Page:Essays in librarianship and bibliography.djvu/59

It might seem that not much could be said respecting the mere purchase of books, but even this department is subject to the general law of specialisation, and the character of a collection must vary as it falls within the category of national, academical, or municipal libraries. The mission of the national library is the simplest: its character is determined for it by the enactment which in most civilised states constitutes it the general receptacle of the national literature, good, bad, and indifferent, and imposes the corresponding obligation of rendering itself the epitome of foreign literatures, as far as its means allow. Every such library is the mirror of its time, and perhaps even its services to contemporaries are of less real account than those which it performs for posterity in preserving the image of the past. This is the apology of the librarian's anxiety to collect what the uninitiated regard as trash. Yesterday's news-sheet, waste paper to-day, will be precious after a century, and invaluable after a millennium. The same principle justifies the heavy expenditure which it is frequently necessary to occur in procuring what is truly illustrative of the history of a life or a nation, even when it comes in the costly shape of a bibliographical rarity. A black-letter ballad on a Smithfield martyrdom, a collection of cuttings illustrating Byron or Dickens, must be secured for the national Museum if at all within the compass of its resources. Hardly as much can be said for another class of rarities—the vellum page or the sumptuous binding which makes a volume a work of art, but adds