GLtfCKSTADT age of 64, ranks among the highest efforts of the composer ; with many, as before stated, it ranks the first. It is still, in a German trans- lation, one of the favorite pieces on the Berlin stage. It was the crowning triumph of Gluck's system of operatic writing, and ended the se- ries of works which gave direction to the ge- nius of Mehul and Cherubini in Paris, Mozart and Beethoven in Germany, in their works for the stage. Another piece brought by Gluck Paris at this time, the Echo et Narcisse, met dth no great success. He returned to Vienna, id in 1783 had an attack of apoplexy, which msed him to decline the text of Les Danaides, it him from Paris. To his dramatic compo- tions Gluck added only for the church a De Profundis, a psalm, Domine Dominus noster, and a part of the sacred cantata, finished by Salieri, Le jugement dernier. For months be- fore his decease, Gluck had been obliged to use the greatest precautions to prevent a return of apoplexy. One day he invited two old Paris- ian friends to dine with him. After the meal, coffee and spirits were placed upon the table, and Mme. Gluck went out to order the carriage for the daily drive prescribed by the physician. One of the friends excusing himself from emp- tying his glass, the host at last seized it, swal- lowed its contents, and laughingly told them not to let his wife know of it, as everything of the kind was forbidden to him. The coach being ready, Mme. Gluck invited the guests to amuse themselves in the garden for a short time. Gluck took leave of them at the coach door. Fifteen minutes afterward he had an- other stroke; the coachman hurried home ; his master had already lost all consciousness, and soon breathed his last. See Gluck et Piccine, by Gustave Desnoiresterres (Paris, 1872). GLliCKSTADT, a town of Prussia, in the prov- ince of Schleswig-Holstein, on the right bank of the Elbe, 27 m. N. W. of Altona ; pop. in 1871, 5,073. The inhabitants are chiefly en- gaged in commerce and the whale fishery. The town was fortified in 1620 by Christian IV. It was unsuccessfully attacked by Wal- lenstein in 1627, by Tilly in 1628, by Torsten- son in 1644, and yielded to the allie's in 1814. The fortifications were demolished in 1815, and it was declared a free town in 1830. It passed into the possession of Prussia in 1866. The town has a gymnasium, and is connect- ed by rail with Altona, Kiel, and Rendsburg. The royal line of the dukes of Holstein assumed from this town the name of Holstein-Gluck- stadt, while the ducal line bore the name of Holstein-Gottorp. GLUE (Lat. gluere, to draw together), an im- pure variety of gelatine, used in the arts for uniting substances through its adhesive quality. It is obtained much in the same manner from the same substances as gelatine, but usually from the more refuse portions, as damaged hides and other tissues undergoing putrefaction. Glue obtained from bones by the use of acids is preferred to that which is obtained by steam, GLUE 45 the latter being more soluble in cold water. The strongest glue is made from the parings of ox hides, which yield over 50 per cent. They are steeped for several days in milk of lime to remove the hair, blood, and other im- purities; then washed in cold water, drained on an inclined plane, and again washed. Ex- posure to the air converts the lime into car- bonate, so that in boiling the caustic action of the lime is prevented. The material is then enclosed in a coarse cloth and put into a cop- per boiler, which is two thirds filled with rain water, and the whole is boiled. The dissolved glue mingles with the water outside of the cloth, and when the liquid sets into a firm jelly on cooling it is run into a deep vessel or set- tling back and kept warm for impurities to sub- side. "Water is again added to the boiler, and the material in the cloth subjected to a second boiling, by which an inferior glue is obtained. The liquid in the settling back is drawn into coolers, where it solidifies, and is then cut into slices with a wire frame. The slices are laid upon netting in a drying room, in which there is a free circulation of air. The operation of drying is a critical one. Too much heat will cause liquefaction ; a fog may cause mouldiness, and frost will split the slices. Good glue is of a pale brown color, hard and brittle, and breaks with a glassy fracture. Its other chem- ical and physical properties are like those of gelatine. The quality of glue may be judged of by the quantity of water which the dry glue will absorb in 24 hours. The best glue kept immersed in water of the temperature of 60 F. has absorbed 12 times its weight. Oth- er qualities, it is said, take up a proportionally less quantity. Besides its use for cementing wood and hard substances, glue is employed in preparing the felt bodies of hats, and as an in- gredient in the composition of inking rollers, to give them flexibility. Several varieties of glue are employed in the arts, some of which may properly be noticed here, although they are not all preparations of gelatine. If glue is treated with a small proportion of nitric acid, it loses its property of gelatinizing when cold, though not that of causing substances to adhere to- gether. With acetic acid a similar effect is produced. What is called liquid glue is made by slowly adding nitric acid to the ordinary preparation of glue in the proportion of 10 oz. of strong acid to 2 Ibs. of dry glue dissolved in a quart of water. The product is a strong glue, which remains in a liquid state, and may be thus kept for years always ready for use. Marine glue is a preparation of caoutchouc dissolved in naphtha or oil of turpentine, with the addition of shell lac after the solution has by standing several days acquired the consis- tency of cream ; two or three parts by weight of shell lac are used for one of the solution. The composition is then heated and run into plates, and when used it is heated to the temperature of about 250 F. It possesses extraordinary adhesive properties, and being
