We must set down a good memory as a cardinal 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 has been said in our hearing by others, or what we have read which has made a marked impression upon us. Thus, some persons can repeat with almost exact accuracy, every word of a long conversation held with another. Others can repeat whole poems, or long passages in prose from favorite authors, after reading them over two or three times, and can retain them perfectly in memory for half a century or more. There have even been persons to whom one single reading of any production was sufficient to enable them to repeat it verbatim. These instances of a great verbal memory are by no means rare, although some of them appear almost incredible. John Locke tells us of the French philosopher Pascal, that he never forgot anything of what he had done, said, or thought, in any part of his natural life. And the same thing is recorded of that great scholar of Holland, Hugo Grotius.

The mathematician Euler could repeat the Aeneid of Virgil from beginning to end, containing nearly nine thousand lines. Mozart, upon hearing the Miserere of Allegri played in the Sistine Chapel at Rome, only once, went to his hotel, and wrote it all down from memory, note for note.

Cardinal Mezzofanti both wrote and spoke thirty languages, and was quite familiar with more than a hundred. He said that if he once heard the meaning of a word in any language, he never forgot it. Yet he was of the opinion, that although he had twenty words for one idea, it was better to have twenty ideas for one word; which is no doubt true, so far as real intellectual culture is concerned. Lord Macaulay, who had a phenomenal memory, said that if all the copies of Milton's Paradise Lost were to be destroyed, he could reproduce the book complete, from memory. In early life he was a great admirer of Walter Scott's poetry, and especially the "Lay of the Last Minstrel", and could repeat the whole of that long poem, more than six hundred lines, from memory. And at the age of fifty-seven he records—"I walked in the portico, and learned by heart the noble fourth act of the Merchant of Venice. There are four hundred lines. I made myself perfect master of the whole in two hours." It was said of him that every incident he heard of, and every page he read, "assumed in his mind a concrete spectral form."

But the memory for names and words has been sometimes called the lowest form of memory. Persons of defective or impaired intellect frequently have strong and retentive verbal memories. Mrs. Somerville records the case of an idiot who could repeat a whole sermon verbatim, after once hearing it, but who was stupid and ignorant as to every thing else. And there are many instances in the books to the same effect.

Another kind of memory may be called, for want of a better name, the local memory. A person who has this strongly developed, if he once goes to a place, whether a room, or a street in a city, or a road in any part of the country, knows the way again, and can find it by instinct ever after. In the same way any one gifted with this almost unerring sense of locality, can find any book on any shelf in any part of a library where he has once been. He knows, in like manner, on which side of the page he saw any given passage in a book, which impressed him at the time, although he may never have had the volume in his hand more than once. He may not remember the number of the page, but he is sure of his recollection that it was the left or the right hand one, as the case may be, and this knowledge will abridge his labor and time in finding it again by just one half. This local memory is invaluable to a librarian or an assistant in shortening the labor of finding things. If you have a good local memory, you can, in no long time, come to dispense with the catalogue and its shelf-marks or classification marks, almost entirely, in finding your books. Although this special gift of memory—the sense of locality—is unquestionably a lower faculty of the mind than some others named, and although there are illiterate persons who can readily find and produce any books in a library which have often passed through their hands, yet it is a faculty by no means to be despised. It is one of the labor-saving, time-saving gifts, which should be welcomed by every librarian. The time saved from searching the catalogues for location-marks of the outside of books, will enable him to make many a research in their inside. This faculty, of course, is indefinitely strengthened and improved by use—and the same is true of the other branches of the sense which we call memory. The oftener you have been to any place, the better you know the way. The more frequently you have found and produced a given book from its proper receptacle, the easier and the quicker will be your finding it again.

Another faculty or phase of memory is found in the ability to call up the impression made by any object once seen by the eye, so as to reproduce it accurately in speech or writing. This may be termed the intuitive memory. There are many applications or illustrations of this faculty. Thus, for example, you see a book on some shelf in your library. You take in its size, its binding, both the material and the color, and its title as lettered on the back. All this you absorb with one glance of the eye. You remember it by the principle of association—that is, you associate with that particular book, in connection with its title, a certain dimension, color, and style of binding. Now, when you have occasion to look up that special volume again, you not only go, aided by your memory of locality, to the very section and shelf of the library where it belongs, but you take with you instinctively, your memory or mental image of the book's appearance. Thus, you perhaps distinctly remember (1) that it was an octavo, and your eye in glancing along the shelf where it belongs, rejects intuitively all the duodecimos or books of lesser size, to come to the octavos. (2) Then you also remember that it was bound in leather, consequently you pass quickly by all the cloth bound volumes on the shelf. (3) in the third place you know that its color was red; and you pay no attention whatever to books of any other color, but quickly seize your red leather-bound octavo, and bear it off to the reading-room in triumph. Of course there are circumstances where this quick operation of the faculties of memory and intuition combined, would not be so easy. For example, all the books (or nearly all) on a given shelf might be octavos; or they might all be leather-bound; or a majority of them with red backs; and the presence of one or more of these conditions would eliminate one or more of the facilities for most rapidly picking out the book wanted. But take a pile of books, we will say returned by many readers, on the library counter. You are searching among them for a particular volume that is again wanted. There is no order or arrangement of the volumes, but you distinctly remember, from having handled it, its size both as to height and thickness, its color, and how it was bound. You know it was a thin 12mo. in green cloth binding. Do you, in your search, take up every book in that mass, to scrutinize its title, and see if it is the one you seek? By no means. You quickly thrust aside, one by one, or by the half-dozen, all the volumes which are not green, cloth-bound, thin duodecimos, without so much as glancing at them. Your special volume is quickly found among hundreds of volumes, and your faculty of memory and intuition has saved you perhaps a quarter of an hour of valuable time, which, without that faculty, might have been wasted in search.

Again, another circumstance which might intervene to diminish the frequency of application of the memory referred to, as to the physical features or appearance of a book sought for, is where the shelf-arrangement is alphabetical, by authors' names, or by the names of the subjects of the books, if it is an alphabet of biographies. Here, the surest and the quickest guide to the book is of course the alphabetical order, in which it must necessarily be found.

This memory of the aspect of any object once looked at, is further well illustrated in the very varied facilities for the spelling of words found in different persons. Thus, there are people who, when they once see any word (we will say a proper name) written or printed, can always afterwards spell that word unerringly, no matter how uncommon it may be. The mental retina, so to speak, receives so clear and exact an impression of the form of that word from the eye, that it retains and reproduces it at will.

But there are others, (and among them persons of much learning in some directions) upon whom the form or orthography of a word makes little or no impression, however frequently it meets the eye in reading. I have known several fine scholars, and among them the head of an institution of learning, who could not for the life of them spell correctly; and this infirmity extended even to some of the commonest words in the language. Why this inaptitude on the part of many, and this extraordinary facility on the part of others, in the memorizing faculty, is a phenomenon which may be noted down, but not solved. That vivid mental picture which is seen by the inward eye of the person favored with a good memory, is wholly wanting, or seen only dimly and rarely in the case of one who easily forgets.