268 THE SCIENTIFIC PAPERS OF 



established, regarding the chemical balance of affinities between 

 carbonic oxide and carbonic acid, in contact with metallic iron at 

 different temperatures. I am willing to admit these facts, which 

 are new to me, to the fullest extent, but I would draw from them 

 different conclusions, inasmuch as I cannot admit that the tem- 

 perature in the blast furnace increases necessarily with the tem- 

 perature of the blast. I believe the temperature of the blast 

 furnace will, on the contrary, be practically the same, whether 

 higher or lower temperature of blast is employed, and the reason 

 why I come to that conclusion is as follows : If blast of very high 

 temperature is employed, the oxygen it contains takes up carbon 

 very readily and is converted into carbonic oxide. Whereas, if a 

 lower temperature of blast is employed, there will be at once a 

 large proportion of carbonic acid gas produced. The carbonic 

 oxide gas would not nearly represent such an augmentation of heat 

 as would be represented by the mixture of the two gases together, 

 hence the reduced iron would, in the one case, be surrounded by 

 an atmosphere of carbonic oxide with nitrogen only ; and in the 

 other case, with a mixture, containing carbonic acid in variable 

 quantity, but the very chemical balance just pointed out to us 

 would tend to equalize the temperature in both cases. These con- 

 ditions would, therefore, not alter the working of the furnace 

 below, but the result of the higher temperature of the blast would 

 make itself felt in the upper portion of the furnace where finally 

 a higher proportion of carbonic acid gas, is realised when blast of 

 high temperature is used. When these favourable circumstances 

 are taken into account, we may expect, I submit, a continuance 

 of the very beneficial result already realized by further raising 

 the temperature of the blast, notwithstanding the interesting 

 circumstances that you have brought before us. 



