about half an hour, and the excess then wiped
off with a soft cloth.

Vaseline is also used in the same way to assist in the preservation of old
leather bindings still in good repair. It is not entirely satisfactory, as
it soon dries out. The best composition for preserving leather is one
suggested by Mr. Douglas Cockerell, made by mixing about two ounces of
castor oil with one ounce of paraffin wax. The oil is heated and the wax,
shredded, melted into it. As the mixture cools it is stirred with a
splinter of wood. If this is thoroughly done, the resulting mixture will
be a whitish jelly. A thin coat of this is applied to the leather,
especially around the hinges, and well rubbed in with the palm of the
hand. Any excess is then wiped off and the book polished with a very soft
white rag. This mixture is best used while still hot, a little being
soaked into a woolen cloth, by means of which it is rubbed on the binding.
If leather bindings could be given this treatment about once a year their
life would be greatly increased.

After the leather of the old book to be rebacked has been treated, a cut
is made down each side of the back, through the leather close to the
broken hinge. (Fig. A.) Care should be taken not to cut through the cords
which are set into the boards at this point. If the back is furnished
with a leather label in a fair state of preservation, this label should be
cut around and lifted off to be used again on the new back.

[Illustration: Fig. A]

All the leather on the back and over the hinges, up to the cut above
mentioned, should then be lifted or scraped off. As a majority of old
books are bound with the leather glued directly to the lining of the back,
a certain amount of the old glue, according to its condition, scraped
smooth, should be left on the lining.

While old calf backs are generally so dry that they must be scraped off in
pieces, it is sometimes possible, when the back is of more solid leather,
to remove the old back; with the label and gilding, in one piece. If this
can be done, the inside of the old back should be scraped and this back
pasted on again over the new leather back. This is, of course, preferable,
as by this means more of the characteristics of the old cover are
preserved.

[Illustration: Fig. B]

When the back is clear of leather, a small cut about half an inch long is
made at the top and bottom of each side, at the ends of, and at right
angles to, the first cu