CHAPTER XXVI 



SOIL BACTERIA 7.V RELATION TO MINERALS 

 IN THE SOIL 



The mists that rise from the sea and gather into 

 clouds travel far, at times, before they rejoin the sea. 

 Very often, they fall on the land as rain or snow and, 

 making their way past the soil-particles, continue their 

 journey until the ocean is reached once more. Thence 

 they may again start on new travels and repeat the 

 cycle. In all cases, the sea is the point of departure 

 as well as the final destination. And yet there is an 

 important difference in the going and the coming of 

 the waters. 



The mists that leave the sea carry nothing with them. 

 They come back laden with booty — treasures gathered 

 by percolating rain, by brooks, rivulets and rivers. 

 With every completed cycle, the sea becomes richer and 

 the land poorer,- — poorer in nitrogen, lime, magnesia, 

 potash, soda, phosphoric acid and sulfur; poorer, like- 

 wise .in other ingredients. The gain of the sea would be 

 slight if the land were an inert mass. As it is, the gains 

 are large, because the weathered crust of the earth is 

 not inert, for there are in it forces making soluble not 

 only the remains of living things (organic matter), but 

 also the purely mineral constituents. 



(275) 



