256 MODERN PAPER-MAKING
the forests of the world to satisfy the demand for newsprint. The question of
the continuity of wood supplies has, as a result, given rise to some anxiety,
and from rime to time it has been concluded that the world is in sight of a
serious shortage. Although these scares appear to have been unjustified, they
have at least drawn attention to the need for organized schemes of wood-
cutting and afforestation to ensure that, with steadily increasing demands, the
wood supply is maintained. Nearly all the major wood-pulp producing
countries, and especially the European ones—Norway, Sweden, and Finland-
have their forests continuously surveyed, in order to check consumption
against the annual rate of growth- As a result the necessary afforestation
measures are enforced.
Fibrous R.aw Materials.—J$y far the most common variety of wood used
for newsprint manufacture in Europe is spruce (see p. 50). This wood is
converted both into groundwood (mechanical pulp), and also into sulphite
pulp. Very exceptionally sulphate pulp is used. Groundwood is the most
inexpensive fibrous material (other than waste paper) available for newsprint,
but apart from this advantage it is particularly well-suited for newsprint pro-
duction. It has the necessary absorbent properties to take the printing-ink
well, and it has good opacity. In fact, it has often been said, quite rightly,
that to obtain the best printing results it would be preferable to use ground-
wood alone. In practice, however, a proportion of pulp, longer fibred than
groundwood, is necessary, mainly to help the immature sheet to have the
requisite strength to be carried on its journey along the paper machine, from
the couch, through the presses to the drying cylinders. The pulp most
commonly used for this purpose is known as news quality, or strong, sulphite
pulp. Occasionally sulphate pulp is preferred to sulphite pulp, but its selection
is justified only on those rare occasions when it is cheaper than sulphite pulp,
due to exceptional market conditions, or because a newsprint mill is in close
proximity to a sulphate mill where supplies of pulp may be available in slush
form at a competitive price. Actually sulphate pulp has the advantages of a
somewhat longer fibre than sulphite pulp, and it is free from resinous sub-
tances. On the other hand, even in the palest grades, it is usually rather
darker in colour than strong sulphite pulp, which is an objectionable feature
if bright, nearly white shades are required, as is mostly the case nowadays in
tbis country*
At the present time the proportion of chemical pulp used with ground-
wood for a newsprint furnish ranges from about 10 per cent to 20 per cent.
Some yeais ago the amount commonly used was as high as 30 per cent, but,
partly dtie to the need for retrieving some profit out of the ever-decreasing
selling price of n0ws|«iDLt, and partly due to a growing understanding of the