The preservation of books, framed as they are of materials so destructible, through a period of twelve, or even fifteen hundred years, is a fact which might seem almost incredible; especially so as the decay of far more durable substances, within a much shorter period, is continually presented to our notice. Yet so it is, that while the massive walls of the monasteries of the middle ages are often seen prostrate, and their materials fast mingling with the soil, the manuscripts, penned within them, or perhaps at a time when these stones were yet in the quarry, are still fair and perfect, and glitter with their gold and silver, their cerulean and their cinnabar. It must be remembered, however, that the materials of books, although destructible, are so far from being in themselves perishable, that so long as they are defended from positive injuries, they appear to suffer scarcely at all from any intrinsic principle of decay, or to be liable to any perceptible process of chemical decomposition. No one, says Mabillon, unless totally unacquainted with what relates to antiquity, can call in question the great durability of parchments; since there are extant innumerable books, written on that material, in the seventh and sixth centuries; and some of a still more remote antiquity, by which all doubt on that subject might be removed. It may suffice here to mention the Virgil of the Vatican Library, which appears to be of more ancient date than the fourth century; and another in the King’s Library little less ancient: also the Prudentius, in the same library, of equal age; to which you may add several, already mentioned, as the Psalter of S. Germanus, the Book of the Councils, and others, which are all of parchment. The paper of Egypt, being more frail and brittle, might be open to greater doubt; and yet there are books of great antiquity, by which its durability may be established. Books have owed their conservation, not merely to the durability of the material of which they were formed; but to the peculiarity of their being, at once precious, and yet (in periods of general ignorance) not marketable articles; they were of inestimable value to a few, while absolutely worthless in the opinion of the multitude. They were also often indebted for their preservation, in periods of disorder and violence, to the sacredness of the roofs under which they were lodged. THE INSTRUMENTS OF WRITING, AND INKS.