See Weitbrecht, Wanderungen durch Geislingen und seine Umgebung (Stuttgart, 1896).
GEISSLER, HEINRICH (1814-1879), German physicist, was born at the village of Igelshieb in Saxe-Meiningen on the 26th of May 1814 and was educated as a glass-blower. In 1854 he settled at Bonn, where he speedily gained a high reputation for his skill and ingenuity of conception in the fabrication of chemical and physical apparatus. With Julius Plücker, in 1852, he ascertained the maximum density of water to be at 3.8° C. He also determined the coefficient of expansion for ice between −24° and −7°, and for water freezing at 0°. In 1869, in conjunction with H.P.J. Vogelsang, he proved the existence of liquid carbon dioxide in cavities in quartz and topaz, and later he obtained amorphous from ordinary phosphorus by means of the electric current. He is best known as the inventor of the sealed glass tubes which bear his name, by means of which are exhibited the phenomena accompanying the discharge of electricity through highly rarefied vapours and gases. Among other apparatus contrived by him were a vaporimeter, mercury air-pump, balances, normal thermometer, and areometer. From the university of Bonn, on the occasion of its jubilee in 1868, he received the honorary degree of doctor of philosophy. He died at Bonn on the 24th of January 1879.
See A.W. Hofmann, Ber. d. deut. chem. Ges. p. 148 (1879).
GELA, a city of Sicily, generally and almost certainly identified with the modern Terranova (q.v.). It was founded by Cretan and Rhodian colonists in 688 B.C., and itself founded Acragas (see [Agrigentum]) in 582 B.C. It also had a treasure-house at Olympia. The town took its name from the river to the east (Thucydides vi. 2), which in turn was so called from its winter frost (γέλα in the Sicel dialect; cf. Lat. gelidus). The Rhodian settlers called it Lindioi (see [Lindus]). Gela enjoyed its greatest prosperity under Hippocrates (498-491 B.C.), whose dominion extended over a considerable part of the island. Gelon, who seized the tyranny on his death, became master of Syracuse in 485 B.C., and transferred his capital thither with half the inhabitants of Gela, leaving his brother Hiero to rule over the rest. Its prosperity returned, however, after the expulsion of Thrasybulus in 466 B.C.,[1] but in 405 it was besieged by the Carthaginians and abandoned by Dionysius’ order, after his failure (perhaps due to treachery) to drive the besiegers away (E.A. Freeman, Hist. of Sic. iii. 562 seq.). The inhabitants later returned and rebuilt the town, but it never regained its position. In 311 B.C. Agathocles put to death 5000 of its inhabitants; and finally, after its destruction by the Mamertines about 281 B.C., Phintias of Agrigentum transferred the remainder to the new town of Phintias (now Licata, q.v.). It seems that in Roman times they still kept the name of Gelenses or Geloi in their new abode (Th. Mommsen in C.I.L. x., Berlin, 1883, p. 737).
(T. As.)
[1] Aeschylus died there in 456 B.C.