ON THE STATISTICAL VIEW OP NATURE. 605 



them ; our observations ranging over very large distances 

 in space and time, from the particles immediately before 

 us in artificial flames to the vibrations of atoms of distant 

 stars, which must have taken millions of years to reach 

 us. " I do not think," says Clerk-Maxwell, 1 " that the 

 perfect identity which we observe between different por- 

 tions of the same kind of matter can be explained on the 

 statistical principle of the stability of the averages of 

 large numbers of quantities, each of which may differ 

 from the mean. . . . For if the molecules of some sub- 

 stance, such as hydrogen, were of sensibly greater mass 

 than others, we have the means of producing a separation 

 between molecules of different masses, and in this way 

 we should be able to produce two kinds of hydrogen, 

 one of which would be somewhat denser than the other. 

 As this cannot be done, we must admit that the equality 

 which we assert to exist between the molecules of hydro- 



' Theory of Heat,' p. 329, &c. 

 Cf. also many passages in the 

 articles on "Atom," "Molecule," 

 " Constitution of Bodies," &c., re- 

 printed in the second volume of 

 ' Scientific Papers ' ; inter alia, p. 

 483 : " But the equality of the 

 constants of the molecules is a fact 

 of a very different order. It arises 

 from a particular distribution of 

 matter, a collocation, to use the ex- 

 pression of Dr Chalmers, of things 

 which we have no difficulty in 

 imagining to have been arranged 

 otherwise. But many of the or- 

 dinary instances of collocation are 

 adjustments of constants, which are 

 not only arbitrary in their own 

 nature, but in which variations 

 actually occur ; and when it is 

 pointed out that these adjustments 

 are beneficial to living beings, and 

 are therefore instances of benevolent 



design, it is replied that those varia- 

 tions which are not conducive to 

 the growth and multiplication of 

 living beings tend to their destruc- 

 tion, and to the removal thereby of 

 the evidence of any adjustment not 

 beneficial. The constitution of an 

 atom, however, is such as to render 

 it, so far as we can judge, independ- 

 ent of all the dangers arising from 

 the struggle for existence. Plaus- 

 ible reasons may, no doubt, be as- 

 signed for believing that if the 

 constants had varied from atom to 

 atom through any sensible range, 

 the bodies formed by aggregates of 

 such atoms would not have been so 

 well fitted for the construction of 

 the world as the bodies which 

 actually exist. But as we have 

 no experience of bodies formed of 

 such variable atoms, this must re- 

 main a bare conjecture." 



