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MODERN SCIENCE READER 



trol of the relative proportions of gas and air the inner 

 cone was made to burn at the orifice i, while the outer cone 

 burned at the orifice o. The outer cone got 

 its oxygen from the surrounding air, while 

 that for the lower flame was supplied along 

 with the gas. The temperature of each 

 cone was measured and the gases entering 

 and leaving each were analyzed. It was 

 Q found that as the proportion of gas to air 

 was increased, the tip of the inner or lower 

 cone became brightly luminous and a col- 

 umn of soot passed upward through the 

 tube, becoming faintly luminous in the 

 outer edge of the upper flame. As soon as 

 the inner cone becomes luminous the un- 

 saturated 1 hydrocarbon compound known, 

 as acetylene begins to appear among the 

 gases passing to the outer cone. 



Vivian B. Lewes now attacked the prob- 

 lem as to how carbon comes to be in the 

 flame in the free state. He analyzed gas 

 drawn from different parts of a coal gas 

 flame, measured the temperature of its dif- 

 ferent parts, etc., publishing his results be- 

 tween 1892 and 1895. These results may 

 be stated as follows: Coal gas consists 

 mainly of a mixture of hydrogen and 

 hydrocarbons, both saturated and unsat- 

 Tirated. In an ordinary "fishtail" burner 

 flame all hydrogen is consumed before the 

 middle of the luminous portion is reached. Of the satu- 

 rated hydrocarbons about seventy-five per cent, disappears 

 as such in the dark portion and about twenty-four per 



ir The terms " saturated " and ' ' unsaturated " have reference, 

 among other things, to the relative quantity of hydrogen to carbon 

 in the molecule, an unsaturated compound having relatively less 

 hydrogen than a saturated one. 



FIG. 1 



