JA’ALIN (from Jā’al, to settle, i.e. “the squatters”), an African tribe of Semitic stock. They formerly occupied the country on both banks of the Nile from Khartum to Abu Hamed. They claim to be of the Koreish tribe and even trace descent from Abbas, uncle of the prophet. They are of Arab origin, but now of very mixed blood. According to their own tradition they emigrated to Nubia in the 12th century. They were at one time subject to the Funj kings, but their position was in a measure independent. At the Egyptian invasion in 1820 they were the most powerful of Arab tribes in the Nile valley. They submitted at first, but in 1822 rebelled and massacred the Egyptian garrison at Shendi. The revolt was mercilessly suppressed, and the Jā’alin were thenceforward looked on with suspicion. They were almost the first of the northern tribes to join the mahdi in 1884, and it was their position to the north of Khartum which made communication with General Gordon so difficult. The Jā’alin are now a semi-nomad agricultural people. Many are employed in Khartum as servants, scribes and watchmen. They are a proud religious people, formerly notorious as cruel slave dealers. J. L. Burckhardt says the true Jā’alin from the eastern desert is exactly like the Bedouin of eastern Arabia.

See The Anglo-Egyptian Sudan, edited by Count Gleichen (London, 1905).

JABIRU, according to Marcgrave the Brazilian name of a bird, subsequently called by Linnaeus Mycteria americana, one of the largest of the storks, Ciconiidae, which occurs from Mexico southwards to the territory of the Argentine Republic. It stands between 4 and 5 ft. in height, and is conspicuous for its massive bill, slightly upturned, and its entirely white plumage; but the head and neck are bare and black, except for about the lower third part of the latter, which is bright red in the living bird. Very nearly allied to Mycteria, and also commonly called jabirus, are the birds of the genera Xenorhynchus and Ephippiorhynchus—the former containing one or (in the opinion of some) two species, X. australis and X. indicus, and the latter one only, E. senegalensis. These belong to the countries indicated by their names, and differ chiefly by their feathered head and neck, while the last is sometimes termed the saddle-billed stork from the very singular shape of its beak. Somewhat more distantly related are the gigantic birds known to Europeans in India and elsewhere as adjutant birds, belonging to the genus Leptoptilus, distinguished by their sad-coloured plumage, their black scabrous head, and their enormous tawny pouch, which depends occasionally some 16 in. or more in length from the lower part of the neck, and seems to be connected with the respiratory and not, as commonly believed, with the digestive system. In many parts of India L. dubius, the largest of these birds, the hargila as Hindus call it, is a most efficient scavenger, sailing aloft at a vast height and descending on the discovery of offal, though frogs and fishes also form part of its diet. It familiarly enters the large towns, in many of which an account of its services it is strictly protected from injury, and, having satisfied its appetite, seeks the repose it has earned, sitting with its feet extended in front in a most grotesque attitude. A second and smaller species, L. javanicus, has a more southern and eastern range; while a third, L. crumenifer, of African origin, and often known as the marabou-stork, gives its name to the beautifully soft feathers so called, which are the under-tail-coverts; the “marabout” feathers of the plume-trade are mostly supplied by other birds, the term being apparently applied to any downy feathers.

(A. N.)

Jabiru.

JABLOCHKOV, PAUL (1847-1894), Russian electrical engineer and inventor, was born at Serdobsk, in the government of Saratov, on the 14th of September 1847, and educated at St Petersburg. In 1871 he was appointed director of the telegraph lines between Moscow and Kursk, but in 1875 he resigned his position in order to devote himself to his researches on electric lighting by arc lamps, which he had already taken up. In 1876 he settled in Paris, and towards the end of the year brought out his famous “candles,” known by his name, which consisted of two carbon parallel rods, separated by a non-conducting partition; alternating currents were employed, and the candle was operated by a high-resistance carbon match connecting the tips of the rods, a true arc forming between the parallel carbons when this burnt off, and the separators volatilizing as the carbons burnt away. For a few years his system of electric lighting was widely adopted, but it was gradually superseded (see [Lighting]: Electric) and is no longer in use. Jablochkov made various other electrical inventions, but he died in poverty, having returned to Russia on the 19th of March 1894.

JABLONSKI, DANIEL ERNST (1660-1741), German theologian, was born at Nassenhuben, near Danzig, on the 20th of November 1660. His father was a minister of the Moravian Church, who had taken the name of Peter Figulus on his baptism; the son, however, preferred the Bohemian family name of Jablonski. His maternal grandfather, Johann Amos Comenius (d. 1670), was a bishop of the Moravian Church. Having studied at Frankfort-on-the-Oder and at Oxford, Jablonski entered upon his career as a preacher at Magdeburg in 1683, and then from 1686 to 1691 he was the head of the Moravian college at Lissa, a position which had been filled by his grandfather. Still retaining his connexion with the Moravians, he was appointed court preacher at Königsberg in 1691 by the elector of Brandenburg, Frederick III., and here, entering upon a career of great activity, he soon became a person of influence in court circles. In 1693 he was transferred to Berlin as court preacher, and in 1699 he was consecrated a bishop of the Moravian Church. At Berlin Jablonski worked hard to bring about a union between the followers of Luther and those of Calvin; the courts of Berlin, Hanover, Brunswick and Gotha were interested in his scheme, and his principal helper was the philosopher Leibnitz. His idea appears to have been to form a general union between the German, the English and the Swiss Protestants, and thus to establish una eademque sancta catholica et apostolica eademque evangelica et reformata ecclesia. For some years negotiations were carried on with a view to attaining this end, but eventually it was found impossible to surmount the many difficulties in the way; Jablonski and Leibnitz, however, did not cease to believe in the possibility of accomplishing their purpose. Jablonski’s next plan was to reform the Church of Prussia by introducing into it the episcopate, and also the liturgy of the English Church, but here again he was unsuccessful. As a scholar Jablonski brought out a Hebrew edition of the Old Testament, and translated Bentley’s A Confutation of Atheism into Latin (1696). He had some share in founding the Berlin Academy of Sciences, of which he was president in 1733, and he received a degree from the university of Oxford. He died on the 25th of May 1741.