2^4 O n the Component Parts of Iron-JIones. 



of colour. I have alfo at times detected crude carbon in tite 

 centre of pieces of ore i{ inch diameter. To the remain- 

 der of this mixture, after the oxygen is taken up, ought to be 

 attributed the natural tendency which moft malleable iron 

 made in this procefs has of becoming red-fhort. 



The average of the refults of the principal clafles of iron- 

 ftones may ferve for information on the produces obtained, 

 by treating thofe of equal quantities of mixture. The ana- 

 lyfis here furnimed is not that of the chemift, or laboratory'; 

 but, though the calculations are lcfs rigorous, yet they are 

 fufticient for the manufacturer, and better fuited for prac- 

 tical information ; as they never once lofe fight of their ap- 

 plication and effects in the large way of manufacture, and 

 as they have been chiefly effected by an agent, which alone, 

 in the large way, can modify the whole, and procure refults 

 confonant to the ufe and exigence of the metal. 



From the amount of the experiments here recorded I 

 would be apt to draw this concLufion, that, in general, iron- 

 ftones are varioufly combined With oxygen as to quantity : 

 argillaceous iron-ftone, leaft ; calcareou?, more; and fili- 

 ceous iron-ftones, moft of all. 



In the general arrangement which I have made of iron- 

 ftones in this and the preceding paper, I wifh not to be un- 

 derftood as having comprehended every variety which may 

 exift ; new clafles may be brought to light, as the progrefs 

 of difcovery and eftablifhment advances. I am at prefent, 

 However, acquainted with only one exception, which, from 

 its fcarcity, I have avoided claffing along with thofe gene- 

 rally ufed. My experiments alfo have hitherto been limited 

 as to the nature, fo that at the prefent time I am only ena- 

 bled to ftate a few, of its diftinguifhing properties. This 

 iron-ftone is found near to Clough Iron Works, in the 

 countv of Lanark. Its appearance is much like a coarfe 

 fchiftous coal ; its average thicknefs is about i^ inch; pof- 

 feffing a dark fandy fracture, and by no means refembling 

 an ore of iron. The mixture. is a union of coal and iron 



with 



