40 



The residuum 

 deflagrated 

 with nitre. 



Silex,alumine, 

 and phosphoric 

 acid separated. 



Chrome. 



Lixivium. 



Residuum 

 treated with 

 muriatic acid. 



Iron Awith silex, 



Contents of 

 the iron. 



Probable rea- 

 son ol our ig- 

 norance of the 

 causes of the 

 badncjsof iron. 



ANALYSIS OF IRON ORES, &C. 



After 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 

 presumed to be contained in it; and a small quantity of 

 these was separated. Limewater added to the filtered li- 

 quor formed in it a copious precipitate, which had all the 

 characters of phosphate of lime. 



To ascertain whether there v/ere any chrome in this li- 

 quor, it was first boiled to volatilise the ammonia, and a few- 

 drops of nitrate of mercury were added, which was preci- 

 j»itated of a brown yellow, in consequence of a little lime 

 remaining. This precipitate however gave a green colour 

 to borax, which proves, that it contained chrome. 



The lixivium from the residuum of the solution calcined 

 with nitrate of potash then contained phosphoric acid, 

 chrome, and silex mixed with a little alumine. There was 

 likewise in it an atom of manganese. 



The residuum having been thus treated and lixiviated 

 was in the form of a reddish powder, which was dissolved 

 for the greater part by muriatic acid. There remained how- 

 ever a small quantity of grayish matter, which was silex 

 mingled with chrome, for it gave a very decided green po- 

 lour to borax. 



The muriatic solution contained a great deal of iron. 

 It assumed the consistence of a jelly on evaporation, 

 which demonstrates, that it contained silex ; and it is pro- 

 bable, that a little chrome and manganese too were con- 

 cealed in it. 



Jt appears then, that this pig iron contains, beside car- 

 buret of iron, phosphr.ret of iron, manganese, chrome, si- 

 lex, and alumine. Next to the iron and carbon, it appeared 

 to Mr. Vauqueljn, that the phosphorus was most abun- 

 dant. It is then in the residuums of the solutions of pig 

 and bar iron that we must htniceforward look for phospho- 

 rus, rather than in the solutions themselves, as has hitherto 

 been done. Probably the neglect of examining these resi- 

 duums with sufficient attention is the reason of our re- 

 maining 



