Iron . 
ring, 100 parts of cokes will contain 8*4 of ashes; and 
8*4 per cent . deducted from 5973*3, gives 54721b. of car- 
bon. This again, reduced by 2240 lb. gives for each lb. 
of metal manufactured, 2*442 lb. 
Again, 7147*1 lb. of cokes produced from soft mix- 
ed coals are consumed for every ton of 2240 avoirdupois 
pounds of crude iron produced ; every 100 parts of the 
same coals contain 3*3 parts of ashes ; and 100 parts of 
cokes contain nearly 6*5 per cent, of ashes, which, deduc- 
ted from 7147*3, gives 6672*6 of carbon, which divided 
by 2240, gives, for the quantity used for 11b. of cast iron, 
2*978 lb. 
From these calculations it appears, that 22401b. of car- 
bonated iron, requires of carbon from clod-coal 4607 lb. ; 
of carbon from splint-coal, 5472 lb. ; and of carbon from i 
mixed coal, 6672 lb. : that 1 lb. of carbonated iron re- 
quires of carbon from clod-coal cokes 2,056 lb. ; from i 
splint, 2,442 lb. ; from mixed, 2,983 lb. : and that carbo- 
nated crude iron may be obtained when widely different 
quantities of carbon have been consumed. 
In seeking for a solution of the latter fact, we must 1 
have recourse to the different degrees of inflammability of 
the carbon, according to the various laws of continuity 
imposed upon it in its fossil construction. It can easily 
be conceived, that, owing to this structure, and the na- 
ture of the interposed ashes, the particles of carbon of 
some cokes will be more easily oxygenated than those of 
others ; in the same way that we find splint- coal, when 
exposed to ignition in contact with open air, affords l-3d 
of more cokes than are obtained from soft mixed coals, 
though the latter, when distilled, yields more pure carbon 
than the former. 
By experiment it is proven, that 100 grains of carbonic 
acid gas is composed of 72 parts of oxygen united with 28 
parts of carbon : if the quantity of carbon of clod coal ? 
