These folios of manuscript, in time, accumulated to thousands, and the places of their deposit became institutions, and received the name of _librarium_. The term “librarian,” however, was applied in those days to the transcriber of books (_librarius_), rather than to the custodian, the latter officer being entitled _custos librariarum_, and who was nothing more than a janitor. The enormous impetus given to education by the invention of printing, although it multiplied copies of books to such an extent as to render them cheap enough to become the property of individuals, still public libraries suffered no diminution, and the very increase of the draught seemed to promote the thirst for information, especially in that class in whom a taste for reading was controlled by a limit of means to become possessed of the necessary books. And although in our day the newspaper, the journal, and the serial, do much to disseminate knowledge among the millions, yet are libraries as much an institution of positive necessity as ever; for, in fact they whet the appetite for reading, and the brief paragraphs and condensed essays editorial are but so many stimulants to more extensive acquisitions of information. The taste grows, and the patronage of libraries increases, and such a progress must continue and enlarge whilst the mind of man lives to accomplish the task set by Him in whose likeness the favored being is made. The history of libraries is one of great interest to the lover of mental progress and the active civilization of our race, and might well call out the most industrious efforts of learned writers to do it justice. However, our business just now is with a local event—the inauguration of a new building by a most popular institution, the MERCANTILE LIBRARY of this city, which took place on the 15th of the past month, in the presence of a large and intellectual number of visitors of both sexes. The rise and progress of this admirable institution is interesting. Started in 1822 in a small second-story room, with few books and fewer members, pinched to pay the rent of $150 per annum, by degrees it gained vigor and steadily advanced to its present position, occupying now a building admirable in all the arrangements of room, light, heat, and ventilation. This spacious building, occupying a prominent position on Tenth street, north of Chestnut, in this city, was purchased and fitted up at a cost of a quarter of a million dollars, and possesses a choice collection of books amounting to fifty-two thousand volumes, besides a well supplied news room, where will be found a great variety of journals from all parts of the civilized world, together with magazines, reviews, quarterlies, and annuals in abundance. The ladies having a separate department to themselves, unapproachable by the masculines.