56 



BEITISH MOSSES. 



it constitutes an insoluble substance which is said to be 

 scarcely subject to decay, so that it is used In Holland 

 for the foundations of houses, and is found unchanged after 

 ages, and when the buildings have fallen into decay. It is 

 even said to have remained unchanged after three months' 

 boiling in a steam-engine boiler. The broad difference 



FIG. 33. Section of Irish Peat bog, showing the growths of three 

 successive submerged forests. ( From Third Report of Commissioners 

 on Irish Peat Sags.) a Present surface with vegetation, b Third peat 

 bog. c Third forest, d Second peat bog. e Second forest, f First 

 peat bog. g First forest. A Limestone gravel at base of bog. 



