XENON, X

Atomic Weight 130°2. One of the inert gases occurring in small quantities in the atmosphere. It is the least volatile constituent, being found in the final residues after evaporating large quantities of liquid air. One hundred and seventy million parts of air contain one part of xenon, and it also occurs in the gases evolved from many thermal springs. It was first discovered by Ramsey and Travers in 1898. It boils at =109°1° C.., its critical temperature is +166° C., and its critical pre ure 58°2 atmospheres. At N.T.P. 1 litre of the gas weighs 5°851 gms. and its density is 65°35, compared with oxygen as 16. (fl. VI. cent. B.C.), a satiric poet who attacked the anthropo-morphism oO: popular religion; sometimes, but without sufficient reason, regarded as the founder of the Eleatic school (q.v.). historian; joined Gk. mercenaries, who followed Cyrus against Persia. Cyrus was slain and Xenophon led the ‘Retreat of the Ten You sand’ through Armenia to the Black Sea; subsequently attached himself to Agesilaus, king of Sparta. Late in life wrote his masterpieces— mainly reminiscences: the Anabasis, & narrative of the retreat of the 10,000; Memorabilia, reminiscences and the d a memoir; and Helleni ca, Agesilaus, covers 49 years of Gk. history. which