CHAPTER V 



SOIL-BINDERS 



The materials being ground up, mixed, and in some 

 cases transported, there are still important matters to be 

 attended to before anything strictly to be called "soil" 

 can be formed. 



The first thing is to make the future soil settle down, 

 since nothing of value can grow in a wandering sand-drift. 

 The deposits, whatever they be, need protection against 

 the washing of the rain and the drying of the wind, which 

 will not only dry the surface, but blow it away in clouds 

 if it is left exposed. 



Even to this day the plains of Hungary suffer from 

 dust-storms, though they have long been covered with 

 vegetation; and we may easily imagine how much worse 

 these must have been when sun and wind had full play, 

 with nothing to check them. 



It is clear, too, that where sand or volcanic ashes have 

 been brought by the wind, the same wind may in many 

 instances scatter them again. And where mud has been 

 brought down by a river and deposited within reach of the 

 tide, there it will be liable to be washed away, unless some 

 means be taken to fix it to the spot. 



Let us even look, for instance, at a railway embank- 

 ment. It has been piled by human hands with a special 

 object, and is a far more solid mass than if it had been 

 merely blown together; but yet it to some extent wastes 



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