. The principles of chemistry . hese particles of charcoal which occur in flames may beeasily observed by introducing a cold object, like a knife, into theflame.* The particles of charcoal burn at the outer surface of theflame if the supply of air b>e suflicient, but if the supply of air—that is, ^ There is, however, no doubt l)ut that very heavy dense vapours or gases underpressure (according to the experiments of Frankhvnd) are kiininous when heated, be-cause, as they become denser they approach a liquid or sohd state. Thus detonatinggas when exploded under pressure gives a brilliant ligh
. The principles of chemistry . hese particles of charcoal which occur in flames may beeasily observed by introducing a cold object, like a knife, into theflame.* The particles of charcoal burn at the outer surface of theflame if the supply of air b>e suflicient, but if the supply of air—that is, ^ There is, however, no doubt l)ut that very heavy dense vapours or gases underpressure (according to the experiments of Frankhvnd) are kiininous when heated, be-cause, as they become denser they approach a liquid or sohd state. Thus detonatinggas when exploded under pressure gives a brilliant light. ? If hydrogen gas be passed through a volatile liquid hydrocarbon—for instance,through benzene (the benzene may be poured directly into the vessel in which hydrogenis generated)—then its vapour burns with the hydrogen and gives a very bright flame,because the resultant particles of carbon (soot) become incandescent. Benzene, orplatinum gauze, introduced into a liydrogen flame may be employed for Fh;. 35.—Farail-ays experiment for investigating thedifferent parts of a candle fiame. OXYGEN AND ITS SALINE COMBINATIONS 179 of oxygen—be insufficient for their combustion the flame smokes, becausethe unconsumecl particles of charcoal are carried off by the current ofair.^^ ^ Inflames the separate parts may be distinguished with more or less portion of the flame whither the combustible vapours or gases flow, is not luminousbecause its temperature is still too low for the process of combustion to take place in is the space which in a candle surrounds the wick, or in a gas jet is immediatelyabove the orifice from which the gas escapes. In a candle the combustible vapours andgases which are formed by the action of heat on the melted tallow or stearin rise in thev,ick, and are heated by the high temperature of the flame. By the action of the heat,the solid or liquid substance is here, as in other cases, decomposed, forming produ
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Keywords: ., bookcentury1800, bookdecade1890, bookpublis, booksubjectchemistry
