GLUCINA cording to the same author, has a peculiar .or resembling that of the perspiration of the t ; it is neither acid nor alkaline, dries rap- ly in the air, seems to coagulate in contact ith dilute acids, is not sensibly soluble in al- cohol, ether, or weak alkaline solutions, but is dissolved in concentrated sulphuric and hydro- chloric acids with the aid of heat; chemical tests exclude the idea of the presence of albu- men, and the ordinary ammoniacal products are disengaged by heat. The oxygen of the at- mosphere introduced by the numerous tracheae comes in contact with this substance, sui gene- ris, composed principally of carbon, hydrogen, oxygen, and nitrogen. The intermittence of the glowworm's light, and its sudden changes m darkness to brightness, as far as present vestigations go, are dependent on the differ- ,t amounts of air introduced into the trachea, d the varying activity of respiration and mus- lar action. The change in the food of the glowworm, from animal juices in the larva state to tender plants in the perfect condition, explains the contradictory statements of au- thors as to the habits of this insect; and the ilure of the attempts to introduce it as an ment to shrubberies and lawns has gener- y arisen from ignorance of the fact that the va cannot be raised on vegetable food alone ; sides moist herbage or damp earth, minute d shells must be supplied. A few specimens an articulated animal which may be called a glowworm have been found of late years in summer in various parts of southern New England. The head is small and flat, with very short antenna ; the color is cream- white, the length about 14 lines, and the whole of this is lighted up at night with a permanent lumi- nousness less than that of the elaters of the West Indies; the light begins to show itself between the segments, of which there are 12, and at the stigmata, from which it spreads un- til the whole animal is illuminated, seeming a stick of light without joints or stigmata ; most brilliant soon after midnight, they gradually fade to the ordinary whitish color at day- break. In all these cases of phosphorescent articulates it is difficult to say what is the pre- cise purpose of the light. (See FIREFLY.) GLUCINA (Gr. yAm^, sweet), an earth, first obtained by Vauquelin in 1798, consisting, ac- cording to Berzelius, of two atoms of the metal glucinum, united with three atoms of oxygen ; but Awdejew and others regard it as a protox- ide, G1O. It is found only in a few minerals, as the emerald, beryl, euclase, &c., being con- tained in the first two in the proportion of 13f per cent., combined with silicic acid. It is ob- tained in the form of a white powder, of specific gravity about 3, closely resembling alumina. It is distinguished by its solubility, when freshly prepared in a cold solution of carbonate of am- monia, and by its tendency to form a carbon- ate by exposure to the air ; also by not giving a blue color in the blowpipe test with nitrate "* u - u The properties of glucinum, the of cobalt. GLUOK 41 metallic base of glucina, have been investigated by Debray (Annales de cliimie et de physique [3], xliv. 5), who obtained it from the chloride by reduction with sodium, the original source being the emerald of Limoges. He found it a white malleable metal, that could be rolled in sheets like gold, of density 2-1, its melting point below that of silver. It cannot be made to burn in pure oxygen, but appears in the trial to be slightly oxidized on the surface, by which it is protected from further change. It resists the action of sulphur, but combines with chlo- rine and iodine. Its alloy with silicium is a hard brittle substance, susceptible of a high polish. Glucinum is soluble in sulphuric and in hydrochloric acids, hydrogen being evolved. Nitric acid acts upon it only when heated, and then slowly. It dissolves in caustic potash. Its symbol is G; chemical equivalent, 9*2. GLUCK, Christoph Wilibald von, a German com- poser, born at Weidenwang in the Upper Pa- latinate, July 2, 1714, died in Vienna, Nov. 15, 1787. The dates and other particulars in this article which differ from those usually given, are drawn from documentary evidence sub- stantiated or first given to the public by Anton Schmid, of the imperial library at Vienna, in 1854 (Gluclcs Leben und tonkunstleriscJies Wir- Tcen). The father, Alexander Johannes Klukh (as he always wrote his name), was first a huntsman of Prince Eugene, afterward remov- ing to Weidenwang as forester. In 1717 he entered the service of Count Kaunitz in Bohe- mia, and thus the young Christoph came at the age of three to the land which, owing to its great number of wealthy nobles and convents, was then the most favorable to the develop- ment of musical talent. In the gymnasia and the Jesuit colleges music was earnestly culti- vated, and every nobleman had his musical chapel ; all churches of any pretensions, very many of the smaller parish churches even, had their choirs supported by ample funds. The treatment of Gluck and his brothers by the father was hard even to tyranny; the composer in his old age well remembered being forced with his brother Anton to follow his father in the coldest winter weather into the forests, sometimes barefoot, "to make them tough." The children had the best school instruction in Kamnitz and Eisenberg, and from his 12th to his 18th year Christoph was sent to the gym- nasium at Kommotau. The boy carried with him a good degree of knowledge both in sing- ing and playing bowed instruments, and in the school of the Jesuits his musical talents were specially cultivated. He became a chorister in the principal church of the place, and gained some knowledge of the harpsichord and organ. At 18 he went to Prague to enter the univer- sity, but was finally obliged to devote himself to music for subsistence. He gave lessons in singing and upon the violoncello, sang and played in several churches for a small salary, and during vacation sang and played in the villages of the surrounding country, sometimes
