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
will decay, and the existence of the books will terminate in a state
of white tinder.

Everything which diminishes the interest of a book is inimical
to its preservation, and in fact is its enemy. Therefore, a few
words upon the destruction of old bindings.