ON GASEOUS COMBUSTION. 



487 



Rales of Explosion, at 10° and 760 mm., for a mixture 200+0^ containing varying 



Proportions of Steam. 



Before entering upon a discussion of the theoretical aspects of the 

 matter, certain other facts must be considered, namely: — 



1. In the detonation of a dried mixture of cyanogen with twice its 

 own volume of oxygen the formation of carbon dioxide is complete; 

 moreover, under such conditions it has been proved that carbon mon- 

 oxide is primarily formed in the wave itself, the second stage of the 

 combustion — namely, 2CO + 0, = 2C0 2 — taking place in the rear of the 

 wave. 1 



2. A well-dried mixture of carbon monoxide (36 per cent.), ozone 

 (8 per cent.), and oxygen cannot be fired with a powerful electric spark; 

 also, on sparking a well-dried mixture of carbon monoxide (60 per 

 cent.), chlorine peroxide (29 per cent.), and oxygen (11 per cent.), 

 although a flame is propagated through the gases, as much as 76 per 

 cent, of the original carbon monoxide may remain unburnt. 3 



3. Dried carbon monoxide and oxygen completely combine without 

 flame in contact with a heated platinum wire ; moreover, the writer has 

 recently proved that the most careful drying possible greatly accelerates 

 the rate at which the gases combine in contact with a hot fire-clay 

 surface at 500°. 



4. There are certain well-established instances in which combustion 

 is not determined by the presence of moisture — namely, the combus- 

 tion of cyanogen, of carbon disulphide, and of hydrocarbons (ethane, 

 ethylene, and acetylene). 



Theories respecting the Function of Moisture. 



1. H. B. Dixon has consistently maintained that, in the combustion 

 of carbon monoxide, steam merely acts as the carrier of oxygen; he 

 contends that in explosions the formation of carbon dioxide is always 

 limited by its dissociation, and that at the highest temperature (e.g., 

 in the wave-front when the mixture C a N 2 + 20 2 is detonated) it is not 

 formed at all by direct interaction of the monoxide and oxygen, because 

 the internal energy which would thereby be imparted momentarily to the 

 newly-born dioxide molecule would bring about its dissolution. For the 



1 H. B. Dixon. 



2 H. B. Dixon and E. J. Russell, Trans. Chem. Soc. 1897, 71, 605. 



