Many other circumstances besides scarcity will contribute to render a book highly prized, and consequently dear. Some of these are obvious at once, such as fine paper, fine print, fine binding, or the autograph of a celebrated man. A book will be valued because it has been the subject of a judicial condemnation, or because it is a copy containing a plate in general deficient or mutilated, or perhaps only because it has an erratum corrected in other copies. Mr. Sidney Lee’s recent discovery of a unique peculiarity in the Baroness Burdett-Coutts’ Shakespeare folio may probably have doubled the value of the book. Sometimes such causes are very singular. King Charles the First dropped a pamphlet into the mud; the stain remains to this day, and centuples the value of a tract which would have been only deteriorated if it had slipped from the fingers of a lord-in-waiting. Such a fact introduces the element of sentiment, a powerful factor, and one of far-reaching influence; for the Quaker or Freemason who collects literature interesting to his society, or the local patriot who buys up the books printed in his native town, sets others upon collecting them too, and raises the value all round. Next to scarcity and great beauty, nothing, perhaps, imparts such stability to the worth of a book as to be addressed to a small but well-defined circle of readers. Books on chess and angling are familiar instances. They are not too numerous to dismay a collector, and every one differs from the rest in some feature sufficient to make it indispensable to a collector ambitious of completeness. A certain description of books would excite lively interest if they could be identified with certainty, those which are not valuable now, but which are about to be. It may probably be considered that almost any book which can manage to exist for five hundred years will find itself augmented in value at the end of this period, but some classes will have proved much better investments than others. Two may be signalised with considerable confidence--illustrated books, which portray the fashions and humours of the age for posterity, and newspapers. Nothing grows in value like a newspaper; the sheets of to-day, which, perhaps, contain nothing of interest to any contemporary reader, will be priceless to the historian and antiquary of the centuries to come. They fructify in silence, and imperceptibly make their possessor rich. Their intellectual as well as their pecuniary value augments by lying still. Nothing so faithfully depicts an age for its successors; they are worth all the histories and all the novels. Their preservation--which involves their assemblage in one place for the sake of accessibility and of comparison with each other and with books--is a momentous trust, neglect of which would strike a heavy blow at historical, archæological, and sociological research, and inflict a grievous injury upon the ages to come.