LIMIT OF PROPAGATION OF DETONATION. 



107 



TABLE V. COMBUSTIBLE GASES, OXYGEN AND INERT GASES (Continued). 



Detonation was not effected in a 

 CO + N 2 + O is doubtful. 



mixture richer in nitrogen. The mixture 



The general relations were the same, except for the com- 

 pounds that border upon the limit at which the detonation 

 ceases to be propagated, such as the mixture of cyanogen with 

 twice its volume of nitrogen, that of methane with four times 

 its volume of nitrogen, carbonic oxide, etc. With hydrogen 

 and an excess of nitrogen, there was also a decided fall in the 

 results. 



7. To sum up, the velocity of translation of the gaseous mole- 

 cules, preserving the whole of the energy corresponding to the 

 heat given off by the reaction, may be regarded as a limit 

 representing the maximum rate of propagation of the explosive 

 wave. 



But this velocity is diminished by the contact of gases and 

 other foreign bodies ; and also when the mass ignited at the 

 beginning is too small and too rapidly cooled by radiation ; and 

 again when the elementary velocity of the chemical reaction 1 

 is too feeble, as seems to be the case with carbonic oxide. Under 

 these conditions the wave slackens, and may even stop alto- 

 gether, the combustion being then propagated from layer to 

 layer at a much slower rate. Reference will be made to this 

 point again. 



1 " Essai de Mecanique Chimique," torn. ii. p. 14. 



