288 PROF. W. A. BONE AND OTHERS ON 



PART II. THE EXPLOSION OF METHANE WITH LESS THAN ITS OWN VOLUME OF 



OXYGEN. 



(With Mr. HAMILTON DAVIES, B.Sc.) 



It has been known since DALTON'S time that at ordinary pressures methane cannot 

 be exploded with much less than its own volume of oxygen. DALTON thus described 

 the behaviour of a mixture of equal volumes of methane and oxygen on explosion 

 (New System, Part II., p. 446) : " If 100 measures of carburetted hydrogen be mixed 

 with 100 measures of oxygen (the least that can be used with effect], and a spark 

 passed through the mixture, there is an explosion without any material change of 

 volume : after passing a few times through lime water, it is reduced a little, 

 manifesting signs of carbonic add. This residue is found to possess the characters 

 of a mixture of equal volumes of carbonic oxide and hydrogen." 



In the light of my work on the slow combustion of methane* this result is best 

 expressed by the following equations : 



or, in ol 



, = [CH,O + H,0] = CO + H 3 +H 3 O. 

 CO+OH a C0 3 +H 3 , 



>ther words, tlie immediate result of the interaction of the hydrocarbon and 

 oxygen is the formation of formaldehyde and steam probably due to the thermal 



H 



decomposition of di/iydroxymethane H C OH. The formaldehyde at once decom- 



OH 



poses, yielding equal volumes of carbon monoxide and hydrogen, and afterwards, as 

 the system CO + H 2 + H a O is cooling, the reversible change CO + ( )H S ~ ^ CO., + H 2 

 comes into play. It is to be noted that there is no deposition of carbon in such an 

 explosion. 



By employing such high initial pressures as were at our command with the new 

 apparatus, it is possible to explode mixtures of methane with even as little as half its 

 own volume of oxygen. The behaviour of a series of mixtures between the limits 

 2CH 4 + O a and CH 4 + O a has been studied with results of considerable interest. 



First Series. (Bomb A.) 



Taking the experiments in their proper sequence, "the results obtained by firing 

 mixtures of methane with as nearly as possible half its own volume of oxygen in 

 bomb, A, at initial pressures gradually increasing from 8 '5 up to 31 '2 5 atmospheres, 



* BONE and WHEELER, 'Trans. Chem. Soc.,' 1902, vol. 81, p. 535; 1903, vol. 83, p. 1074. 



