110 THE FITNESS OF THE ENVIRONMENT 



fitness of water. But not only is it almost 

 inconceivable that ammonia should ever occur 

 in sufficiently vast quantities upon a planet's 

 surface, but it is evident as well that am- 

 monia wholly lacks the qualification of anoma- 

 lous expansion, and also in some of the most 

 important of the other thermal properties 

 falls far short of water ; while in latent heat 

 of melting and in specific heat its advantage 

 over water is inconsiderable. 



It is obvious that upon a body like the 

 earth the state of the oceans and the meteor- 

 ological phenomena are of the utmost impor- 

 tance to all living things. Unless these be 

 favorable, human experience and reflection 

 alike agree that life could not widely exist. 

 It seems, therefore, almost safe to say, on the 

 basis of its thermal properties alone, that 

 water is the one fit substance for its place in 

 the process of universal evolution, when we 

 regard that process biocentrically. 



II 



THE ACTION OF WATER UPON OTHER SUB- 

 STANCES 



Although the thermal properties of water 

 make up the classical subject-matter for dis- 

 cussions of the fitness of the natural en- 



