kept _librarii_, or book-writers, in his house; and many _servi_, or
slaves, were trained to this service, so that they were a numerous class.

Papyrus is a very durable substance, made of the innermost pellicles of
the stalk, glued together transversely, with the glutinous water of
the Nile. It was for many centuries the great staple of Egypt, and was
exported in large quantities to almost every part of Europe and Asia, but
never, it would appear, to England or Germany. After the seventh century
its use was gradually superseded by the introduction of parchment; and
before the end of the twelfth century it had gone generally out of use.
From "papyrus" the name of "paper," which, with slight variations, is
common to many languages, is no doubt derived.

Parchment and vellum--which are made from the skin of animals, the former
from sheep or goat, the latter from calf, both prepared with lime--were
in use at a very early period, long before their accredited introduction.
It has been by some supposed that Eumenes, King of Pergamus, who lived
about B.C. 190, was the inventor of parchment; but it was known much
earlier, as may be seen by several references to it in the Bible (Isaiah,
viii. i; Jeremiah, xxxvi. 2; Ezekiel, xi. 9). It is, however, very
probable that it may have been brought to perfection at Pergamus, as it
was one of the principal articles of commerce of that kingdom.

Parchment, in early times, was not only expensive, but often very
difficult to procure; whence arose the practice of erasing old writing
from it, and engrossing it a second time. Such manuscripts are called
"palimpsests." Modern art has found the means of discharging the more
recent ink, and thus restoring the original writing, by which means we
have recovered many valuable pieces, particularly Cicero's lost book, _de
Republica_ and some fragments of his _Orations_.