BURNING HYDEOGEX. 



will cause it to be inflamed. It burns tranquilly without ex- 

 plosion, producing a pale yellowish, flame and very feeble light, 

 but intense heat. This is the effect attending the gradual and 

 continual combination of the hydrogen, as it escapes from 

 the aperture, with the oxygen of the surrounding air. It may 

 be asked why the hydrogen issuing from the aperture does 

 not combine with the oxygen of the air without the application 

 of a flame to it ? And also, why being once inflamed by the 

 application of such a body, its continued application becomes 

 unnecessary *i 



These questions are easily resolved. The hydrogen gas has an 

 affinity or attraction for oxygen, which is not strong enough to 

 cause their combination at common temperatures, but when the 

 temperature of the hydrogen is greatly elevated, its attraction for 

 the oxygen becomes so exalted, that it enters into instant and 

 spontaneous combination with it. Now by applying the flame 

 of & lamp or candle, or any other burning body, to the jet of 

 hydrogen, its temperature becomes so greatly raised, and its 

 attraction for oxygen consequently so exalted, that it enters 

 directly into combination with the oxygen of the air which is 

 in immediate contact with it at the moment. 



10. But it is also asked, How the continuance of the combina- 

 tion and the consequent maintenance of the flame takes place the 

 candle or lamp which produced its commencement being with- 

 drawn ? This is explained by the great quantity of heat produced 

 by the combination of the hydrogen with the oxygen. The com- 

 mencement of the combination being produced by the candle or 

 lamp, the hydrogen and oxygen themselves in the act of com- 

 bining develop an intense heat, and the succeeding portion of 

 hydrogen gas being in contact with them becomes heated and 

 combines like the former with a fresh portion of oxygen. In the 

 same manner, the heat developed by these being shared by the 

 succeeding portion of gas, a further combination and development 

 of heat takes place, and so on. Thus the combustion being once 

 commenced, the heat necessary for its maintenance and contin- 

 uance is developed in the process itself, which accordingly goes on 

 without the necessity of being again kindled by the application of 

 any flame. 



The continuance of the combustion of carbon, whether in pure 

 oxygen gas or in common air, is explained in the same manner. 



11. The combustion of carbon differs from that of hydrogen in 

 this, that the former takes place without the production of flame. 

 The charcoal being heated to redness, and still in the solid form, enters 

 directly into combination with the oxvgen of the surrounding air, 

 and the carbonic acid which is formed being a gas which is not 



197 



