from AIRtHREK 267 



weighed 1 grain, and was arfenic. The diflblved portion I 

 confidered as fulphur. 



10. The potafh folution, being mixed with nitric acid, 4 

 grains of fulphur fell. The remaining 7.6 grains mult have 

 been converted into fulphuric acid, by the aclion of the nitric 

 acid. Accordingly, muriate of barytes occafioned a copious 

 precipitate. 



11. The 84 grains of roafled ore being reduced to a fine 

 powder, mixed with half their weight of pounded charcoal, and 

 roafled a fecond time in a glafs-tube, one grain of fulphur fu- 

 blimed. But the tube breaking before the roafling had been 

 continued long enough, the procefs was completed in a cru- 

 cible. The roafled ore weighed 70 grains. 



12. From the preceding analyfis, we lea 



rn that the confli 



tuents of the Airthrey ore, are as 



follows : 





Iron, 



Copper, - 

 Arfenic, - 



45-5 

 17.2 



14.0 





Sulphur, - 12.6 

 Water, - 3.4 

 Foreign bodies, 6.9 





Lofs, 



99.6 

 •4 





100.0 



If we fuppofe the water and the earthy refidue to be only acci- 

 dentally prefent, then the only eflential conflituents are the firft 

 four, and the ore would be a compound of 



Iron, 51.0 



Copper, 19.2 



Arfenic, 15.7 



Sulphur, 1 4. 1 



100.0 

 Vol. VI.— P. II. LI If 



