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showing a percentage of 0.885% and Kuromatsu of 0.855%. Broad-leaves 

 are generally richer in nitrogen than needle-leaves, those of Kunugi 

 containing 1.116%, Shirakashi 1.0%, and Konara 0.945%. 



(b) Ash. 



Broad-leaved trees have a larger proportion of ash in their leaves 

 than conifers. Among conifers, Sugi, however, is relatively rich in ash 

 containing 6.1% of the air-dried substance which is 3 times of the ash 

 content of Akamatsu or Kuromatsu. Among broad-leaved trees, Kunugi 

 has an ash content of 3.55% while Konara contains nearly twice as much 

 of the preceding and Shirakashi has a still larger quantity, the content 

 being 9.12%. 



Taking the three important ash ingredients known as phosphoric 

 acid, potash and lime among the fallen leaves of the six aforesaid trees, 

 Sugi leaves are richest in phosphoric acid and lime. Its richness in lime 

 is particularly noteworthy as it contains 2.999% of the air-dried substance 

 or 49.164% of the total ash. Phosphoric acid too is found in considerable 

 amount in Sugi leaves. Akamatsu and Kuromatsu leaves despite the 

 small quantity of ash they contain, are rich in phosphoric acid being not 

 inferior to those of broad-leaved trees, although they are poor in potash 

 content. The content of silica in Kuromatsu is richer than that in Akamatsu, 

 and to this, is due the difference in the total ash contents of the two pines, 

 though there is no particular difference in other ingredients of the ash. 

 Further, among broad-leaved trees, Shirakashi and Konara are rich in 

 ash content owing to the large amount of silica while phosphoric acid and 

 lime are found almost in the same quantity as in other oaks such as 

 Kunugi. 



Shirakashi is further characterised by the rich content of potash. 



11. Quantities of Fallen Leaves 



What quantity of leaves fall every year in the forests? Researches 

 on this subject were made on Kunugi in 1911 at the Forest of the Experi- 

 ment Station. A similar study was made simultaneously on Kuromatsu 

 and is still carried on every year in the State Forest of Nakayama, 

 Higashi Ibaraki County, Ibaraki Prefecture, by the Major Forest Reserve 

 of Tokyo. 



