37 
ant, induces us to suppose, that no proportion of carbon or 
cokes, however large, will prevent the iron from being, in some 
degree, oxygenated by the oxygen of that vapour ; however, 
as we have not data whereon to form any precise estimate of 
its direct effects upon the metal, we will suppose this oxygen 
wholly to unite with the carbon of the cokes, for the sake of 
calculation, and because its affinity for that substance stands 
in the first rank. 
The hydrogen gas of vapour has not, as far as we can find, 
any other action upon iron than that of taking off the excess 
of oxygen from it, when it possesses a larger portion than is 
necessary to form the black oxide ; and as occasion for 
this action, we presume, cannot occur in a blast furnace, 
we take it for granted that the whole of the hydrogen 
also combines with carbon, and constitutes carbonated hydro- 
gen gas.* 
We then propose the following positions, which we have 
gathered from the best authorities, and which, for perspi- 
cuity, we have reduced to the same denomination, the oz. 
avoirdupois : — 
1st. In summer time, at the temperature of 80", it is possi- 
ble for 2000 cubic feet of air to contain 37 oz. of vapour, 
but as the air is seldom or perhaps never completely 
saturated with vapour at that temperature, we will say 35 
oz. of vapour for 2000 feet of air, or suppose that quantity 
thrown into a furnace per minute. 
2nd. 100 oz. of this vapour is composed of 85 oz. of oxygen, 
and 15 oz. hydrogen. 
* By throwing water upon the outside of a blast-bag, it will be seen that a 
small portion of air makes its escape through the same, however thick or dense 
the leather may be. This has often suggested the idea, that very probably the 
air so oozing out may be hydrogen, that gas being the lightest. A report in the 
Mechanic's Magazine, about a year ago, gives a series of experiments, proving 
that hydrogen is composed of ultimate atoms, smaller than those of any other 
gas, and that that gas will pass through, by pressure, a finer substance, and 
thereby be separated from any gas it may be mixed with. 
