. 
164 On the Principles of Iron and Sieel. 
parts with this proportion of mixture, which renders the 
remainder malleable. A conclufive inference from this 
would be, that fome crude irons contain one half, fome three 
fourths, and others again an equal portion of mixture for 
iron; feeing thefe are the proportions loft by iron in the 
operation of rendering it malleable. The mifchief with 
which this fallacious opinion is fraught is inconceivable ; 
efpécially as it has been fupported by men who have laid 
claim to fcientific and practical abilities: the belief of it 
flackens the indefiry of individuals to attempt leffening the 
lofs of real metal ; on the contrary, workmen are taught to 
look upon a Jarge proportion of it as incapable of being me- 
tallized, and as only fit for deftruction. 
If manufaciurers of bar iron would more frequently deprive 
2 given weight of the fcoria of the refinery and puddlins 
furnaces, of its iron, they would be more able to eftimate the 
portion of unmetallic parts contained in their crude iron : 
upon finding the feoria to contain 30, 40, to 50 per cent of 
iron, equally fit for converting into’ malleable iron as any 
part of the original mafs, their attention would be more 
frequently arrefled, and employed to devife means, either to 
prevent the cfcape of fuch a confiderable proportion of iron, or 
to fufe fuch fcoria fo as to deprive it of the laft portion of metal. 
"The relative proportion by weight of carbon and oxygen 
united to crude iron is {mall indeed: the poffible proportion 
in, which they can exift will be more eafily conceived by ad- 
ducing the weight of a fpecific bulk of each and their analogy. 
a Cubic foot of oxy zen gas "0792859 lb. av. S_ gravity ‘oo105308%e 
¥ ditto carbon 24-519 S. gravity 39214 
? ditto carbonated crude iron 4:3°70325 lb do. 8. gravity 72593680 
The vaft difproportion betwixt the cube ‘of iron ‘and the 
aggregate of the mixtures renders further iluftration on this 
head {uperfluous *, though at fome future period I hope to 
be 
* IT with not to be underftood as if I meant to fay that the quantity of 
oxygen ina concrete form in iron is to be confidered.as having no greater | 
fpecific 
