Janoyer on the Injluence of Sulphur on Iron. 331 



Biiring the year 1850, I treated in tlie high furnace of L'Onne 



(Loire) only the ore from Privas (Ard^che), of which I have 



given the analysis (Annales des Mines, t. :sx, 1855). This ore is 



a hematite (anhydrous sesquioxyd of iron), with shining lustre, 



unctuous to the touch, leaving upon the fingers a greasy coating ' 



of a red color. It is very pure, and of course well adapted to 



make iron of excellent quality. As evidence, it will be sufficient 



to consult the excellent memoir by M. Gruner, Ingenieur in chef, 



des Mines, '^Ou the ores of Privas and Lavoutte," (Ann. des 



Mines, 3^ Serie). From pages 374 and 375 of this memoir the 



following analyses are taken, proving the purity of the Privas 

 ores. 



Rich ores. Average ores. 



Sesquioxyd of iron, - - . - 83*9 60-2 

 Alumina, • . - - * 0*8 



Carbonate of lime, ^ . . - 74 Carb. lime, Mag.^ <fcc. 29-6 



Silica and clay, - • - - 6*5 70 



Water, 1-2 Water and bitum. 32 



Oxyd of manganese, . - • trace 



9as lOO-O 



-ixcuoruing to xae auLoor, iiiis ore couiams scarcely a percepu- 

 ble trace of sulphur and phosphorus. On page 376 he says, 

 ''Sulphur has in vain been sought for, and only the slightest 

 trace of phosphorus has been detected* I ought therefore, from 

 the purity of the ores, to obtain an iron superior to any made 

 in the neighborhood. Notwithstanding this, the iron afforded 

 'W'as moderately ^'hot-short." It presented, when cold, all the 

 qualities of the best iron ; soft, with black fibres and without 

 grain ; it could be bent and twisted in every way without pro- 

 ducing a flaw. On the contrary, at a cherry -red heat it was very 

 brittle and had lost all its tenacity. 



The gangue of the ore was then assayed to determine if it 

 contained barytes, for it is known often to occur with this kind 

 of ore. * * ^ The experiments proved that sulphate of ba- 

 ryta did not exist in the gangue. The following 

 of two complete analyses of the ore in which all these researches 

 for sulphur were made : 



Ore (Agatise), Rich and laminated. 

 . . ^ . - 1*4 64 



ll'O 124 



Sesquioxyd of iron, - - - 82 74'0 



Alutnioa, - - - - ^'^ 1'^ 



Lime. S-6 6'0 



Manganese, Sulphur, - - - ^^^ne none 



It will be seen from the above that the '^ hot-short '^ property of 

 the iron w^as not owing to the sulphur contained in the ore. It 

 can therefore result only from the sulpliids contained in the 

 <^oke with which it was fused. The coke used in these experi- 

 ments was invariably that lof Peronni^re^ near RIve-de-Gier 



are 



Volatile matters, 

 Silica, 



