Altranstädt (a˙lt′-ra˙n-stet), a village of Saxony, where a treaty was concluded between Charles XII, King of Sweden, and Augustus, Elector of Saxony and King of Poland, 24th Sept., 1706, by which the latter resigned the crown of Poland.
Alt′ringham, or Altrincham, a town of England, in Cheshire, 8 miles south-west of Manchester, resorted to by invalids; large quantities of fruit and vegetables are raised; and there are several industrial works. Pop. 20,461. Also a parliamentary division of the county.
Al′truism, a term first employed by the French philosopher Comte, to signify devotion to others or to humanity: the opposite of selfishness or egoism. It was adopted by the English positivists and applied to sociological problems of the physical theory of organic evolution. Herbert Spencer gives considerable space to the discussion of altruism and egoism in his Data of Ethics.
Altstätten (a˙lt′stet-n), a town of Switzerland, canton St. Gall, in the valley of the Rhine, 10 miles south of the Lake of Constance, with manufactures of cotton and woollen goods. Pop. 8743.
Altwasser (a˙lt′va˙s-ėr), a town of Prussia, in Silesia, 35 miles south-west of Breslau; here are made porcelain, machinery, iron, yarn, mirrors, &c. Pop. 17,321.
Al′um, a well-known crystalline, astringent substance with a sweetish taste, a double sulphate of potassium and aluminium with water of crystallization; formula, K2SO4.Al2(SO4)3.24 H2O. It crystallizes in colourless regular octahedra. Its solution reddens vegetable blues. When heated, its water of crystallization is driven off, and it becomes light and spongy with slightly corrosive properties, and is used as a caustic under the name of burnt alum. Alum is prepared in Great Britain at Whitby from alum-slate—where it forms the cliffs for miles—and was once manufactured near Glasgow from bituminous alum-shale and slate-clay, obtained from old coal-pits. It is also prepared near Rome from alum-stone. Common alum is strictly potash alum; other two varieties are soda alum and ammonia alum, both similar in properties. Iron alum (pale mauve) and chrome alum (deep purple) are compounds containing iron and chromium in place of aluminium. Alum is employed to harden tallow, to remove grease from printers' cushions and blocks in calico manufactories, and in dyeing as a mordant. It is also largely used in the composition of crayons, in tannery, and in medicine (as an astringent and styptic). Wood and paper are dipped in a solution of alum to render them less combustible.
Alumbagh (a-lam-bäg′), a palace and connected buildings in Hindustan, about 4 miles south of Lucknow. On the outbreak of the Indian Mutiny it was occupied by the revolted sepoys, and converted into a fort. On the 23rd Sept., 1857, it was captured by the British, and during the following winter a British garrison, under Sir James Outram, held out there, though repeatedly attacked by overwhelming numbers of the rebels, till in March, 1858, it was finally relieved. Sir Henry Havelock was buried within the grounds.
Alu′mina (Al2O3), the single oxide of the metal aluminium. As found native it is called corundum, when crystallized ruby or sapphire, when amorphous emery. It is next to the diamond in hardness. In combination with silica it is one of the most widely distributed of substances, as it enters in large quantity into the composition of granite, traps, slates, schists, clays, loams, and other rocks. The porcelain clays and kaolins contain about half their weight of this earth, to which they owe their most valuable properties. It forms compounds with certain colouring matters, which causes it to be employed in the preparation of the colours called lakes in dyeing and calico-printing. It combines with the acids and forms numerous salts, the most important of which are the sulphate (see Alum) and acetate, the latter of extensive use as a mordant.
Alumin′ium (symbol Al, atomic weight 27.1), a metal discovered in 1827, but nowhere found native, although its oxide, alumina (which see), is abundantly distributed. The minerals bauxite and cryolite are sources of aluminium, but the chief source is the pure oxide, from which the metal is obtained by means of a strong electric current. It is a shining white metal, of a colour between that of silver and platinum, very light (specific gravity, 2.56 cast, 2.67 hammered), not liable to tarnish nor undergo oxidation in the air, very ductile and malleable, and remarkably sonorous. It forms several useful alloys with iron and copper; one of the latter (aluminium gold) much resembles gold, and is made into cheap trinkets. Another, known as aluminium bronze, possesses great hardness and tenacity. Spoons, tea and coffee pots, dish-covers, musical and mathematical instruments, trinkets, &c., are made of aluminium.