38 Scientific Proceedings, Royal Dublin Society. 



about the oxidation of carbon and the deoxidation of water, 

 30*2 heat-units must be continuously supplied to the two sub- 

 stances. 



The reducing action of carbon monoxide will be seen by 

 equations (1) and (3) to be superior to that of hydrogen by 10-8 

 heat-units, inasmuch as the former evolves 69 heat-units for every 

 atom of oxygen removed from an oxide, while the latter evolves 

 58 "2 heat-units. Consequently it is necessary to consider the 

 action of carbon monoxide and of carbon in smelting processes, 

 but not that of hydrogen. 



All those metallic oxides the heat of formation of which is less 

 than 69 heat-units are capable of reduction in a reverberatory 

 furnace. 



Thermo-Chemical Equations. 



(1.) Eeduction accomplished by means of Furnace Gtases. 



Smelting of Lead Ores. — Reduction of Lead Oxide : — 



PbO + CO = Pb + CO2 + (69 - 51) heat-units. 

 Heat evolved =18 units. 



Reduction of Cojjper Oxide : — 



CuO + CO = Cu + CO2 + (69 - 38-4) heat-units. 

 Heat evolved = 30*6 units. 



Reduction of F err so-ferric Oxide : — 



FesOi + 4 CO = 3 Fe + 4 COo + (69 X 4 - 269) heat -units. 

 Heat evolved = 7 units. 



The process of reducing ferroso-ferric oxide in the smelting of 

 iron probably takes place in the two stages : — 



(1.) FesOi + CO = 3 FeO + CO2, 

 (2.) FeO + CO = Fe + CO2, 



but exact thermal data concerning these reactions are wanting. 



