38 On the Manufacture of Bar Iron in India. 



tact with the gases, evolving in doing so, a heat so tremen- 

 dous, that instead of the furnace being "injuriously cooled," 

 the great difficulty is to prevent the furnace itself from 

 being completely fused and destroyed. 



9. The statement, that oxides burn and evolve heat dur- 

 ing combustion in carboniferous gases, I conceive to be a 

 new fact in experimental chemistry ; and although I have at 

 present but few books to refer to, in support of my assertion, 

 I think the following extract (from Dr. Ure's Dictionary of 

 Arts and Manufactures, page 913,) sufficient for my purpose 

 at present : " It is probable that the coaly matter employ- 

 " ed in the process is not the immediate agent of their reduc- 

 " tion ; but the charcoal seems first of all to be transformed 

 " by the atmospheric oxygen into the oxide of carbon, which 

 "gaseous product then surrounds and penetrates the interi- 

 " or substance of the oxides, with the effect of decomposing 

 " them, and carrying off their oxygen." Here we have no 

 mention of any combustion or evolution of either heat or 

 light, and as it is not likely that Dr. Ure would have been 

 unacquainted with experiments on a subject to which he 

 had given so much interest and practical attention, perhaps 

 I may be allowed to claim the merit of having first discover- 

 ed it. I cannot, however, at present describe the method of 

 making the experiment, which is attended with phenomena 

 as beautiful and dazzling as the combustion of iron wire 

 in oxygen gas : because the mode of observing and manag- 

 ing the combustion forms a part of the practical manage- 

 ment of my furnaces, and I would not now have mentioned 

 the subject, but that any one endeavouring to repeat Mr. 

 Clay's experiment, must have the opportunity of observ- 

 ing it. 



10. While discussing the merits of Mr. Clay's process, 

 Mr. Heath alluded to his own process of tf cementation," 

 with specular iron ore, and Indian pig-iron, by which he 

 stated, that excellent iron for steel-making has been pro- 



. 



