4 The Law of Evolution : is it General ? [January, 
such as aluminium, silicon, iron, oxygen, sodium, &c. : others 
comparatively rare, such as indium, vanadium, thallium, 
iridium, &c. How is this ? On the hypothesis of primordial 
existence such a distinction is not easily to be explained. 
On the evolutionary view it may be fairly contended that the 
circumstances under which the rarer elements have been 
produced may have been of unfrequent occurrence as com- 
pared with those under which the common simple bodies 
were developed. To the objection that we never find any 
elementary substances changing their nature, or reverting 
into the primordial state of matter, — an objection which 
reminds us of the cavil that we never see a man reverting to 
an ape,= — it may be replied that under given conditions 
matter has reached forms which are stable, and that none of 
the original “ raw material ” remains. We may here refer 
to the view expressed by the late Prof. Clerk Maxwell, and 
by Sir John Herschell, that the elementary atoms bear the 
impress of a “ manufactured article.” But every manufac- 
tured article presupposes an original material. Thus this 
hypothesis agrees in its requirements with the evolutionist 
view, and the impossibility of producing a specimen of the 
“ raw material ” is of little weight against either. 
But let us now suppose some sixty kinds of elemental 
bodies, some of them more and some of them less plentiful, 
either co-existing from all eternity or called into independent 
existence. Were all these bodies indifferent to each other 
the probability is surely that the atoms of each kind would 
be distributed with approximate uniformity, regard only 
being had to their relative abundance. If, as is actually the 
case, they are not indifferent, but have those various tenden- 
cies to combine together which are commonly called affini- 
ties, we should find those bodies accumulated together 
which have the strongest affinities for each other, whilst 
those which have but feeble mutual affinities, or substantially 
none, would be found mutually apart. Now as a general 
rule it may be asserted that those elements which have 
strong affinities for each other are at the same time such as 
differ widely in their properties, and that, on the contrary, 
such as approximate closely in their properties have little 
mutual affinity. But if we examine into the composition of 
the earth, the rocks, and the waters, we very commonly find 
bodies associated together which are very similar to each 
other, and which have very feeble mutual affinities. To take 
a very common case, we find in the waters of the sea, of 
certain lakes, and springs, the three true halogens — chlorine 
bromine, and iodine — associated together, the two latter 
