CJSE OP WOOD IN PAPER-MAKING. 123 



solution of caustic alkali in close, iron vessels under high pressure of 

 steam, and afterward taken out, washed, and bleached with chlorine.^ 



The American Wood-Paper Company introduced this process at Mana- 

 yunk, near Philadelphia, some twelve or fifteen years ago, and have 

 continued since. Some other mills have been started upon the chemical 

 process, and we have an estimate of a papermaker well acquainted with 

 the business, that about twenty tons of pulp a day are made, using sixty 

 cords of wood. 



The mechanical process most in use, bears the name of Henry Voelter,^ 

 of Germany, and consists in grinding the wood to a pulp by pressing it 

 against the edge of a broad grindstone. The wood is first cut into 

 lengths equal to the width of the stones, the bark is shaved off, large 

 pieces are quartered, and the pith and knots removed. These blocks 

 are then placed in position, the fiber of the wood parallel with the axis 

 of the grindstone, and firmly pressed against the stone by a screw 

 worked automatically, and descending as the wood is ground away. 

 Four or five of these fixtures for holding the wood are attached to each 

 stone, and water is supplied freely to facilitate the grinding, and to 

 wash away the pulp. This pulp is generally mixed with that from other 

 fibrous substances before being finally made into paper. 



The Voelter process came into use about twenty years ago, and was 

 introduced in this country in 1868. A large number of mills have been 

 built in various parts of the country, and are now making, daily, about 

 100 tons of dry pulp, using for this 200 cords of wood. The timber 

 chiefly used is poplar, and to less extent spruce, pine, basswood, and 

 birch. The fiber from the birch and beech is shorter than that from 

 the pine and fir, and it is whiter, but not as strong. 



In Germany, there were about the year 1870 thirty mills for grinding 

 wood into paper pulp. The industry has extended into Russia and 

 other countries where material is cheap, and with the increasing de- 

 mands for paper, it is probable that the business will largely increase.^ 



It is found at times convenient to be able to distinguish with cer- 

 tainty the presence and proportion of wood-fiber in paper. The micro- 

 scope will do this to a certain extent, more especially when the conifer- 

 ous woods have beeu used. The oval openings or thin places between 

 adjacent cells are generally distinguishable in the fiber when thus ex- 

 amined. But a simple chemical test has been proposed by M. Schach- 

 riuger, of Vienna, by the aid of analine. Some drops of this, as found 

 iu commerce, are placed in a test-tube, to which a little sulphuric acid 

 and water are added, and the whole is heated over a spirit-lamp. A 

 little scroll of paper supposed to contain wood-fiber, if then dropped in, 

 becomes of a lemon-yellow color, more or less intense, iu proportion as 

 the wood is more or less considerable in amount. 



It is found that wood-fibre is distinguishable in some cases, as to nat- 

 ural orders and genera of the timber used in making it, when carefully 

 prepared and examined under a microscope. The fiber of coniferous 



1 A French patent granted to the Montgollier Brothers, February 7, 183c, used wood 

 rasped down, steeped in lime-water to soften the wood, ground and boiled in caustic 

 alkaJi in solution, underpressure. It was then crushed under rollers, reboiled in alkali, 

 and bleached. 



' The true inventor is said to have been one F. G. Keller, who, in 1844, took out let- 

 ters-patent in Germany for a wood-pulp grinding machine, but, lacking means, sold 

 to Voelter, and subsequently fell into want, so that the German papermakers came to 

 his relief bv subscription. — (MunaclVa Chronology of the Origin and Progress of Paper 

 and Paper-Maling, Fifth ed., pp. 110-114.) 



3 A somewhat extended account of the wood-paper manufacture by both mechanical 

 and chemical processes is given in an article by William K. Patrick, of Marinette, 

 Wis., published in The Lumberman's Gazette, vol. xi, p. 133. 



