a gold coin, known first as the ducat, afterwards as the zecchino or sequin, the ducat becoming merely a money of account. The ducat was also current in Holland, Austria, the Netherlands, Spain and Denmark (see Numismatics). A gold coin termed a ducat was current in Hanover during the reigns of George I. and George III. A pattern gold coin was also struck by the English mint in 1887 for a proposed decimal coinage. On the reverse was the inscription “one ducat” within an oak wreath; above “one hundred pence,” and below the date between two small roses. There is a gold coin termed a ducat in the Austria-Hungary currency, of the value of nine shillings and fourpence.
DU CHAILLU, PAUL BELLONI (1835–1903), traveller and anthropologist, was born either at Paris or at New Orleans (accounts conflict) on the 31st of July 1835. In his youth he accompanied his father, an African trader in the employment of a Parisian firm, to the west coast of Africa. Here, at a station on the Gabun, the boy received some education from missionaries, and acquired an interest in and knowledge of the country, its natural history, and its natives, which guided him to his subsequent career. In 1852 he exhibited this knowledge in the New York press, and was sent in 1855 by the Academy of Natural Sciences at Philadelphia on an African expedition. From 1855 to 1859 he regularly explored the regions of West Africa in the neighbourhood of the equator, gaining considerable knowledge of the delta of the Ogowé river and the estuary of the Gabun. During his travels he saw numbers of the great anthropoid apes called the gorilla (possibly the great ape described by Carthaginian navigators), then known to scientists only by a few skeletons. A subsequent expedition, from 1863 to 1865, enabled him to confirm the accounts given by the ancients of a pygmy people inhabiting the African forests. Narratives of both expeditions were published, in 1861 and 1867 respectively, under the titles Explorations and Adventures in Equatorial Africa, with Accounts of the Manners and Customs of the People, and of the Chace of the Gorilla, Crocodile, and other Animals; and A Journey to Ashango-land, and further penetration into Equatorial Africa. The first work excited much controversy on the score of its veracity, but subsequent investigation proved the correctness of du Chaillu’s statements as to the facts of natural history; though possibly some of the adventures he described as happening to himself were reproductions of the hunting stories of natives (see Proc. Zool. Soc. vol. i., 1905, p. 66). The map accompanying Ashango-land was of unique value, but the explorer’s photographs and collections were lost when he was forced to flee from the hostility of the natives. After some years’ residence in America, during which he wrote several books for the young founded upon his African adventures, du Chaillu turned his attention to northern Europe, and published in 1881 The Land of the Midnight Sun, in 1889 The Viking Age, and in 1900 The Land of the Long Night. He died at St Petersburg on the 29th of April 1903.
DUCHENNE, GUILLAUME BENJAMIN AMAND (1806–1875), French physician, was born on the 17th of September 1806 at Boulogne, the son of a sea-captain. He was educated at Douai, and then studied medicine in Paris until the year 1831, when he returned to his native town to practise his profession. Two years later he first tried the effect of electro-puncture of the muscles on a patient under his care, and from this time on devoted himself more and more to the medical applications of electricity, thereby laying the foundation of the modern science of electro-therapeutics. In 1842 he removed to Paris for the sake of its wider clinical opportunities, and there he worked until his death over thirty years later. His greatest work, L’Électrisation localisée (1855), passed through three editions during his lifetime, though by many his Physiologie des mouvements (1867) is considered his masterpiece. He published over fifty volumes containing his researches on muscular and nervous diseases, and on the applications of electricity both for diagnostic purposes and for treatment. His name is especially connected with the first description of locomotor ataxy, progressive muscular atrophy, pseudo-hypertrophic paralysis, glosso-labio laryngeal paralysis and other nervous troubles. He died in Paris on the 17th of September 1875.
For a detailed life see Archives générales de médicine (December 1875), and for a complete list of his works the 3rd edition of L’Électrisation localisée (1872).
DU CHESNE [Latinized Duchenius, Querneus, or Quercetanus], ANDRÉ (1584–1640), French geographer and historian, generally styled the father of French history, was born at Ile-Bouchard, in the province of Touraine, in May 1584. He was educated at Loudun and afterwards at Paris. From his earliest years he devoted himself to historical and geographical research, and his first work, Egregiarum seu selectarum lectionum et antiquitatum liber, published in his eighteenth year, displayed great erudition. He enjoyed the patronage of Cardinal Richelieu, a native of the same district with himself, through whose influence he was appointed historiographer and geographer to the king. He died in 1640, in consequence of having been run over by a carriage when on his way from Paris to his country house at Verrière. Du Chesne’s works were very numerous and varied, and in addition to what he published, he left behind him more than 100 folio volumes of manuscript extracts now preserved in the Bibliothèque Nationale (L. Delisle, Le Cabinet des manuscrits de la bibliothèque impériale, t. L, 333-334). Several of his larger works were continued by his only son François du Chesne (1616–1693), who succeeded him in the office of historiographer to the king. The principal works of André du Chesne are—Les Antiquités et recherches de la grandeur et majesté des rois de France (Paris, 1609), Les Antiquités et recherches des villes, châteaux, &c., de toute la France (Paris, 1609), Histoire d’Angleterre, d’Écosse, et d’Irelande (Paris, 1614), Histoire des Papes jusqu’à Paul V (Paris, 1619), Histoire des rois, ducs, et comtes de Bourgogne (1619–1628, 2 vols. fol.), Historiae Normanorum scriptores antiqui (1619, fol., now the only source for some of the texts), and his Historiae Francorum scriptores (5 vols. fol., 1636–1649). This last was intended to comprise 24 volumes, and to contain all the narrative sources for French history in the middle ages; only two volumes were published by the author, his son François published three more, and the work remained unfinished. Besides these du Chesne published a great number of genealogical histories of illustrious families, of which the best is that of the house of Montmorency. His Histoire des cardinaux français (2 vols. fol. 1660–1666) and Histoire des chanceliers et gardes des sceaux de France (1630) were published by his son François. André also published a translation of the Satires of Juvenal, and editions of the works of Alcuin, Abelard, Alain Chartier and Étienne Pasquier.
DUCHESNE, LOUIS MARIE OLIVIER (1843– ), French scholar and ecclesiastic, was born at Saint Servan in Brittany on the 13th of September 1843. Two scientific missions—to Mount Athos in 1874 and to Asia Minor in 1876—appeared at first to incline him towards the study of the ancient history of the Christian churches of the East. Afterwards, however, it was the Western church which absorbed almost his whole attention. In 1877 he received the degree of docteur ès lettres with two remarkable theses, a dissertation De Macario magnete, and an Étude sur le Liber pontificalis, in which he explained with unerring critical acumen the origin of that celebrated chronicle, determined the different editions and their interrelation, and stated precisely the value of his evidence. Immediately afterwards he was appointed professor at the Catholic Institute in Paris, and for eight years presented the example and model, then rare in France, of a priest teaching church history according to the rules of scientific criticism. His course, bold even to the point of rashness in the eyes of the traditionalist exegetists, was at length suspended. In November 1885 he was appointed lecturer at the École Pratique des Hautes Études. In 1886 he published volume i. of his learned edition of the Liber pontificalis (completed in 1892 by volume ii.), in which he resumed and completed the results he had attained in his French thesis. In 1888 he was elected member of the Académie des Inscriptions et Belles-Lettres, and was afterwards appointed director of the French school of archaeology at Rome. Much light is thrown upon the Christian origins, especially those of France, by his Origines du culte chrétien, étude sur la liturgie latine avant Charlemagne
