Mr. Mickley's most remarkable success in life was obtained as a numismatist. His habit of collecting coins began almost in childhood. It has been stated that at the age of seventeen he first became interested in coin-hunting, owing to his difficulty in finding a copper cent coined in 1799, the year of his birth. Every student of numismatism knows that this piece is exceedingly rare. The one sold in Mr. Mickley's collection after his decease brought no less than forty dollars. The taste thus formed continued a prevailing one for sixty years. It is surprising to find how speedily he became a leading and recognized authority. Although as guileless as a child and the easy victim of numerous thefts throughout his life, he was scarcely ever deceived in the value of a coin, token, or medal. Once, at Stockholm, in 1871, he visited a museum where rare coins were exhibited. "The collection," says his diary, "is very, very rich in Greek and Roman, but particularly in Scandinavian and Anglo-Saxon. There are not many United States coins, but among them I was astonished to find a very fine half-eagle of 1815." The known rarity of this coin thus on exhibition in a far country very naturally attracted the keen eyes of the aged collector. These researches, continuing year after year, grew to be more and more valuable, until they became widely celebrated. By the time he had reached middle age he was as well known among the guild of antiquarians as a Quaker is known by his costume. Before his death he had been elected a member of all the prominent societies in numismatics, history, and archaeology throughout the world. The last honor of this kind, which reached him in his eightieth year, was a notice of his election to membership in the Société Française de Numismatique et d'Archéologie. His great collections in this department of knowledge were not confined to coins, but extended also to the literature of the subject. This was splendidly illustrated in his famous library, which comprised many works of the utmost value and scarcity. A taste thus developed in early youth naturally became in the course of years a habit, a sentiment, a leading passion of Mickley's nature. By the year 1867 his coin-collection had become the most extensive in this country. By this time also the entertainment of curious visitors absorbed a good share of the collector's daily duties. He was naturally proud of his treasures, and took a great delight in showing them to all who came. Utterly devoid of suspicion, he was a ready victim to designing persons. The following memorandum, which was found among his later papers, will show how he suffered from this source: