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 an extinct volcano, 12 m. from the city, or from Mont Cimini, still farther to the north. Several papers by him, on mineralogical subjects, appeared in the Biblioteca Italiana from 1816 to 1823. In the latter year Brocchi sailed for Egypt, in order to explore the geology of that country and report on its mineral resources. Every facility was granted by Mehemet Ali, who in 1823 appointed him one of a commission to examine the district of Sennaar; but Brocchi, unfortunately for science, fell a victim to the climate, and died at Khartum on the 25th of September 1826.

BROCHANT DE VILLIERS, ANDRÉ JEAN FRANÇOIS MARIE (1772–1840), French mineralogist and geologist, was born at Villiers, near Nantes, on the 6th of August 1772. After studying at the École Polytechnique, he was in 1794 the first pupil admitted to the École des Mines. In 1804 he was appointed professor of geology and mineralogy in the École des Mines, which had been temporarily transferred to Pezay in Savoy, and he returned with the school to Paris in 1815. Later on he became inspector general of mines and a member of the Academy of Sciences. He investigated the transition strata of the Tarantaise, wrote on the position of the granite rocks of Mont Blanc, and on the lead minerals of Derbyshire and Cumberland. He was charged with the superintendence of the construction of the geological map of France, undertaken by his pupils Dufrénoy and Elie de Beaumont. He died in Paris on the 16th of May 1840. His publications include Traité élémentaire de minéralogie (2 vols., 1801–1802; 2nd ed., 1808), and Traité abrégé de cristallographie (Paris, 1818).

BROCHANTITE, a mineral species consisting of a basic copper sulphate Cu4(OH)6SO4, crystallizing in the orthorhombic system. The crystals are usually small and are prismatic or acicular in habit; they have a perfect cleavage parallel to the face lettered a in the adjoining figure. They are transparent to translucent, with a vitreous lustre, and are of an emerald-green to blackish-green colour. Specific gravity 3.907; hardness 3–4. The mineral was first found associated with malachite and native copper in the copper mines of the Urals, and was named by A. Lévy in 1824 after A. J. M. Brochant de Villiers. Several varieties, differing somewhat in crystalline form, have been distinguished, some of them having originally been described as distinct species, but afterwards proved to be essentially identical with brochantite; these are königine from the Urals, brongniartine from Mexico, krisuvigite from Iceland, and warringtonite from Cornwall. Of other localities, mention may be made of Roughten Gill, Caldbeck Fells, Cumberland, where small brilliant crystals are associated with malachite and chrysocolla in a quartzose rock; Rézbánya in the Bihar Mountains, Hungary; Atacama in Chile, with atacamite, which closely resembles brochantite in general appearance; the Tintic district in Utah. A microscopical examination of the green copper ores of secondary origin in the Clifton and Morenci district of Arizona proves brochantite to be of extremely common occurrence mostly intergrown with malachite which effectually masks its presence: it is not unlikely that the malachite of other localities will on examination be found to be intergrown with brochantite.

Mention may be here made of another orthorhombic basic copper sulphate not unlike brochantite in general characters, but differing from it in containing water of crystallization and in its fine blue colour; this is the Cornish mineral langite, which has the composition CuSO4·3Cu(OH)2+H2O.

BROCK, SIR ISAAC (1769–1812), British soldier and administrator, was born at St Peter Port, Guernsey, on the 6th of October 1769. Joining the army at the age of fifteen as an ensign of the 8th regiment, he became a lieutenant-colonel in 1797, after less than thirteen years’ service. He commanded the 49th regiment in the expedition to North Holland in 1799, was wounded at the battle of Egmont-op-Zee, and subsequently served on board the British fleet at the battle of Copenhagen. From 1802 to 1805 he was with his regiment in Canada, returning thither in 1806 in view of the imminence of war between Great Britain and the United States. From September 1806 till August 1810 he was in charge of the garrison at Quebec; in the latter year he assumed the command of the troops in Upper Canada, and soon afterwards took over the civil administration of that province as provisional lieutenant-governor. On the outbreak of the war of 1812 Brock had to defend Upper Canada against invasion by the United States. In the face of many difficulties and not a little disaffection, he organized the militia of the province, drove back the invaders, and on the 16th of August 1812, with about 730 men and 600 Indians commanded by their chief Tecumseh, compelled the American force of 2500 men under General William Hull (1753–1825) to surrender at Detroit, an achievement which gained him a knighthood of the Bath and the popular title of “the hero of Upper Canada” From Detroit he hurried to the Niagara frontier, but on the 13th of October in the same year was killed at the battle of Queenston Heights. The House of Commons voted a public monument to his memory, which was erected in Saint Paul’s cathedral, London. On the 13th of October 1824, the twelfth anniversary of his death, his remains were removed from the bastions of Fort George, where they had been originally interred, and placed beneath a monument on Queenston Heights, erected by the provincial legislature. This was blown up by a fanatic in 1840, but as the result of a mass-meeting of over 8000 citizens held on the spot, a new and more stately monument was erected.

BROCK, THOMAS (1847–), English sculptor, was the chief pupil of Foley, and later became influenced by the new romantic movement. His group “The Moment of Peril” was followed by “The Genius of Poetry,” “Eve,” and other ideal works that mark his development. His busts, such as those of Lord Leighton and Queen Victoria; his statues, such as “Sir Richard Owen” and “Dr Philpott, bishop of Worcester”; his sepulchral monuments, such as that to Lord Leighton in St Paul’s cathedral, a work of singular significance, refinement and beauty; and his memorial statues of Queen Victoria, at Hove and elsewhere, are examples of his power as a portraitist, sympathetic in feeling, sound and restrained in execution, and dignified and decorative in arrangement. The colossal equestrian statue of “Edward the Black Prince” was set up in the City Square in Leeds in 1901, the year in which the sculptor was awarded the commission to execute the vast Imperial Memorial to Queen Victoria in front of Buckingham Palace. Brock was elected an associate of the Royal Academy in 1883 and full member in 1891.

BROCKEN, a mountain of Germany, in Prussian Saxony, the highest point (3733 ft.) of the Harz. It is a huge, bare, granite-strewn, dome-shaped mass and, owing to its being the greatest elevation in north Germany, commands magnificent views in all directions. From it Magdeburg and the Elbe, the towers of Leipzig and the Thuringian forest are distinctly visible in clear weather. Access to the summit is attained by a mountain railway (12 m.) from Dreiannen-Hohne, a station on the normal gauge line Wernigerode-Nordhausen, and by two carriage roads from the Bodetal and Ilsenburg respectively. In the folklore of north Germany the Brocken holds an important place, and to it cling many legends. Long after Christianity had penetrated to these regions, the Brocken remained a place of heathen worship. Annually, on Walpurgis night (1st of May), curious rites were here enacted, which, condemned by the priests of the Christian church, led to the belief that the devil and witches here held their orgies. Even to this day, this superstition possesses the minds of many country people around, who believe the mountain to be haunted on this night. In literature