OXYGEN (symbol O, atomic weight 16), a non-metallic chemical component. It was apparently first obtained in 1727 by Stephen Hales by strongly heating minium, but he does not seem to have acknowledged that he had obtained a new component, and the primary printed description of its properties was attributable to J. Priestley in 1774, who obtained the gasoline by igniting mercuric oxide, and gave it the title "dephlogistigated air." K. W. Scheele, working independently, also introduced in 1775 the invention of this ingredient which he called "empyreal air" (Crells’ Annalen, 1785, 2, pp. 229, 291). A. L. Lavoisier repeated Priestley’s experiments and named the gas "oxygen" (from Gr. Oxygen occurs naturally as one of the chief constituents of the ambiance, and together with other parts it's present in very giant quantities; it constitutes approximately eight-ninths by weight of water and practically one-half by weight of the rocks composing the earth’s crust. It's also disengaged by rising vegetation, plants possessing the ability of absorbing carbon dioxide, assimilating the carbon and rejecting the oxygen.

Oxygen may be prepared by heating mercuric oxide; by strongly heating manganese dioxide and many other peroxides; by heating the oxides of treasured metals; and by heating many oxy-acids and oxy-salts to excessive temperatures, for example, nitric acid, sulphuric acid, nitre, lead nitrate, zinc sulphate, BloodVitals SPO2 potassium chlorate, &c. Potassium chlorate is usually used and the reaction is accelerated and carried out at a lower temperature by beforehand mixing the salt with about one-third of its weight of manganese dioxide, which acts as a catalytic agent. The actual decomposition of the chlorate will not be settled definitely; the following equations give the outcomes obtained by P. F. Frankland and Dingwall (Chem. News, 1887, 55, p. 67):-at a moderate heat: 8KClO3＝5KClO4＋3KCl＋2O2, BloodVitals SPO2 succeeded by the next reactions as the temperature increases: 2KClO3＝KClO4＋KCl＋O2 and 2KClO3＝2KCl＋3O2 (see additionally F. Teed, ibid., 1887, 55, p. 91; H. N. Warren, ibid., 1888, BloodVitals SPO2 58, p. 247; W. H. Sodeau, Proc. Chem Soc., 1901, 17, p.

149). It could even be obtained by heating manganese dioxide or BloodVitals SPO2 potassium bichromate or potassium permanganate with sulphuric acid; by the action of cobalt salts or manganese dioxide on an answer of bleaching powder (Th. Fleitmann, Ann., 1865, 134, p. 64); by the motion of a ferrous or manganous salt with a salt of cobalt, nickel or BloodVitals SPO2 copper on bleaching powder (G. F. Jaubert, Ger. pat. 157171); by passing chlorine into milk of lime (C. Winkler, Jour, prakt. Chem., 1866, 98, p. 340); by the motion of chlorine on steam at a bright crimson heat; by the decomposition of hydrogen peroxide by bleaching powder, manganese dioxide, potassium ferricyanide in alkaline solution, or potassium permanganate in acid answer; by heating barium peroxide with an aqueous answer of potassium ferricyanide (G. Kassner, Zeit. angew. Chem., 1890, p. 2＋O2; by the decomposition of sodium and potassium peroxides with an answer of potassium permanganate within the presence of a hint of nickel salts (G.

F. Jaubert, Comptes rendus, 1902, 134, p. Numerous strategies have been devised for the manufacture of oxygen. The extra necessary are as follows: by decomposing strongly heated sulphuric acid in the presence of a contact substance; by heating an intimate mixture of 1 part of sodium nitrate with two components of zinc oxide (T. H. Pepper, Dingler’s Jour., 1863, at-home blood monitoring 167, p. 39): 2ZnO＋4NaNO3＝2Zn(ONa)2＋2N2＋5O2; by means of cuprous chloride which when blended with clay and sand, BloodVitals SPO2 moistened with water and heated in a present of air at 100-200° C. yields an oxychloride, which latter yields oxygen when heated to 400° C (A. Mallet, Comptes rendus, 1867, 64, p. 226; 1868, 66, p. 349); by the electrolysis of options of sodium hydroxide, utilizing nickel electrodes; by heating calcium plumbate (obtained from litharge and calcium carbonate) in a present of carbon dioxide (G. Kassner, Monit. Scient., 1890, pp. 503, 614); and BloodVitals SPO2 from air by the technique of Tessié du Motay (Ding.