Cast Steeh 
369 
Disappeared of Charcoal - I ron gained. 
When one half was used, 34*4 per cent. - 2 o^ t ^ , part. 
When one fourth was used, 45 per cent. - ~^th part. 
When one sixth was used, 57 percent. - ■^—-thpart. 
1 o 
When one eighth was used, 67*2 per cent. “j-ih part. 
"To 
When one ninth was used, 80 per cent. - Wh part* 
When one twelfth was used, 83*5 per cent. ~d part. 
Upon the whole, if the results of these six experiments, 
performed in open vessels, are compared with the three 
first detailed in last communication, where a similar qua- 
lity of crude iron was obtained in vessels perfectly close, 
no material difference will be found. They mutually sup- 
port each other, as to the quantity of carbon necessary to 
form crude iron, while they still leave In doubt the cause 
of the disappearance of the charcoal in close vessels. In 
the case of open vessels, it is highly probable that a consi- 
derable portion of the charcoal is destroyed before the 
heat of the furnace is sufficiently strong to lute the cover 
of the crucible. 
This still, however, leaves unexplained, why, In expe- 
riment L a loss of l 5 2 grains of charcoal is sustained; 
while in No. VI. the original quantity introduced did not 
amount to half that quantity, yet 12 grains of the latter 
was found entire resting upon the surface of the reduced 
metal. The thickness and capacity of the crucible in 
both cases, and, indeed, all these experiments, were near- 
ly alike. 
The fact of malleable iron belli convertible into the 
most carbonated state of crude iron, either in close or open 
vessels, where a portion of the carbonaceous matter was 
found reposing upon the surface of the newly-changed me- 
tal., creates some doubts as to the existence of oxygen in 
