6 MODERN PAPER-MAKING

esparto in that they are short and fine, but they are much flatter than esparto
fibres, and do not give such good bulk, for the same finish and substance.
When suitably treated (by the soda process) these pulps from poplar wood
make fairly good substitutes for esparto, and they are extensively used for the
manufacture of better-grade printing papers in America.

The fibres of strong sulphite are used chiefly for giving strength and binding
properties to newsprint, and also for the manufacture of strong envelope, bag
and wrapping papers.

The fibres of bleached or easy-bleaching sulphites are used alone or in
conjunction with esparto in printings and writings, and also with cotton and
linen in writings and ledger papers.

From the foregoing remarks it will be gathered that the fibres from trees are
of many kinds and have many different uses, which may be roughly tabulated.

TREES

Deciduous (or Foliage)

Poplar

Coniferous

Spruce, Pine

Sulphite Process

Soda Process

Mechanical or

Chemical Wood

Short and Free like Esparto
Printings and Blottmgs
Ground Wood

Newsprint and Cheap Printings, Boards, etc.
Brown Mechanical
Cheap Coloured Papers

Sulpl

>hite

Soda

Sulphate

Strong and Flexible

Strc
>ng Bleached Easy-ble
i
'aching
suitable to Kraft Pape

| i Writings Banks, etc.

Wrappings
' M.C B*
I
Newsprint
?. Sulphite g Papers
Best Printings (with esparto)
Writings (with or without rags)

Same as
Soda

Thin Banks, Manifolds,
G.LP., and Tissues

We therefore see that the two classes of trees, treated in different ways,
will give us fibres suitable for making practically every kind of paper, from
tije strongest 'manilla' wrappings to the most brittle and weak newsprint.
They will also produce fairly good blotting-paper.
The wood fibres are easily distinguished under the microscope, for mechani-
cal wood fibres can almost always be recognized by the medullary rays or