68 



varieties of course admit of some allowance, and each may 

 be right; but their specimens probably differed. 



The lower figure is of a regular texture and smaller grain ; 

 it came from Huel Scoria, by favour of my kind friend 

 Mr. R. Phillips. There is among it something like Mis- 

 pickel, or Arsenical Iron, of a grayish white colour : — see 

 Descr. tab. 150. It has a bloom and dark tarnish on the 

 outside. I was lately favoured with a specimen by my 

 kind friend the Rev. W. Gregor, from Huel Rock in 

 St. Agnes's parish, which i3 a mixed specimen, including 

 Sulphuret of Copper and Iron. It had some indications of 

 the Growan matrix about it. 



Klaproth's analysis seems perfectly to agree with this 

 substance, as under: 



Tin .34 



Copper 36 



Sulphur 25 



Iron 3 



Earth 2 



100 



It is arranged by most authors as Sulphuret of Tin, al- 

 though this analysis gives more Copper than Tin ; but the 

 Copper is generally thought to be merely mixed with the 

 Sulphuret of Tin : indeed its granular texture prevents a 

 complete separation from the Copper Pyrites that accom- 

 panies it. 



