GYPSIES. 416 GYPSUM. wholly by ear and most accurate in technique. In their relations with (jujc (gajos) or non-gyp- sies, they are genial, friendly, ready to do busi- ness; but in matters pertaining to themselves, their life, and language, often inclined to be reti- cent. When, however, they have confidence in a r.on-g3'p.sy friend, their sincerity and fidelity know no bounds. jhicli has been written about the gypsies in a spirit of hostile prejudice or commiseration: it must be admitted, none the less, that those who have gained their confidence and learned (heir ways and their point of view, have ahvay.-i spoken well of the roniani. BlBLlOGK,piiY. Baudrimont, Vocuhulaire de la langue des BoJieiniciis habitant les pays hasques frantais (Bordeaux, 1862); Bischott', Deutsch-Ziiieunerischcti Worterbiich ( Ilmenau, 1827) ; Borrow, T)w Ziiwali, or an Account of the Gypsies of fipain (London, 1801); id.. Ro- mano Lavo-Lil, Word-hook of the Romany [Eng- lish dialect] (ibid., 1874); Colocci, Gli Zingari (Turin, 1889) ; Dirks, (Icschiedkundigc Ondcr- zoekingen aanga/itide hct Verblijf der Beidens of Eyyptiers in de noordclijke yederlanden (Utrecht, 18.50) ; Drylund, Tatere og Xatimands- folk i Danmark (Copenhagen, 1872) ; De Goeje, Bijdrayc lot de Ocschiedenis der Zigeuners (Amsterdam, 1875) ; Grellmann, Die Zigcuner (Dessau, 1783) ; Graffunder, Ueher die Sprache der Zigeniicr (Erfurt, 18.3.5) : Groome. In (lipsy- tents (Edinburgh. 1880): Jesina, Romani-Oih Oder die Zigeuner-Hprache (Leipzig, 1880) ; Arch- duke .Joseph of Austria-Hungary, Czigany Kyelc- tan (Budapest, 1888) ; Kalina, La langiie des Tziganes slovaques (Posen, 1882); Leland, The English Gypsies and Their Lanquaqe (London, 1874): id.. The Gypsies (ibid., "l88'2) ; Liebieh, Die Zigcuner in ihreni Wesen und in ihrer Sprache (Leipzig. 1803) ; Liszt, Des Boh&miens et dc Icur mtisiqiie en Uongrie (Leipzig, 1881) ; Miklosich, Veher die Mundartcn vnd die Wan- derungen der Zigcuner Europas (Vienna, 1872- 80) : Paspati. Etudes sur Ics Tchinghianes. on Bohemiens dc VEinpirc Ottoman (C'nnstantinople. 1870) ; Pott, Die Zigcuner in Enropa und Asicn (Halle, 1844-45) ; Simson, A History of the Gypsies (New York, 1878) ; Smart and Crofton, The Dialect of the English Gypsies (London, 1875) ; von Sowa, Die Mundart der sloimkisehen Zigeuner (Gottingen, 1887): Sundt, Beretning om Fante-ellcr Landstrygerfolket i Norge (Chris- tiania, 1853) : Von Wlislocki, Tom wandcrnden Zigcunervoike (KAmhurf:. 1890) : id.. Volksglanbe vnd reUgio!<er Brniich der Zigcuner (Miinster, 1891) ; id.. Aiis dcm inneren Leben der Zigcuner (Berlin. 1892). GYP'STJM (Lat., from Gk.7<!fos,.<7.!/psos, chalk, probably of Semitic origin, cf. Ar. jibs, gypsum, from jabusa. to walk haughtily ). A hydrated calcium sulphate comjiosed of lime 32.50 per cent., sulphuric acid 40.51 per cent., and water 20.93 per cent. It crystallizes in the monoclinic system, has a hardness of 2, and a specific grav- ity of 2.31. The crystals are found in beds of massive g^•psum. in veins, or scattered through beds of marl and clay: When transparent they are called selenite. Alaliaster is a massive white, opaque variety of gvpsum, and satin spar is a fibrous variety. A loose, earthy gypsum found in Kansas passes under the name of g-psite. The color of gv'psum mav be white, red. green, blue, gray, or brown. When gypsum is heated to a temperature of 120° to 130° C. about 14 per cent, of the water of crystallization is driven ofl' and llie i)roduct left has the eumposiliiin of (CaSOj, H.O; the mineral is tlicn easily reduced to a 2)owder, in which state it is known as plaster of Paris. Plaster of Paris when mixed again with water forms a hard mass, and this setting is due to the reci'ystallization of the calcium sulphate. If the gA'psum is underburned its setting power is injured, and tlic same ellect may be produced by over-caleining, for the reason that the latter so conuninutes the g^'psum i)artieles that none are left to serve as nuclei around which the crys- tals can begin to form when the setting takes place. Fine grinding docs not liave any ett'ect on the setting power. Underburned gj'psum is tough and soluble in cold water to the extent of about one part in 461, and it is scarcely more soluble in acids or warm water. Origin and Distkiiution. The origin of gyp- sum may be'explained in several ways. Some beds of the material have been formed Ijy the changes of existing deposits by chemical reactions, a.s wlien sulphuric acid liberated > the decomposi- tion of pyrite attacks carbonate of lime, and con- verts it into calcium sulphate. In such cases there may be a gradual passage from the lime- stone into the gypsum rock. Gypsum may also be formed by the evaporation and concentration of sea-water ; and in fact most deposits of gypsum found in the world are considered to have been derived in this manner, although the gj'psum is not deposited until about 80 [ler cent, of the salt ater has been evaporated. Gypsum is widely distributed geologically, being found in various formations, ranging from the Sihirian up to the Tertiary'. Extensive beds of g;'psum are found in the Silurian formation in New York, the Carboniferous of Ohio and ilichigan, and the Cretaceous of Iowa and Kansas. Deposits also occur in Arizona, California, Colorado, Wyoming, Indian Territory, Texas, Utah, and Virginia. In foreign countries it is found in Canada, Ger- many, Norway, France, Austria, Bohemia, Italy, Eg)pt. Aiabia, and Persia. It is mined some- tinu's by quarry methods and sometimes b}' un- derground ^^orkincs. U.SES. The use of gypsum seems to have been known at a very early period, for the Greeks were familiar with it, as shown by the writings of Theophrastus and Pliny. Tlie commercial value of the mineral gypsum depends largely on the color, the whiter grades being calcined and used for plaster. This calcining is commonly done in large kettles, the material having been previouslj' ground in crushers and mills. The kettles are iisually about six feet deep and eight feet in diameter, and are filled to a depth of five feet. They are heated from below, and the g^'psum is constantly stirred during the calcining process by revoh'ing arms. Aside from its uses for ordinary plastering, it is also extensively em- ])loyed in the manufacture of ornamental stucco work, as a filler in paper, in making imitations of marble, and sometimes for caleimining. Where a slow set is desired a retarder is sometimes used, such as glue, hair, lime, etc. Raw gypsum is also ised as a basis for paints, the pigments being mixed with it. The impure crude gypsum finds application only for fertilizing purposes, and is extensively employed in both England and America for increasing the fertilit.y of soils.
