33 
fixed in the metal, forms a new oxide of iron, and the heat 
developed thereby, being somewhat more in proportion to 
that given off by the formation of carbonic acid gas than 3 
to 2, the temperature of the furnace is found considerably 
higher; while the metal, owing to the want of carbon, be- 
coming again oxygenated, though very hot, runs stiff, soon 
dies, and exhibits a very imperfect reduction.* 
Mr. Dawson having, by the united agency before noticed, 
made out a deficiency of oxygen in warm weather, says, 
*' That the furnaces in this state always worked cool, and 
" that the metal had every appearance of an imperfect re- 
" gulus." 
We must confess we have not yet seen an instance of a 
furnace working cool, and producing an imperfect regulus, 
except the same has been occasioned by a stoppage of some 
considerable time, or by a foul, mismanaged, or new, or cold 
hearth. 
Mr. Dawson also states, that by the introduction of 
steam above the Twyere, the temperature of the furnace 
was effectually raised, " but the heat, which the steam 
" took from the lower part of the furnace, to be converted 
" into air, so cooled the furnace in that part, as in a great 
" measure to scaffold it over and prevent its working." We 
can easily conceive, that the metal by oxidation with the 
oxygen of the steam and air, almost before its separation 
from its earthy matrix, would be precipitated in a state 
partly fluid and partly solid, and which, from its inability to 
run out of the furnace, whatever might be its temperature, 
might therefore be termed cool. But to conceive that 
heat could, by any means, be taken or abstracted from 
* While the carbon of the cokes unites with the free oxygen gas of the 
atmosphere, and also with the fixed oxygen in the iron stone, may not the oxygen 
of the vapour become fixed in the iron, and to a degree correspondent to the 
quantity of such vapour, oxygenate the iron, or destroy of neutralize a portion 
of additional carbon to prevent such oxidation ? 
D 
