110 PROFESSOR H. B. DIXOR OX THE RATE OF EXPLOSION IN GASES. 
The small differences in the rate of explosion of hydrogen and oxygen, and of 
ethylene and oxygen at 10° and at 100° show that the effect of ordinary atmospheric 
changes of temperature may be neglected. 
§6. Comparison of the Rate of ExpAosion of different Gaseous Alixtures 
ivith Berthelot’s results . 
The results obtained, under ordinary conditions of pressure and temperature, with 
hydrogen and oxygen, with hydrogen and nitrous oxide, and with marsh gas and 
oxygen, in exact proportions for complete combustion, were in close accordance with 
the mean results of Berthelot ; for ethylene, acetylene, and cyanogen my numbers 
differed appreciably, but in no case differed by more than 7 per cent, from the rates 
observed by Berthelot. In the following table our measurements for the same 
mixtures are compared :— 
Table X.—Mean Velocity of Explosion in Metres per Second. 
Berthelot. 
Dixox. 
Hydrogen and oxygen .... 
. . . Ho + 0. . 
2810 
2821 
Hydrogen and nitrous oxide 
. . . H0 + N3O . 
2284 
2305 
Marsh gas and oxygen. 
. . . CH,+ 0, . 
2287 , 
2322 
Ethylene and oxygen. 
. . . CjH.-hO,. 
2210 
2364 
Acetylene and oxygen. 
. . . G.m+o,. 
2482 
2391 
Cyanogen and oxygen. 
. . . C.,No + Oi. 
2195 
2321 
The general agreement between these measurements leaves, I think, no I’oom for 
doubt about the substantial accuracy of the results. 
Cap. IV.—The Influence of Steam on the Bate of Explosion of 
Carbonic Oxide and Oxygen. 
The results already described show that the formula proposed by Berthelot 
expresses with a close degree of approximation the rates of explosion of several gaseous 
mixtures. The formula fails for the explosion of carbonic oxide with oxygen or with 
nitrous oxide. This was to be expected if, in the detonation of carbonic oxide in a 
long tube, the oxidation is effected indirectly by means of steam—as it is in the ordi¬ 
nary combustion of the gas. Measurements of the rate of explosion of carbonic oxide 
and oxygen in a long tube showed that the rate increased as steam was added to the 
