CHAP. IV.] 



The Food of Trees 



of wood only, the demands vary as follows in high-forest 

 crops of various sorts : 



With regard to Lime from 4 to 20 Ibs. per acre per annum. 



Potash 2 to 10 



Phosphoric Acid % to ^ 



In order to arrive at more definite estimates than these 

 investigations alone could yield, Ebermayer made analyses for 

 the purpose of determining the amount of mineral ash con- 

 tained in the dried foliage of the more important kinds of 

 forest trees, and obtained the following results as to the 

 percentage of pure ash deposited in the dry leaf-tissue. 



A. DECIDUOUS, BROAD-LEAVED TREES. 



