hment, which were used
by the binders to strengthen the backs of their newly-printed rivals.
These slips of vellum or parchment are quite common in old books.
Sometimes whole sheets are used as fly-leaves, and often reveal the
existence of most valuable works, unknown before--proving, at the same
time, the small value formerly attached to them.

Many a bibliographer, while examining old books, has to his great
puzzlement come across short slips of parchment, nearly always from some
old manuscript, sticking out like "guards" from the midst of the leaves.
These suggest, at first, imperfections or damage done to the volume; but
if examined closely it will be found that they are always in the middle
of a paper section, and the real reason of their existence is just the
same as when two leaves of parchment occur here and there in a paper
volume, viz.: strength--strength to resist the lug which the strong
thread makes against the middle of each section. These slips represent
old books destroyed, and like the slips already noticed, should always
be carefully examined.

When valuable books have been evil-entreated, when they have become
soiled by dirty hands, or spoiled by water stains, or injured by
grease spots, nothing is more astonishing to the uninitiated than the
transformation they undergo in the hands of a skilful restorer. The
covers are first carefully dissected, the eye of the operator keeping
a careful outlook for any fragments of old MSS. or early printed books,
which may have been used by the original binder. No force should be
applied to separate parts which adhere together; a little warm water
and care is sure to overcome that difficulty. When all the sections are
loose, the separate sheets are placed singly in a bath of cold water,
and allowed to remain there until all the dirt has soaked out. If not
sufficiently purified, a little hydrochloric or oxalic acid, or caustic
potash may be put in the water, according as the stains are from grease
or from ink. Here is where an unpractised binder will probably injure a
book for life. If the chemicals are too strong, or the sheets remain too
long in the bath, or are not thoroughly cleansed from the bleach before
they are re-sized, the certain seeds of decay are planted in the paper,
and although for a time the leaves may look bright to the eye, and even
crackle under the hand like the soundest paper, yet in the course of a
few years the enemy will appear, the fibre wi