Page:Encyclopædia Britannica, Ninth Edition, v. 10.djvu/697

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1em  GLATZ (Slav. Kiwis/lo), a fortiﬁed towu of Prussian Silesia, chief town of a countship in the government- dis- trict of Breslau, is situated 50 miles S.S.\V. of the town of that name. It stands in a narrow valley on the left bank of the Neisse, not far from the Austrian frontier. ~It is strongly walled, and is further defended by an old castle built on ahigh hill on one side of the town, and by a regular modern fortress erected on a hill on the opposite side. Before the town on both banks of the river there is also a strongly fortiﬁed camp, by which its bombardment from the neighbouring heights may be hindered, and which affords accommodation for as many as 10,000 men. The town is the seat of a circle court and of an agricultural union, and possesses one Lutheran and three Catholic churches, one of which is very old and contains several monuments of Silesian dukes. Among the otherrbnildings the principal are the nunncry, the royal Catholic gymnasium, the asylum for destitute children, and the military hospital. The in— dustries include the manufacture of spirits, linen, damask, broad cloth, hosiery, beads, and leather. Gla'tz existed as early as the. In the Thirty Years’ War it was several times besieged and taken. It surrendered to Frederick the Great in 1742, was retakcn by the Austrians in 1760, and was restored to Prussia at the peace of 1763. The population in 1875 was 12,553.  GLAUBER, (1603–1668), alchemist and medicinal chemist, was born at Carlstadt in 1603, and died at Amsterdam in 1668. There is no authentic record of details Concerning his life; his name has been somewhat marred by tradition, but it is not unreasonable to suppose that this originated Willi persons who did not heed the varning given by the chemist himself, in one of his more important memoirs, “let no one rasth judge of this work, until he be thoroughly informed concerning the same.” Commencing his career as a chemist at the time he did, it was not unnatural that he imbibed the notion, prevalent among his contemporaries, of the existence of “ alkaheat,” a liquid which was to be universal in its uses as asolvent and a medicine, and of the “ philosophcr’s stone.” But whatever the motive which induced him to toil in his laboratory, it is certain that he, by ascertaining the preparation of many valuable medicines, contributed largely to pharmacy. He undoubtedly was the ﬁrst, in 1618, to procure hydrochloric acid by the action of oil of vitriol on common salt, and also in all probability to obtain nitric acid by means of oil of vitriol and nitre. Sodium sulphate, discovered by him, and commonly therefore termed Glaubcr’s salt (see below), he obtained by the action of oil of vitriol on salt.

1em  GLAUBER’S SALT, the popular term for neutral sul- phate of sodium (Na2804), discovered by the chemist whose name it bears, and formerly known as “ sal mirabile Glauberi.” It occurs in nature in combination with calcium sulphate as the mineral glauberite, and uncombined in right rliombic prisms, as thenardite, being found in this form in Bolivia and Peru, and near Madrid ; or in monoclinic prisms, with ten molecules of water as glaubei‘ite or ordinary Glauber’s salt, in Austria, Hungary, Italy, and in great quantity as a deposit from the hot springs of Carlsbad. .It is also a constituent of sea—water, and the chief active prin- ciple of medicinal waters, and occurs in minute traces in the blood. It has a bitter but not acrid taste. It is somewhat anomalous in its solubility, the maximum occurring at about 34° 0. According to Lowe], it exists in aqueous solution at temperatures as high as 34° C. as a decahydrate, but above that temperature as an anhydride, the solubility of the former increasing, and of the latter decreasing, with a a rise of temperature (see, ). Under ordinary circumstances it crystallizes from solution in large colourless prisms ; these, when exposed to the air or heated, eﬂloresce, giving a white powder, which melts at a strong red heat, and on cooling forms a transparent mass. The salt has also been the subject of some interesting ex- periments made by Guthrie, who at- — 7° C'. procured it in combination with 166 molecules of water. From his investigation of this and other substances, he concluded that the solution of a solid body consists in the formation of a liquid hydrate which ultimately diffuses iiito the rest of the solvent. In the manufacture of sodium carbonate from salt and sulphuric acid, this sulphate is prepared in large quantities. In medicine it is employed as a purgative.