Cast Steel 
405 
| the process is a quantity of carbonic acid. This is fur- 
ther confirmed by an observation of Rinman’s that the in- 
flammable gas arising from the solution of steel, affords by 
combustion more fixed air than that which is produced 
from the solution of bar iron. From the numerous ex- 
periments of Berthollet on this subject, we have selected 
the six following as sufficient for our purpose, and having 
converted the weights and measures into English, it ap- 
pears that at 29.84 Bar. and 59° Fahr. 
Grs, measures of inflammable gasi 
100 of grey cast iron yield with diluted sulphuric acid 104.8 oz. 
!00 of bar iron made from the preceding - - 111.5 do. 
100 of Steel from the preceding - - 108.3 do. 
100 of Swedish bar iron - - - 114. do, 
100 of Steel from the preceding - - 106.7 do. 
100 of white cast iron from Eisenerz - - 97.4 do.. 
It might at first be supposed that a given quantity of 
hydrogen would increase in bulk in proportion to the car- 
bon taken up by it, the reverse of this however is in fact 
the case : therefore if Swedish bar iron be considered as 
the pure state of this metal, represented by the number 
114, the proportion of iron contained in an equal weight 
of steel made from the same will be more than 106.7, be- 
cause the former number indicates pure hydrogen, but the 
latter carburetted hydrogen. 
Dr. Pearson on the other hand, in his experiments on 
Wootz, assures us that when dilute sulphuric acid is act- 
ing on steel at the common temperature, a quantity of black 
carbonaceous matter is separated, which continues to aug- 
ment so as to impede the effect of the acid ; if at this pe- 
riod a lamp is applied, the increased temperature brings on 
a more rapid action, and the black sediment appears ra- 
ther to diminish in quantity. This diminution however 
Dr. P. attributes only to the solution of the iron with 
which the carbon was combined, and not to the solution 
3 F 
