On the Component Parts of Iron-Jiones . 241 



The ftone had now aflumed a claret colour, and was pof- 

 fefled of regular internal fibres, adheiive to the tongue, 

 obedient to the magnet, and exhibiting every property pecu- 

 liar to excellent iron-ftone. 



I returned the refidue, which, as above, weighed 1 160 grs. 

 and cxpofed it in an open crucible for 4 hours 

 to an incrcafing heat till a flight degree of fufion 

 was perceived to take place. This was indicated 

 by the angles of the pieces becoming rounded, 

 and fwelling a little in bulk — When cool they 

 were found (lightly porous, and weighed - 1309 



Inc^eafed in weight by the combination of 

 oxygen - - - 149 grs. 



Equal to 12*8 per cent. Specific gravity in this ftate 



3'3 6 3 6 - 



The fracture of the pieces now wore a femi-vitrified ap- 

 pearance, of a dark blue colour, refractory to part, inad- 

 hefive to the tongue, unmagnetic, but much more metallic 

 and ponderous. A calcareous iron-ftone treated after the 

 fame manner, of which I alfo ufed fmall pieces, weigh- 

 ing - - - - - 1750 grs. 

 which had yielded a fimilar product in iron in 

 the aflay-furnace with the former, when cool 

 weighed - - 1090 



Loft in fimple diftillation equal to 37*7 per 

 cent. - - 660 grs. 



The fracture of this iron-ftone was now of a bright brown 

 colour, ftreaked with lime, faintly marked with internal 

 fibre, lefs tenacious to the tongue than the former clafs, 

 but equally obedient to the magnet. 



Vol. III. R The 



