IMPORTANT TYPES OF PEAT MATERIAL. 31 



plant remains or with water pockets as delimiting layers, the ac- 

 cumulation of bog peat may settle to a considerable extent. A change 

 in the elevation of the gravity outlet or drainage by pumping may 

 later be the only feasible method of relief. It is important, there- 

 fore, in designing drainage improvements to anticipate a subsidence 

 of 10 to 25 per cent in the original profile of the deposit. Many 

 bog peat-land areas are now deteriorating because the drainage 

 systems laid out by an earlier generation have not provided for 

 this shrinkage or have been allowed to get out of repair. Where 

 seepage waters and springs arise along the hills bordering the valley 

 or basin, intercepting ditches are extended along the lower edge of 

 the high lands and provision is also made for the annual removal 

 from the drains of any iron or other compound, sand, silt, or invading 

 vegetation. The washing in of mineral impurities should be re- 

 stricted to the lateral ditches. Saline constituents when present in 

 these types of peat tend to appear and to accumulate at the margins 

 as iron pan and bog iron or in the form of irregular patches of con- 

 cretions near the ditches or overlying subterranean drainage waters 

 and springs. The ground-water supply, springs, and the mineral 

 subsoil especially require attention in regions of rock formation 

 which contain an excess of soluble salts. 



Only the fibrous and poorly disintegrated surface layers of these 

 types are of value as litter and mull if properly dried and shredded 

 (Table I). A rapidly growing industry in Europe is using these 

 plant remains for manufacturing purposes, and they are greatly 

 to be recommended for use in this country. The materials are 

 shredded by simple tearing machinery and passed through rotary 

 sieves to separate the finer mull from the fibrous material, which 

 may be used for bedding live stock, for insulation and packing, in the 

 manufacture of special grades of charcoal for metallurgical pur- 

 poses, of pulp, pads, fiber, or alcohol (by converting cellulosic com- 

 ponents into sugar with diluted sulphuric acid). Shredded }3eat ma- 

 terial from certain species of sphagnum mosses, relatively free from 

 inorganic impurities and of uniform composition, has been used as 

 surgical dressings for wounds and as pads for patients with dj'sen- 

 tery on account of its high absorbent value. It is in many respects 

 a good substitute for medicated cotton. 



There is an increased demand in Europe for sphagnum mull prod- 

 ucts, the particles of which are not larger than one-eighth of an inch 

 (3 mm.) in diameter, as an ingredient with molasses in stock feed 

 for fattening purposes and to prevent disorders. Mull from sphag- 

 nums as well as from Hypnum mosses and fibrous sedge peat has 

 been employed profitably for packing, as an effective deodorizer and 

 disinfectant for use in receptacles holding waste animal matter, and 



