( i6 9 ) 



CHAP. X. 



Of the A r s e n i c in the P y r i t e s. 



WE are here diftinctly and orderly to mew, 

 whence arfenic proceeds, what it is, and 

 what analogy it bears to other bodies ; it being a 

 dangerous fubject, few are very fond of entering 

 into an intimate familiarity with it -, for which rear 

 fon, it is a matter hitherto but little underftood. 



Arfenic , in its proper, entire form and colour, 

 greatly refembles a white metal, nay, almoft its 

 own ore, mijfpickel, alfo cobald ; but in its texture, 

 its relation to the fire, air, and hammer, we foon 

 find it differ confiderably from the nature of ge- 

 nuine metals, nay, fomething from that of the 

 femi- metals : and I know not whether I mould 

 allow it to have fomething more, or fomething lefs 

 than thefe* 



In itfelf it melts in the fire, not as a metal ufu- 

 ally does •, nay, not even as a bifmuth or regulus, 

 unlefs fomething fixing, as iron, be added to it, 

 without which it begins directly to fume, and fo 

 flies entirely off. Thus it is fugitive •, but in clofe 

 veffels returns again to its prifline metallic form ; 

 nay, though regulated by means of iron, not a little 

 of which goes to make up the regulus, yet, by a 

 gentle roafting, it not only feparates again from 

 the iron, but, by fublimation, recovers its former 

 ftate. Under the hammer it manifefts a great 



degree 



