192 Of the Arsenic 



beat out with an iron, and called fweep. From 

 the lead- working, to which are taken, together with 

 the crude -ft one ^ and the glitter-ores, the burnt rich 

 filver-ores, little or nothing is procured ; as mod 

 ores, both the (mailed or poored fort, have, by 

 the operation of crude-working, and the rich ores, 

 by that of roafting, already lolt their aptitude for, 

 and virtue of yielding zink : befides, the glittery or 

 lead-ores being, with us at Friberg, not in any 

 considerable quantity, they cannot, without the 

 evaporation of thefe lad, exhibit thole zinky flow- 

 ers they might otherwife contribute to ripen. 



Were I to pick out, among the many ores and 

 minerals, that come into the operation of crude- 

 working, thofe that contribute to form this zinky 

 furnace-fragment, I would take the glitter and $y- 

 rit es together 1 from the former I could derive the 

 body, from the latter, the foul, and fay, that the 

 fulphur and lead are become incorporated and ani- 

 mated by a peculiar appropriation and aptitude, 

 and a number of unimaginable incidents, fuch as 

 eafily happen in the large way of working, though 

 not in the fmall way of proof. 



What the nature of this furnace- fragment, or 

 cadmia fornacum, at the fmelting-houfts of the 

 Hartz, is, I know not ; but referring the reader' 

 to Lohneifs, ihall only relate the fuctefs of an ex- 

 periment tried on Friberg cadmia-fornacum for brafs; 

 for this purpofe, I roalted, after rubbing, the ca- 

 lamy under the muffle very fmall, 'till it no longer 

 fmelt of arfenic : I took the lort that, being longed 

 expofed to the air and weather, was become tender, 

 or opened, as they fpeak at the huts, this being 

 edeemed the bed fort, though for what reafon I 

 cannot imagine. After being well roaded, I mixed 



it 



