The late Joseph J. Mickley comprised qualities at once more attractive and more unusual than are often met with in one person. He was distinguished throughout the world, during more than a generation, for the diligence and success of his numismatic researches, and his collection of rare coins was for a long time the most valuable in this country. As a collector of scarce books and autographs he was hardly less noted or less successful. But in Philadelphia he was most of all admired for his delightful social qualities and his extensive information on a surprising variety of topics. During forty years his house was a rendezvous for a numerous group of specialists,--not alone in his own favorite pursuits, which, indeed, were both many and diverse, but in any and every department of art or learning. Coin-hunters, autograph-dealers, historical students, philosophers, musical-instrument-makers, noted performers, and performers of less note, all the way down to "scratch-clubs," were his constant visitors for years. It is probable that no private house in Philadelphia has entertained a greater number of intellectually distinguished people than the old mansion just referred to, where Mickley resided from 1842 to 1869. Musical celebrities from every country hastened to make his acquaintance, and such was the magnetism of his personality that acquaintances thus formed seem never to have been lost sight of by either host or guest. During his European tour, which lasted from 1869 to 1872, the then venerable traveller was continually meeting friends among persons who had called upon him at various times, dating back in one case as long before as 1820. They always appeared to have known beforehand of his coming, and he always remembered them and the circumstances under which he had first met them. The social reunions at Mickley's were informal to the last degree, and the accommodations correspondingly primitive. They usually took place in his workshop. Crazy stools or empty piano-boxes generally served for seats. The surrounding furniture comprised barrels, cases, and chests, filled to overflowing with the host's ever-increasing antiquarian treasures. If a quartette were assembled,--and many times the musical party was enlarged to a quintette or a septette,--an adjournment was necessary to a room less crowded, but equally sparse of conventional furniture.