Chemistry Reference
In-Depth Information
(see Chapter 11) began to be used for writing. Sheets of these materials were
bound into topics, or
codices
, as the earliest topics are known, which began
to replace papyrus scrolls for writing texts. Papyrus, it was found, was too
fragile a material for folding, stacking, and binding together, and it was grad-
ually and almost entirely superseded by parchment and vellum. After the
tenth century C.E. parchment and vellum began, in turn, to be superseded
by paper.
Paper
Paper
, made mostly for writing in the past, consists almost exclusively of
cellulose fibers derived from straw or wood. Paper was first made in China,
apparently at the beginning of the first century C.E., from fibers of the hemp
plant. Making paper in relatively large quantities, however, began only
about 150 years later, also in China. By the middle of the eighth century,
when the Arabs conquered central Asia, papermaking began to spread
throughout the Arab world, gradually displacing papyrus, parchment, and
vellum as a writing material. In Europe, paper did not become widespread
until the late fourteenth century (Hunter 1978).
The basic principles of
papermaking
(not so the technology) have
remained virtually unchanged since the process was first invented. To make
paper, the raw material - cotton or linen rags, straw, or nowadays mainly
wood - are first ground, mixed with water, and macerated so as to break
them down into separate cellulose fibers (
maceration
is a natural biochemi-
cal process that softens and separates tissues, such as those that make up
wood and straw). After the maceration process is completed, the detached
cellulose fibers are separated from the water by pouring the suspension of
fibers onto a screen. This leaves on the screen a matted layer of intertwined
fibers that, after being subjected to pressure and finally dried, make up a
sheet of paper (Goedvriend 1988).
Rice paper
is the widely used misnomer for two entirely different mate-
rials also made in the form of thin sheets: Chinese kung-shu, which is not
paper (see text below) and
washi
. Also known as
Japanese rice paper
, washi is
paper made from the cellulose fibers derived from the bark and branches
of mulberry trees (
Broussonetia kajinoki
) (Inaba and Sugisita 1988; Barrett
1988).
Nonpaper Flat Materials
Kung-shu
, a material akin to paper, is made by drying thin sheets cut
spirally from the inner pith of
Tetrapanax papyriferum
, the kung-shu tree,
