XX 



THE GENESIS OF THE SOIL AND ITS POSSIBILITIES 



THE ordinary, intelligent farmer may be very suc- 

 cessful, understand thoroughly the principles of 

 agriculture and the methods of applying them, without 

 being a specialist in geology or chemistry. At the same 

 time he is interested in a general way in the genesis 

 of the soil, how it has arisen, what is its constitution, 

 and other scientific facts connected with it. An at- 

 tempt to present some of the principal facts and theories 

 in connection with soil evolution, without going into the 

 refinement of the sciences or details and illustrations, 

 may be pardoned. Such an attempt I made in an ad- 

 dress before the National Geographic Society, in the 

 winter of 1911 and 1912: With the permission of the 

 editors of the National Geographic Magazine, Wash- 

 ington, D. C., the address is given below : 



THE GENESIS OF THE EARTH. 



" One of the oft-repeated theories concerning the ori- 

 gin of our earth is that at a remote period all the matter 

 of which the earth consists at present was a part of 

 the incandescent gas which filled the space now assigned 

 to our solar system. As the cooling of this mass of 

 gas progressed vortex rings were formed of gaseous 

 matter. These on further cooling broke and rolled to- 

 gether, forming the sun, the planets, and the satellites 



of our present system. The next condition of the in- 



173 



