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On the Blast Furnace in the Manufaet Poof Iron. 177 
three last gases alluded to, it would appear ‘that the gaseous pro- 
ducts, as they ascended the furnace, lost completely a portion of 
the carbonic oxide, without a replacement by carbonic acid or 
other compound ; in other words, a portion of it would appear to 
be completely annihilated, which of course is an impossibility. 
This apparent anomaly is easily. accounted for, when it is stated 
how the gas was collected. 
In order to obtain the gas from different portions of the fur- 
nace, holes were bored into the side, and a tube inserted, by 
which it was drawn off. Allusion has already been made to the 
fact that a pasty mass adheres to the sides of the hearth, contain- 
ing silicate of iron and charcoal, in which there is a constant re- 
duction of the iron, with the formation of carbonic oxide. Now 
it is evident that the gas drawn off by a hole bored into the side 
of the hearth, will be largely mixed with this carbonic oxide 
forming in the immediate neighborhood of the opening, and that 
it cannot serve as an index to the character of gas passing through 
the centre of the hearth. M. Ebelman was aware of this fact, 
t he was not able to overcome the — in the ihe of 
obtalging the gas under the proper circumstance 
_ Gas taken at the tuyer. —Here it is little else hd aumespor 
mixed with a few per cent. of carbonic acid. 
From these results it will not be difficult to admit, that the 
oxygen of the air is converted immediately into carbonic acid, 
which is rapidly changed into carbonic oxide under the influence 
of an excess of carbon and the high temperature developed near 
the tuyer. 
5. The causes that render necessary the great heat of the blast 
furnace.—Theeweight of the ore, flux and combustible, which 
enters the furnace, being only one half that of the ascending col- 
umn, and as the specific heat of these three materials is very 
much below that of the gas of the ascending mass, it is not the 
heating of them that explains the necessity of the very great 
heat of the blast furnace... But the principal cooling causes are— 
1. The drying of the ore, flux and coal, and the expulsion of 
carbonic acid from the flux, é&c., rendering much of the heat la- 
tent; for what was solid is now transformed to the gaseous state. 
2. The reduction of the ore, or in other words, the transfor- 
mation of the solid oxygen of the ore into gaseous oxygen. If 
the ore has been deprived of its oxygen by i action of carbonic 
” yateatad Series, Vol. I, No. %.—March, 1846. 
