34° Dr. Pearson's Experhnents 
With respect to interior structure : 
i. Wrought iron is to be considered as a simple or unde- 
compounded body, but it has not been hitherto manufactured 
quite free from carbon ; which is to be reckoned an impurity. 
The least impure iron, as indicated by properties,, is that 
which possesses the greatest softness, toughness, and strength ; 
but if it be soft, independent of combination, it will of course 
be of the toughest and strongest quality. To denominate it 
from properties, I would call it soft malleable iron : and from 
internal structure, it should be called pure iron , or iron. 
The ore from the deep mines of Dannemora, produces the 
purest iron. It is in England called Oeregrund iron * It is al- 
most the only iron manufactured which by cementation affords 
what our artists reckon good steel. 
ii. Steel has composition. It is a compound of iron and 
carbon, the proportions of which have not been accurately de- 
termined, but may be estimated to be one of carbon and 300 
of iron. I would call this state of iron from external properties, 
hard malleable iron : and from interior structure and compo- 
sition it may be called, as in the new system, carburet of iron. 
Steel of the best imaginable kind is that which has not yet 
been manufactured : for it is that which has the most ex- 
tensive range of degrees of hardness, or temper; the greatest 
strength, malleability, ductility, and elasticity ; which has the 
greatest compactness or specific gravity, and which takes the 
finest polish ; and lastly, which possesses these qualities equally 
in every part. Steel made by cementation, of the best qua- 
* Oeregrund is not the name of the country in which the ore of this iron is gotten ; 
or of the place where it is manufactured ; but it is the name of a sea-port town, from 
which the iron of Dannemora was formerly exported. 
