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 of this mixture, suitable for small library purposes, can be made by boiling half an ounce (by weight) of the stearic acid, and one-sixteenth of an ounce (by weight) of the caustic soda, in three liquid ounces of water and then adding nine liquid ounces of cold water. It is best to stir the mixture gently while cooling; the entire process of preparation will take only a few minutes. If kept for more than a week or two, this mixture may become mouldy. It is better to prepare it only when it can be used on a number of books at once.
Books in closed cases should be removed and thoroughly dusted at least once a year, the tops especially being carefully wiped clean, if gilt, or brushed, if uncut, in either case while holding the book tightly closed. They should be aired at the same time, particularly those not in frequent use. For this airing and cleaning a warm, sunny day should be selected and, whenever possible, on such days the cases should be opened; books, like people, are healthier when well supplied with good, fresh air.
Books on the shelves should set in firmly among their neighbors, as a certain amount of pressure on the sides is essential to keep the boards from warping. Care must be taken, however, not to wedge them in too tightly; such a cure is worse in its effects than the disease. The usual method of removing a book from the shelf is to hook a finger into the top of the back, or head-cap, and pull. Paper or cloth backs are often torn at the top in this way. It is far preferable to reach in with the hand and push the book out from the fore-edge or, at least, to tilt it outward by a slight pressure of several fingers on the top beyond the head-band. If the shelves are lined with velvet, as elsewhere suggested, it will be necessary to lift the heavier books into place when returning them to the shelves; if they are shoved in on the lower edges of the boards the velvet will follow them in.
Books in delicate bindings or fragile covers may often, with advantage, be fitted with slip-covers of silk, cloth, Japan vellum, or even soft, heavy paper. These covers are simple and easy to make, but they can be used only when the condition of the book will permit both boards to bend backward without injury, while slipping the cover on or off. (Fig. A.) Covers of this kind, made of leather and provided with a label on the back, are especially adaptable to paper-covered books which, for any reason, one may wish to preserve in their original wrappers without rebinding.
Book-worms are practically unknown in America, but should active traces of these be found in a book the volume should be isolated at once and placed in a tight box with cotton well moistened with ether. Several treatments of this kind, at intervals of two or three days, will kill any worms or eggs. Snuff or tobacco, to be renewed at intervals, placed along the back of the shelves, is said to discourage worms or other insects. Worm holes in old books may sometimes be filled in, if one has time for the operation, with a paste obtained by boiling down shreds of paper in sizing. The writer has an edition of Homer printed at Basel in 1535, in which a worm hole varying in size from one-eighth inch in diameter downwards, and extending through nearly one hundred sheets, has been filled in so carefully on each sheet, in this way, that the repair is noticeable only on the closest inspection.
Moths should never be allowed to breed in the cases. Were it not for increasing this danger the shelf lining mentioned above could be made of felt instead of velvet, the former being, otherwise, a more satisfactory material for the purpose.
While it is only in extremely large collections, where books are left undisturbed for years, that worms, moths, dust, and other enemies of books obtain enough of a foothold to do any serious damage, the careful supervision of even a small collection may sometimes prove of unexpected preventive value and, in any case, the slight extra trouble involved is in no sense a wasted effort.