148 Coal From What Formed. 



13. You learned in the previous chapter how 

 necessary leaves are to the life and growth of a 

 tree, and how valuable some kinds are, such as 

 those of the tea and the tobacco plant ; but do 

 you see any use in the leaves of the forest after 

 they have withered and fallen in the autumn ? 



14. If you should dig down in the ground 

 you would see that the soil at the top is black 

 and rich, while deeper down it is light-colored 

 and poor. The blackness and richness of the 

 surface soil is due chiefly to the withered leaves 

 which fell from year to year and went to decay ; 

 thus you may trace back the abundance of 

 your bread, through large crops of wheat and 

 rich soil, to dead leaves or dead grass. 



15. That is not all: geologists* tell us, 

 among many other wonderful and interesting 

 things, that they have traced the coal which 

 miners dig out of the earth away back to 

 trees, plants, leaves, etc., which had become 

 buried in great masses under the surface of the 

 earth. 



1 6. Just how all these immense beds of coal 

 were made, learned men have not agreed. They 

 appear to have been made in some mysterious 

 manner, long, long ago, from trees, plants, and 

 seeds (especially ferns and mosses), because the 



* Men who have studied the formation of the earth its rocks, mountains, 

 soils, etc. 



