1 8 82.] The Law of Evolution': is it General ? 5 
always in exceedingly minute proportions as compared with 
the former. Now these three substances have such very 
doubtful affinities for each other that, if primordially existing 
or created separately, we cannot reasonably suppose them 
becoming grouped together as they now occur. But if they 
have been developed from some common primary material, 
or if bromine and iodine are transformation-produdts of 
chlorine, their joint occurrence is what we should naturally 
expedl. Or, again, we may take the case of nickel and 
cobalt. These metals, as a rule, accompany each other in 
Nature. Wherefore ? The teleologist has nothing to urge; 
for even if we grant that man is the objedt and measure of 
all things, we remember that these two metals and their 
respective combinations are rendered of much less value to 
man by being mixed up together. It may be said that the 
very considerable similarity of these two metals in their 
physical and chemical properties opposes every natural 
agency for their separation, just as it obstructs and delays 
the analyst and the metallurgist in the same operation. We 
grant the difficulty of separating them when once in associ- 
ation ; but what should first bring into such general juxta- 
position two kinds of bodies, not over-abundant, if there has 
ever been a grand game of hide and seek played by the 
elements ? But on the supposition of development the case 
is easily understood. There are other groups of elements 
which in like manner are met with together in Nature, and 
which certainly do not manifest any especial mutual attrac- 
tion. Thus there are the platinum metals, and — most 
striking case of all — those recently discovered elements 
which have been obtained from samarskite. These bodies 
are not only exceedingly rare, and confined to a very few 
localities (as regards chemical elements the particular rock 
or mineral in which they occur seems to take the place of 
the habitat of organic species), but they differ so slightly in 
their properties that we cannot help regarding them as varie- 
ties formed by a process of development. 
The periodic law of Prof. Mendelejeff, to which successive 
researches seem to give confirmation, can scarcely be inter- 
preted as otherwise than in favour of the evolution of the 
elements from some common fundamental material. If 
primordially existing it seems to us that the probability of 
regular relations being detected among them would be ex- 
ceedingly trifling. Nor do such relations* become at all more 
probable if regarded from a teleological point of view. 
Journal of Science, 1877, P* 291. 
