44 
Iron . 
:oa!s being unavoidably used, under such a degreee of 
compression, as to resist entire decomposition in the ig- 
nited passage. In that case, the iron does not so imme- 
diately come into contact with oxygen, as the decompo- 
sition is chiefly effected in the superior strata of the sepa- 
rating materials. Under the former circumstance, of a 
loose unconnected stream of air being thrown upon coaks 
easily combustible, the quality of the metal, with the 
same quantity of fuel, becomes oxygenated, the tuyere 
becomes fiery, and frequently emits sparks of metallic 
oxydc The separating iron may be viewed as it oozes 
from the ore in small gobular masses, frequently on fire, 
changing its state to that of an oxyd. The combination 
of oxygen, by altering its density, makes it subject to the 
re- action of the blast, which at times gives it a direction 
from the tuyere with considerable violence. Those parts 
of the iron (by far the greatest) thus oxydated, which S 
escape not at the tuyere, mix along with the fused earths 
of the ores and limestone, alter their colour, and flow from 
the furnace more unrevived than at their first introduction. 
It is, however, very different, even with this inferior quali- 
ty of coal, where the density of the blast is proportioned ! 
to the inflammability of the fuel. Qualities and quanti- 
ties of crude iron may be produced from this, equal to 
those from coals reckoned of a superior nature. The metal lj 
becomes as highly saturated with carbonic principle as 
that made from clod or splint coal. The tuyere evinces 
that decomposition is effected in its proper place. The 
fluid masses of iron, as they become expressed from the 
ore, are shivered into spray, before the dense column of 
air, without exhibiting the least symptom of decompo- 
sition. 'They again unite under the level of the blast, in- 
crease in size, and sink through the fluid- stratum of earths 
to the bottom of the furnace. This fact holds out one of ft 
the strongest proofs of the great affinity which carbon and 
