108 



The right hand lower figure shows the regular tetrahedron, 

 or primitive crystal, and that on the left hand shows some 

 of its modifications, which are sometimes rather irregular. 

 A fragment of this specimen heated by the blowpipe was 

 found to be difficult of fusion : it gave out arsenical va- 

 pours, and was reduced to malleable Copper without showing 

 any signs of Lead. Spec. Grav. 4 # 4460 — 4*4560. 



A specimen from Freyberg, according to Klaproth, was 

 found to contain ? 



Copper 48* 



Sulphur . . . . . . . 10* 



Arsenic 14* 



Silver 0*5 



Iron 25*5 



Loss 2*0 



100-0 



This analysis corresponds with the effect the blowpipe" 

 iias upon the Welsh specimen. 



