86 



particles show some signs of being thread-like confused 

 octaedrons, somewhat resembling those on the following 

 plate, tab. 147- They are externally between a copper colour 

 and red, scarcely metallic in the lustre, until cut, and then 

 perfectly so. It is, as the Count de Bournon observes, useful 

 in many instances to use a magnifier to examine crystals ; 

 and we should lose some very interesting beauties without it. 

 These indeed may be pretty well seen by the eye alone, but 

 it is admirable to observe how neatly these are formed by 

 such help as the magnifying glass. We do not know of 

 any other specimen of this kind. 



