er, who seems to have anticipated the
positive philosophy by an attempt to make bibliography, as the Germans
have named it, one of the exact sciences, lays it down with authority,
that "a book which it is difficult to find in the country where it is
sought ought to be called simply _rare_; a book which it is difficult to
find in any country may be called _very rare_; a book of which there are
only fifty or sixty copies existing, or which appears so seldom as if
there never had been more at any time than that number of copies, ranks
as _extremely rare_; and when the whole number of copies does not exceed
ten, this constitutes _excessive rarity_, or rarity in the highest
degree." This has been received as a settled doctrine in bibliography;
but it is utter pedantry. Books may be rare enough in the real or
objective sense of the term, but if they are not so in the nominal or
subjective sense, by being sought after, their rarity goes for nothing.
A volume may be unique--may stand quite alone in the world--but whether
it is so, or one of a numerous family, is never known, for no one has
ever desired to possess it, and no one ever will.

But it is a curious phenomenon in the old-book trade, that rarities do
not always remain rare; volumes seeming to multiply through some
cryptogamic process, when we know perfectly that no additional copies
are printed and thrown off. The fact is, that the rumour of scarcity,
and value, and of a hunt after them, draws them from their
hiding-places. If we may judge from the esteem in which they were once
held, the Elzevirs must have been great rarities in this country; but
they are now plentiful enough--the heavy prices in the British market
having no doubt sucked them out of dingy repositories in Germany and
Holland--so that, even in this department of commerce the law of supply
and demand is not entirely abrogated. He who dashes at all the books
called rare, or even very rare, by Clement and his brethren, will be apt
to suffer the keen disappointment of finding that there are many who
participate with him in the possession of the same treasures. In fact,
let a book but make its appearance in that author's Bibliotheque
Curieuse, Historique, et Critique, ou Catalogue Raisonne des Livres
difficiles a trouver; or in Graesses's Tresor des Livres Rares et
Precieux; or in the Dictionnaire Bibliographique des Livres Rares,
published by Caileau--or let it be mentioned as a rarity in Eibert's
Allgemein