observed 

 among these rare metals on-ly because they present 

 greater individual divergences between their atoms 

 than the rest, and perhaps it may be suggested that 

 it was this very individualts?n, this lack of coherence 

 and similarity between their more heterogeneous and 

 loosely knitted constituents, which accounts for their 

 comparative failure in the evolution of the elements. 



