O'HALLORAN, Sylvester, a medical and historical writer

of the last century, was born in 1728. He studied surgery at Paris and in London, and seems to have lived an active professional life, for he alludes to the scantiness of his leisure in the dedication to his history. Besides some medical treatises, he is the author of "A General History of Ireland, from the earliest accounts to the close of the twelfth century," published in two quarto volumes in 1778. His capacity for writing history may be judged of from the fact of his gravely commencing his labours with the account of the invasion of Ireland in the year of the world 1956, by Partholan, the eighth in descent from Noah! He died at Limerick in 1807, at a very advanced age.—T. A. O'HARA, Kane, an Irish play-writer of the last century, was born about the year 1722. In Baker's Biographia Dramatica, 1782, it is stated that little was known of O'Hara beyond the fact of his belonging to "a genteel family," residing near Dublin, and from his appearance and manners "by no means promising the festivity that enlivens all his compositions." He is the author of four burlettas—"Midas," "The Golden Pippin," "April Day," "Tom Thumb"—and of a musical farce entitled "The Two Misers;" all of which were tolerably successful in their day. "Midas" and "Tom Thumb" may be found among Mrs. Inchbald's selected plays. O'Hara died in 1782.—T. A. OHLMÜLLER, Daniel Joseph, an eminent German architect, was born at Bamberg in 1791, studied under Karl Fischer, and completed his education by a professional tour of four years in Italy and Sicily. In 1819 he was invited to Munich by Ludwig, to superintend the erection of the Glyptothek from the designs of Klenze. This work occupied Ohlmüller for several years, but introduced him to important independent commissions. His chief buildings are churches. Of these the principal is the Maria-Hilf church, in the Au suburb, Munich, a spacious Gothic edifice commenced in 1831 and completed in 1839. For some years before his death he held the office of inspector of the public buildings, Munich. He died April 22, 1839.—J. T—e. OHMACHT, Landelin, a celebrated German sculptor, born in 1760 at Dunningen, near Rottweil, Würtemberg, was a pupil of J. P. Melchior. Having executed some sculpture for the choir of a church at Rottweil, a bust of Lavater, and one or two minor works, he in 1790 went to Rome, where he stayed two years. In 1801 he settled at Strasburg, where he remained till his death in 1834. Ohmacht has been called the Correggio of sculptors, and the epithet may serve to mark the fulness rather than correctness of his style. He executed various classical statues and groups—as a Judgment of Paris, Venus, Psyche, &c. But he is best known perhaps by his monuments, among the most celebrated of which are those of General Desaix, on the Rheininsel, near Strasburg; General Kleber, in Strasburg cathedral; Professors Oberlin and Koch, in the church of St. Thomas; and the colossal statue of Adolph von Nassau, in the cathedral of Speyer. His busts are much admired.—J. T—e. OJEDA, Alonzo de, one of the earliest Spanish discoverers who followed in the footsteps of Columbus, was born about 1472, and brought up in the house of the duke of Medina Celi. He accompanied Columbus in his second voyage (1493); but having obtained the patronage of the archbishop, Fonseca, he aspired to an independent command, and did not accompany the admiral in his third voyage (1498). When letters were received in Spain announcing the discovery by Columbus of the coast of Paria, with its pearl fishery and other natural riches, Ojeda obtained a commission permitting him to fit out an expedition in search of new territories. His four vessels sailed in 1499, and among his comrades were Amerigo Vespucci (whose name was afterwards given to the whole continent), and Juan de la Cosa, a Biscayan, who had accompanied Columbus in his former voyages. The expedition first touched the New World on the coast of Surinam, and afterwards reached the island of Trinidad, which Columbus had recently visited. From thence, passing through the Boca del Drago, he visited the island of Margarita. Returning to the mainland, he essayed to found a settlement at Maracapana, but was induced by the natives to embark in a fresh expedition against the Caribs of the neighbouring islands, which was partially successful. Again setting sail, he discovered the gulf to which, from its resemblance to Venice, he gave the name of Venezuela. Thence he pursued his voyage along the coast; but finding nothing to reward his search he sailed for Hispaniola, and thence returned to Spain, little the richer for all his toils (June, 1500). In 1502 he again sailed, with a commission to colonize the province he had discovered, and to pursue his investigations southward. He reached the seat of his government in safety, and attempted to erect a fortress at the spot now named as Bahia Honda; but a fierce quarrel arose between the chief and his associates, which led to his being conveyed back in chains to Hispaniola, and involved in a ruinous lawsuit. In 1508 King Ferdinand resolved to found regular colonies along the coast of Terra Firma, and the commission was intrusted to Ojeda, the veteran Juan de la Cosa volunteering his aid both in purse and person. Eventually, however, a portion of his command was intrusted to Diego Nicuesa, and the province known as Nueva Andalusia was assigned to Ojeda. Sailing from San Domingo, 10th November, 1509, with four vessels, they arrived at Carthagena; but the first attempt at a settlement involved them in hostilities with the natives, and Juan de la Cosa, with seventy men, fell victims to their poisoned arrows. Ojeda himself, with the remnant of his force, only escaped by the friendly aid of his rival Nicuesa. Rallying his followers, Ojeda founded a settlement, to which he gave the name of San Sebastian, on the east side of the Gulf of Uraba. In an expedition against the natives, Ojeda, for the first time, received a wound from a poisoned arrow, but resolutely cured himself by the application of red-hot iron. A more serious disaster—lack of provisions—threatened the infant colony, when a band of outlaws from Hispaniola, under Bernardino de Talavera, arrived, in the hope of sharing the fortunes of the adventurers. It was agreed that Ojeda should return in their vessel to seek supplies from Hispaniola. They landed at the east end of the island of Cuba, and after incredible hardships, Ojeda at length succeeded in obtaining a passage to Hispaniola. But the charm which once attached to his name was gone, and all his efforts to obtain assistance failed. He lived a broken-hearted man for some time in San Domingo, and at his death requested that he might be buried on the threshold of the monastery of San Francisco.—F. M. W. O'KEEFFE, John, the prolific and once popular dramatist, was born in Dublin in 1747, of a family respectable but decayed. He was fairly educated, and specially with a view to become a painter by profession; but an early perusal of Farquhar's comedies gave him a taste for the stage, which overpowered every other. At eighteen he saw his first play, "The Gallant," performed in Dublin, and he not only turned dramatist, but actor. Finally he settled in London, and wrote for the stage till nearly the close of the eighteenth century. Of some fifty or sixty of his acted pieces, a few, such as his comedy of "Wild Oats," are agreeably remembered by the play-goers of the last generation. Most of them, overflowing with Irish vivacity, fun, and sentiment, were very popular in their day. For many years of his life he was nearly blind. Besides plays, he published in 1826 the "Recollections of the Life of John O'Keeffe, written by himself," readable and amusing volumes. He died at Southampton in 1833.—F. E. OKEN, Lorenz, the celebrated German naturalist and natural philosopher, was born, according to the generally received accounts, on the 1st of August, 1779, in the Suabian village of Bohlsbach. His real name was "Ockenfuss," which in his first published work he contracted and altered into Oken. He studied medicine and the natural sciences at the universities of Würtzburg and of Göttingen, becoming privat-docent at the latter. In 1802 he published his first work, the "Grundriss der Naturphilosophie, der Theorie der Sinne, und der darauf gegründeten Classification der Thiere," the earliest of his daring attempts to apply systematically to natural history and philosophy the principles advanced by Schelling. In his own curious preface to the English translation, published by the Ray Society in 1847, of his "Lehrbuch der Naturphilosophie," Oken thus refers to his first work:—"I still abide by the position then taken, namely, that the animal classes are virtually nothing else than a representation of the sense-organs, and that they must be arranged in accordance with them. Thus, strictly speaking, there are only five animal classes—Dermatozoa, or the invertebrate; Glossozoa, or the fishes, as being those animals in which a true tongue makes for the first time its appearance; Rhinozoa, or the reptiles, wherein the nose opens for the first time into the mouth and inhales air; Otozoa, or the birds, in which the ear for the first time opens externally; Ophthalmozoa or the Thricozoa, in whom all the organs of sense are present and complete, the eyes being movable, and covered with two palpebræ or lids."