nd, is an acid-free leather used
for expensive bindings. This leather is rather hard to secure, but its
desirability is indicated by the fact that it is the only leather on which
the severe tests described in the Report of the Committee on Leather for
Bookbindings, elsewhere mentioned, had no effect.

CHAPTER VI

_THE BOOK SHELVES_

[Illustration: LEATHER SLIP-COVERS]

Open shelves undoubtedly form the ideal resting place for books, since
they are not only convenient for access, but also allow a free circulation
of air around the volumes. They are, however, often impracticable as
affording insufficient protection against dust and dirt, especially in
cities, where closed cases are very necessary. No case with movable doors
is absolutely dust-proof, but some types very closely approach this
desirable state.

Closed cases are, of course, to be preferred with glass doors to reveal a
glimpse of the treasures within. They should be set a few inches away from
the wall, to permit a free circulation of air around them, and should
never be so placed that the books are exposed to direct sunlight or a
strong glare, as this will fade or discolor the bindings, particularly
green leather, which is very apt to turn brown. The room in which cases
are placed should be free from damp, and the windows should be kept closed
at night. If the windows admit an excess of sunlight or glare, they are
best furnished with yellowish or olive-green glass, which will neutralize
any harmful effects of the light on the books. Such colored glass, if
"leaded," may be made a very attractive addition to the appearance of the
room. Red glass verging toward the orange is equally effective, but less
adaptable to the purpose.

A full description of the effects of light on various kinds and colors of
leathers will be found in the Report of the Committee on Leather for
Bookbindings, London, Bell, 1905. This report also gives the following
suggestion for a preservative finish to be used on leather bindings: "Boil
eight parts of stearic acid and one part of caustic soda in fifty parts of
water, until dissolved. Then add one hundred and fifty parts of cold water
and stir until the substance sets into a jelly. Apply this jelly thinly
with a sponge or rag and, when it has dried, polish the leather with a
soft flannel. If a white film rises to the surface of the leather this can
be wiped away with a damp cloth and the leather repolished." A fair supply
o