296 



PKOF. W. A. BONE AND OTHERS ON 



EXPERIMENTS with Mixture 2CH 4 + 0, in Bomb A. 



In the case of experiments with the mixture 2CH 4 + O 2 , in bomb B, where, owing 

 to the much smaller wall-surface per unit volume of mixture exploded, the maximum 

 temperature would be somewhat higher, and the cooling period longer, than in the 

 corresponding experiments in bomb A, the ratios "R" varied between 0'400 and 

 0'346. 



PART III. EXPERIMENTS SHOWING THE RELATIVE AFFINITIES OF METHANE AND 

 HYDROGEN FOR OXYGEN IN EXPLOSIONS, AND CONCLUSIONS ARISING THERE- 

 FROM AS TO THE MODE OF COMBUSTION OF HYDROGEN. 



(With Messrs. HAMILTON DAVIES and H. H. GRAY.) 



The observations made during the preceding experiments that there is no 

 deposition whatever of carbon when mixtures of composition intermediate between 

 3CH 4 + 20 2 and CH 4 + O 2 are exploded under pressure, opened up the possibility of 

 comparing the relative affinities of methane and hydrogen for oxygen under the 

 conditions of homogeneous flame combustion, in the manner hereinafter to be 

 described. 



The theoretical importance of such a comparison is enhanced by the fact that it 

 provides not only a basis for the discussion of the question whether or not the known 

 rates of flame propagation through explosive mixtures of different combustible gases 

 are governed by their relative affinities for oxygen, but also affords decisive evidence 

 as to the mode of combustion of hydrogen in explosions. 



Ever since Sir HUMPHREY DAVY'S experiments on flame, the combustibility of 

 hydrogen has been considered superior to that of methane, and, as a matter of fact, 

 not only is the ignition temperature in air of hydrogen (580 C. to 590 C.) lower 

 than that of methane (650 C. to 750 C.),* but also the rates of inflammation (i.e., of 



H. B. DIXON and H. F. COWARD, 'Trans. Chem. Soc.,' 1909, vol. 95, p. 519. 



