ACETYLENE, ETHINE

(C:H.), colorle , inflammable gas having a faint odor resembling garlic. The pungent smell usually noticeable is due to im91°. Liquid and solid a, are explosive, developing a pre ure up to 100,000 Ib. per sq. inch. Compre ed a. and several of its compounds, especially with copper and silver, are explosive. A. polymerises under the influence of heat, and an immense number of organic compounds can. be built up from it. It can be prepared by the direct union of carbon and hydrogen under the influence of the electric arc, but it is now universally generated by the action of water on calcium carbide (CaC.). The latter, a crystalline, semimetallic, frequently iridescent solid, is manufactured by the fusion of a mixture of ground limestone and anthracite in an electric furnace, carbide works being erected in localities where electricity is cheap owing to the presence of water power, (e.g.), Niagara, Switzerland, Falls of Foyers. Various kinds of a. generators have been designed, the main feature being the method by which the water is brought into contact with the carbide. The safest are those in which carbide is dropped into an exce of water, as the dropping of the latter on to carbide creates a great amount of heat, causing the gas to decompose into compounds which choke the burner, As under low pre ure and without a small admixture of air the gas burns with a very sooty iflame, and a large amount of air not only produces great heat (utilized in the oxyacetylene blowpipc), but is highly daneas, the nece ary air for a brilliant me is obtained from small openings just below the burner tip. It yields 35-48 candle hours per cubic ft. Owing to its many advantages a. is being increasingly used for the lighting of vehicles, streets, and buildings. marrow coast region, Peloponnesus; chief town, Patras; produces currants; A. also applied to whole Pelponnesus or, Greece. rior race, who invaded Greece under Pelops, seized territory of dark-haired Pelasgians, and subsequently became the dominant race. Achaean League, ancient Gk. confederation of A. towns; probably first formed for protection against pirates; became important in IV. cent.; took part in wars against Philip and Anti pater; di olved, 288 B.C.; revived, 280, subsequently became chief wer in Greece,; warred against Rome; Ronis crushed by Romans, 146 B.C. ed ancestor of ancient Persian royal family (Ach seme nides).