Page:Collier's New Encyclopedia v. 01.djvu/176

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ALTSHELER
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ALUMINUM

mous for its castle, where, on Sept, 24, 1706, Charles XII. of Sweden signed the peace with August II., King of Poland. By this treaty, August II. agreed to vacate the Polish throne, not to enter any alliances against Sweden, especially any with the Czar, and to give up the Livlander Patkul, to grant the Swedish winter quarters in Saxony, and pledge himself not to persecute the Evangelical Church. This treaty did not go into effect until Nov. 26, because August felt that, by reason of a previous peace, he was obliged to support the Russians in their attack upon the Swedish General Mardefeld. After the defeat of Charles XII. at Poltava, August II., on Aug. 8, 1709, declared the Peace of Altranstädt to be void under the pretext that his representatives had exceeded their authority. Through the Treaty of Altranstädt of Aug. 30, 1707, Charles XII. obtained from the Emperor Joseph I. religious liberty and toleration of the Protestants of Silesia.

ALTSHELER, JOSEPH ALEXANDER, an American writer, born in Three Springs, Ky., in 1862. He studied at Liberty College, Ky., and Vanderbilt University. After newspaper work on the staff of the Louisville "Courier-Journal," he joined the staff of the New York "World" in 1892, where he remained until his death. He was the author of many novels and stories. Among these are "A Soldier of Manhattan" (1897); "The Horsemen of the Plains" (1901); "The Border Watch" (1912); "The Forest of Swords" (1915); "The Hunters of the Hills" (1916); "The Rulers of the Lakes" (1917). He died in 1919.

ALUM, the name given to double salts of sulphate of aluminum with sulphates of potassium, sodium, ammonium, or of other monatomic metals, as silver, thallium cæsium, rubidium. They crystallize in octohedra. Potash alum, Al2K2(SO4)4+24H2O, is prepared by the decomposition of a shale containing iron pyrites. Alum has a sweet astringent taste, reddens litmus paper, and dissolves in its own weight of boiling water. Sodium alum is very soluble. Ammonia alum is often prepared by adding the ammonia liquor of gas-works instead of potash. Alum is used in dyeing and in preparing skins, etc. Alum is used in medicine as an astringent in doses of 10 to 20 grains. Ammonia alum, a mineral, called also tschermigite. Feather alum, a mineral, called also halotrichite. Iron alum, a mineral, called also halotrichite. Magnesia alum, a mineral, called also pickeringite. Manganese alum, a mineral, called also apjohnite. Native alum, a mineral, called also kalinite. Soda alum, a mineral, called also mendozite. Saccharine alum, a composition made of common alum, with rose-water and the white of eggs boiled together to the consistence of a paste, and thus capable of being molded at pleasure. As it cools it grows as hard as an ordinary stone.

ALUMINO-THERMICS, that branch of metallurgy which has to do with the utilization of heat developed by burning metallic aluminum. Its chief uses are to separate oxides, chlorides, and sulphides from other metals; to increase the temperature of other metals so that they may be welded by force of pressure; to obtain molten iron to be used in preparing broken iron and steel. It was first employed by Frederick Wöhler, the discoverer of aluminum. The process was perfected by other German scientists, especially by Hans Goldschmidt. He was the first to succeed in employing it on a large scale. It is now used widely in mechanical engineering.

ALUMINUM, a metal discovered by Wöhler in 1827, as a gray powder, but in 1847 in the form of small, glittering metallic globules. In 1854, H. St. Clair Deville isolated aluminum into a state of almost perfect purity. He found that aluminum could be prepared in a compact form at a comparatively small expense. It is a white metal, somewhat resembling silver, but possessing a bluish hue, which reminds one of zinc. Exposed to dry or moist air, it is unalterable, and does not oxidize or tarnish like most common metals. Salt water affects it less than it does silver, tin, or copper. Neither cold nor hot water has any action upon it. When cast into molds, it is a soft metal like pure silver, and has a density of 2.56; but when hammered or rolled, it becomes as hard as iron, and its density increases to 2.67. It is, therefore, a very light metal, being lighter than glass, and only one-fourth as heavy as silver.

Aluminum has, in recent years, come into common use for culinary utensils and other domestic uses, and in manufactured articles where strength and lightness are requisites. It is especially valuable in the making of aeroplanes and automobiles. Not being acted upon by organic secretions, it is used for optical, surgical, and chemical instruments and apparatus. Aluminum leaf and wire may be employed with great advantage in place of silver leaf for decoration, or silver wire for embroidery. Of late it has come to be used in shipbuilding, especially for torpedo-boats. And as it is especially suitable