Book-plates having been briefly referred to above, a few words as to their styles and uses may here be pertinent. The name "book-plate" is a clumsy and misleading title, suggesting to the uninitiated the illustrations or plates which embellish the text of a book. The name _Ex libris_, two latin words used for book-plate in all European languages, is clearer, but still not exact, as a definition of the thing, signifying simply "out of books." A book-plate is the owner's or the library's distinctive mark of ownership, pasted upon the inside cover, whether it be a simple name-label, or an elaborately engraved heraldic or pictorial device. The earliest known book-plates date back to the fifteenth century, and are of German origin, though English plates are known as early as 1700. In France, specimens appear for the first time between 1600 and 1650. Foreign book-plates are, as a rule, heraldic in design, as are also the early American plates, representing the coat of arms or family crest of the owner of the books, with a motto of some kind. The fashion of collecting these owners' marks, as such, irrespective of the books containing them, is a recent and very possibly a passing mania. Still, there is something of interest in early American plates, and in those used by distinguished men, aside from the collector's fad. Some of the first American engravers showed their skill in these designs, and a signed and dated plate engraved by Nathaniel Hurd, for example, of Boston, is of some historic value as an example of early American art. He engraved many plates about the middle of the last century, and died in 1777. Paul Revere, who was an engraver, designed and executed some few plates, which are rare, and highly prized, more for his name than for his skill, for, as generally known, he was a noted patriot of the Revolutionary period, belonging by his acts to the heroic age of American history. A book of George Washington's containing his book-plate has an added interest, though the plate itself is an armorial design, not at all well executed. Its motto is "_exitus acta probat_"--the event justifies the deed. From its rarity and the high price it commands, it has probably been the only American book-plate ever counterfeited. At an auction sale of books in Washington in 1863, this counterfeit plate had been placed in many books to give a fictitious value, but the fraud was discovered and announced by the present writer, just before the books were sold. Yet the sale was attended by many attracted to bid upon books said to have been owned by Washington, and among them the late Dr. W. F. Poole, then librarian of the Boston Athenaeum, which possesses most of the library authentically known to have been at Mount Vernon.