Analyfii of an Ore of Iron, Qc. ^cj 



llic fkin. It docs not, like plumbago, leave a fluning trace on paper, but only a few 

 glittering particles, which are removed by a fiidden blow of the finger. If fprinkled 

 lightly on the furface of a veffel of water, it fubfides flowly; and a fraall part even 

 remains fiifpendcd at laft. Its fpcciic gravity is but moderate; but difficult t» 

 determine precifely on account of its flate of difintegra'.ion. 



By calcination, in a low red heat, during an hour, it loft about one per cent, which 

 was probably nothing but a little accidental moifture. It was not altered by being heated 

 with free accefsof air. The dilute mineral acids, by long digeftion, took up about ten 

 per cent, which proved to be oxyd of iron. After this treatment, I thouglit its reddifh 

 hue evidently diminiflied, but its luftre and other external charafters remained unaltered. 

 When projeftcd on red hot and melted nitre, not the fmal left, deflagration enfued; and, 

 after walhing off the fait, the mineral was recovered without diminution of weight or 

 change of qualities. 



Two hundred grains of the ore were next expofed to a ftrong red heat, during two 

 hours, with 30 grains of charcoal. The refidue weighed 152 grains ; i. e. there had beea 

 a lofs of 48 grains. Of this refidue all but 17 grains were diffolved by dilute muriatic 

 acid, with a copious difcharge of hydrogenous gas. In order to afcertain how much of 

 the infoluble part was unconfumed charcoal, it v^as projected on melted nitre with which 

 it deflagrated. The part that refilled this treatment being collefted after the fait was 

 waftied off, weighed 11 grains. If, therefore, to 48 We add 6, (the amount of the 

 unconfumed coal) we obtain the true lofs of 200 grains of the ore, viz, 54, or 27 pet 

 cent. But of thefe 20O grains, 14 will be fhewn not to be oxyd of iron. The lof» 

 of 54 grains was therefore filftained in reality by only 189 grains of oxyd of iron; and 

 the truly Gxydated part of the ore loft, as nearly as poffiblc, at the rat« of aSf per 

 cent. 



The iron diffolved by the muriatic acid, was next precipitated by carbonate of foda, 

 and repeatedly heated to drynefs with nitric acid. After this, it was digefted with dilute 

 nitric acid> which took up no portion of the oxyd. This fliews that no ofher metal was 

 preicnt. 



This infoluble refidue of 11 grains, which had the form of a white and impalpable 

 powder, was repeatedly boiled to drynefs with ftrong fulphuric acid, and then waflied 

 "with hot dlftilled Water. By this treatment it loft af grains, which proved to be a lumi- 

 nous earth. The retnaining 8| grains were founds by the refuh of their fufioh' wit-h 

 iTiineral alcali, to be fiUceous earth. 



A mixture of 200 grains of the ore with the propir fiuxes and charcoal, expofed to a 

 Vioftent fire in- a- blaft furnace, afforded me a button of metal, weighing 144 grains. The 

 ii-oft thus obtaiaed has the fpecific gravity of 7,300^ was fomewhat, but not peifeclly 



3 N 2 , malleable^ 



