Janoyer on the Injluence of Sulphur on Iron. 333 



Independent of the influence of the sulphur in coke, this ex- 

 periment shows that it is important to demonstrate a fact practi- 

 cally : the action of sulphur, as will be clearly perceived, was in 

 the fusion of the ore in contact with the combustible mineral, and 

 not in the transformation of the cast iron into wrought iron by 

 puddhng. 



It may hence be concluded that the sulphurous acid disengaged 

 from the coal upon the grate of the puddling furnace and in re- 

 heating has no sensible effect on the iron. The sulphid which 

 pay be formed in the transformation of the cast iron into wrought 

 n-on at the surface of the metallic bath, is always where it is 

 exposed to oxydation, and as M. Berthier has said, it combines 

 with the oxyd of iron, to form oxysulphids, which separate 

 from the iron in the state of scoria and scales. I have never 

 assayed the scoria from the refining without obtaining considera- 

 ble quantities of sulphur. A careful analysis of a scoria from 

 the refining that was very compact and contained no free iron, 

 gave me 0'152 per cent of sulphur. 



These facts established^ I sought to prevent this action of sul- 

 phur in the high furnace, at least in part, by combining the ob- 

 servations of the learned Karsten (according to whom the best 

 hons appear to contain at least 0002 to 0'003 per cent of phos- 

 horus) with the observations that I have made upon strong and 

 ard irons made with coke mixed with very pure argillaceous 

 and phosphatic ores. These last mentioned irons possessing none 

 of the properties of the "fers de coulcurs," are produced under 

 the same circumstances as the ^^ hot-short" iron which I ob- 

 tained when the ores contained not the least sulphur, and the 

 coke employed for their fusion was equally sulphurous. 



The very soft iron ''hot-short" resisted fracture when cold; 

 the two extremities of the bar were brought to within O^^'OOS (j\ 

 of an inch) of each other without the least flaw or crack being 

 distinguished in the bend, when the very hard iron has broken 

 'vrhen the two extremities were within of inches of each other, 

 (the two pieces of iron used in these trials were of the same 

 length). On the contrary, when the very so^ iron, heated at a 

 "cherry-red" was bent to two points, say A and B, it broke with- 

 out presenting the least tenacity; while the very hard iron per- 

 fectly resisted the trial when heated at the same temperature. 



The very hard iron, although less good when cold than the 

 ^^ry soft iron, generally considered was preferable to the ^'hot- 

 short" iron, the working of it heated being easier. These irons, 

 ^ has already been said, were produced under the same circum- 

 f^^tances, excepting the mixture of phosphatic ores for the very 

 hard iron. 



Persuaded then that phosphorus here plays an important part, 

 I J^ade some tiials on a large scale in the high furnace by intro- 



it 

 ^ 



