232 THE BIOLOGY OF THE SEASONS 



to another, or have what is vaguely called a " cosmic 

 origin " ; whether it be the up-blown powdery ashes of 

 distant volcanoes, or merely the dismal " smoke-nuisance " 

 of the world's workshop, dust is not wholly vile. For dust 

 is the heart of the beneficent rain, and in its gentle dropping 

 it has helped the earthworm to form the soil ; it has no 

 small share in making the sky blue above us ; and it adds 

 glory to the setting sun. Even if the east wind gloom, 

 so familiar in Britain, be due, as Lord Kelvin said, to " the 

 smoke of Europe moistened by the North Sea," against 

 this we must place the fact that without dust to form the 

 framework of the clouds, we should have no scenery in our 

 heavens. 



