84 
Iron o 
These three distinct stages of de-oxygenation are pro* 
duced by a continuation of the same cause to which all 
iron-stones may at pleasure be subjected. With primary 
ores, richer in iron, the results are more certain, ponder- 
ous, and much better suited to operate upon, for the pro- 
duction of erood malleable iron and steel : these are ah 
o 
most universal^ capable of being de~ oxygenated, for the 
production of both these modifications of the metaL I 
have met with no exception, indeed, but in the case of a 
few granulated Norwegian ores, a blue speckled Danish 
©re, a few Russian bog ores, and the Scotch ore of the 
island of Islay. 
In the present paper I shall confine myself to a minute 
detail of the first stage of de- oxygenation ; the second 
and third stages, as they more immediately belong to the 
manufacture of iron and steel, shall be fully considered in 
c onnection with this curious mode of manufacturing these 
states of the metal from ores without fusion, which, from 
its novelty and simplicity, deserves a thorough investiga- 
tion of operation and principle,, 
De-oxygenation, by roasting, simply consists in expos- 
ing iron-stone or ore, stratified with coaly matter, such as 
the dust of pit- coal coaks, or the charcoal of wood unex- 
posed to air, at a high temperature. The oxygen con- 
tained in the ore is taken up by the charcoal, and passed 
©IF in the state of carbonic acid j while the water, carbo- 
nic acid, See. is evaporated by the heat. In proportion 
as the ore becomes cleared from these mixtures, the me- 
tal becomes more and more revived, approaching however 
to the state of malleable iron, though still interspersed with 
the original quantity of earthy parts united in the stone. 
By increasing the temperature, and continuing its dura- 
tion, the particles of iron unite, and form themselves into 
fibres, which even when cold, may be twisted and bent a. 
little ; still however having the original quantity of earthy 
