295 On the Converjion of Iron info Steel 



was iotroduced as a fnbftitute for the carbonate, the fufion 

 and the quahty of the button produced were in every refpeft 

 the fame ! The metal, fubjeifted to a variety of lefts, exhi- 

 bited the various phfenoniena mentioned in a former part of 

 this paper. Convinced that, from whatever caufe this ap- 

 pearance of ftecl was derived, the carbonic acid was entirely 

 neutral, I next ventured to fubjccl iron to fufion per fe; and 

 the refult anfwered the novelty of my expeilations. Beautiful 

 buttons wore obtained, of various magnitudes, poflefted of 

 iimilar properties with ihofe obtained wiih the carbonate and 

 clay, and with the de-acidified lime and clay. The quality 

 of thefe unalloyed buttons varied, and exhibited, in a greater 

 or lefs degree, the properties afcribed to the others. From 

 frequent repetitions of the fame experiment with various fized 

 crucibles, [ found the iron lefs altered in a crucible whofe 

 capacity was little more than the contents introduced, than 

 when a larger crucible was ufed to the fame weight of iron. 



Thus circumftanced, and unable to account for this appa- 

 rent formation of Iteel in any other way, I concluded that 

 fueh was the afHnity of iron for carbon, that when protecSled 

 from common air, and expofcd to a high temperature, it de- 

 compofed the ignited gas of the furnace, feized its carbon, 

 and conftituted lleel ; and that the degree of faturation de- 

 pended upon the area prefcnted by the interior furface of the 

 crucible to any given quantity ot iron. 



I had advanced thus far when I communicated the general 

 refult of thefe experiments in the Philofophical Magazine for 

 November 1799. 



Soon after this. Sir George M'Kenzie read the paper for- 

 merly alluded to. In it he informs us that, when he pro- 

 duced heat enough, malleable iron was fufible per fe; but 

 he alleges that in no cafe was the quality of the metal 

 altered. 



In the prcfcnt Rate of my information upon the fibjeft at 

 iliue, I ihall cheerfully giv-e up the conclufiou 1 had formerly 

 draw-n, of ftcel being formed by carbon dilfolved in caloric, 

 I have ftated the progreis of my mind fo far as it was biafled 

 by the experiments formerly communicated •, and, far from 

 wifhing to confound by any arguments ad\'anced in favour 

 of the deduftion I formerly made, I regret the facility with 

 which the mind is naturally inclined to indulge in favour of 

 received opinions. 



The long received opinion, that pure malleable iron was 

 infulible, and the unqualified approbation paflcd upon a mo. 

 tlification of iron exactly liniilar in quality, by the ableft ciie- 

 mills in Paris, led me into a falfe appreciation of the quality 



of 



