FLAME

When a gas, or mixture of gases, is heated to a certain temperature it burns with production of light and heat. The amount and color of light varies with the gas burned. Ooal gas burns with a yellowish, hydrogen with an almost colorle f. Tie luminosity of the f. depends (1) on the temperature —the higher it is, the greater the luminosity; (2) on the density of the ases of the f.—the more compre ed the gases are, the greater the luminosity; 3) on the amount of solid matter in the f. Powdered charcoal in a hydrogen f. will make it luminous. The incandescent mantle, a film of alkaline earths, increases the luminosity of the ordinary gas jet, and a block of lime placed in the oxyhydrogen f. produces an intense white light. ‘The chief constituents of the ordinary f. is ethylene, which when burned produces carben dioxide and water. Four regions can be distinguished in a f.: (1) the inner cone of unburned 2s, (2) a non-luminous blue region, 3) a luminous f. with (4) a faintly luminous mantle. In the blue region carbon monoxide and water are formed, with traces of carbon dioxide and aydrogen. The carbon monoxide and aydrogen are oxidized into carbon| lioxide and water in the outer cone. Inj he faintly luminous mantle, carbon non oxide, hydrogen, and small quan-| ities of hydrocarbons which have|/the scaped combustion in the luminous | arts of the f. are burned. The non-|tions uminous character of this area is due to | = cooling Loge i the a ee wn into the f. e gases as they reac he luminous area are surrounded by urning material which raises them to | he temperature at which marsh gas and | thylene are decomposed into acetylene | nd hydrogen i