Cast Ij'on, 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 0'1595C0 



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 made 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 



