136 Of the S ul p h u ft 



remains behind, which is doubtlefs a fulphur, as 

 appears from the odour of the exhaufted pyrites- 

 eartb 9 though not to be retained. 



(2) 1 he pyrites, that in crude ful[hur -yield ex- 

 ceeds one third, is to be iufpected to partake of 

 arfenic ; as is the cafe of the Halfebrucke pyrites, 

 which, in its fulphureous, and other volatile por- 

 tion, amounting to 36 pounds in the center, and 

 confequentiy above one third is remarkably arfe- 

 nical, and therefore called cobald. 



In pyrites, impregnated with arfenic, as is com- 

 monly the fort where copper lodges along with 

 the ground-earth, it proves a difficult matter to 

 make a calculus of tht fulphur \ fuch pyrites readily 

 caking, and running together in the fire, and the 

 more 10, by how much richer it is in copper; the 

 reafon, doubtlefs, is principally owing to the arfe- 

 nic •, for, the white pyrites, which abounds in arienic, 

 does the fame; that is, running together, it ufuaily 

 cakes : fo that the arfenic to the fulphur, in the 

 iopper-pyrites, or copper-ore, rarely exceeds one 

 fifth or one fixth. 



Now, the fulphur pmcured from pyrites, particu- 

 larly from the yellowim, or the fort called iron and 

 fulphur pyrites, generally manifelts a yellowifh grey 

 call, and is occasionally called either crude fulphur ^ 

 becaufe it comes from the firft procefs, and is (till 

 unpurified •, or caballine, or hdrfe fulphur, as it is 

 proper enough to be ufed for difeafed cattle. This 

 crude, ox h or fe fulphur is re-committed to the re- 

 tort, and once more diftilled or fined ; whereby it 

 turns out beautifully yellow, pure, and fine, the 

 foreign arfenical matter, called (uhhur-Jlag, re- 



maining behind at the bottom of the retort 



I can- 





