470 On phlogiston. 



He lliys, when the purefl malleable iron is heated in 

 ucphlogiiliaitcd air, a confiderable quantity of fixed air is 

 formed. He tells us, in the firft edition of his works, 

 that there is but a fmall portion of fixed air, formed in 

 this procefs. 



tour experiments were nuide to determine this qu«ftion. 



Melting by the burning lens, half a drachm of the fil- 

 ings of bar iron, filed for the purpofe, in twenty-four 

 ounce meafures of oxygenous gas, which had been well 

 wafhed in lime water, eleven ounce meafures of the air 

 were imbibed by the metal, and half an ounce meafure of 

 carbonic acid gas was produced. 



One drachm of the flime kind of filings, melted in 

 thirty-fix ounce meafures of oxygenous gas, gave one 

 ounce meafure ; one drachm and a half, an ounce and the 

 eighth of an ounce meafure ; and two drachms, one ounce 

 and the fixth part of an ounce meafure of carbonic acid 



gas. ... . ' . 



One ounce of this iron in fmall pieces, diflblved in the 

 fulphuric acid and water, left a refiduum of one half grain 

 of charcoal. 



There was evidently then not a fuilicient quantity of 

 coal, contained in this iron, to account for the carbonic 

 acid produced, by melting the iron in oxygenous gas, ac- 

 cording to this analyfis, which is certainly, very imperfedt. 



The inflammable air, produced by diffolving bar iron, 

 in diluted fulphuric acid, holds a portion of charcoal in 

 folution, which is not eafily detected, owing to the very fmall 

 quantity of coal, being equally diffufed through a large 

 quantity of hydrogenous gas, for the portion of coal can- 

 not be more than three grains, in three hundred and fixty- 

 five ounce meafures of inflammable air. 



That the carbonic acid produced in this procefs, does 

 a<ftually proceed from the charcoal contained in the metal, 

 we have the moft conclufive proofs, for the quantity of it 



obtained 



