di§'ere7tt Earths for Carbon. 1D9 



foreign irons the residua afforded by our various qualities in 

 the different stages of manufacture. 



The third and not the least interesting province of na- 

 tional inquiry, and which would form an essential epoch irj 

 the history of iron making, would be a practical analysis of 

 the numerous qualities ot pit coal ; not HRrely to ascertain 

 the quantities of bitumen, carbon, and ashes which they 

 contain, but by forminsj real metallic products by means of 

 each quality, and subjecting these to por^itive and compa- 

 rative trials, enable us to pronounce which are best calcu- 

 lated to promote the general interest of the manufacture. 



In the pursuit of knowledge in this laborious, sable, but 

 verv interesting field, science might ere long, and without 

 any visionary effects of a fanciful iniagination, establish her 

 empire ever the regions of the foundry, and by her enlight- 

 ened steps exhibit to us, even in the most remote and inglo- 

 rious manipulation of this art, the unerring operation of 

 prniciplc and the general harmony of estabhshcd causes. 

 Then, perhaps, our labours might be productive of a classi- 

 fication descriptive of the natural product of our ores and 

 fuel. The Germans have long had their steel ore and the 

 Swedes their steel iron ; and may not analysis point out, ac- 

 cording to the various combinations of our ores, however 

 inferior in many respects, what particular mixture would 

 form the best bar iron, and which the best steel ? Already 

 the nianufacturc of melting cast iron, so far as it relates to 

 a judicious choice of ores, seems thoroughly understood. 



The first of these divisions now pointed out being the 

 task I have assigned to myself, I shall proceed to state the 

 train of reasoning which was the foundation of the extensive 

 series of experiments meant to be detailed. 



Every day, convinced of the correctness of the practical 

 deductions formerly stated, relative to ores combined with 

 different earths, I was anxious to form an explanation of 

 the causes which would in every particular prove satisfac- 

 tory of the facts. At one time I attributed the effects of 

 the calcareous iron-stone to the decomposition of carbonic 

 acid in burning the iron-stone, and part of the carbon either 

 uniting to the particles of metal, or, which in effect would 

 nearly be the same thing, canying off a portion of its oxy- 

 gen. I again supposed that this effect might be produced 

 by a stronger affinity existing betw ixt the iron-stone and 

 the raw hmestone added as a flux, the carbonic acid of 

 which might be decomposed, and the carbon attracted by 

 the iron. Having satisfied myself, by direct experiment, 

 that carbonic acid (even admitting it as deeomjK)scd) never 

 N 4 affords 



