193 On the Affinities of 



destroy' or secrete the existing carbon in the furnace ', reduce 

 its absokite quantity in the pig, and lower its value to the 

 manufacturer. From this arrangement it will be easy to 

 explain the full meaning of the manufacturer when he de- 

 signates the product of any ore " bad iron." The phrase 

 is mt-rely relative, and onlv implies a want of saturation of 

 the coaly principle, and does not extend to the after results 

 of the metal, supposing it underwent the manipulations of 

 the forge. The contrary is the fact ; for the " bad iron" of 

 the pig iron maker is the most suitable to the purposes of 

 the iorge, whether its intrinsic value in the market is con- 

 sidered, or its facilitv in forming bar iron with much less 

 loss than when carbonated metal is operated upon. 



With this fact before us, ar^:' we justifiable in condemning 

 to perpetual oblivicn, without trial and without examina- 

 tion, every ore of iron that is not as proiltabie as another in 

 the blasi-furnace for the manufacturing of gray or melt- 

 ing pig iron ? Alav not the converse of the above proposi- 

 tions hold good ? and may it not ultimately be discovered, 

 that argillaceous and siliceous iron-sloncs, which yield in- 

 ferior qualities of melting pig iron, lorm a quality best cal- 

 culated for the purposes of the bar iron forge? 



The universal run in favour of easily carbonated iron, and 

 the general result of the quality of bar iron at most of the 

 forges in the kmgdom, give a shade of probability to this 

 supposition. 



To prosecute an inquiry into the fact itself would open 

 an extensive field of rich investigation. The subject di- 

 vides itself into three principal branches. The first, to 

 which this paper is meant as introductory, is an incjuiry 

 into the affinities exerted by the different earths, which 

 commonly enter into the composition of iron-stones, upon 

 the carbon of the furnace, and to ascertain how far and to 

 what extent these retard or promote the carbonation of the 

 metal. 



The second and most laborious branch would be, by di- 

 rect experiment to form portions of cast iron, malleable 

 iron, and steel, from one particular oxide of iron, (or from 

 anv iron ore w hose properties were nicely ascertained, to serve 

 as a general standard,) mixed and fused with difierent earths, 

 and in various proportions. Thus a rigorous scale of com- 

 parison would be easily formed from the results thus ob- 

 tained, as to every possible shade of quality which most pro- 

 bably results from certain affinities existing betwixt the me- 

 tal and earths Chemical analyses would finally close this 

 division of useful labour^ by enabling us to compare with 



foreijra 



