Page:The New International Encyclopædia 1st ed. v. 12.djvu/887

* MANGAXORE. 793 MANGALORE, mfin'ga-lur', or MANGA- liUR, iiian'ga-loor'. The capital of the district of South Kanara, Madras, British India, 407 miles south-soutlieast of Bombay, on the Arabian Se;i (Map: India, B G). The residential section of the city is pleasantly situated on several hills which afford an extensive view of the sea and the thickly forested surrounding region. It has a German mission where instruction is given in the different crafts, and is the seat of a Gov- ernment college and the .Jesuit College of Saint Alojsius, both of which are connected with Madras University. A large trade is carried on in coffee, nuts, and pepper, and various grades of cloth are manufactured, ilangalore is renowned for the brave resistance its little garrison of- fered the armv of Tippu Sahil> in 17S2-SS3. Popu- lation, in 1891, 40.922; in 1001, 44,108. MAN'GAN, James (known as James Clar- E^•CE .Ianuax) (1803-49). An Irish poet, born in Dublin, May 1, 1803. He served for ten years, first in a scrivener's and then in an attorney's office, and in spite of many hardships learned Latin, Spanish, French, Italian, and German. Subsequently he was employed in the library of Trinity College and in tlie office of the Irish ordnance survey. Weakened by dissipation, he died of cholera, June 20, 1849. Mangan holds the first rank among the Irish song writers of his day. Consult: Poems (incomplete), ed. by Mitchel (New York, 18.59) : and O'Donoghue, Life riiirl Wi-itiiifis (London, 1897). MAN'GANESE (Neo-Lat. manganesium, an arbitrary variant of magnesium, magnesium). A metallic" element first isolated by Gahn in 1774. It is generally accepted that Pliny was ac- quainted with pyrolusite, or manganese dioxide, and assuming it to be a variety of magnetic iron ore, which was called lapis magncsius, he called the manganese compound magnesia. Basil Valentine and later chemists regarded the com- pound as an ore of iron, and mentioned its use in glass-making under the name of lapis man- ganensis. That the compound really contains no iron was first shown by Pott in 1740, and later researches by Scheele and Bergman estab- lished the fact of its being a distinct chemical species. Tlie name magnesium, at first applied to its isolated metal, was changed to manganese by Buttmann in 1808. Manganese ores are found in many parts of the United States, notably in California, Colorado, Arkansas, Georgia, ilichigan. New Jersey, and Virginia, but the deposits have nowhere proved to be sufficiently extensive to supply the domestic requirements. One of the largest mines, situated near Crimora, Augusta County, Va., has been operated for nearly fifty years and is still pro- ductive. The ore occurs in pockets in a thick bed of clay, and is mined by the hydraulic process. There are similar occurrences of manganese in Bartow County. Ga.. and at other localities along the Appalachian Mountain system. Colo- rado is an important producer of low-grade man- ganese ores which carry a large percentage of iron. The total output" of the L^nited States in 1901 was 11,995 long tons, valued at .$116,722. In addition there was a production of .574,489 long tons of manganiferous iron ore. Enormous deposits of manganese are found in Southern Russia and in the State of Minas Geraes. Brazil. Small quantities of manganese are also present MANGANESE. in certain mineral waters, in many plants, espe- cially the cereals and vegetables used as human food, and it is a constituent of the sun's atmos- phere. The metal itself is readily obtained by reducing the oxide with carbon, or by heating manganese chloride with metallic sodium. Man- ganese (symbol Mn; atomic weight, 55) is a very hard, grayish-white metal with a reddish lustre. It takes a high polish and is not mal- leable. Its specific gravity varies between C.89 and 7.99. Its melting point is about 1897° C. (about 3447° F.). The metal itself has no uses, but forms valuable alloys with aluminum, copper, iron, and mercury. Those with iron, containing from 8 to 80 per cent, of manganese, are used in the manufacture of steel under the names of Spiegeleisen and ferromanganese. The presence of manganese in iron and steel is said greatly to increase their elasticity and hardness, and even one per cent, of manganese will render cast steel more tenacious. With oxygen manganese forms several oxides, including a monoxide (MnO), a sesquioxide (MnA). a dioxide (MnOj), a trioxide (MnO,), and a heptoxide (Mn,Oi). Besides these, a number of intermediate oxides are believed to exist. The most important of the oxides, is the dioxide or peroxide, which occurs native as pyrolusite and is the 'black manganese' of com- merce, a substance largely used in the manufac- ture of chlorine (q.v. ), and in the preparation of oxygen (q.v.), as well as in the making of black enamel for pottery, and in the manufac- ture of glass. The sesquioxide of manganese, or manganic oxide, occurs in nature as the mineral braunite, or, in a hydrated form (iln^jOj), as the mineral manganite. The monoxide of man- ganese, or manganous oxide, occurs in nature as the mineral nianganosite, or, in a hydratetl form (MnH.O™). as the mineral pyrochroite. It is the manganese salts corresponding to this oxide that are found, always together with iron salts, in mineral water and in the organisms of animals and plants. For the trioxide of manganese, see Manganic and Permanganic Acids. While salts have been obtained corresponding to several of the oxides of manganese, many of those salts are unstable and hardly deserve men- tion. Manganous chloride, ^InCL, is obtained as a by-product in the manufacture of chlorine by the "action of hydrochloric acid on manganese dioxide. To isolate the chloride from the solu- tion thus obtained, the latter is evaporated until it contains no more free hydrochloric acid, then part of it (about one-quarter) is precipitated with an excess of sodium carbonate, the precipi- tate (manganous carbonate) is washed with water and added to the rest of the solution, and the latter is kept boiling for some time. On cooling, the solution is filtered, and the filtrate is allowed to evaporate, hydrated manganese chlo- ride seiiarating out in the crystalline state. When freed from its water of crystallization, man- ganous chloride forms pink crystals that may be distilled in a current of chlorine. The chloride is used for the production of a brown color in calico printing and is employed, in small quan- tities, in certain operations of analytical chem- istry. Manganous sulphate. MnSOj. or rather the hydrated form, JlnSO, -1- 4H,0. may be obtained by the action of sulphuric acid on manganese dioxide. It is used in dyeing and is official in the pharmacoposia. For other important com-