THE GRIST OF THE GODS 



and death play into the hands of life than the soil 

 underfoot. The earth dies daily and has done so 

 through countless ages. But life and youth spring 

 forever from its decay; indeed, could not spring 

 at all till the decay began. All the soil was once 

 rock, perhaps many times rock, as the water that 

 flows by may have been many times ice. 



The soft, slow, aerial forces, how long and pa- 

 tiently they have worked! Oxygen has played its 

 part in the way of oxidation and dioxidation of 

 minerals. Carbon or carbonic acid has played its 

 part, hydrogen has played its. Even granite yields 

 slowly but surely to the action of rain-water. The 

 sun is of course the great dynamo that runs the 

 earth machinery and, through moisture and the air 

 currents, reduces the rocks to soil. Without solar 

 heat we should have no rain, and without rain we 

 should have no soil. The decay of a mountain makes 

 a hill of fertile fields. The soil, as we know it, is 

 the product of three great processes — mechanical, 

 chemical, and vital — which have been going on for 

 untold ages. The mechanical we see in the friction 

 of winds and waves and the grinding of glaciers, 

 and in the destructive effects of heat and cold upon 

 the rocks ; the chemical in the solvent ■ power of 

 rain-water and of water charged with various acids 

 and gases. The soil is rarely the color of the under- 

 lying rock from which it came, by reason of the 

 action of the various gases of the atmosphere. Iron 

 205 



