different Earths for Ca? Ion. I95 



to assert, that after proper distillation, or coaking, the resi- 

 duum coke is equally purely compounded, at least in many 

 instances, as the charcoal obtained from the combustion 

 of wood, then the chief weight will hinge upon the different 

 qualities of the ores introduced into the smelting furnace 

 here and abroad *. 



If this supposition is well founded, the constituent parts 

 of our ores, and the effects of their mixtures respeclivti}^, 

 surely become an object oi' ihe highest consideration. 



There are now nearly 150 b;?.st -furnaces at work in Bri- 

 tain, the produce of many or which, as V) quantity, may- 

 be alike, but each of which will most likely possess some 

 distmguishiirg characteristic mark as to qualitv. It is also 

 very generally understood, that the native impression or pe- 

 culiarity of quality adheres to the metal in every 5:ub3equent 

 stage of operation. Weak or iu-lble pig iron requires not 

 only a greater quantity to waste to form a ton of oars, but 

 is afterwards found possessing an inferior degree of mallea- 

 bility and tenacity. On the contrary, strong or refrictoiy 

 pig iron forms malleable iron with greater facility, of course 

 with a less loss of metallic matter, and constitutes what is 

 well understood by the term a strong body of iron. 



The means employed to render each of them malleable 

 being alike in both case?, though an investigation of this 

 subject might not be immtdiately productive of any advan- 

 tage to the mere manufacturer of pig iron ; yet, as it mi^ht 

 tend to unfold the causes of several admitted efl'ects in The 

 operations of the blast-furnace, and tend to develop some 

 affinities not hitherto suspected of being brought into play, 

 it would ultimately throw light upon the fabrication of bar 

 iron and steel : a desideratum of much importance to the 

 community. 



Arrangement and classification seem in all systems and 

 theories the grand primary steps towards knowledge and 

 perfection. Impressed with this truth, I ventured several 



* I mean that this assertion should be confined to some pit coals only, 

 and to the quantities of caihoii and a>hes which enter into their composi- 

 tion. In many instances I have fo\]nd the coke of pit coal more free 

 from ashes, and cdniauiing of course a larger proportion of carbon than 

 the gtneriil run of woods. What difference niay result in the manu- 

 facturing of iron with such c< als, arising from the residuum or ash biin<r 

 chiefly an earthy mixture, and wood, the residuum of which is chiefly 

 alkaline, 1 never have determined by direct experiment. This imjort- 

 ant and extensive field of investigation still lies open and unexplored to 

 the manufacturer and the chemist, or both. I have alluded to it in 

 one of the subseq'jcnt paragraphs of this paper, as forming a part of an 

 imponanc and national bcaniii of inquiry. 



N 2 vears 



