French Nutlonal Institute. 270 



Irnt we know equally well how much this metal differs in 

 goodness, according to the mines from which it comes^ and 

 the forges in which it is wrought. 



M. Vauquelin, in order to discover the causes of these 

 differences, has begun to analyse with great exactitude the 

 minerals and fluxes generally exposed to the furnace, and the 

 scoriae or other matters which are separated from it. 



He found in the scaly iron ores of Burgundy and Franchc 

 CoHite, besides oxide of iron, silex, alumine, lime, oxklated 

 manganese, phosphoric acid, magnesia and chromic acid. 

 A part of these substances remains in the flux, and they are 

 ever found in the best refined iron, although the greater 

 quantity passes into scoriae, and those substances which are 

 sublimed in the furnaces. 



It is to the remains of chrome, phosphorus, and manga- 

 nese, that M. Vauquelin attributes the bad 'qualities of cer- 

 tain kinds of iron which are brittle both when hot or cold ; 

 and all the attention of forge-masters should be directed to 

 free their metal from these noxious substances. 



Besides these useful remarks, M. Vauquelin has made a 

 very curious one: viz. that this composition, whether in ores 

 or particularly in the sublimate of furnaces, resembles much 

 that of meteoric stones. Nothing but nickel is to fee fuund 

 in the latter. As all those substances which .are sublimed 

 do not remain in the flue of the furnace, and some are with- 

 out doubt elevated into the air, he thinks it not improbable 

 that these substances enter into the composition of meteoric 

 stones : the only difficulty would be, to ascertain how sub- 

 limed metals could unite in the atmosphere in such large 

 masses as we find. 



This subject of iron ores has been treated in another point 

 of view by Mess. Descoslils and Hassenfratz in the Me- 

 moir under the title of Spathic Iron. (See Phil. Mag. vol. 

 XXV.) These ores are more or less fusible, and furnish iron 

 of various qualities. M. Descoslils thinks that the ditficully 

 of melting some of them is owing to the magnesia which 

 enters into their composition. All the infusible spathic irons 

 lie has analysed furuished him with this earth j and having 



S 4 added 



