Ca^t Iron, Steel, and Malleable Iron. 579 
specimen lost after the first ignition instead of gaining as all 
the other specimens did, and the gain after the first ignition 
was extremely small in comparison with that of all the other 
specimens mentioned in the beginning. 
If we look back to the specimen of iron first analysed at 
the Maesteg iron-works, we shall find, that we came to the 
conclusion, that the second part of this residuum, which 
during the first ignition neither gained nor lost weight, was 
combined as follows, in three grains : 
Metallic carburet of iron . . 1*040728 
Metallic iron 1 *122681 
Carbon 0*441 38 J 
Silicon 0*159500 
Carbon 0*270500 
In fact, this property of thus becoming ignited depends 
entirely on the carburet of iron. The residuum from acids 
loses this facility of being burnt or oxidised, as well as the 
corresponding iron in the puddling and boiling furnace, 
and the difficulty of converting cast iron into malleable iron 
increases in the ratio of the diminution of the carburet of 
iron in the cast irons. 
The specimen [e) was made from gray cast iron, produced 
in the same furnace from the same ore. It melted in the 
puddling furnace into a very liquid state, and filled the oven 
during its ebullition with innumerable brilliant sparks, emit- 
ting a hissing sound as if a great mass of white hot iron was 
burning and oxidizing. I ma1de excellent soft malleable iron 
of it, but the bars had the peculiarity of not welding under 
any circumstances whatever, notwithstanding the iron was not 
in the slightest degree red-short. 
I kept a pile of this iron, consisting of six single broad 
puddled bars in a balling or reheating furnace for six hours, 
during which time the furnace had been several times re- 
charged with similar piles of other iron ; yet this pile showed 
not the slightest inclination to weld: the pile looked as dry as 
possible in the flames, and seemed to become harder and 
drier every moment at a white heat, when all the other irons 
welded easily ; and after being taken out of the furnace it was 
found to be covered with large blisters, exactly like those of 
blistered steel from the converting furnace. Its outside was 
silver-white, showing very little traces of oxidation. The in- 
side of the broken bar was very similar in appearance to 
blistered steel, showing the cubical crystalline form and the 
large blisters in the inside, covered with the usual colours of 
blue and yellow. It forged very well, yet hardened but very 
