by evaporating a solution of the hydroxide in nitric acid. Aluminium phosphates may be prepared by precipitating a soluble aluminium salt with sodium phosphate. Wavellite Al8(PO4)3(OH)15·9H2O, is a naturally occurring basic phosphate, while the gem-stone turquoise (q.v.) is Al(PO4) (OH)3·H2O, coloured by traces of copper. Aluminium silicates are widely diffused in the mineral kingdom, being present in the commonest rock-forming minerals (felspars, &c.), and in the gem-stones, topaz, beryl, garnet, &c. It also constitutes with sodium silicate the mineral lapis-lazuli and the pigment ultramarine (q.v.). Forming the basis of all clays, aluminium silicates play a prominent part in the manufacture of pottery and porcelain.
Bibliography.—The metallurgy and uses of aluminium are treated in detail in P. Moissonnier, L’Aluminium (Paris, 1903); in J. W. Richards, Aluminium (1896); and in A. Minet, Production of Aluminium, Eng. trans. by L. Waldo (1905); reference may also be made to treatises on general metallurgy, e.g. C. Schnabel, Handbook of Metallurgy, vol. ii. (1907). For the chemistry see Roscoe and Schlorlemmer, Treatise on Inorganic Chemistry, vol. ii. (1908); H. Moissan, Traité de chimie minérale; Abegg, Handbuch der anorganischen Chemie; and O. Dammer, Handbuch der anorganischen Chemie. Aluminium alloys have been studied in detail by Guillet.
ALUNITE, or Alumstone, a mineral first observed in the 15th century at Tolfa, near Rome, where it is mined for the manufacture of alum. Extensive deposits are also worked in Tuscany and Hungary, and at Bulladelah in New South Wales. By repeatedly roasting and lixiviating the mineral, alum is obtained in solution, and this is crystallized out by evaporation.
Alunite occurs as seams in trachytic and allied volcanic rocks, having been formed by the action of sulphureous vapours on these rocks. The white, finely granular masses somewhat resemble limestone in appearance, and the more compact kinds from Hungary are so hard and tough that they are used for millstones. Distinct crystals of alunite are rarely met with in cavities in the massive material; these are rhombohedra with interfacial angles of 90° 50′, so that they resemble cubes in appearance. Minute glistening crystals have also been found loose in cavities in altered rhyolite. The hardness is 4 and the specific gravity 2·6. The mineral is a hydrated basic aluminium and potassium sulphate, KAl3(SO4)2(OH)6. It is insoluble in water, but soluble in sulphuric acid. First called aluminilite by J. C. Delamétherie in 1797, this name was contracted by F. S. Beudant in 1824 to alunite. (L. J. S.)
ALUR (Lur, Luri, Lurem), a Negro people of the Nile valley, living on the north-west coast of Albert Nyanza. They are akin to the Acholi (q.v.), speaking practically the same language.
ALURE (O. Fr., from aller, to walk), an architectural term for an alley, passage, the water-way or flat gutter behind a parapet, the galleries of a clerestory, sometimes even the aisle itself of a church. The term is sometimes written valure or valoring.
ALVA, or Alba, FERNANDO ALVAREZ DE TOLEDO, Duke of, (1508–1583), Spanish soldier, descended from one of the most illustrious (families in Spain, was born in 1508. His grandfather, Ferdinand of Toledo, educated him in military science and politics; and he was engaged with distinction at the battle of Pavia while still a youth. Selected for a military command by Charles V., he took part in the siege of Tunis (1535), and successfully defended Perpignan against the dauphin of France. He was present at the battle of Mühlberg (1547), and the victory gained there over John of Saxony was due mainly to his exertions. He took part in the subsequent siege of Wittenberg, and presided at the court-martial which tried the elector and condemned him to death. In 1552 Alva was intrusted with the command of the army intended to invade France, and was engaged for several months in an unsuccessful siege of Metz. In consequence of the success of the French arms in Piedmont, he was made commander-in-chief of all the emperor’s forces in Italy, and at the same time invested with unlimited power. Success did not, however, attend his first attempts, and after several unfortunate attacks he was obliged to retire into winter quarters. After the abdication of Charles he was continued in the command by Philip II., who, however, restrained him from extreme measures. Alva had subdued the whole Campagna and was at the gates of Rome, when he was compelled by Philip’s orders to negotiate a peace. One of its terms was that the duke of Alva should in person ask forgiveness of the haughty pontiff whom he had conquered. Proud as the duke was by nature, and accustomed to treat with persons of the highest dignity, he confessed his voice failed him at the interview and his presence of mind forsook him. Not long after this (1559) he was sent at the head of a splendid embassy to Paris to espouse, in the name of his master, Elizabeth, daughter of Henry, king of France. In 1567, Philip, who was a bigoted Catholic, sent Alva into the Netherlands at the head of an army of 10,000 men, with unlimited powers for the extirpation of heretics. When he arrived he soon showed how much he merited the confidence which his master reposed in him, and instantly erected a tribunal which soon became known to its victims as the “Court of Blood,” to try all persons who had been engaged in the late commotions which the civil and religious tyranny of Philip had excited. He imprisoned the counts Egmont and Horn, the two popular leaders of the Protestants, brought them to an unjust trial and condemned them to death. In a short time he totally annihilated every privilege of the people, and with unrelenting cruelty put multitudes of them to death. The executioner was employed in removing all those friends of freedom whom the sword had spared. In most of the considerable towns Alva built citadels. In the city of Antwerp he erected a statue of himself, which was a monument no less of his vanity than of his tyranny: he was figured trampling on the necks of two smaller statues, representing the two estates of the Low Countries. His attempt to raise money by imposing the Spanish alcabala, a tax of 5% on all sales, aroused the opposition of the Catholic Netherlands themselves. The exiles from the Low Countries, encouraged by the general resistance to his government, fitted out a fleet of privateers, and after strengthening themselves by successful depredations, ventured upon the bold exploit of seizing the town of Brielle. Thus Alva by his cruelty became the unwitting instrument of the future independence of the seven Dutch provinces. The fleet of the exiles, having met the Spanish fleet, totally defeated it, and reduced North Holland and Mons. Many cities hastened to throw off the yoke; while the states-general, assembling at Dordrecht, openly declared against Alva’s government, and marshalled under the banners of the prince of Orange. Alva’s preparations to oppose the gathering storm were made with his usual vigour, and he succeeded in recovering Mons, Mechlin and Zutphen, under the conduct of his son Frederick. With the exception of Zealand and Holland, he regained all the provinces; and at last his son stormed Naarden, and massacring its inhabitants, proceeded to invest the city of Haarlem, which, after standing an obstinate siege, was taken and pillaged. Their next attack was upon Alkmaar; but the spirit of desperate resistance was raised to such a height in the breasts of the Hollanders that the Spanish veterans were repulsed with great loss and Frederick constrained reluctantly to retire. Alva’s feeble state of health and continued disasters induced him to solicit his recall from the government of the Low Countries; a measure which, in all probability, was not displeasing to Philip, who was now resolved to make trial of a milder administration. In December 1573 the much-oppressed country was relieved from the presence of the duke of Alva, who, returning home accompanied by his son, made the infamous boast that during the course of six years, besides the multitudes destroyed in battle and massacred after victory, he had consigned 18,000 persons to the executioner.
On his return he was treated for some time with great distinction by Philip. A tardy and imperfect justice, however, overtook him, when he was banished from court and confined in the castle of Uzeda for complicity in certain disgraceful conduct of his son. Here he had remained two years, when the success of Don Antonio in assuming the crown of Portugal determined Philip to turn his eyes towards Alva as the person in whose fidelity and abilities he could most confide. A secretary was instantly
