62 
Jrotio 
pciiy exposed to the action of the ignited gas, soon loses 
its fluidity, and passes into the state of strong malleable 
iron. If this operation is performed upon a large quanti- 
ty, without agitating or turning the mass, the upper sur- 
face of malleable iron will early acquire the cold short qua- 
lit}^ and will be subject, at the same time, to an uncom- 
mon waste by the rapid oxydation of its parts. In assay- 
ing this ore for the production of carbonated crude iron, 
the results are obtained with considerable difficulty ; sel- 
dom perfect till the second or third experiment. This is 
chiefly owing to the great variety of quality in the stratum, 
two pieces seldom being alike either in appearance or in 
reality. The inferior masses yield from 44 to 48 per 
cent ; and the superior qualities I have found as rich as 
56 to 61 per cent . To obtain carbonated crude iron from 
the richest varieties of this ore, add to 1 avoirdupois lb. of 
It, 7 ounces of dried chalk, 3 of bottle-glass, and 1 of char- 
coal. This mixture will produce soft crude iron, possess- 
ing great strength, and an uncommonly large crystallised 
grain. The poorer qualities require an additional quan- 
tity of calcareous earth, to restore the equilibrium lost by 
the substitution of silex in place of iron. This ore had 
a trial in the large way at Clyde Iron Works, but was 
found to yield bad iron with the usual proportion of fuel. 
Opposite in its quality and results is the Swedish ore 
of the island of Elba. This, when presented to a requisite 
proportion of carbonaceous matter, to take up its oxygen, 
not only clears itself of this hurtful mixture, but also takes 
up a considerable portion of carbon, which, in fusion, be- 
comes united to the metal, and constitutes it perfectly car- 
bonated. In experiments with this ore, I found that when 
2 oz. of it were treated with 2 and a half oz. chalk, half an 
oz. bottle-glass and a quarter os. charcoal, the mixture was 
with difficulty reduced to a white glass ; which at no time 
had been sufficiently divided to allow a general gravitation 
