LIFE AND CHANCE 
if we consider the fortuitous and the accidental, not 
as they occur in a world of mechanical movements, 
but as they occur in a world of chemical reactions. 
The fortuitous among chemical bodies is quite a dif- 
ferent thing from the fortuitous among ponderable 
bodies. We might shake together the parts of a watch 
for all eternity and not get that adjustment of the 
wheels and springs that makes a watch. If a thou- 
sand of brick are dumped upon the ground, is there 
any probability that they will take the form of a 
house? Or if the letters of the alphabet are shaken 
up together in a bag, is there the slightest chance 
that they will arrange themselves into words and 
that the words will arrange themselves into intelli- 
gent sentences? In all these things the parts have 
no attraction for one another, but among chemical 
compounds, out of which living bodies are built up, 
there rules the selective force of chemical affinity. 
The elements select their partners. It is a marriage 
in which two literally become one. Chemistry is on 
the road to life; chemical transformations lead up 
to the transformations we call vital. The physical 
forces transport and transpose and seek a state of 
test; they sort and sift the sands and gravels and 
clays of the soil, depositing them in a regular series, 
but they never get beyond the realm of mere chance. 
The clouds are ever changing, but they never change 
into living forms. The waves shift and pile the 
sands endlessly upon the shore, but the shore is 
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