51 



so in the manufacture of news and wall papers, very largely so in the 

 manufacture of hook and wrapping papers and to a considerable propor- 

 tion in writing and other grades. In fact fifty per cent, of our paper is 

 manufactured from wood pulp. 



Wood pidp is used for many other purposes besides paper making, 

 sometimes usefully, at other times with doubtful advantage. Such are: 

 the use of compressed pulp bricks for construction purposes; its use in 

 textiles such as silk and cotton; in panelings and interior house decora- 

 tions; in celluloid, surgical bandages, car wheels, pulleys, paper boxes, 

 pails, barrels, etc.; for niters in breweries and sugar factories; for fuel, 

 etc. As compared with paper making, however, these other uses of wood 

 pulp are only of subordinate importance and perhaps hardly consume one 

 per cent, of all the wood pulp thrown onto the market. 



Raw Material and Preparation. 



The raw material of wood pulp is spruce, poplar, and in smaller 

 quantities various other woods such as balsam, hemlock, birch, according 

 to the location of the industry, the process employed, and the kind of 

 paper in which the material is to be used. The variety as to the kinds 

 of trees that have been used with varying success at various times and 

 places is extensive; such are soft pine (hard pine containing too much 

 resin), fir, spruce, balsam, hemlock, birch, large-toothed aspen, cotton- 

 wood, Carolina poplar, buckeye, basswood, box elder, quaking asp, beech, 

 bamboo, linn, willow, soft maple, catalpa and perhaps others — in fact 

 any tree can be used, it is merely a question of relative value and rela- 

 tive expense. The kinds of timber most largely used in pulp manufac- 

 ture are soft, easily worked, light both in weight and color, possessed of 

 long fibers, not fading easily, and containing little resin or other infiltra- 

 tions. It will be seen that spruce among conifers and poplar among broad- 

 leaved trees possess the requisite qualities in a remarkable degree. In the 

 United States spruce forms 76 per cent, of all Avood for both mechanical 

 pulp and chemical fiber. Poplar being softer (and used most for soda 

 fiber) forms . 12.9 per cent, of all woods consumed in making different 

 kinds of pulp. Other unspecified woods for pulp or fiber make up the 

 remaining 11.1 per cent. 



In the preparation of pulp, the wood should be worked up green and 

 the bark and defective parts must first be taken off. There are two 

 principal methods of reducing wood to pulp — the mechanical and the 



