Cast Steel » 
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In this experiment, also, the charcoal had completely 
disappeared. The present product was minutely exa- 
mined, but gave no indications of steel. After being 
deeply cut with a chisel, it was broken with very great 
difficulty across the anvil. It was then forged, and plung- 
ed hot into water ; but did not harden. It generally re- 
sembled those qualities of iron obtained by fusion with 
earths and glasses. This experiment was repeated four 
times, and always attended with a similar result; so that 
it seemed deducible from it, that — th part of carbon in ad- 
dition to any quantity of iron was insufficient to form 
steel; and, referring to the result of No. VI. it appeared 
; that even “th part formed a steel much too soft for the 
general purposes of manufacture. This conclusion, how-' 
ever, being at variance with facts I had already establish- 
ed upon the formation of cast steel in common crucibles^ 
was here inadmissible. It was therefore necessary to seek 
for an explanation of the phenomenon of the charcoal dis- 
appearing in close vessels, formerly alluded to, before any 
certain knowledge of the exact quantities of charcoal 
could be ascertained, which were necessary to form either 
cast iron or steel in vessels made impervious to the air. 
I uniformly remarked in the present experiments, that 
when the quantity of charcoal introduced was from —th 
to “-th the weight of the iron, a portion of glass was con- 
stantly formed upon the surface of the metallic button. 
The quantity generally increased as the proportion of char- 
coal decreased ; so that, in some experiments, 300, 350, 
and 400 grains of amber- colour glass was obtained. The 
The colour was blueish black, smooth in the centre but 
a little oxdated towards the edges. Its fracture presented 
close dark grey crude iron. The crystals much closer 
and more minute than in those experiments where richly 
carbonated crude iron was obtained. Appreciating its 
