Analysis of Iron Ores, b'c. 23 



selection from places tolerably distant from each other, it 

 is probable that all ores of the same kind contain the same 

 substances. 



3. That these ores want only nickel, to contain the same 

 substances as the stones that have fallen from the atmo- 

 sphere. 



4. That part of these substances remains in the bar iron, 

 and probably in larger quantity in pig iron, which may be 

 the cause of its greater hardness and brittleness. 



5. That the greater part of these substances is separated 

 during the refining of the pig iron, when this operation is 

 well executed ; since they are found in the scoriae, and in 

 the sublimed iron that adheres to the insides of the chim- 

 neys of the refining furnaces. 



6. That traces of them, however, are found in bar iron of 

 good quality ; and that probably chrome, phosphorus, and 

 manganese are the chief causes that render iron hot short 

 or cold short. 



7. '('hat the process of refining merits the greatest atten- 

 tion from iron-masters, since it appears that the good 

 quality of iron depends on its skilful execution. 



8. That the presence of phosphorus and of chrome is to 

 be sought for not in the solutions of pig and bar iron alone, 

 but also in the residuums of their solutions. 



9. That by the union of hydrogen and carbon during the 

 dissolution of iron, and particularly of gray cast iron, an oil 

 is formed, which, in conjunction with a small quantity of 

 phosphorus, communicates a fetid smell to the hydrogen 

 gas that dissolves them. 



10. That it is to these two substances the hydrogen gas 

 owes its properties of burning with a blue flame, and being 

 heavier than when pure. 



11. Lastly, That the oil and the phosphorus are separated 

 from the hydrogen gas by oxygenized muriatic acid, which 

 destroys them. 



B4 IV. On 



