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Conservation and Civilization. 



Arthur L. Foley, Head of the Department of Physics, Indiana University. 



Not until recently has man begun to think of nature's resources in 

 the light of the old saying that "one can not eat his cake and have it." 

 Today the subject of the conservation of these resources is being discussed 

 by men of science in every civilized country on the globe. Nevertheless 

 it must be admitted that the full import of the question is not j'et appre- 

 ciated by many science men. while the public generally scarcely knows 

 what the discussion is about. A few years ago the writer heard an 

 address in which the speaker pointed out the importance of conserving 

 the soil. A fellow citizen in speaking of the address said he did not under- 

 stand what the speaker meant, that the earth is made of mud and that no 

 one need be fearful of a shortage. The observation led to the reflection 

 that people too are made of mud, some of it not very fertile. Perhaps our 

 citizen did not know that the average productivity of the unfertilized soil 

 of Indiana is but half of what it was when he was a boy. Perhaps he 

 does not know that all animal life is dependent on plant life, and that 

 plant life is dependent on a few soluble constituents of the soil which 

 form but a small and diminishing per cent, of what he calls mud. Per- 

 haps he does not know that the removal of timber and the cultivation 

 of hillsides permit the rains to dissolve and carry away tbe soluble 

 constituents and so impoverish the soil, and that every year thousands 

 of acres of land, here in his own State, Indiana, are ruined in this man- 

 ner. He does not know that every year the Mississippi River robs the 

 Mississippi Valley of hundreds of millions of tons of that upon which its 

 fertility depends, and that all other streams are doing relatively the same 

 thing. 



But I am not to discuss the conservation of our soil, nor the con- 

 servation of our timber or our food supply. I shall not discuss the con- 

 servation of air or water, although the time has passed wben we can say 

 "as free as the air we breathe or the water we drink." Good pure air 

 is not free to everybody, by any means. If it were there would be no 



