Analysis of Iron Ores, &c. 1 9 



Furnishes these scoriae, at Jeast for the most part, in the pro- 

 cess of refining. This fact was fully confirmed by analysis. 



He proceeded thus. Ten grammes (154*5 grains) of gray 

 pig iron of Drambon reduced to filings were dissolved in 

 sulphuric acid diluted with six parts of water. The hydro- 

 gen gas evolved during the solution was collected. It had 

 an extremely fetid smell, very much resembling that of phos- 

 phuretted hydrogen gas, though it had a certain pungency, 

 which the phosphuretted hydrogen has not. The nature of 

 this gas will be noticed presently. 



The residuum was of a very deep black, and diffused an 

 extremely strong smell of phosphorus. It weighed 53 

 cent. (8*2 grains), or a little more than a twentieth of the 

 iron employed. The upper part of the bottle in which the 

 solution was made, and the tube through which the hydro- 

 gen had passed, being so greasy that water would not ad- 

 here to them, M. Vauquelin suspected that oil had been 

 formed ; a fact fist announced by M. Proust a few years ago 

 on a similar occasion, and which M. Vauquelin adds he had 

 himself observed before that, when dissolving certain kinds 

 of tin. — To know whether any of this oil remained in the 

 residuum of the pig iron dissolved in the sulphuric acid, he 

 boiled it with highly dephlegmated alcohol, and filtered the 

 liquor hot. 



On the addition of water this alcohol became milky ; and 

 being exposed to a gentle heat, drops of oil separated from 

 it as the alcohol evaporated. This oil was clear and trans- 

 parent; it had a slight yellow tinge ; its taste was hot and 

 a little pungent. It appeared to be of a middle kind between 

 the volatile and fat oils. 



When the oil it contained was separated from the resi- 

 duum of the pig iron, this residuum was deflagrated in a 

 silver crucible with a little very pure nitrate of potash, the 

 matter was washed with distilled water, and a light yellow 

 liquor was obtained. This was mixed with a solution of the 

 nitrate of ammonia, to precipitate the silex and alumine 

 supposed to be contained in it ; and a small quantity of these 

 was separated. Limewater added to the filtered liquor formed 



B 2 in 



