332 Janoyer on the Influence of 



Mines 



afforded 0*28 per cent of sulpliur. 



The combustible material consumed at this time amounted to 

 22,000 kilograms (57,200 lbs.) every twenty-four hours ; intro- 

 'ducing into the furnace in this space of time 61^'"600 of sul- 

 phur (160 ft)S.), which, according to a preceding memoir, is only 

 able to go from the high furnaces as a proto-sulpliid in the iron, 

 or in the state of sulphide of calcium in the slags. These last 

 being slightly silicious, the cast iron contained the principal por- 

 tion of the sulphur. 



It was therefore by no means impossible that this quantity 

 should exert, in the high furnace, a very pernicious influence on 

 the product, the cast iron obtained containing 0*003 per cent 

 of sulphur (the yield being 20,000 kilogrammes every twenty- 

 four hours, and supposing, which was not the case, that all the 

 sulphur passed into the cast iron). This protosulphid of iron 

 formed in the metal, should be found from its stability in the 

 wrought iron produced, so that there will then be more than suf- 

 ficient sulphur to render the iron very ''hot-short." 



The objection may be made that the sulphur might have been 

 introduced during the transformation of the cast into w^rought 

 iron during the puddling in the presence of coal containing much 

 pyrites, which permits a disengagement of half its sulphur at a 

 red heat. 



But I saj still that the passage of sulphur into the iron cer- 

 tainly takes place in the fusion of the ore in contact with the 

 coke in the furnace stack. For at this time the same ore from 

 Privas was treated in the same high furnace with charcoal, and 

 under the same very careful conditions which were used in fus- 

 ing the same with coke. The slags were entirely siliceous, like 

 those obtained in the experiments with the mineral coal, which 

 would favor the complete passage of the sulphur into the cast 

 iron by preventing it from escaping as a sulphid of calcium, in 

 the slags. The slag contained Silica 63-77, alumina 17-93,* lime 

 28-30=100. * * * 



The lime was found to be entirely taken up by the silica and 

 consequently could have no affinity for the sulphur. Notwith- 

 standmg, the cast iron obtained, puddled in the same furnaces 



t by the same 



prescn 



the characters of the best iron ; its tenacity was perfect at all 

 temperatures, presenting none of the characters of a brittle iron 

 at a cherry-red heat. 



The protoxjd of iron, owing to its small quantity, was not separated from the 



f The coal employed came from the mine Du Bois d'Areize, concession de Terre 

 ^oire. It 13 classified and des^cribed by M, Gruner in his memoir (Annales des 

 iilines, t. ir, 5e s^rie, p. 160). 



