. The manufacture of pulp and paper : a textbook of modern pulp and paper mill practice. hroughthe trunk of the tree, through the sapwood, which lies betweenthe heart wood and the bark. The sap passes through thebranches and, finally, to the green leaves. In the leaves, thesap is combined with carbon dioxide gas CO,., which is takeninto the leaves from the air, and the final product of the chemicalreaction is sugar. This sugar is carried, in solution, downthrough the inner bark of the tree, and from thence into thewood, through what are called medvUary rays M, (see Fig. 4).For explanation of r
. The manufacture of pulp and paper : a textbook of modern pulp and paper mill practice. hroughthe trunk of the tree, through the sapwood, which lies betweenthe heart wood and the bark. The sap passes through thebranches and, finally, to the green leaves. In the leaves, thesap is combined with carbon dioxide gas CO,., which is takeninto the leaves from the air, and the final product of the chemicalreaction is sugar. This sugar is carried, in solution, downthrough the inner bark of the tree, and from thence into thewood, through what are called medvUary rays M, (see Fig. 4).For explanation of reference letters, see Art. 4. For definitionof terms, see Glossary, Art. 24. At the part of the tree where the bark is attached to the wood,there is a special layer of cells, called the cambium cells, Cm,which take up this sugar solution and grow and divide, making PROPERTIES OF PULP WOOD Si more and more cells. The new cells on the wood side graduallydevelop into wood fibers and the other types of woody cells, whilethose on the bark side form bark fibers; thus it is that a new layer. Fig. 4.—Diagram of a Log of Wood, Cut to Show Cross. Radial, andTangential Sections. C, cross section; R, radial section; T, tangential section: S, sapwood; //, heartwood: A,annual ring; 5m, summerwood; Sp, springwood; M, medullary rav; P, pith: A, bark; Cm,cambium. of wood cells, or fibers, are added to the surface of the wood eachyear. Each years growth ring, or annual ring, A. is dividedinto two parts: that which is formed in the early part of the §1 PROPERTIES OF WOOD 0 growing season, which is composed of fibers with thin walls thatenclose a comparatively large space Sp; and thai which is formedduring the later pari of the growing season, which is made up offibers having thicker walls that enclose a smaller space is because of this difference between the two parts of theannual growth that the annual rings can be distinguished in wood,the early growth of each year being lighter in col
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectpaperma, bookyear1921
