. Canadian forest industries 1916. Lumbering; Forests and forestry; Forest products; Wood-pulp industry; Wood-using industries. Fig 5—Poplar Fibre x 20. Fig. 6—Poplar Wood, Transverse section x 25. 31. Fig. 9-Ground Wood (Spruce) x 30. Fig. 10-Sulphite Pulp (Spruce) x 25. and bordered pits in the case of coniferous woods make it easy to distinguish them from other somewhat similar fibers. For examination the paper is broken up into pulp by boiling with a weak solution of caustic soda, is then thoroughly washed and the fibers carefully separated out on a glass slide with needles. Before treatin
. Canadian forest industries 1916. Lumbering; Forests and forestry; Forest products; Wood-pulp industry; Wood-using industries. Fig 5—Poplar Fibre x 20. Fig. 6—Poplar Wood, Transverse section x 25. 31. Fig. 9-Ground Wood (Spruce) x 30. Fig. 10-Sulphite Pulp (Spruce) x 25. and bordered pits in the case of coniferous woods make it easy to distinguish them from other somewhat similar fibers. For examination the paper is broken up into pulp by boiling with a weak solution of caustic soda, is then thoroughly washed and the fibers carefully separated out on a glass slide with needles. Before treating with the re-agent it is desirable to remove as much water from the fibers as is possible, and in estimating it is best to examine several mounts to get an average. The reagent most easily used is chlorzinciodide. The colorations produced by the more important paper-making fibers are shown in figure 11. It is sometimes desirable to distinguish positively between the wood of spruce and that of balsam fir. A simple method is as fol- lows: wet the piece of wood and cut a transverse section, not too thin, with a sharp pocket knife. Hold this up to the light and ex- amine, preferably with a magnifying glass, giving a few diameters enlargement. If the wood is spruce, resin canals will show as little darker spots. In figure 2 they are seen as somewhat circular open spaces surrounded by darker rims—it is the darker rims that give the shaded appearance seen in the slices cut with an ordinary knife, as described above. In balsam fir there is no such appearance as this, so the wood may be positively distinguished. After a little practice one will have little difficulty in telling the difference between these two woods, especially if the color, weight and grain are taken into consideration. How to Distinguish Wood Fibres Single fibers from coniferous trees may be distinguished from those of the broad-leaved trees by means of the marks made by the openings through which the sap passe
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectforestsandforestry
