WOOD-PULP. 319 



that of good coal. Additional uses for sawdust are constantly being 

 found. Flour made from it can be used as a component material in 

 manufacturing dynamite, linoleum, xyolite, &c. The wood-flour can be 

 ground in a cheap mill, similar to those for grinding corn and rye ; and 

 pine and spruce sawdust passed though the stones and packed ready for 

 shipment is worth about 50s. a ton. One important use for wood-flour is 

 in making dynamite, as it absorbs nitro-glycerine, the explosive ingredient. 

 But wood-flour dynamite is inferior to that made with infusorial earth, 

 though there are many purposes for which it serves and is cheaper. It is 

 also used for linoleum, mixed with linseed oil, to give body to floor 

 coverings. It is not equal to ground cork for this purpose, as it is less 

 elastic ; but it is cheaper, and suitable for medium grades. Wood-flour 

 is also used for xyolite, an artificial flooring resembling wood in weight 

 and stone in other respects, for kitchen floors, halls, corridors, &c. It is 

 impervious to water, and practically fireproof. It is even used for floor 

 material in German war-vessels, as it is not liable to take fire or splinter 

 if struck by shells. 



The Preparation of Wood-pulp and Cellulose is, next to 

 saw-mills, now by far the largest and most important woodland 

 industry, which has assumed enormous dimensions during 

 recent years. The woods most suitable for pulping are those 

 that are soft Lime, Aspen, Poplar, Willow, and among 

 Conifers Spruce especially, then Silver Fir. Scots Pine and 

 other very resinous Conifers are difficult to pulp owing to their 

 resin. 



When the woody substance is prepared by mechanical means 

 only it is called Wood-pulp, and when it .is obtained chemically 

 it is called Cellulose, which is always worth over one-half more 

 than wood-pulp. 



Lime, Aspen, and Poplar give the finest and whitest pulp ; 

 but Spruce, which gives a pale yellow pulp, becoming darker 

 and duller, is now chiefly used both for wood-pulp and for 

 cellulose, owing to its being the only wood obtainable in the 

 enormous quantities that are now needed throughout the world 

 for paper-making. 



Wood-pulp is the disintegrated woody fibres separated 

 mechanically by grinding. It retains its original colour, and is 



