4 1 2 On the Heat developed in Combustion 



as 1.55 to 0.7036 (according to Crawford), all the heat 

 in question will be divided so that the steam shall 

 retain the part of it represented by the number 9.5832 

 (=8.3333 X I -SS) ' an< ^ the nitrogen will receive the 

 other part of it, = 19.41 (being the product of 27.587 

 multiplied by 0.7036). 



Now, as the two numbers 9.5832 and 19.41 are bo.th 

 in the proportion of i to 2.0254, it is evident that the 

 temperature will be the same which we should have if 

 all the heat in question was equally divided between 

 the steam which would result from the combustion 

 of 3.0254 pounds of hydrogen, i. e. between 25.2113 

 pounds of steam. 



And as we have seen that the heat manifested in the 

 combustion of i pound of hydrogen, which is in the 

 8.3333 pounds of steam which are the products of this 

 combustion, is sufficient for raising the temperature of 

 this steam to that of 8750 F., it is evident that if this 

 same quantity of heat is divided among 25.2113 pounds 

 of steam, the temperature of this steam could not be 

 higher than 2891 F. 



This is, therefore, the highest temperature which we 

 ought to find in the midst of a strong fire fed by the 

 atmospheric air in which the combustible burned is 

 pure hydrogen. 



As this temperature is much lower than that which 

 we can excite by combustion, even without employing 

 pure hydrogen or pure oxygen, the result of this calcu- 

 lation furnishes a demonstrative proof that the capacity 

 for heat of steam, or rather that of nitrogen, is diminished 

 when its temperature is increased. In all probability, 

 the capacities of both, and generally of all elastic fluids, 

 are diminished when their temperature is increased. 



