320 'Element s of Mineralogy* 



Mr. Bergman firft expelled the water, and 

 part of the fuphur by diftillation ; the refi- 

 duum he treated with 3 times its weight of 

 oil of vitriol evaporated to drynefs, this lixi- 

 viated with warm water, left only 6 parts 

 undiffolved ; in this folution a polifhed plate 

 of iron was boiled, which precipitated the 

 copper. He then by means of the phlogifticated 

 alkali, precipitated the zinc and iron. This 

 precipitate being calcined in an open fire, was 

 feveral times treated with nitrous acid, evapo- 

 rated to drynefs, until the iron was perfectly 

 dephlogifticated j frefh nitrous acid being 

 then added, diffolved the zinc only, which 

 being precipitated by the P ruffian alkali, the 

 proportion of zinc, in its metallic ftate, was 

 found as in N? 10. Neither metal, as con- 

 tained in the ore, is much dephlogifticated. 



II. VARIETY. 

 Black, Pechebknde. 



17. Of moderate hardnefs, does not give 

 fire with fteel, frequently cryftalized, and 

 then fometimes tranfparent, or femi tranf- 

 parent; when pulverized, it gives a reddifh 

 powder, when heated it decrepitates, and if 

 laid on a burning coal it emits a fulfureous 

 fmell, and depofes white and yellow flowers y 

 it is not magnetic even after torrefadion, but 

 lofes 25 per cent, of its weight. It is fre- 



quertfly 



