is obvious that a book of reference in this form would be subjected to
great wear. In our dictionaries it is as easy to find Z as A; but in a
papyrus book, to find the end meant to unroll the whole. The Latin word
for roll was "volumen," hence our "volume." A long work could obviously
not be produced conveniently in a single roll, therefore Homer's "Iliad"
and "Odyssey," for instance, were each divided into twenty-four books,
and that is why the divisions of an epic poem are still called books,
though they are really chapters. The rolls composing a single work were
kept together in a case something like a bandbox. The roll was the book
form of the Greek and Roman as well as the Egyptian world, but it left
no descendants. Our book form was derived from a different source, which
we will now consider.

Just as we speak of Russia leather, so the ancients spoke of Pergamum
skins, or parchment. The story is that Eumenes II, King of Pergamum, a
city of Asia Minor, tried to build up a library rivaling that of
Alexandria, and the Ptolemies, seeking to thwart him, forbade the export
of papyrus from Egypt. Eumenes, however, developed the manufacture of
Pergamum skin, or parchment, or vellum, which not only enabled him to
go on with his library, but also incidentally changed the whole
character of the book for future ages. This material is not only much
more serviceable than the fragile papyrus, but, being tough enough to
stand folding and sewing, permitted the book to be made in its present
or codex form, the original codex being two or three Roman waxed tablets
of wood, fastened together like hinged slates, and thus opening very
crudely in the manner of our books. This development of parchment
occurred in the first half of the second century before Christ. The new
material and book form gradually made their way into favor and came to
constitute the book of the early Christian and medieval world. Though
paper was introduced into Europe soon after the year seven hundred, it
did not displace parchment until the invention of printing called for a
material of its cheaper and more adaptable character.

But, though we have traced the origin of our present book form, we have
not yet filled in the background of its history. Several other notable
types of the book deserve our attention; first of all that of China, one
of the most attractive of all book forms, to which we devote our next
chapter. Though it superficially resembles our own bo