dinal qualification of the
librarian. This faculty of the mind, in fact, is more important to him
than to the members of any other profession whatever, because it is more
incessantly drawn upon. Every hour in the day, and sometimes every minute
in the hour, he has to recall the names of certain books, the authors of
the same, including both their surnames and Christian or forenames, the
subjects principally treated in them, the words of some proverb or
quotation, or elegant extract in poetry or prose, the period of time of
an author or other noted person, the standard measurements and weights in
use, with their equivalents, the moneys of foreign nations and their
American values, the time of certain notable events in history, whether
foreign or American, ancient or modern, the names and succession of
rulers, the prices of many books, the rules observed in the catalogue,
both of authors and subjects, the names and schools of great artists,
with their period, the meaning in various foreign languages of certain
words, the geographical location of any place on the earth's surface, the
region of the library in which any book is located--and, in short, an
infinitude of items of information which he wants to know out of hand,
for his own use, or in aid of Library readers or assistants. The immense
variety of these drafts upon his memory seldom perplexes one who is well
endowed with a natural gift in that direction. In fact, it seems actually
true of such minds, that the more numerous the calls upon the memory, the
more ready is the response.

The metaphysicians have spent many words in attempting to define the
various qualities of the mind, and to account for a strong or a weak
memory; but after all is said, we find that the surprising difference
between different memories is unaccounted for; as unaccountable, indeed,
as what differences the man of genius from the mere plodder. The
principle of association of ideas is doubtless the leading element in a
memory which is not merely verbal. We associate in our minds, almost
instinctively, ideas of time, or space, or persons, or events, and these
connect or compare one with another, so that what we want is called up
or recalled in memory, by a train of endless suggestion. We all have this
kind of memory, which may be termed the rational or ideal, as
distinguished from the verbal and the local memory. The verbal memory is
that which retains in the mind, and reproduces at will what ha