Chemical lecture experiments . ctionjust above the flame makes it especially desir-able in connection with this experiment. Apiece of sheet copper or galvanized iron, witha 7 mm. hole in the centre, is laid over the topof the chimney after the gas is lighted andburning with a flame approximately 2 cm. the disk is placed over the chimney, thegas smokes inside the chimney, the flame re-cedes, and may be seen to be burning at thecentral air-draft instead of at the ring wherethe gas issues through the burner. By regulating the supply of gas, a flame some1 or 2 cm. high may be obtained. T
Chemical lecture experiments . ctionjust above the flame makes it especially desir-able in connection with this experiment. Apiece of sheet copper or galvanized iron, witha 7 mm. hole in the centre, is laid over the topof the chimney after the gas is lighted andburning with a flame approximately 2 cm. the disk is placed over the chimney, thegas smokes inside the chimney, the flame re-cedes, and may be seen to be burning at thecentral air-draft instead of at the ring wherethe gas issues through the burner. By regulating the supply of gas, a flame some1 or 2 cm. high may be obtained. The gas issu-ing from the hole in the disk may be lighted,and it will burn with a feebly luminous flame. It is thus possible to have a flame of air burning in illu-minating gas at the base of the burner and a flame of gasburning in air at the top. This is one of the simplest meth-ods of showing the phenomenon of reciprocal combustion. Argand burner and chimney (Fig. 146); copper or galvanized irondisk with 7 mm. hole in Fig. U6 346 CHEMICAL LECTURE EXPERIMENTS 7. Combustion of oxidizing agents in an atmosphere ofhydrogen. — A number of substances furnishing a supply ofoxygen may be made to burn in an atmosphere of hydrogen is held in a liter bell-jar clamped mouthdownwards, or use may be made of a lamp chimney throughwhich a stream of hydrogen is sent from the top, issuing atthe bottom. Potassium chlorate is placed in a small porce-lain crucible suspended in the loop of a stout iron wirelong enough to extend up into the jar or lamp potassium chlorate is then melted and strongly oxygen begins to be liberated it is suddenly thrustthrough the burning hydrogen at the mouth of the bell-jaror lamp chimney. The salt will burn with intense bril-liancy with the characteristic color of potassium salts. Bythe use of strontium or barium chlorates the flame will becolored respectively red and green. An intense yellowflame may be obtained by usi
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectchemist, bookyear1901
