22 Analysis of Iron Ores, &c. 



analogous to that of hydrogen gas. It weighed 15 cent. 

 (-2-3 grains), amounting to three per cent. The solution of 

 the iron had the same smel], which was not dissipated but 

 by evaporation. 



A kw particles of this residuum, thrown on a burning 

 coal, emitted a white vapour, with a smell resembling that 

 of arsenic and phosphorus. Heated red-hot in a silver cru- 

 cible, it burned with flame, and left behind a yellowish 

 powder. This was mixed with a little caustic potash, cal- 

 cined, and lixiviated. The liquor being filtered, saturated- 

 with nitric acid, and subjected for a few minutes to heat, 

 limewater was added, which threw down a white fiocculent 

 precipitate, consisting chiefly of phosphate of lime, but with 

 a minute portion of silex, and perhaps of alumine. 



It is certain from these experiments, which M. Vauquelin 

 repeated several times, that the iron of Drambon, though it 

 is considered as of pretty good quality, contains very per- 

 ceptible traces of phosphorus. He likewise found some slight 

 traces of it in the solution by sulphuric acid. 



The iron of Pesmes afforded nearly the same results. 

 The residuum, however, was less by one half, amounting 

 only to lj per cent.; and it contained less phosphorus. 

 This iron is very tough, and is reckoned one of the best in 

 Franche-Comte. 



VII. Of the Hydrogen Gas. 

 Various experiments, which M. Vauquelin made by the 

 help of oxygenated muriatic acid on the hydrogen gas evolved 

 from the pig and bar iron, led him to conclude that phos- 

 phorus is the chief cause of its fetid smell. 



VIII. Recapitulation and Inferences. 

 From the experiments I have related, says M. Vauquelin, 

 it follows : 



1. That the five sorts of bog ore I analysed are composed 

 of the same principles, which, beside iron, are silex, alu- 

 mine, lime, oxide of manganese, phosphoric acid, magne- 

 sia, and chromic acid. 



2. That the five sorts of ore having been taken without 



selection 



