The entry in Robert Chambers's Biographical Dictionary of Eminent Scotsmen, published in Glasgow in 1835, begins "KER, JOHN, third Duke of Roxburgh, distinguished by his eminent bibliographical knowledge, and his extensive and valuable collection of books . . . ," and many later dictionaries of biography follow suit. A duke he was, but his chief claim to fame is as a bibliophile. As such, he earned the distinction of having named after him one of the most exclusive and famous of bibliographical societies, the Roxburghe Club, which came into being at the sale of the Roxburghe Library in 1812 and still thrives. The sale of 1812 has gone down in the history of book collecting as the high point of bibliomania, when the edition of Giovanni Boccaccio's Decamerone (Venice: Christophorus Valdarfer, 1471) sold for £2,260, a record for a single printed book that lasted until 1884. While it may be argued that the Boccaccio was quite exceptional and...