222 
Iron \ 
sent relation of the simple principles of the metal does not 
Immediately interfere with that distinction, it will more 
properly arrange itself along with the observations on the 
various modes practised for rendering iron malleable. 
However variously conducted the modes of operation 
are at different works, and in different countries, to pro- 
duce malleable iron, yet the principle of operation is the 
same, namely, that by dissipating the carbon and oxygen, 
contained in the crude iron, bar or malleable iron is the re- 
sult. 
Furnaces of a multiplicity of shapes have been erected 
for this purpose ; but in the most perfect conducted pro- 
cesses hitherto, it has been found, that a heavy loss of me- 
tallic parts accompanied the manufacture : 40, 35, to 30 
cwt. of crude iron have been used to fabricate 1 ton of 
finished bars ; the quantity used always depending upon 
its aptness to become malleable, the skillfulness of the 
workmen, the operation adopted, andthe quality of the mal- 
leable iron wished to be produced. These observations 
more immediately relate to the home manufactures of iron 
with pit- coal ; but in many instances they will also apply to 
those of other countries, where the charcoal of wood is 
used for fuel.. 
Since crude iron exists of such a variety of quantities, 
owing to the various proportions of mixture united with 
it ; and since it is almost universally used to produce bar 
or malleable iron ; it is natural to infer, that there must 
exist one particular variety of it, which could be appro- 
priated to the manufacture in preference to any other. 
Theory says that that crude iron, carbo-oxygenated, 
which contains the alterative principles in equal portions* 
requires only to be exposed in a fluid state to the action 
of fire, either in a wind furnace or small blast, By this 
exposure the carbon becomes volatilized in combination 
with the oxygen. Practice has however confined the opera- 
